This setting might actually be ruining your prints, instead of helping them.

[@ScottHess]

The bane of 3d printing is the extensive overlap between solutions and problems. It is what it is, but … did you make sure your bed was level?

[@stshstsh07]

lol

[@davidosterberg]

This is funny. But also true. And it is actually true for a lot of engineering. At least it is my experience. I think it is a sign of a complex system.

[@ScottHess]

@@davidosterberg Definitely! But I don't think a lot of people realize that what they are buying is an engineering problem.

[@Grivius1014]

Best problem I've ever bought tho hahaha @@ScottHess

[@davidboop3550]

That is so accurate and I am 100% guilty of it. 3D musketeers refers to it as chasing zeros. And I forget I think it was teaching tech. That said, when things get bad just start back over with a generic default profile

[@carpdog42]

I love how you captured one of the most amusing things in 3d printing... how a print can fail, and then.... half recover and start making good layers again on top of the junk is spewed.

[@unity3938]

I run a small print farm and from my experience Zhop is a great peice in my reliability toolbox. Zhop, retraction, avoid printed pieces, mesh bed leveling and temperature all play a needed part in making sure that I have as few failed parts as possible while printing at 100+mm/s

[@thekidd2323]

@@liam4686 not with stock ender 3s.

[@GiovanniGiorgo]

@@liam4686 you think you could reliably print at 500 and have consistently good quality results?

[@partickstar1135]

@@GiovanniGiorgo I sell prints and run at 500 on my x1c. They aren't crazy detailed small models ofc but it's at 500-600mms in abs and is way better quality than my old printers

[@francisnitsch-jones5908]

i print at 350mm/s at 35k without it perfectly

[@unity3938]

@@liam4686 sure if you've got an x1c or a highly tuned voron v2 but that's not reasonable for a print farm, I don't have $15k to drop on a new bank of gucci printers with untested reliability. I use ender 5+ base printers with btt mobo, bgm extruder and V6 volcano hotends and they are happyest around 150mm/s with 10k acc. I'm currently looking into upgrading to orbiter v2 with V6 heatsinks and sprite heatblocks with CHT nozzle which I hope will let me go to 200-300mm/s while still maintaining the quality I need. Which when you factor over 12 printers running near 24/7 is a massive throughput.

[@saraczwei6850]

I have actually successfully printed a very similar part. It was a print in place roller bearing for filament spools. It worked actually pretty well, but i usually use PETG and an adhesive for the bed (and my parts usually stick really, really well). Since I use PETG, the viscosity is not the issue when knocking over parts. Molten PETG is more like thin honey consistency wise compared to the toothpaste like PLA. The issues were more with the outermost perimeter being pulled up by surface tension, making these areas higher than the innermost parts. This accumulates until the nozzle touches, then pushes down these areas. This leads to the nozzle slightly wiggling the part until it is ripped from the bed. There is a combination of ways to mitigate this, from extrusion multiplier to finding the optimal layer height - though this will highly depend on printer, filament and the model you want to print. As said, this seems to depend on printer too. My delta will tends to have issues like this, even with z-hop, while my i3 clone works with just the teeeeniest bit of z-hop and almost never knocks anything over. Levelling and bed flatness might also be a factor to consider. Advice though: Don't design parts like this, thin pillars just don't print well. If you absolutely need to then use adhesive, slightly under-extrude and use a raft.

[@jesuschal3802]

This explanation deserves being included in the Bible of 3D Printing by however is to write it. I've been banging my head to understand this phenomenon that happens with certain filaments. Now I need to understand how to overcome it.

[@T_TanksTinkers1066]

for me printing in ABS i've found that Z hop saves the print from being whacked over from the inevitable curling that happens on overhangs an arches but thats in air or in a enclosure

[@Waltkat]

Interesting thoughts about Z hopping. Just to satisfy my own curiosity, I decided to try printing the circular Z hop test .STL, with and without Z hop turned on. The printer I used is one of the most underrated printers on the market and is my second cheapest printer, a Kingroon KP3S (US$150) that is totally stock except for the addition of a BL Touch sensor and a PEI flexible bed (smooth surface). The filament I used was a silk PLA made by Tttyt3D (I know, screwy name, but it prints really well). The slicer is Cura 5.4. The Z hopped model was done with 0.4 hop distance, 220C hot end, 60C bed, no supports, and no brim. Printed without problems in about 34 minutes with just a few very, very fine hairs of stringing, mostly on the first 10mm of the model. For the second print I turned off the Z hop and everything else remained the same. Again, the part printed with no issues in about 32 minutes, a two minute savings over having Z hop turned on. The major difference was a perfectly clean print, no stringing at all. Both prints came out flawless as far as surface finish. Another thing to note, the spool of PLA has been sitting on my printer for several months and shows no issues with moisture contamination. So the bottom line is printing WITHOUT Z hop turned on results in shorter print times and greatly reduced stringing. Lastly, it just goes to show that an expensive printer doesn't always guarantee quality prints. I've been using this printer for almost two years and the only thing it has needed was a new nozzle.

[@guruthossindarin3563]

I've been using Z-Hop religously ever since my early printing days when I would hear the "grinding" my nozzle made scraping across my print due to over-extrusion. I hadn't thought about the time retraction takes. Thanks!

[@ArcAiN6]

i use z-hop all the time, and it's quite useful.. from what you've shown so far (TS 00:02:48) Most of your z-hop woes are caused by improper use. you should always "wipe" before doing a z-hop, this lets the built up pressure in the nozzle to be aleviated BEFORE the z-hop, which greatly reduces the blobs and boogers. the scarring you're seeing on your ironing, probably has more to do with your ironing height &speed, than it does with z-hop. Also, you keep blaming z-hop for the stringing, when in fact, most of the stringing issues you're having are due to incorrect retraction settings. the whole point, is to reduce, or eliminate the "oozing" of filament due to back-pressure when you're traveling

[@aztrose1023]

agreed

[@sierraecho884]

Ozzing is made worse by z-hop. Once you retract and pressure decreases material will still flow out of the nozzle, especially if the nozzle instead of moving quickly to the next colum has to move up then over and then down it takes a longer time where the material can and will ooze out.

[@Penofhell]

@@sierraecho884 That does not happen with proper pressure advance tuning, especially with direct extruders.

[@sierraecho884]

@@Penofhell It does because pressure can only be relieved but it does not disappear. Pressure advance tells you what kind of pressure there will be at that curve in advance but pressure will be there no matter what you do it is inherit in the FDM print process. You can decrease the pressure but you can not suck the material back into the nozzle. It will ooze the question is how much. That´s why fast movements are important.

[@fouzaialaa7962]

thank you , wipe is the most useful tool in prusha slicer , it completely eliminate blobs and in combination with retraction can completely remove stringing , at that point Z hop is redundant, also wipe can forgive and actually prefers over-retraction

[@covodex516]

I went through the rabbit hole of this too and went back and forth between z-hop enabled and disabled for about 6 months now - and since I've got all my other setting dialed in, I ended up with leaving Z-Hop on. Z-Hop *can* harm your prints' quality, but from my experience *only if improperly used* - while it provides quite a few advantages. If used correctly however - particularly paired with fitting retraction and a well configured wipe move - I end up with much less problems and higher print quality overall. I tend to argue that it depends a lot on your particular printer model, and of course all the other variables like particularly the type of filament do play a role as well. As stated, with my Ender3 S1, after very long testing I found that it not only improves my print quality, but also avoids lots of issues some prints may cause. Particularly it avoids catastrophic print failures when having to deal with warpy filaments.

[@SouthernVaRidin]

When I add z-hop when retracted on my ender 3 s1, stringing is absolutely terrible. I can't figure out how to get rid of the stringing when z-hop is on. Do you have any tips? Thanks.

[@covodex516]

@@SouthernVaRidin the main variable that causes stringing is the retraction. you'll want to calibrate that to get rid of it.

[@citizenclown]

I agree with your points if you are printing slow. Once I started printing at 300+ mm/s, i needed it on with more complex prints otherwise it was knocking my tree supports off. I will continue to dial in the trees to help see if I can make them better, but for now this setting seems to correct that.

[@i_suck_at_this_game7601]

yeah my p1p thinks it's a lumberjack too the way it mows over trees. I ended up going back to regular supports, could never get it to stop mowing over trees and got tired of wasting so much time and filaments. While watching it, I noticed it seems like the slicer don't remember where trees are and avoid them while traveling. At high speeds, trees knock over so easily, even with giant brims. I seen a bunch of times it rips the tree right off the brim.

[@juliejones8785]

Thank you! Thank you! I have wasted so much time and plastic trying to get a model to print without ripping parts loose. After turning off Z hop, prints are successful, not on the ones that worked part of the time, but even the one that never worked no matter what settings I changed.

[@troyj3292]

Not sure if this video will stop me from using Z hop, but the info here is really useful and interesting. It could be filament, tuning and such, but I don't see any of the stringing that appears in the video. I'll definitely be looking for some of these situations, especially with smaller parts. One of the reasons I like z hop is when printing complex parts since it does eliminate the nozzle scraping over the part. Moves within complex parts are a different thing than traveling in the spaces between multiple parts. With complex sides, multiple holes, etc. it's not always possible to avoid moves over areas that have already been printed for that layer.

[@billallen6109]

Yes an over analyzation video. My favorite!

[@novicereloader]

Channel name fits, doesn't it?

[@DeagleBingo]

@@novicereloader oh.. reloading and this kind of video fit together perfectly. chasing zeros as another person said.

[@novicereloader]

@@DeagleBingo yep. Tinkering fits certain personality types. RC planes, drones, reloading, 3D printers, woodworking, etc. There's a lot of overlap between these.

[@hebijirik]

I once had a use case where I had to turn on Z-hop: I was printing TPU patterns onto some fabric on my V-Core 3 500 and the only way to avoid the hot TPU staining the fabric where I did not want it to was 2mm high Z-hop. With the large heavy bed this made for very impressive sounds and visuals 🙂.

[@troyj3292]

Given the demonstration on when the print fails, I think a follow up video on techniques like linear (or pressure) advance might be interesting to see if that has anything to do with the failed prints. It probably doesn't have to be z-hop focused, since both settings failed in the same way. Also, even though I like video, it is not fair to say from this video that z-hop is ruining these prints. This printer/slicer setup is clearly not tuned for z-hop. I and many others get high quality prints and low failure rates with z-hop.

[@LostInTech3D]

I probably should have been more clear on the process behind the video, which seems to be what's annoying people. I spend typically many days investigating a subject without filming. What makes the video is usually not nearly the amount of work done behind the scenes, it's actually mostly filmed afterwards. I have tried to work in other ways but it results in too much footage and a poor narrative. I think around three weeks of experimentation went into the findings here, overall.

[@DeagleBingo]

@@LostInTech3D regardless i think its important to define the problem properly or at least try. in as much as that is what you are doing... that is why i watch. can't figure out a solution if we can't even describe whats happening right?

[@Gryfang451]

Thanks for the video. Newer to 3D printing, and went down the path of using Z Hop. It didn't help so much and added stringing every time. The best solution I found was to turn up bed temps during initial layer. For me, this seems to work, and I have fewer failures overall.

[@TheAnoniemo]

I enabled Z-hop in Cura a while ago because I found the nozzle scraping when moving over infill or solid layers, haven't noticed a decrease in quality but then again my Ender 3 is far from stock anymore. I do notice the Z stepper gets pretty toasty... For mods I have the dual lead screw belted together with a single Z stepper. I also added thrust bearings at the top of the leadscrew so they turn smoothly even when pulled down. Edit: I did notice the fluff too, the very light stuff is easy to clear with a lighter thankfully. I might try it without for some prints to see if it makes a difference.

[@claws61821]

Add some cooling to your steppers. Some people here on KZbin have had success using even PLA to print stepper heatsinks if you don't want to buy one, or you can bend some tubing around them for liquid or compressed air cooling. (Not strippers, DYAC! There's no paint or poles here!)

[@Gengh13]

@@claws61821 PLA heatsinks! That's the first time hearing that, I guess for low power applications it could help some.

[@Shinobubu]

when my print slightly cools it expands a little causing the scrapes. it gets worst when the surface is a large surface area causing excessive drag on the head resulting in layer shifting.

[@DeagleBingo]

@@Shinobubu i don't know the real solution but you're hitting on the thing thats become the obvious elephant in the room to me. its plastic. literally in the definition of the word. no matter what kind... its still changing shape slightly even after its been printed. and no matter what we have to acknowledge that we are asking this plastic to do two things at once and it can only do one thing at once. heat up and stick to yourself... no wait cool down immediately and don't move! nope. theres a balance there somewhere. only thing i've been able to do to get around this kind of thing is watch closely for when what you are describing is happening and baby step ? is that what its called... the z up a couple thousandths. maybe thats already something that is in a setting somewhere. i don't think its the same as z fade at all. and now that ive said this i'm considering simply adding something into the g code every 5 layers or something that moves the z up just a tiny bit more than what it would normally. if i'm dumb and this is already something i can enable please tell me and i will.

[@rafaelguida2317]

This is a brilliant video! I think the kind of " sticky " nature of molten plastic is like really overlooked and is such an important concept that in some cases it even prevents some prints to finish!

[@DeagleBingo]

i feel like he's found why this happens for this model. at these settings... at this nozzle size... and with this filament. and imho this naturally should lead us to consider the physics of the plastic itself as it cools (which i am NOT saying i understand at all btw). which i think is what pro level 3d printer mfrs sellling 10k+ units to engineers have done more of. the fact that as the print cools down or does whatever it does in whatever specific circumstances... changes the way it reacts to the "drag" of the viscous molten material pulling as the nozzle moves... imo there's no getting around the fact that no matter the glue or bed surface that the bed adhesion itself changes over the course of the print time. its something i keep noticing no matter what i do. none of the printers we use as consumers ... and maybe none of them in existence even... can completely control all the variables. and a different astute commenter made the great point that these variables we try to alter all seem to overlap each other to a certain extent too... obviously enclosing the area is better, having it stick down harder to start with helps... etc etc etc.. even then my understanding is that all plastic still warps or contracts/changes shape as it changes temperature. so until we can have some way of like... i dunno.. printing a ledge that then gets clamped down to the bed, or theoretically screwing the print down to the bed from the underside or having some ideal situation where the stuff is a heated liquid only when it needs to be but then is immediately cooled to room temp solid once its put where it needs to be that we're always going to be fighting adhesion or subtle changes in the shape or size especially with any models that have small contact patches like this one that he made.

[@CheerfulChipa]

I was very surprised to successfully print this on the first go with no issues... Ender 5-S1, out of the box... No z-hop, 0.4 nozzle, 0.2 layer height, 120mmps, no raft or brim, single skirt, 3D-LAC spray on the bed (as always). 35min print time. Minor wispy stringing was the only issue... I posted my make on your printables... Cool video and certainly got me thinking about my printer's capabilities. I also printed Angus's @MakersMuse Clearance Castle and the torture toaster with perfect results and all clearances are free moving. I feel like the 5-S1 has taken the skill out of 3D Printing as this was surprisingly straight forward.

[@dineauxjones]

Your channel has helped me more with troubleshooting 3D print issues than any other. Thank you.

[@lindseyjohnson1130]

Most of my prints are small parts, 6mm diameter cylinders and up, and others of various sizes. The filament varies depending on the end use. The range of plastics is Nylon (Taulman 910), CF-Nylon(Different manufacturers depending on what nylon content.), PCTPE (Taulman), 75D TPU (NinjaTek), 95A ( NinjaTek, Sainsmart), 95A (Overture - a little softer than the other 95As), PETG (Oveture - over 200k used), PLA (Rarely used). The key element to successfully printing small parts like you were testing is to print them sequentially. I have been using this strategy for close to five years with a very high success rate, close to 100%. Granted, you don't get as many parts per build but the fit and finish, and the strength are near perfect. Oh, and your stringing between parts is close to zero. I also keep my prints under 3 hours. Prusa Slicer 2.6.1. No Z hop and very low retraction. Avoid crossing perimeters: setting. I also use Garolite to print almost all of these filaments. I use gluestick for the nylons and Aquanet hairspray for the TPUs and PETG, More as a release agent than for bed adhesion. I hardly ever need a bring on the smallest of parts. I'm using Prusa MK3S and Prusa MK2s.

[@oleurgast730]

Actually in my opinion z-hop is a must to have on multi material prints. I often do manual filament changes at the 3 bottom layers to embed coloured text or graphics. As each colour is printed after each other, on small areas the nozzle can kick of already printed layers of the bed. For example if you print an "O" (like on the display case of an "Original Prusa") and print the text colour first, pinting the inside of the O with case colour the line of the O is very easaly touched and caried away. In oposite order (case colour first) the inside of the "o" can easaly be catched away. So here z-hop (and printing very slow) seems mandatory. But many thanks, I have not thought about turning z-hop on only for the layers I use colourchange before. I might try it on one of my next prints.

[@AsterDreamweaver]

This is what I only use Z Hop for as well. When I do these type of multi-color prints I only enable the Z-Hop for the first three layers and then anything printed above those three layers Z-Hop gets disabled again.

[@KyberNexus42]

So I simply _had_ to turn on z-hop while using prusaslicer because every time it would move over the tree supports (i haven’t had a single print get knocked over due to nozzle travel since, though I have run into that viscosity issue you mentioned), it would knock them over and fail the print. I honestly don’t care about the stringing because a heat gun easily takes care of anything like that and produces a perfect print.

[@creativitybyph]

When printing BIG parts with 1mm layer height, no perimiters and top layers, the Z-hop come very much in handy. As there are hundreds of places with no or very little bond to the previous layer, the filament curls up and make the steppers skip

[@TheSupertecnology]

I discovered such stringing myself with z hop as well. And took me days to figure it out, by literally staring at the print as it was being done to see that that little hop carries the smallest amount of already laid down plastic with it. Luckily, in the end it got me to realize my belts were too loose anyway.

[@SheriffJackCarter]

I was doing a print that had a fair amount of tower supports. Afraid the print head would knock over a support, I turned Z-Hop. Every time, the print failed. When I was re-slicing, I accidentally turned Z-hop off and that print was successful. Two other settings I found useful for the quality of the print is Z-Seam Alignment and Infill Start Point both set to Random. This prevents a single seam line to be visible on the piece because of the print layer starting in the same place every layer. Same goes for the infill start point. "Random" is your friend!

[@DonovanBaarda]

I had a print that was consistently giving me severe layer shifts at one point in the print. This was after switching to flashprint from flashcloud for slicing. This piece had an overhang edge the slicer was moving past and hitting with the head. I have a textured build plate with truely awesome adhesion. Rather than dislodge the part it was shifting the build plate a bit and/or making the stepper motor skip steps. This was fixed by turning on z-hop "when crossing part edges". In retrospect perhaps the default 109% extrusion rate was also contributing. Calibration tests since then suggest this is excessive for part dimensioning, but definitely helps with layer adhesion.

[@matteoparenti741]

I remember the community post with the question! Thanks for the great research, it's much needed. It's really hard to convince people that what they're observing might be affected by concurrent causes when discussing any parameter.

[@JoshuaRilliet]

Hello, I've been using Z-hop since I started with the Sidewinder X1 and it has definitely solved the problem you mentioned. I've never removed this setting again because, after checking, it doesn't save me any printing time or very little, which, compared to having to start a print again, isn't worth the risk. On the other hand, I don't notice any deterioration in my prints, they come out clean and without the stringing you have on the prints you show us, perhaps a setting on your own printer is to blame for these filaments because on the X1 I don't have this phenomenon. I've downloaded your model, and I'll be testing it soon (if I don't forget) with and without the Z-hop, whose height I've set at 0.125mm so that the nozzle no longer touches other parts of the part being printed. So if I don't forget to do the test, I'll come back and report what I find with and without the Z-hop in your file.

[@ashleys3dprintshop]

I just sliced and printed your impossible file and it printed fine. Bambu lab x1carbon, bambu studio slicer, default pla settings and there is a z-hop. 1 wisp of stringing and some minor droop of filament on the 90 degree top/curve.

[@chrisdixon5241]

Isn't your model a great use case for a raft? The small base area of each pin doesn't give a lot of adhesion with the bed, and as the model gets wider as you travel up the Z axis, it becomes unable to stay stuck. Certainly I'd be looking at using a raft if I didn't have much surface area on my model in direct contact with the build plate and had a comparatively large height to print

[@oleurgast730]

Actually it would be only if it were not a test print. The whole reason for such a test is to find out if you actually can avoid the towers been kicked by using z-hop. If you use a raft, it wouldnt be kicked in both szenarios, so no use in the test. But of course, being kicked in both szenarios also proves nothing. In my opinion the test simply has to be scaled down in z. If there is a hight there with z-hop the towers do not fall but without they do, than you prove an advantage of z-hop for this case. If not, this proves z-hop being useless here too.

[@AwestrikeFearofGods]

Good job finding the cause. Ways to cut viscous drag (shear force) in half: 1) Raise nozzle temperature by some amount, which you already tried. 2) Double height of Z-hop. 3) Half the travel speed. 4) Double the layer height. 5) Without reducing layer height, select a 0.3mm nozzle instead of a 0.4mm nozzle. Also, the tip should be narrow and pointy, without a large flat surface for ironing. Of course, the problem with most of these solutions is that they increase the time and/or tendency for filament to ooze from the nozzle during the travel move.

[@802Garage]

Checked last night if you had a new vid out and I'm starting a print as I see this notification. 😂

[@RandomLOLGamer]

Great video! Personally i will be leaving Z hop ON when printing multiple parts(with collision avoidance aswell jic). In Cura, using it with COMBING MODE "not on outer surface" gives me amazing results with good top surface finishes. Zhop has to be configured correctly to get nice results, i have it raise 0.7mm and 40mm/s - faster means minimal stringing and it never hits printed parts off the bed or misses steps because of a collision... Finally one more thing to concider is filament ooze - could it create high spots while moving over parts (with z hop)? Most likely yes - in my case tuning in Linear Advance to eliminate ooze helped A LOT with parts getting knocked off.

[@Steve-bs7bo]

I use Z-Hop when printing thin multi colour parts, such as earrings. Enables me to leave each part on the plate and fill in the gaps. Z-Hop at about 1mm for 0.5 - 0.9mm parts.

[@xXKisskerXx]

I agree on this. Z-hop seemed fine, but in all my prints I had issues with it - and it does add a bit of time to each print, every up/down time adds up over the hours of printing after all. there were some attempts to turn Z-hop into a V shape, so it retracts, moves both over and up at the same time, then back down while still moving over, and then begins to print again as well - which seems better for the time loss, but still can leave unwanted melted spots, and the issue of vicious melted filament sticking and instantly connecting and being cooled to harden - then causes 'grabbing' and can move/destroy parts. better part cooling exists now too - which helps that curling effect go away.

[@lawrenceshraybman621]

In my experience, my parts were failing. When I was new to printing, I switched from Z hop OFF to Z hop ON. I never had a problem since, nor have I changed the setting. Good results, clean ironing. I set my printer to print at 60mm/s. Biqu B1, stock. No catastrophic failures. I'll experiment. But as for those pins not sticking, I'd use a raft. If nozzle hits, have to reassess. I need functional parts.

[@MegaPlayerXxX]

Tried to make that model of yours. Printed fine with or without the Z-hot. Though of course, Z-hop had a lot more stringing. For reference: Creality Ender 3 V2 Neo Modified with hardened glass bed and direct drive for Ender 3 Steel grey PETG from C-tech 0.12 mm layer height standard 0.4 mm nozzle 50mm/s printing speed Full infill no supports 230 C nozzle temp 80 C bed temp

[@802Garage]

Love this vid and recommend it fairly frequently. Would be cool if you added chapters.

[@LostInTech3D]

noted!

[@64bitcrafts]

My biggest issue in Prusaslicer was that the 'equivalent' settings, 'avoid crossing perimeters' and 'avoid curled overhangs', decidedly did NOT avoid crossing supports. This cause me big issues during the 2.6 alpha, because all those shiny new organic supports had a tendency to get sideslammed and that amount of torque on either very tall or very thin branches would very quickly cause them to fail, and I'd be lucky if the failed support didn't take the rest of the print with it. I'd be curious if the higher temperature idea would work in my case, but zhop was a simple fix to the problem at the time. Honestly, I wish there was a was to identify a surface or object (like supports), and specifically enable zhop when entering that specific area.

[@danthemancasey]

I always use z-hop, and I rarely have ANY stringing. Any stringing issue can generally be dealt with through adjustment in print temp, retraction distance, retraction speed, wipe distance, and combing.

[@user-co6ww2cm9k]

why would you use Z hop unless you need it? It adds print time even if you're not stringing

[@ommachining154]

​​@@user-co6ww2cm9k For me it's the noise, can't sleep with z hop off on big piece

[@thomasheisler]

Thanks for your info. I wasnt sure z hop really helped any way. but with printers going faster the knocking over is going to be alot more common. i think a reall indepth analysis on thhis is sorely needed, to find whats going on. very informative video, great job.

[@Penofhell]

Seriously man you're over thinking this way too much. Z hop is not the issue here, barely sufficient bed adhesion is. If you have no oozing, good pressure advance and a very fast printer (including Z), z hop basically has no disadvantages and it solves a few unlikely failure modes, namely hitting a small corner area that curled up and is thus sticking out.

[@BikeGuyFPV]

I was just going to say the same thing. The test is flawed. ZHop is not the issue, the bed adhesion is the bigger issue with the pin ZHop torture test. Also the claim that ZHop doesn't prevent scarring is not true either. With it turned on and also combing for me in Cura set to off I don't get scaring of the top layer anymore. And the fine whisps of stringing, that could honestly be retraction settings or depending on the material being used may need to be put in a filament dryer box. Point being, putting all blame on one thing is wrong. It's more likely several other things could lead someone to believe it's only one issue when they're not looking at the entire scope.

[@RegularOldDan]

Most of the time Z-hop isn't necessary. I think the time I've needed it most is when I don't have adequate cooling in combination with thin, steep overhangs; that's when the most extreme curling will occur. (You should have seen the prints on my first kit printer that had NO cooling. Curling was a huge struggle, as was warping on long parts on the non-heated bed. I'm having PTSD thinking about that.) Generally, speaking, however, you are right about it just causing unnecessary stringing. Being that I forget to turn it off, it's probably why some of my modified PLA (so-called PLA+) filaments will string like heck.

[@chuck2501]

when i discovered combing i turned off z hop "not in skin" being important for the quality finish.

[@LostInTech3D]

I need to cover combing....good call

[@TheAndyroo770]

Very interesting video. Reasons I use z hop (1mm)- Pretty sure I had a sticky point on my z axis so having a 1 mm z hop allowed the hotend to force rise through the sticky point and loosen it before it became an issue on the print - I used to get a line at a certain height on each print now eliminated. I've also had prints where it curls up a lot more than you demonstrated so any impact is/ might be prevented. On a complex 15+ hour print it might be just a small area that curls so avoiding an impact might save a print and the defect sanded/repaired in post-processing. I use a highly tweaked prusaslicer profile. Not sure if they have an "avoid printed parts" option? Good video, thanks

[@LostInTech3D]

yeah correct - prusa relies on a better routing algorithm, which...usually...avoids printed parts by not having printed them yet, rather than moving around them

[@TheAndyroo770]

@@LostInTech3D Since the Arachne algorithm and lightning infill, my print quality has improved a lot and print times decreased - win-win

[@heavyweather]

V400 here...bed adhesion is essential when printing high at high speed. Make sure your print can't get knocked over. Hotter extrusion, better cooling all helps. A hotter nozzle will also just go through the old layer instead of hitting it.

[@RRak]

On certain printers like Voron 2.4 that have belt driven Z for the exact reason of having extremely fast z-hops I think it does not apply as much. I may need to do some testing but from the printing done so far it looks like with a very fast Z move it actually helps break the plastic string and works reasonably.

[@l3d-3dmaker58]

z hop helps mitigate the nozzle dragging across infill, since cura overlaps infill lines at crossing points giving them virtually 200-300% extrusion right at the crossing, which causes it to get raised a bit and without 1 layer of lift it usually drags. the fix would actually be to not overlap those infills but ultimaker couldn't care less (it's the only reason ive gone from cubic subdivided to gyroid, its worse but when going at 250mm/s cubic tends to grab the nozzle so hard it skips steps and ruins your print)

[@LostInTech3D]

Ohhh...that makes sense!

[@FAB1150]

I need some infill lore- why is gyroid worse?

[@Alien81055]

The failure at 11:12 does not appear to be caused by the nozzle knocking into the printed piece. Rather it appears that the piece falls over while the nozzle is partway through printing the next layer of material there. To me this looks like an either a print speed issue, temperature issue, retraction issue, bed adhesion issue, or some combination of those. But clearly the part wasn’t knocked over by the nozzle during the travel move.

[@mystixa]

I usually print initially without it, and if there are problems I give it a try and use the version that works better. There were maker videos here about 2 years ago that were fairly thorough as well showing specific cases and printers that Z-hop fixed the problems they were having, particularly with stringing iirc and ironically enough. Combining the 2 thoughts together I would imagine that improvements in slicers and printers and print surfaces have changed the playing field. Ive learned over time that when changing some variable of printing there are almost always at least 2 other variables that need to be considered, its almost always a 3 way problem or more. So with each modernization we'll have different settings that need to be adjusted.

[@Urza9814]

Man, Z hop was disabled by default on my printer. After one particularly difficult print kept failing I found that and enabled it, and solved a TON of other issues as well! SO MANY problems are caused by the nozzle just barely grazing the edge of a print as it moves around and throwing off the alignment and Z hop completely removes that issue. (With Cura and a Ender 3 Max Neo) But all of these settings interact...and unless you're spending half your time on just calibration prints you're not going to get everything perfect. Maybe Z-hop is easier for you; maybe you'd rather spend a couple hours dialing everything in to hundredths of millimeters of precision...all depends on what you're printing and why. For my own use case, z hop is excellent.

[@poepflater]

usefull when you have high areas around edge of some build plates as the X axis sags in the middle, making it possible to hit the sides of the high areas when it comes up from the middle. My printer has a removable plate, that means the bed isnt fixed either, so pressing on to at the edges imparts more force due to lever action, which affects that actual z position on tall pieces.

[@igiannakas]

I ve had the same issue as you when using z hop with my klipperised ender 3 s1. However with the Bambu Lab X1 carbon there is absolutely no stringing when using z hop. Possibly because if the 15k accelerations when doing the spiral lift, the strings get cut off and dont have a chance to form. So I've kept it on to avoid part collision as at that speed and acceleration I'm risking a nozzle bend!

[@LostInTech3D]

Sadly the x1 came in too late in the process to really test on it properly with the z hop variants, but it does perform well with z hop off, I've been throwing everything at it.

[@igiannakas]

@@LostInTech3Dabsolutely it works great with z hop off but due to the high speeds it’s running I’ve had occasions where there was a print collision with the walls strong enough to cause a layer shift. Especially in models where the walls have a tendency to curl up. Also because the nozzle is only held in place by the heat break it tends to bend in a collision. Have seen a few examples like that in the Bambu forums where the nozzle bent even by using the default grid infill as the lines cross over themselves causing slight bumps in the surface that are “deadly” at high speeds. Hence why gyroid is recommended as it doesn’t cross over itself. Anyway, loved the video! Keep at it, channel is awesome!!😊

[@tomboxyz5564]

Tried the "unprintable" on my ender 3 pro, the surface was a bit rough but it printed succesfully the first time, ASA filament, no Z hop, sliced with CURA with skirt, no brim, printer is a bit modified, V6 all metal hotend, print bed is coropad on a spring steel plate, SKR board running marlin, linear advance, ABL, and a closed enclosure (heats up to about 35-40C from the 90C bed temp)

[@jmunkki]

If hop is off, the nozzle may wipe itself on the print as it moves. When hop is on, you should wipe before the lift to eliminate the stringing. I have wipe+hop in the profile I use.

[@JamieHarveyJr]

Slow motion wobbling of bed slingers rocking up & down definitely shows where a lot of high-speed contact can occur when the bed have large travels.

[@kapa7197]

In my experience, filament is not viscose enough to overcome bed or layer adhesion. When filament viscosity causes a part to fail, that is usually because the part has already partially failed earlier, e.g. the printhead already bumped into the part in an earlier layer causing the part to break, it just didn't fall over yet.

[@fc3sbob]

disabling Z hop except for first and last layer in Orca Slicer completely fixed my horrible stringing issue. It went from a string connecting every layer on a tower test to absolutely zero strings.

[@visrupt]

I've never used z hop ever. I print articulated figures that requires printing multiple small parts. I've dealt with issues mentioned above and for me the biggest game changer is part cooling. It'll help with dialing in your retraction, tempreture, and help prevent stringing and curling of overhangs. Some useful slicer features to further help with these problems is the per model settings in cura. I could set a slower printing speed independently for some tall, norrow parts that are prone to failure. Stay away from z hop specially if you have an old ender 3 style printer with a single lead screw.

[@wyattsmith391]

From what I've found you don't need z hop if you actually level your bed then use the your auto leveling probe, but if you just let the probe do all the work or are not good at leveling your bed you will crash

[@StillConfusing]

I only have z hop enabled for the first two layers as that's where my bed adhesion tends to fail if it's gonna fail

[@Woreec]

interesting that for you it causes more stringing, i find it reduces stringing and especially blobs forming also, idk about cura but doesnt both prusa and bambuslicer have newer better types of z-hop? well i tried printing it on the bambulabs printer with basically stock 2mm profile i just removed infill(didnt see the point in it filling half the print solid), turned off the brim. printed it on the cool plate wich i turned up from 35 to 45°C no glue just cleaned the plate with iso and it printed perfecly first try.

[@EXTREMERC416]

I havent had problems with Z hop. Maybe i did? Prints coming off the bed nearly never happens. Some stringing does happen because i dont dry my filaments when they get wer until winter where i use my little heater as a dryer

[@Jdbye]

I disabled Z-hop after watching this video, which led to issues with the nozzle slamming into printed parts at the end of a travel move. On one model, I had 4 failures in a row in exactly the same place, when the nozzle would slam into one of the tree supports so violently that it was ripped off the bed and thrown off to the side (I missed it happening the first 3 times, only hearing the sound, and the 4th time I caught it. It was VIOLENT) It might've been partly caused by OrcaSlicer's "independent support layer height" (not sure). I had been trying to bulk up the supports, but when I saw it happen in front of me I realized that no amount of support would've prevented that from happening. I've also had issues with the nozzle ramming into my prints after the first layer or 2, ripping it partly up from the bed and leading to a messed up bottom surface, and those prints had no supports so that setting can't have had anything to do with that. I also noticed as it was passing over already printed parts with Z-hop disabled, it was consistently leaving slight marks on the top surface. It would only be noticeable on flat top surfaces, and since it was so slight it wasn't a huge deal to me. Z-hop seems to solve all these issues, and with Z-hop on and independent support layer height off, even that particularly problematic model that seemed impossible to print is now printing perfectly. I did not try it with just one or the other to see what made the difference, as it takes about 2.5 hours to get to the point where it would slam into the support and I am quite sick of wasting time and filament trying to print that model. Avoid printed parts while travelling is sadly not an option in OrcaSlicer, nor PrusaSlicer or any of its other derivatives. The closest option is "Avoid crossing walls" and it ignores supports so it wouldn't help much for my problematic print. Z-hop only on supports is also not an option. I don't get much stringing or oozing, so Z-hop doesn't seem to make much difference to that either way, but for reliability's sake, in my case it seems to be worth having Z-hop enabled, even at the cost of increased print time. At least for longer or complicated prints where you want to minimize potential failures as much as possible, as increased print time is still better than having to redo hours of printing because it failed halfway through. So I guess the lesson to be learned from this is do your own testing, don't blindly trust advice from a random KZbin video because it might not work for you.

[@bepstein111]

Also, you're using silk filament for those pins, which is WAY more viscous than regular non-silk PLA. I'd be curious to see a comparison video about THAT

[@LostInTech3D]

yeah I was hitting it hard with my worst filaments, to try to cause extreme issues. It definitely would be a good video, but if this one is anything to go by, it will be....uncooperative

[@mutosanrc1933]

oh boy glad yt algorythm showed me your video. I was struggling with printing things and now I changed the slicer but maybe its zhop. I will test it with what I was printing and your torture test.

[@receiving9067]

I turned on this feature as it is in Prusaslicer and it solved a lot of issues I was having with prints getting knocked over or nudged

[@thenextlayer]

Grrr... twitter banter bedamned, I had to give you a thumbs up for this video. Well researched. Thanks for this one.

[@LostInTech3D]

Hahaha thanks

[@EverImmortal]

Like others in the comments have said, poor retraction is the cause of the stringing. I had Z-hop woes when I started 3D printing where having it enabled would cause missing outer walls and other weird problems. It can also exacerbate stringing and branching if retraction isn't tuned right. Turns out, Z-hop causes that if it lifts up too fast, too far. Generally it should be equal to or less than your layer height. I find Z-hop very useful when printing delicate bridges and overhangs, like on E3D's Spider's Web stress test. The print almost always fails without Z-hop.

[@Alluvian567]

You mention a textured bed for better adhesion. I can state that at least for prusa springsteel beds, the smooth bed has FAR more adhesion than the satin textured one. The satin bed is mainly used to limit adhesion for things like petg that can stick too well to smooth pei. I find my luck with pla on the satin is very hit or miss, and seems to change a lot for individual filaments.

[@LostInTech3D]

prusa's bed is something else - no 3rd party bed performs the same as that thing

[@paulstrealer5414]

I use Z hop for tall, narrow pieces where any nozzle bump may cause a failed print. Strangely, and seemingly counter intuitively, when printing with materials that have poor bed adhesion, the "pulling" effect causes it to unstick from the bed and makes it more likely to fail. When I /do/ use Z hop, I tend to use a pretty high hop, enough to make sure to break any ooze, usually 2mm.

[@bardockvermeulen]

With the FLsun V400, you acctually need Zhop on. Otherwise a lot of prints fail.

[@bxkxhxkg82]

The same with the SR

[@perrinsilveira6759]

I never use zhop, mostly because I believe that the issues that cause prints being knocked over are indicators that there is a problem with the machines tuning, and I can usually fix the issue and have good prints again with a little troubleshooting. Any setting that doesn't make the fact that there are issues with the print obvious is a complete no-go in my book. Not everybody wants to deal with every problem if they don't absolutely have to, but I would suggest eventually dealing with all printer problems if you want a better long term prints.

[@josharghhhh]

just came here by chance. you nailed this. this took me a month to figure out a few years ago lol

[@henninghoefer]

Interesting video, but completely opposite to my experience. On my Biqu B1, Z-Hop eliminated the nozzle knocking over curled up PLA overhangs. On my Bambu Lab X1 Carbon, Z-Hop is on by default and has never been an issue (temperatures are set a bit higher than normal though). I also never saw any additional stringing in PLA with Z-Hop enabled (to me, stringing is more indicative of wrong temperature or retraction settings).

[@fouzaialaa7962]

i have a glass bed and for some reason the part sticks so good , i actually struggle to remove the parts ,sometimes the glass will chip and not give up the part , the reason is i use low quality glass from the top of normal 2D paper printers , its so cheap, mass produced and the surface is so bad that 3D prints just stick to it im confident i can print your model probably without a brim , i will try it tomorrow

[@SianaGearz]

If you're printing in PETG, it actually does stick spectacularly to glass, as if they were one and the same.

[@Mark-uz8xx]

printed the pins in circle n ABS no brim without any problems, took about 24 minutes. printed with 0.1 mm z-hop. came out fine. Machine: Voron V2.4 R2 stealthburner with LGX-lite extruder, klipper

[@Bnryzombie]

I don't always run z-hop but when i do its because of tree supports catching the nozzle and killing the rest of the build. Although sometimes tree supports can be rebuilt by new layers lol.

[@dakotapahel-short3192]

a... decade of 3d printing both professionally and on my own time has told me that z-hop is 100% a must for tall, thin parts. though i do wonder how speed factors into this. I tend to print slower for quality reasons but because I have delta printers, i have pretty aggressive movement speeds. So I wonder if slower print speeds plus fast travels. Also the settings for the Z hope matter a lot. Are you wiping before travel? What is the speed of your z movement? How far are you z hopping up?

[@bobingabout]

I'm not sure my 3D printer's slicer even has Z Hop support. I've never seen a setting for it. I have a flashforge printer, so use the official flashforge slicer. I have however had issues when printing sometimes where a print head moves and collides with an island when travelling past it, sometimes knocking over and breaking more delicate vertical segments. If I could, I'd turn on Z Hop around these delicate vertical parts. Temperature is a fine balance too, as if you make it too cold, you get some quality issues, but turn it too high and you get a lot of stringing.

[@LostInTech3D]

flashforge slicer has zhop in it since about 2 years ago, I can't help you as to where, it's a while since I used it.

[@bobingabout]

@@LostInTech3D I did find it. the default setting is "Always disabled"

[@Kimkim-gl6qc]

I 3d print for architecture and zhop is pure gold. Many Overhang cause curl edge which zhop prevent nozzle from hitting them and fail the print.

[@forivall]

I was wondering at the beginning of the video if you were going to mention "avoid printed parts", because that's always been my solution. I've never been a user of zhop, just avoid printed parts; I'm somewhat new, and so I had never heard of using zhop to avoid those surface lines.

[@dtibor5903]

I use 0.08mm zhop only to avoid kicking off the print and to reduce nozzle wear. The nozzle going through the infill without Zhop sounds really bad. With this small amount of Zhop there is nearly no stringing even with quite wet PETG filaments.

[@jensgoerke3819]

I just printed the test on an FLsun QQS Pro, using cheap PLA and default settings in Cura 5.3.0, without any problems, just a tiny bit of stringing between the pins.

[@dennisolsson3119]

I like zhop on the first few layers to lessen the risk of scratching the surface. But I will tyu turning it off further up after this and see if I notice any issues

[@EQINOX187]

I have Z hop on almost all the time if the print needs supports, because no mater what i did i would hear scraping on the infill and i would often come back to a printer 10 or more hours later to find that one or more of the supports had been pushed over and the print failed, however if all you are printing is a flat object or something that does not need supports then it is not needed. There is no real disadvantage yo having Z hop on as it completely removes the possibility of the nozzle striking the print or support material, people often say it considerably increases print time which is false because if you like my set up have it set to twice the layer height so 0.4 but then dial up the speed of the Z hop it actually adds a very small amount of time ( about 22min on my last 12 hour print ) as for the stringing you experienced looks like a profile issue ether you are running to hot or your retraction is not set correctly or a common error people make is not turning on retraction during zhop

[@spartan001zadkiel]

So I started using Z-hop when I switched to ABS and ASA printing as I kept getting failures during printing rafts. It is very true that it has increased the print times of my models significantly but I am not seeing any of the stringing. when things slow down in my current production schedule i'll have to see if I can find another solution for the failures during rafts.

[@timderks5960]

Yup, Z-hop was a massive issue for me. I turned it on in the beginning when I had some other issues, causing filament to curl up, which the nozzle then ran into, ripping the print off. Z-hop fixed that issue, but caused SO many other issues. With more experience, the other issues I experienced were fixed with better designs, better bed adhesion, better leveling, etc., so Z-hop did nothing but hurt my prints. It also massively increased stringing in my case.

[@jesusday87]

Makes me wonder if z-hop needs to be higher then the filament stick out to be useful at all... which would be clearly higher then one layer since the nozzle is double the layer height. I would bet the filament sticks out at least more then three layers worth (comes out as 0.4mm diameter and is not being squished).

[@dschaedler]

The stronging comes from hopping before going 'off' the print; wouldn't it be better to move the nozzle off the print into the air, then move it upwards, then travel, then move it back down where it needs to go?

[@LostInTech3D]

Yes, in fact teaching tech spoke about this a couple of weeks ago.

[@noturbeezwaxbeaulac1383]

I agree Z hop is not always a good thing. but I can say that if you have a model / structure that has a 45° or lower angle (from the print bed) the last layer will have a small amout of it with no support and this will curl up and when the nozzle comes back from and other area if it aporaches direcly twoards the little curling up lip from the edge you will get a collision and this may knock the part off or cause some astifacts in the layers.

[@bysalla]

I have only used z hop for 2 color inlay on a one color printer.

[@webslinger2011]

Bedslingers: On Corexy: Off (since bed does not move back and forth) Your print might have failed on z-hop since the base had little support. The nozzle basically picked it up on the way.

[@crawlerin]

ABS is shrinking more than PLA or PETG and it will curl up. Z-hop of 0.4 mm definitely helps printing ABS, when your toolhead whizzes at 160 mm/s speed and 300 mm/s travel moves. You have v0, you can easily tune it to those speeds, load up ABS and try yourself 🙂 If you think Z hops are slowing you down, you can do Z on belts - CoreXZ, flying gantry, belted Z mods.

[@rumingjiang9645]

Is z-hop potentially useful for reducing nozzle wear for printing abrasive filaments? Even hardened steel nozzles will wear out after going over the top surfaces a lot.

[@LostInTech3D]

yeah maybe. Given how cheap nozzles are, depends on how much it affects quality, I guess. Nozzles do wear down vertically that way but I dont know how much by dragging vs normal extrusion etc. It's definitely a thought for abrasives.

[@MAJ_T_Bagger]

Gunna give your model a go tonight haha, pretty sure my cr10 smart will do it with no z-hop but we'll see, mainly cause i have a profile specifically for parts like that which I sell... The cr10 smart is a good example of a printer that doesnt like z-hop out of the box, was giving me really inconsistent layers, will give it another go once ive put the anti backlash nuts on but i feel z-hop should only really be used on belted z axis. Adds a lot of wear to lead screw type z axis from my understanding aswell.

[@JesseBakerH]

I like the takeaway that if you're trying to use bedhop you probably have other problems (in the design or with the printer) that need to be addressed or better solutions lol.

[@LordDarthNihilus]

I only use z hop for larger nozzles like 0.8 and big layer heights and widths. Otherwise the nozzle always knocks off the prints when the filament expands a bit over time

[@rondlh20]

Agree, I mostly gave up on Z-hop, even small hops cause stringing, which is not a big problem actually, but Z-hop doesn't bring much to the table