2273 What We Seem To Forget About In 3D Printing

[@CCoburn3]

During WWII, the German manufacturers often created masterpieces of machining. Their weapon systems were often machined to the most exacting tolerances. The problem was that battlefields are dirty. And the tight tolerances would get clogged with dirt. Plus, the weapons were not being maintained by trained engineers. The weapons were extremely difficult to maintain and they were often breaking down just because of the dirt and mud. So these tolerances worked against the weapons in the field. Contrast that with the American M-3 machine gun (the "grease gun"). It was made from stamped parts and it looked like it was thrown together by children. But it could be thrown in the mud and pulled out and it would still work like a champ. The point is that people get all worked up over tolerances and efficiency and forget the function of the device and the environment in which it will be used.

[@f.a.5865]

I would hate my 3D printed generator to stop working after I cover it in mud like I usually do. Jk thanks for sharing an interesting point tho

[@CCoburn3]

@@f.a.5865 The point of the post is that people often get so wrapped up in "precision" that they design products that the design doesn't function in the intended environment.

[@ThinkingandTinkering]

very good point mate - I enjoyed reading it - cheers

[@tommontgomery2674]

I had some epic disagreements with stubborn inspectors and young designers during my 50 year machinist career...A .250" shaft WILL NOT go into a .250" hole!!!...Get those tolerances right!!

[@disklamer]

We'll just dip the shaft in liquid nitrogen first, and heat up the bearing in the autoclave, that won't affect the material, like, at all ;D

[@RandomNoob]

@@tommontgomery2674 Technically it will go in if made fro metal but you need to heat and/or cool one of the parts to make them expand/contract BUT it's not coming back out.

[@steviegwhizz345]

Only real engineers understand fits, clearance fit, interference fit etc. When you've machined bores with a +0.02 to +0.04 tolerance , then you know about fits.

[@bascomnextion5639]

Yes it will just need a big enough hammer !😊

[@pcka12]

​@@steviegwhizz345anyone with an inkling of knowledge in physics should be able to get it!

[@k.o.0]

Robert, surprised nobody mentioned but it is well known that PLA, PETG, ABS, etc all have specific expansion and contraction factors in the X,Y and Z axis. These values have been published, so it should always be considered when designing fitted parts. Cheers.

[@steveallen8987]

Cura slicer has a slicing tolerance setting. This allows you to specify inclusive or excluding as extra settings to normal. Example, if you extrude a circle of a set dimension inclusive will create a circle slightly larger and exclusive slightly smaller. Exclusive thus shrinks parts slightly allowing more space between close fitting parts. It works at each layer but also affects layers creating a slope. Example a square based pyramid, exclusive creates each square layer slightly smaller resulting in a slightly narrower pyramid. In practice this can mean the difference between not fitting and fitting. In my older version of cura there is no scalability just the three settings. Perhaps the current version has this. Steve

[@adventurousloner]

Yeah, this sounds like user error to me

[@ThinkingandTinkering]

nice tip mate - cheers

[@Vibe77Guy]

In my machine design engineering career I had the opportunity to design a few machines for casting lead and babbit parts. The coefficients of thermal expansion were critical considerations for the success of these designs. One was for a replaceable negative printing ring for printing embossed nylon tape for large cable identification, applied during the extrusion process, and removed after final vulcanizing. This negative cavity lead ring was used for one printing run, then replaced and recast for the next run. The casting die equipment was automated to eject the ring at a particular temperature shortly after solidification, still hot. So the die was a good 0.080", or a bit more than 2mm oversized, in order to get a tight fit on the rolling mandrel at room temperature. Even at that, the new ring would have to be heated to around 95°F in order to place it on the mandrel, and at 75°F would then have a snug shrink fit to prevent slippage.

[@ThinkingandTinkering]

good design always takes account of the materials and process mate - designing for that is part of the fun in my mind - it's a challenge to do and fun to achive

[@CCoburn3]

While 3D printers can be calibrated to get a better fit, most of us don't know how to do that and wouldn't take the time even if we did. (Most of us are lazy -- especially including me.) But even calibrated, a 3D printer is not going to create parts that are done to the tolerances some designers call for. You're right, people need to design for the tools they are going to be using.

[@irreverend_]

Yep that's what I try to do because I know in the past my things don't fit. I have actually very well calibrated my printer now, and most of the time other people's designs do fit now when I print them, but I still design for me having tolerance issues. Biggest issue causing tolerance problems (I've found anyway) it's just firstly calibrating the extrude step number so it's definitely moving the amount it's supposed to. Then a flow rate calibration which you put into the slicer. That fixes most of my problems. Need to redo the flow rate when you replace the nozzle, and in theory you ought to check for each different filament you use (which I'll admit I don't).

[@CCoburn3]

@@irreverend_ You have more patience than I do. But then, I don't try to print machine parts. I'm sure that if I did, I'd find calibration to be essential.

[@irreverend_]

@@CCoburn3 It's really just a matter of printing an open top cube with a single line wall thickness and measuring the wall width in several places with calipers and averaging them. Then (100/0.4)*your measurement (assuming a 0.4mm nozzle) and put that in the slicer. Also I'm running Klipper and I attached a couple of accelerometers so input shaping calibration is just a matter of sending a command, which is nice

[@CCoburn3]

@@irreverend_ Thanks. I saw a video about calibration -- but it said it lasted an hour. I wasn't ready to do anything that takes an hour to explain. But not all of our KZbin presenters are like Robert. They don't all understand that brevity is the soul of wit.

[@irreverend_]

@@CCoburn3 To do a full initial calibration certainly does take some time, but most of that you should only really need to do once, or after major part replacement. The stuff you should do more regularly really doesn't take much effort. There's a good full calibration guide on Teaching Techs website, not sure if KZbin will get shirty with me if I link it here. Just Google "teaching tech 3d printer calibration" if you're interested. It's what I used to get mine pretty decent

[@rednecksciencenerds8616]

Very well said. Your channel is one of the best on youtube. You are very knowledgeable, and I love your infectious laugh. You are like a big kid in a candy store. You show science can be fun and not boring. I have been a development chemist for 25 years, and I get ideas from your videos. Thank you for all you do.

[@ThinkingandTinkering]

Wow, thank you! and I am glad i have helped even just a little

[@rednecksciencenerds8616]

​@ThinkingandTinkering The Zinc Bromide battery made me stop and think. Because of that episode, I developed a method to analyze metallic zinc in zinc oxide.

[@markscarborough1018]

Very, very true Robert! Senior designer here.... I'm developing 'production' items to be 3D printed which we we're hoping to use on a current project, but I had to make the call to revert back to traditional fabrication as I knew the tolerance issue would require 2-3 more weeks in trials and re-designs to fully understand the parameters of this particular application. If I had stuck with the 3D route, we'd've missed our deadline and drained our budget. Uneducated end users of our equipment often ask 'why don't you just 3D print them?', to which I sensitively inform them that it is not a suitable process, when I really want to say, 'don't be monumentally stupid'!! Whilst we can't 3D print 90% of what we do, I am finding ways in which it can be another tool in our box to complement all other processes. If I, or any of my design staff didn't design to suit the manufacturing method, then we wouldn't last long in our trade. All processes need thorough understanding before approving their suitability for any given application. It's all fun and games :)

[@josephpk4878]

Once you've dialed in your filaments and gotten used to the particulars of your machine, you'll know what tolerances will work for you and your parts will pretty-much always fit. There's a lot to be said for doing some cubic intersections in your CAD and printing some test sections, when you're in question. My .25mm always gives me the snug slip I need - the .30mm always gives the play I need - the .40mm always gives the gap I need.

[@ThinkingandTinkering]

nice thanks mate

[@bobcalhoun3714]

Cheers Robert! I've started making reference templates for my 3D printer so that I can know the tolerances that I need to build in to make things like bolts, rods, bearings, etc, fit into the printed product. I now know that when I create a 5mm hole in my design, my printer will print a hole that is 4.8-4.9 in PLA+. What is interesting is that same .1 tolerance holds at 10mm. Calibrating the tool helps enormously. Using a 3D printing has been quite a learning experience.

[@seewaage]

Thanks for the great video. I think that the fantastic thing about 3d printers is that is allows lots of every day people to develop ideas quickly. I'm excited about the innovative ideas that I think will be developed in the coming years.

[@ThinkingandTinkering]

i absolutely agree mate

[@6teeth318-w5k]

Brilliant explanation. It is like making music. You start at home with equipment that is not top dollars, to make a product you can get made, or rent a studio, later. when all is ready to go.

[@ezone913]

Brilliant indeed. A screwdriver makes a terrible chisel, but it can be one with enough force.

[@ThinkingandTinkering]

lol - absolutely

[@Karmabim123]

A lot of people seem to produce their designs with just one material (plastic) in mind. Another way to design for a 3D printer is to use it for a combination of materials. For example, I will often use stainless steel tubes when I need a close but sliding or rotating fit. And of course, I use ball bearing races for rotating parts which need to rotate faster. Then I draw the plastic parts to work as the supporting structure for the parts. I will often also combine plywood parts cut with my laser engraver. There will still often remain the task of making things fit but this is easy with a drill or file to open out holes or reduce surfaces to suit.

[@ThinkingandTinkering]

I absolutely agree mate

[@richardglickman7203]

I agree. Designs work when they account for the manufacturing process. Because my first prints, with parts, did not fit, I learned to design for my Elegoo N4. Now, when I make something with parts, they tend to fit. If I sent those designs to a machine shop, I suspect the “fit” would be very sloppy and nothing would work properly, if at all!

[@ThinkingandTinkering]

exactly mate -t hanks for dharing

[@vidard9863]

That's a very good point. 3d printers are effectively rapid prototyping machines if you want perfection you need to buy a machine shop. Tolerance for prints should be relatively loose.

[@ThinkingandTinkering]

cheers mate

[@grantdeisig1360]

Yes so true... Sometimes it is printer variance, say like within 100um, but there are times when the design clearly is faulty because the designer didn't take the time to think if it would work on a 3D printer. People ask me all the time to print them stuff they find online, and I always have to tell them that if for some reason it doesn't print correctly, I can't be held responsible, because it's not my design.

[@westwashere2214]

I always tell them the print head is broken right now and the can go to PCB way. LOL

[@ThinkingandTinkering]

a very useful suggestion mate - cheers lol

[@douglasmckinley-sr1507]

Having a controlled temperature environment can make a difference in tolerances. At Lockheed, we did aircraft prototypes in Burbank, CA and assembly was flawless. Then went into production and machining parts in Marietta, GA and Burbank, with production assembly in Palmdale, CA. The parts did not fit. One facility was not temperature-controlled and we had to reprogram all the CNC machines to allow for the thermal expansion. Point being if you are doing precision work it would behoove you to get a 3D printer with a temperature controlled enclosure.

[@___chill]

This advice applies to the person printing as well. If you aren't taking the time to calibrate your printer, don't expect every design to function perfectly. Taking measurements, feeding them back into the slicer, and fine tuning every setting you can find will get you production level prints no matter the printer. I've still got the $99 Anet A8 kit my mom bought for me in 8th grade, and that thing could deliver

[@ThinkingandTinkering]

nicely said mate - cheers

[@Patriarchtech]

Absolutely right. I design all the stuff I'm 3d printing myself using Fusion360. I have two Printers, a modified CoreXY Sapphire SP5 Pro and a modified Ender 3. Both Printers use the same MicroSwiss hot end and the same cooling housing. I ALWAYS use the same PETG, I ALWAYS print at the same temperatures because knowing your tools and materials is key in my opinion. If you leave as many variables as constant as possible, then when designing you can account for tolerances in your CAD software easily. eg an 8 millimeter hole will always need a specific offset of say 0.2mm. Changing materials and print speed and cooling will affect shrinkages or thermal expansion and therefore tolerances - don't do it if you want consistency. Find a good all round filament which is cheap and consistent and likely to stay available where ever you buy it - then fine tune your slicer/ print settings / printer and designing to that filament.

[@ThinkingandTinkering]

that is good advice mate - thanks for sharing

[@jsincoherency]

Well said. And re PLA gears wearing out quickly, it really depends on how much load they're carrying. In a clock-like application the loads are really really small so the gears will last for ages. Source: I have a clock next to me right now with gears made out of PLA, it has been running for probably 9 months and shows no visible wear whatsoever.

[@ThinkingandTinkering]

nice! cheers mate

[@stevvieb]

Different 3d Printers have different tolerances. I can't print size critical parts on my different printers. If I need size critical parts that's I've designed then my go to is the P1S, I've had good results with this. The only time I've had tolerance issues is when I've downloaded a model.

[@ThinkingandTinkering]

same here mate

[@bradleykurtz2605]

Fairly tight tolerances are possible with FDM printers, but you have to work to attain it, and then maintain it.

[@ThinkingandTinkering]

they are indeed

[@ryanjamesloyd6733]

I'm also reminded of the early days of mass production- it always took some work with a file to get the standardized parts to fit right. This seems the same sort of thing. And I think it's brilliant how you often get around the tolerance issue by using things like standard sized rods and bearings that Are made to those tolerances. You only need the parts to fit perfectly that Must do so. the rest? Eh, it'll do.

[@ThinkingandTinkering]

exactly mate - it often astounds me that folks don't appreciate an it will do approach for some things - they want perfect all the way

[@withourhandsAB]

Hey Robert, not sure if you're already doing it or not, but there is a setting in most slicers the will print outside walls first, this helps with tolerances, but things like thermal creep and elephants foot/squish will still be a problem, just a decreased amount. So that in mind with more precision parts I will always print outside walls first.

[@ThinkingandTinkering]

cheers mate

[@bobwerner6512]

This is casting in plastic without the 2000 C* temps and yes one has to sand and mill up whats needed. Great point sir. My heart still goes out to you.

[@ThinkingandTinkering]

thank you mate and thank you for taking the time to say that

[@hel1copter]

You've long been an advocate of 3D printing, in a way that would encourage viewers to give it a try. And you've mentioned the topic of tolerance a couple of times in recent videos. Would you consider doing something a little more in-depth about tolerance and some of the other things we need to take into account when we design our prototypes?

[@3DJapan]

You can adjust tolerances in the slicer. If it doesn't fit you need to learn your slicer better.

[@ThinkingandTinkering]

cheers mate

[@stewartpalmer2456]

I watch a variety of 3D modeling online tutorials. Why, because they all teach differently. You must build in tolerances. And every 3D printer has its own specifics. Once you dial-in a model for one printer, don't expect it to work for another without having to tweak a few things. I learned this the hard way of course. Sandpaper is your friend.

[@kurenai5000]

Yes. I always make my pegs a little bit smaller than my holes. There is a sweet spot where it fits tight. If you go too far it becomes a loose joint, which can be useful in some cases. Another good point which you mentioned, the larger you make things, the easier it is.

[@ThinkingandTinkering]

cheers mate

[@makeitreality457]

I find that a tolerance of 0.8mm will fit parts loosely. And 0.4mm for a tight fit. Of course it depends on materials and flow rate. Additionally, printer kits usually come uncalibrated. You have to calibrate it to get reasonable tolerances. TeachingTech has some calibration info on KZbin.

[@grendel1960a]

I totally agree, with my 3d printer it prints internal holes smaller than the size it measures, but conversely prints external circles dead to size, the difference, if I want an internal hole to fit an external cylinder, the difference for a tight fit is 0.4mm, for a running fit, and extra 0.05mm makes all the difference. for me a 3d prnter is a rapid prototyping tool, i can rapidly try things and change the parameters and try again, then when I am happy, I can go to the lathe or the mill and produce the part to whatever tolerance i please. think on this, drawings used to precisely machine parts have the tolerance stated on them, a shaft might be 10mm plus 0mm - 0.1mm as an example- the mating hole might be quoted at 10mm plus 0.1mm -0mm this would guarantee the shaft would fit the hole- the problem being that if both parts were at the extreme range of their tolerance the fit would be sloppy by 0.2mm. thus when someone is designing a set of parts that need to fit together, they need to decide how snug a fit and how loose a fit between parts they want to allow, and the tolerances are put on the drawing for the person making that part, maybe if the part is more than .01mm off its tolerance it will be scrap and another part needs to be made. Engineers are always designing things to tolerances, so why dont 3d designers follow this industry practice?, engineers take into account what the lathes and mills can reasonably achieve and the materials that are being used- so should 3d designers. when doing a 3d design, do I have to tweak and reprint the part to get the fit I want, heck yes I do, all the time. especially if I want a nice tight fit, sometimes its the surface texture that causes an issue, the layering, so I expect (even after desgning in the allowances I think i need) to have to tweak the design and try again. thats the beauty of a 3d printer, I only have to wait a few hours to get a new part to try, if I was making it on the lathe or mill, that could be a few hours remaking the part, not to mention the cost of material.

[@westwashere2214]

Upon exploration some may find the Vallhalla of the Machine shop numbers in tools more than 1, the king of tools, the metal lathe, is supportend by chisels and hammers, drills and reamers, His fine majestic lady at his side, the milling machine doeth not stand alone, members of the tool court at her side, welders, drivers, spanners, who are these fools suffering unrealistic expectations the 3D printer is an island to itself?

[@ThinkingandTinkering]

that is excellent advice mate - thank you for taking the time to say it - and - of course - we know each other well and I have great respect for your work so i would recommend anyone reading this pay attention!

[@donniewatson9120]

So true! You have to make sure the settings in the slicer or the model is going to work with the 3D printer.

[@ThinkingandTinkering]

absolutely mate

[@leiflindqvist9095]

It should be obvious that design and manufacturing require thought and knowledge. When it comes to engineering, you always have to design for the manufacturing method to be used. Even the good methods such as milling and turning have tolerances, the better tolerances you require, the more expensive the product. When you design and 3D print yourself, you need to take the role of designer and production technician, there are probably many people who don't see the whole picture. You can often do a lot with settings in the slicer to get pretty good tolerances on outer and inner dimensions (also with cheap printers). When you have tested and documented the printer, the designed parts usually fit together well. But some people probably believe that everything should go by itself and that knowledge and preparation is unnecessary in this context.

[@ThinkingandTinkering]

it is true lots of folks don't consider that - and you can understand why

[@leiflindqvist9095]

@@ThinkingandTinkering Absolutely, we can't all be engineers. That would not be good for humanity.

[@quantumenergysolutions9128]

Thanks Robert.

[@ThinkingandTinkering]

cheers mate

[@michaelvaughn7137]

Fost show sense your back very glad to see you !

[@lagunafishing]

It's important to have the proper clearances in the design for parts to fit. Of course It's perfectly possible to import raw STL files and edit them to suit your needs. Lots of CAD programs allow this.

[@ThinkingandTinkering]

yes i do that too

[@BurntKittyForge-pl8ol]

what i mentioned regarding a type linear steam motor , design was when you kick one direction on a bicycle like a half pedal but any amount it doesn't have to be half, the sprocket turns and the freewheel spocket is the key i guess to this potential of linear only piston travel , simplifies a crankshaft where the cylinder is filled off a chamber with a quick exhaust valve or pston type valve with a solenoid pilot , so it's set for pressure switch and only needs to shoot the piston linear to press the now crankshaft rear portion of bicycle ..for bigger power they could be "daisy chained " maybe 2- 3 hp each or so

[@ThinkingandTinkering]

like a compound engine?

[@CubbyBear-cn5kh]

When I started 3d printing I was always added or removing 0.2mm to every measurement to compensate. Now I use a Fine Detail profile on Cura when tolerances matter. CHEP has a video about it "Fine Detail to Hyper Fast" I also design all holes for being drill or taped as I've found taped threads are better than printed threads. When Casting Bronze I model to scale and before making the cast I scale it up by the expected shrinkage, this gives good results and I don't have to worry about anything other than will it cast

[@ThinkingandTinkering]

cheers mate

[@Charlie-Oooooo]

💯👍Excellent points! (IMHO, as one who has not yet entered the realm of 3D printing.) Cheers Robert! 😊

[@ThinkingandTinkering]

cheers to you too mate

[@gerryplayz4532]

Hi Robert, I suppose you could make a test to work out how much flow your printer has and then work that into your calculations. I think it would make sense to check how thick your line of filament is compared to the digital line it's trying to replicate too.

[@ThinkingandTinkering]

cheers mate

[@DadofScience]

I've seen this complaint several times and, as humans have want to do, they're always looking for the easy outcome with the least effort. Having spent money on the printer (or anything else for that matter) and it doesn't perform the way they dreamt it would, they whine. I'd rather get on with the job, get things working, and then wine at my leisure.

[@aerotro]

Robert it is all in the settings, if you set the layers to have offsets such as -0.1mm or wall thickness -0.1mm you can subtract some layers to make stuff fit better. or just scale some stuff down or up!

[@ThinkingandTinkering]

I am sorry mate I don't agree - settings play an important role for sure - but every other industry and design work involves an understanding of the manufacturing process and application of the limitations and nature of the material and process incorporated into that design - we should do the same with 3d printing.

[@Tiemu93]

Printing outside wall first will massively help with part accuracity.

[@ThinkingandTinkering]

cheers

[@OZtwo]

Well, it depends on the printer you have. My QIDI X-Plus prints perfectly. I print very small parts like what you have with no issue. One of the latest project I needed to print 12.6 MM custom bearings. (using steel balls)

[@ThinkingandTinkering]

cheers mate

[@baware80]

Alot of theories and lectures Rob, lets see some projects already!

[@wacomtexas]

5:26 Knuckles meshing perfectly to illustrate point lol.

[@ThinkingandTinkering]

lol - well spotted!

[@MrMatthewPR]

I've really enjoyed the last few design subject videos.

[@ThinkingandTinkering]

wow - cheers mate

[@kennedy67951]

Well explained Robert.😊 Nice to see you back sir.😊

[@ThinkingandTinkering]

thank you mate and good to hear from you

[@JFSmith-nb8hf]

I'm considering getting a printer to produce patterns for investment casting. Most of these castings will be machined anyway, so the tolerance issue never arises. Great vid, thanks.

[@ThinkingandTinkering]

nice one mate - cheers

[@preciousplasticph]

I will add that when doing 3D printed machines, you do NOT have to 3D print every single component if you can buy it from the local hardware store. for example bearings and connecting rods. I see people doing 3D printed parts that will fail easily when they should be using a metal part. The strength of 3D printing is to use it to make those custom plastic items that you can NOT EASILY purchase. As a example, we are building a Flash graphene machine and it will have a lot of 3D printed parts, but not at the cost of reducing the machine durability. As a Example, one machine I designed, had holes in it to insert long steel bolts to reinforce the part. other times I printed a item hollow, and then filled it with resin.

[@ThinkingandTinkering]

I absolutely agree mate and you make a very good point

[@pcka12]

The original machine tools were hand fettled to make the parts fit, then a better machine was made with what the engineers had, & so on. I am repeatedly amazed by what 3d printers can achieve!

[@ThinkingandTinkering]

me too and nice point mate

[@roscoepatternworks3471]

If you design anything, design for the process. You can't fit a 30mm shaft into a 30mm hole. You have to design with the tolerances required. Doesn't matter if it's an as cast part, machined, or 3d printed part. Tolerances are a very much overlooked part of home designing.

[@TheSimonarne]

My P1S's layer width is 0.42mm at the highest in my settings. So all my x and y corners are designed with a fillet with a radius of 0.42mm. my other edges are based on 0.2mm wich is my standard layer height. 0.1 mm between parts seems to make everything fit fine for me might even be. a bit tight for some applications but for a hole and a pin that won't be taken apart it's good

[@BurntKittyForge-pl8ol]

in high precision work i ALWAYS cut too big and then size down , actually with firearms metal work variety ,similar "match grade" means needs hand fitted for precise fit ...

[@ThinkingandTinkering]

always mate

[@haytrvilleusa3696]

User error 100% of the time. Math is hard for most people apparently! I use my cheap creality s1 pro to make stainless steel, nickel, etc, and it's flawless. 3d printers are not set it and forget it. Just like anything. You actually have to learn to do it right.

[@ThinkingandTinkering]

spot on mate

[@blandman3471]

Another advantage to using a larger scale is that the air motor for other devices, could do practical work. Let's design a 3D printed lawn mower or vacuum cleaner.

[@ThinkingandTinkering]

i like that mate - and to my mind it is very 'do-able'

[@dudleysmith5111]

Given your experience, for the typical home 3D printer (Ender 3D Pro as an example), what tolerances do you typically incorporate in your designs? I realize different parts, such as gears, will be different than others. Just looking if you’ve developed some “rules of thumb”.

[@ThinkingandTinkering]

i leave 0.2mm mate - then print and test

[@dudleysmith5111]

@@ThinkingandTinkering Thanks!

[@Morbazan125]

If I ever wanted parts to fit I had to give a 0.2mm tolerance and it worked for me

[@nicksantitoro]

What happened to that low temp Stirling engine with a magnet idea? I was looking forward to that.

[@disklamer]

GD&T for the uninitiated - Geometric Dimensioning and Tolerances, it's another useful expertise

[@ThinkingandTinkering]

nice good pointer mate - cheers

[@Borgedesigns]

I cannot believe that some designers release files without ever printing them, especially ones with mechanical elements. Its just disrespectful to the people whos time and filament you will waste.

[@ThinkingandTinkering]

yesp - for sure

[@tbabbittt]

I had a rough idea about replacing air displacement in a sterling engine with weights and springs so I 3d print it.

[@ThinkingandTinkering]

nice!

[@kurtandlazanneilander724]

As Rob says, "it comes at a cost". A Formula-One racecar has tighter tolerances and a resulting higer efficiency than a family station wagon. And that's ok. (The average person couldn't afford one otherwise.)

[@ThinkingandTinkering]

exactly mate

[@scotttovey]

The problem cited by the individual is not with the equipment, it's with the CAD program being used. I'd say it lies more so in the CAD program rather than the machine. In 3D printing, a 3mm hole is the exact same size as a 3 mm pin. The end result is that the pin will not go into the hole because the heated plastic, as any liquid, flows out from it's point of origin. Even though it's not all that viscous. When using a milling lathe, a 3 mm pin may go inside a 3 mm hole, but your using solid material to make those parts and will not experience any change of tolerance for a greater period of time. With 3D printing; if you do not allow that part to cool completely before taking it off the build plate, you risk warping the part. If the part has a hole, that hole may no longer be round which will prevent a pin from being inserted into it. Part of the problem as Rob demonstrated is with the CAD programs. Being able to instruct the CAD program to scale down the model by the .05 mm to .3 mm, would go a long way to resolve this problem. The end result would be that an inside radius' would be a bit larger, while an outside radius' would be a bit smaller. I've been using FreeCAD, and while there is a tutorial that tells you how to scale an object, the menu command to scale an object is not where the tutorial says it is supposed to be. In fact, I've looked through all the menu commands and there is no scale command. As I am progressing in the use of my printer, I will print a 3mm high test part and make size adjustments to the original design until I find the tolerances that work. This means that I won't print an actual part until I have tested and adjusted all unions that need to move or come together. I don't see much point in expecting perfect tolerances when I'm not working with wood or metal. But even with these materials, you sometimes have to remove additional material for the parts to fit together as intended.

[@ThinkingandTinkering]

again mate a CAD program is just a tool for design a 3mm hole in a cad drawing is never a 3mm hole in a real object and it doesn't matter if it is 3d printing or traditional manufacture. But your suggestion of design and test is spot on

[@mauriceupp9381]

I've missed you I'm off to push the wrong button here a while back and you were just gone I couldn't find you I'm so glad to see you again

[@ThinkingandTinkering]

thank you mate

[@Rantandreason]

You want to design a 0.4 mm tolerance as a good general number It may take a couple attempts to figure out the exact fit, but I REGULARLY have prints that are 0.01 mm accuracy That is INCREDIBLE! I use a Creality K1 fyi

[@ThinkingandTinkering]

nice rule of thumb mate - thanks for sharing it

[@Warp9pnt9]

Robert brings up a very good point. But I am wondering if there's an alternate strategy, purely for the sake of argument. Can people spend another $250 or so for a home CNC machine that can then trim off the excess from a 3D printed model? Then one might have the 3D printer designs for various tolerances, say 0.1-0.3mm, and a CNC design with 0.01-0.5mm or something? Or is it still the same resolution because both end up using essentially the same servos and motor control circuits. Even in the worst case, just accepting oversized designs, it's still cheaper and faster to get 99.9% of the way there, so an hour or two filing off excess is tolerable. I mean, if it's a "final" prototype for a demo, which may result in paying a factory to run a small batch of (cast?) milled metal parts.

[@grendel1960a]

I have mills, I have lathes, I have a cnc router, for $250 you are not going to get any better accuracy than a 3d printer, my CNC router was a cheap model and over £1500 and that is great to a 0.1mm tolerance, but still needs to be properly tuned to achieve that regularly. if you dont get your x and y axises perfect you dont get round holes, non round holes dont allow non round shafts to rotate unless you have a good tolerance.

[@ThinkingandTinkering]

engineering always costs mate - if you want accuracy you are going to have to spend

[@blah4264]

Good to see you back chap :)

[@ThinkingandTinkering]

thank you mate and good to hear from you

[@blah4264]

@@ThinkingandTinkering when you do your ride and head through Cornwall, I'll keep an eye out :)

[@BurntKittyForge-pl8ol]

i wish i had a tandem bicycle and on the back seat i'd use a motor with proper rpm to have an opposing pin each (one pin top one side shaft other pin bottom on the wheel , each side of motor) side to work the legs to the rear pedals so the battery would be in the body or chest and i'd control my buddies speed fro the front seat ...i like the tandem frame just for the length maybe for electric , i think we realize at motorcycle speed you need a motorcycle but i like an add on pedaller concept ..../daydream i got tons lol...thanks for the vids I'm intersted in different investments in tools including 3D IF i could just find the side income potential for certain but i see more and more ads from 3d products too, i'd like even a lumber mill but then it's best the trailer version for mobile lumber recovery compared to the weight ......i'll find some i hope, the dollar value flipped down so fast i think retal or manufacure type ideas , maybe stocks will go nuts in ways next political cycle etc....God Bless

[@ThinkingandTinkering]

cheers mate

[@daveherd6864]

Gears are a prime example, but scale is your friend

[@ThinkingandTinkering]

yes it is lol

[@user-by5yj7wf3q]

Be careful of "measure with micrometer, mark out with chalk and cut with Axe" accuracy of the weakest link in the whole process will dictate the accuracy of the outcome.

[@ThinkingandTinkering]

i like that mate lol

[@dSquared0162]

Sage advice as always.

[@ThinkingandTinkering]

cheers mate

[@TheLaXandro]

3D printing has issues with precision, but not as much with tolerances. A calibrated printer (including filament calibration, or just using the same spool) can get consistent parts, they will just consistently have wrong sizes, and that is solved by engineering these tolerances into the part itself. If a 4mm hole prints as 3.8mm, you can drill it out, or if you are making more you can change it so it's a 4.2mm hole in CAD and then turns into perfect 4 in the flesh.

[@ThinkingandTinkering]

cheers mate

[@JessWLStuart]

Good point, and well said!

[@ThinkingandTinkering]

thank you mate

[@conorstewart2214]

This is an attitude that I have come across a lot, that 3D printers can print anything so just design the part first then think of the 3D printing later when you are slicing it, often the same people that say you shouldn’t have to design for 3D printing. Every tool and method needs designed for though, if you are injection moulding something you will design it differently to casting or CNC machining or turning on a lathe or making it out of flat panels, but people see 3D printing and think that none of that applies that you don’t need to design for 3D printing like you need to for every other manufacturing method. I think part of the problem is that a 3D printer can produce an awfully designed part with little fuss, especially if supports are used. You can print parts in the worst possible orientations for strength but they will likely still print. I have even seen demos from professional engineers that just completely fail at the basic stages of orienting the model in the slicer, sure they get a good looking model out but it will be so much weaker than it could have been. So I do think it is too easy, people can ignore all material properties or design principles and still end up with a semi functional part, you can’t do that with other methods.

[@liamwinter4512]

I'd like to see your take on electroplating your prints.

[@ThinkingandTinkering]

i have done that l aready mate

[@JamesThompson-xl4yu]

Please get a remote microphone for your camera, the big room echoes are so annoying. But do keep on the great videos :)

[@ThinkingandTinkering]

Working on it!

[@garrenosborne9623]

Hold on just hearing some suger landing in a nice Brownian motion generator😉

[@red00eye]

'It's terrible' is much easier than 'i can't work it'

[@ThinkingandTinkering]

yes it is

[@SpaceDeviant]

Sometimes a little of both. Using a SLS 3D printer I agree you would probably run into that far less. There is a home build out there to cheaply build an SLS (I believe hack-a-day has one). Time on the other hand, I'm sure it would be a huge investment. It almost seems like those who have attempted it end up trying to turn it into a product to market, back to square one tens of thousands of dollars to average joe. A thought, perhaps someone will create an AI algorithm to adapt designs on the fly for 3D printers.

[@ThinkingandTinkering]

we can hope mate

[@westwashere2214]

let's examine the effeciency of acting in regard to not acting, I'm a daydreamer that puts ideas to action and this compounds effeciency, zero action confounds effeciency in all cases but Buddha's. This 3D printing is a great success and has high effeciencey, butmileage may vary depeding on how cheap a printer is put into service. The Elegoo Neptune 3 Plus you promoted has served well and above expectations in every way, it's build plate size is of practical use and it's accuracy is precise for something spitting out a glob of glue. For future printists keep in mind the earlier a model design is the less accurracy can be expected. I am no print wizad but i can tell you a cheap refurbished thimble printing toy will bore quickly and soon be just a memory.

[@ThinkingandTinkering]

you miss 100% of the goals you never try for mate

[@brawndo8726]

Sorry but you're wrong. You should design to spec and adjust your slicer settings to compensate for your specific printer. For example, search Cura for a setting called "horizontal expansion" which allows you to push or pull the external dimensions to suit your needs. Embedding loose tolerances into object files is an anti-pattern since there's no universal constant between printers. For example, my printer might be much sloppier than yours due to ambient heat and humidity.

[@ThinkingandTinkering]

I don't mind being wrong mate - if it works for you that's awesome and thank you for sharing it in case others want to go the route you suggest - I am really just sharing my own experiences and part of this video is so folks share theres and folks can make a good suggestion like you just did - i really do appreciate your input

[@paulgee1952]

Tolerances ,always err too tight than too lose. Rules of engineering practice with moving parts that generate friction . Materials all have expansion and contraction levels , metals especially ,that is what when prototyping anything better to make it tighter , unless the compression levels are too high ,causing a stall or worse the destruction of the machine . The crux is getting the sweet spot , which is low friction and maximum use of the force imputed to generate movement usable , not lost in the conversion. Efficiency. Long time since school, but hope a more practical explanation , if I have understood this ? All the laws of physics are just math equations, without being able to apply them ,paperwork exercises.

[@arbjful]

Is that an owl hooting in the background…🤔🤔

[@ThinkingandTinkering]

yes

[@superuser13]

Bad design, contracting, expansion and all sorts of things can go wrong, just like any other machine. Resize, reprint or redesign till you get it right, just like any other machine work.

[@ThinkingandTinkering]

exactly

[@BurntKittyForge-pl8ol]

...i like metal work , i get stuck on gun designs because the similarity high carbon and compactness , but anyway i wish they made a black powder colt 1851 type revolver BUT it has a top strap frame like the colt 1873 or remington 1858 ....so then it uses a simple [edit: cylinder insert] bushing to have a 1873 size cylinder pin , you'd replace the solid cylinder pin 1851 with a threaded bushing insert or smooth but the point is you could fast change the cylinder to loaded ones like a remington but it handles like an overpriced 1873 ..../deep thoughts EDIT": to clarify the hammer, trigger lock up; and cylinder lock mechanisms, the springs usually interchange 1851/1873 , the 1873 was colt's brass shell cased shell model so it has the firing pin hammer but the geometry exactly the same in the frames first generation , the screws have different threads between brands of remakes , they 3d print play real copies but expensive ....there's different platforms worthy of study like glock , colt 1911 colt 1873/1851, the old double barrel 12 gauges all similar usually , the ar 15s , ak47/ 74s ....all common designs worth familiarization imo ...i find the precision trigger groups and such proprietary ...

[@ThinkingandTinkering]

cheers mate

[@zacharyybarra]

I'm thinking 3d print molds made from metal then fill them with the plastic. Yes a 3d printer that creates the molds from metal then another laser for melting the plastic inside the molds. The designer needs to make a scanner, a laser for metal and a laser for plastic.

[@ThinkingandTinkering]

that would be cool

[@BurntKittyForge-pl8ol]

...i teach a young relative driving so i was explaining our cars can go very fast because we carry passengers and cargo and when we need to pass there's a burst of power needed to get the little extra speed to pass and it's really no fun driving with a vehicle floored nonstop, the motor would feel terrible and not as much milage lifespan probably and that's why cars can go fast but it's very dangerous to use the cars total power ..... i ride to the store in a nice size car and there;s golf carts , would be nice to ride free but they cost $10,000 minimum range i think for the tagged golf cart stuff ...i can order a rebuilt jdm motor with trnasmission maybe $1500 i think with Trump even EV sales will go up because it's luxury buy stuff , extra tech money ...imo

[@ThinkingandTinkering]

good one mate

[@tenij000]

is not like layers or nozzle thing does 0.2 make part of 2cm cube then it works dont think that a 1.9 cm cube gone be exact 1.9

[@ThinkingandTinkering]

no it won't be

[@lwhack458]

You need a sound baffle.

[@ThinkingandTinkering]

cheers

[@leonbarry5403]

I agree about the cost prohibiting. I'm doing an Axial flux atm. I have the magnets I have the coils made up, I have the bits and bobs needed to connect everything up. But I'm having a hard time sourcing some 15cm steel disks. . Crazy prices.

[@ThinkingandTinkering]

steel has got expensive and perfect circles even more so

[@leonbarry5403]

@@ThinkingandTinkering initially I had bought two acrylic discs of temu but I read a lot of information saying you needed a metal backing on the magnet rotors to direct the flux back inward. Last night I had a root through the shed and found a few older pc cases made from steel. My plan is to cut then sandwich a couple to make them more rigid. I had an idea to place the rough cut circles into a roses tub lid and pack the edge with some resin putty I have that can be sanded when set. I like the thought of having lovely machine cut disks but half of me loves the tinkering. For anybody interested the wire came from two broken electric lawnmowers the connectors came from temu for pennies, the magnets came from a broken electric scooter and another broken scooter of the same I bought on Facebook market for 10 euro.

[@PhilR0gers]

I think the biggest problem is peoples' mentality. They have come to believe that you can just make something with a 3D printer without having to do any extra work. If you cast something in metal, it still needs some machining to get the exact piece that you want. The same is true for mechanical parts that are 3D printed. Most owners are not engineers, so they don't understand this.

[@ThinkingandTinkering]

very true

[@401ksolar]

Why not just call them prototype printers?

[@ThinkingandTinkering]

indeed mate

[@johnwynne-qx6br]

Thumbs 👍 😊

[@ThinkingandTinkering]

awesome mate lol

[@Ammoniummetavanadate]

This design mindset is the difference between good engineers and what I am going to lovingly call "computer jockeys". It is actually extremely important that engineers early in their education and career understand how thing are actually made and differ from their sketches and calculations. It also speaks a lot to those who understand design trade-offs. It is super easy to shut out the real world and think things must be perfect but working with a printer in your bedroom can often show you directly and physically that you can make an awesome design that has relaxed tolerances.

[@ThinkingandTinkering]

nicely put mate - cheers

[@totherarf]

Quick, Cheap, Accurate ...... You get to chose any two! In the real world you do not need accurate, you just need accurate enough! I have to say I do like the occasional glimpse of a model (or part of one) to be seen in the background occasionally!

[@qwertyqwerty9587]

Accurate and cheap all day 😂

[@ThinkingandTinkering]

lol - a lot of the time folks want the lot - good luck with that if that is what they want lol

[@doogee6157]

I have owned 2 quality printers and i would have to say there awful. So many prints that didn't work plus the cost of good filament which 85% ends up in the bin.

[@ThinkingandTinkering]

it sounds like a rethink of the model design is needed mate

[@doogee6157]

@@ThinkingandTinkering well yes maybe , but all the files were created in Fusion 360 and exported for 3d printing then sliced in slicer, nuts and bolts never fitted, very disappointing

[@Mark_Linford]

🙂

[@ThinkingandTinkering]

cheers mate

[@filepz629]

🫂

[@ThinkingandTinkering]

cheers mate