Can we cut steel on a desktop gantry router?

Avid CNC Benchtop Pro vs Mild Steel - can we cut steel on a desktop gantry router?
Testing out recipes for cutting A36 mild steel on my Avid CNC Benchtop Pro CNC router, using the CNCDepot S30C 2.2kW spindle and a Fogbuster. Aluminum is comparatively more forgiving than steel, and it really becomes apparent on lighter desktop gantry routers. My Aluminum testing had some chatter, but generally cut well even on poorly optimized recipes. But steel took a lot more tuning and tweaking to find a recipe.
📢 Twitter: / breakingtaps
In this video I walk through my thought process as I tune towards a good recipe, discuss how HSMAdvisor can be misleading for lightweight machines, break a few endmills and have questions about carbide thermal shock. Spoiler: with some fiddling it's defnitely possible to cut mild steel on a gantry router, keep a good finish and maintain tolerances!
End mill was a Lakeshore Carbide 1/4" variable 4 flute standard length end mill, AlTiN coating (L14MTMXZ)
Typo at 4:41 - should say 0.0335" WOC, not 0.00335" 😅

[@4O4FileNotFound]

All the cuts are climb cuts. Try cutting in the other direction. In the climb cut the bit and the rest of the spindle are pulled into the work, and rebound back when the chip releases. That is the tone you are hearing. Like a violin string and bow. Climb cuts have advantages on a real, stiff, VMC. It may also help here to add a tightly attached mass to the spindle to move the resonant frequency further below the cutting frequency.

[@brahtrumpwonbigly7309]

I think this is one of the more useful suggestions. Too many people come into cnc and are trying to use toolpaths that extremely expensive and rigid machines would use when there are completely differant ways to go about cutting on less rigid machines, not just continually adapting the same toolpaths down to lower performance specs.

[@matthewrossilini5808]

The end mill is pushed AWAY from the work on a climb cut. It is pulled INTO the work on a conventional cut. The toolpaths he programed are the only way to use this light duty machine. The only problem with climb milling is backlash.

[@davidlong2691]

Matthew Rossilini's concern below is true. Conventional cutting may simply pull the cutter into the work on a less-stiff router table (given the high efficiency milling he is trying to achieve). Also, re-welding of chips onto the workpiece is another very real concern with conventional milling, and this just doesn't happen as much with climb milling. Yes, I know that conventional milling is usually the better choice with a loosey goosey table. You may very well be correct.

[@christophermussel5783]

Not true at all!!! With climb cutting the cutter wants to PULL itself into the workpiece. (like climbing up a hill) Conventional pushes it away. Google a picture of climb milling and you will see the difference. The problem with climb milling is that it will intermittently pull any backlash out of the system. That's where the chatter comes from. Conventional milling forces continuously push the the nut firmly against the lead screw. @@matthewrossilini5808

[@paulketcham9905]

Great video! Your incremental adjustments were going the wrong direction. Adaptive (High Efficiency Milling/"HEM") should, as a rule, not exceed a Radial DOC/WOC of 8%-10% of tool diameter, depending on the projection length to diameter ratio. The whole point of this is to relieve radial forces in the cut through such a light radial load, but make up the MRR through a very high federate (325-400 IPM) and FULL axial engagement. All of the heat goes into the chip rather than the tool, and deflection is so slight that cutting 3 x Diameter results in wall taper of less than 0.001". I use High Efficiency milling techniques almost exclusively at work now. In a standard milling machine (vertical or horizontal), we would run, say, a 1/4" tool at 1/2 - 3/4" Axial DOC, with a .0038" feed per tooth. While your machine wasn't designed for milling steel, it can easily handle these tool paths in smaller 1/4" and 3/8" tools. You could easily handle that cut in terms of HP (you wouldn't even pull 1hp), but your spindle torque at 420 SFM would probably be getting dangerously low. If you increase the RPM, your feed would quickly climb outside of your machines ability to perform. To fix this, you could go up in diameter to keep your SFM constant, but resulting in lower RPM. If you are willing to do another video, I would be happy to send you a several solid carbide end mills for you play with. I love watching guys accomplish what most people say you shouldn't be doing for everyone benefit.

[@BreakingTaps]

Thanks for the help! Really appreciate it! I admit, despite knowing that HSMAdvisor was giving skewed suggestions... I still used it as a guide while tweaking. I'm definitely interested in trying more tests, especially as I get a better feel for how the machine performs. That's interesting re: larger end mills. It's one of the issues I was battling, my spindle max is 24k RPM... but feeds faster than >150-200 IPM start to visibly shake the machine. So I found myself running up against the 150'ish IPM limit, which was driving bigger chipload instead of faster feeds. I didn't think about stepping up to larger end mills though. I guess I was mentally assuming the machine couldn't handle larger than 1/4" end mills, but that's probably silly in retrospect. I think I'm going to try and address the feed rate issues first before trying another test; I want to significantly increase the mass of the machine (both so that I can deck off a known flat surface, and to increase the mass) and improve how it's mounted to the table. After that I think it'll be a lot happier moving 200-300 IPM But ++ to retesting with appropriate HSM methodology, rather than increasing chipload like I was doing. Definitely makes sense having been through it once and seeing how the machine reacts. Out of curiousity, what's the best way to measure wall taper? Would be interesting to measure how much the tool is deflecting, since that's probably directly related to the gantry being torqued rather than tool deflecting (just a guess). Micrometers and gage blocks seem subjective to get good wall taper readings, and I don't think I can quite afford a CMM yet :) Are micrometers my best bet?

[@paulketcham9905]

@@BreakingTaps Use a dial test indicator clamped to a dowel and held in your spindle, then just move your Z-axis. One important point about HEM machining. Always repeat your last finish pass convention milling to remove that last 0.001 (or whatever) taper. You aren't stepping over, mind-you, your just recutting. If you conventional mill to remove taper, your end result won't be as good because your tool will deflect trying to "climb" the material. Some will argue you need a more rigid machine to do that. Concentional does require more rigidity, but were only talking about a very slight amount of material here do you'll have no problems.

[@BreakingTaps]

Doh, yeah a dial indicator makes sense to measure that. Thanks! Noted on the spring pass, will make sure I add those in the future.

[@bohmapik3586]

Would you be willing to point a learning machinist in the direction of some documentation on HEM?

[@8ttiknio8]

I am looking for a CNC that is capable of cutting small parts (watch hands) out of .3 to .5mm steel. Do you know of anything suitable?

[@dannapert4199]

With carbide, either completely flood it with coolant, or just run it dry

[@matthewrossilini5808]

Mist is OK on uncoated, but you're right. Most coatings are made to handle heat and can't withstand the thermal shock of hot cut and then coolant. AlTiN coating especially

[@bigmanlars40]

That's interesting because I run flood coolant on all my carbide end mills...no worry about thermo shock...now an insert cutter I run dry as thermo shock then becomes an issue

[@luke144]

it lubricates the cutting edge. I've always flooded it with coolant using full carbide tool, with inserts the COE of the two different materials will crack the insert so I run most of them dry depending on the stock material.

[@MrDynamik1]

Your channel is exactly what I have been looking for. Great editing and content, thank you and keep up the good work!!

[@dmyers9230]

That is amazing. I would have never though this was possible with such a high spindle speed. Thank you for this.

[@IdeaWarehouse]

This is AWESOME. I have the same machine and never thought that it might do steel. This is great seeing the limits of the machine being tested.

[@BreakingTaps]

Glad it was helpful! There's another video on cutting steel if you're interested, has some more refined recipes once I figured out what I was doing (as well as experimenting with conventional vs climb, high-feed tools, etc).

[@mv3dnerd]

Great vids. I just bought a 2x2 version 2 weeks ago and I was wandering about steel. I think this will pass my expectations. Please keep the vids coming.

[@BreakingTaps]

Thanks for stopping by! I would guess the 2z2 will do even better, I suspect it will be slightly more rigid due to being a bit more compact. Good luck, lemme know how it goes!

[@MrCrankyface]

Related to how you "missloaded" your endmills in the collets. Let me tell you one worse, I figured my super-cheap-made-in-china nut had a defect in it since the collets wouldn't seat, so I spun it up in the lathe and removed the bit that locks the collet into the nut... At least it still works but I felt mighty stupid once I figured out that I was the problem, not the nut.

[@brahtrumpwonbigly7309]

That's hilarious honestly. Gotta learn somehow though. I've seen some pretty bad stuff in the shop from people who should know what they're doing so don't feel too bad.

[@JohnHoranzy]

I was going to return my first set of collets until one of the collets snapped into the nut. Then it all became clear.

[@wald3mar]

Great vid - impressive results. Nice work.

[@bgib23451]

I'm used to larger, corded routers kzbin.infoUgkxfQ5_mgwq6PcudJvAH25t-I4D-3cTPz4z so this was a different experience for me. Basically, this is an incredibly sweet machine, fits well in the hand, etc. It has slightly less power than I'm used to, but that's understandable. Maneuvering freehand takes some practice. These days, it's especially nice to be able to avoid power cords. This is above the level of a hobbyist but below a pro level.

[@Clough42]

Which ISO30 tightening fixture are you using?

[@BreakingTaps]

This variety: www.ebay.com/itm/Tool-Holder-Clamping-Locking-Tightening-Fixture-50mm-ISO30-SK30-HSK50-C5-Capto/352472546124 Looking forward to seeing how your FM30 performs! The slower speed is very compelling for steel, I bet you'll have a lot less trouble than I did finding a good recipe.

[@ianschutt6242]

Fantastic video thanks for taking the time to document and explain so thoroughly.

[@BreakingTaps]

Glad it was helpful! Thanks for watching

[@traviswiebe3711]

Journeyman machinist here, you're doing a good job figuring out speeds feeds and step over, I think my 2¢ would be to be sure your collet is quite tight. The helix of the endmill is trying to pull it out of the collet while it's cutting and if you look up the torque specs for how much to tighten them, it's normally higher than you'd think. Otherwise, great job, great video!

[@michaelkelly3158]

Just wanted to say, thank you for this video. I think I posted a comment here a few months ago, but I just decided to go for one of these. Really impressed with it and looking forward to receiving it!

[@BreakingTaps]

Awesome, congrats! Have to let me know how it goes once you get it up and running. Feel free to ping me if you have questions :)

[@michaelkelly3158]

@@BreakingTaps Thank you! I have to say, I actually spent an awful lot of money a few years ago on a grantry style router which while perfect for my needs at the time (accuracy on it is fantastic!), wouldn't touch steel - nothing like this anyway! I'll keep you posted! If you're interested, this is my Instagram: instagram.com/outpostworkshopuk/

[@jakesmachinery8195]

Nice video! Some times you will find that when an end mill chatters, pushing on it a little harder can actually quiet it down a bit.

[@BreakingTaps]

Will keep that in mind! I guess pushing it a little harder gets it out of the current resonance that it's in, so helps settle down the chatter.

[@brianmoore1164]

Climb cuts are tough on systems with low rigidity. Try conventional milling.

[@captainmcderpyderp]

That's an interesting idea. Conventional cuts take more force and should be worse on a light machine in general, but if there's any significant play in the axes then conventional would be a lot more stable in the cut.

[@brianmoore1164]

@@captainmcderpyderp I have a small milling machine and fight rigidity issues with it. It looks to me like you have the same thing going on. What works best for me is to do most of my material removal with conventional milling and then take the last few thousandths with climb milling. The climb milling leaves a beautiful surface finish, but I have to keep the cuts light to avoid the chatter and vibration.

[@BreakingTaps]

I wasn't planning on doing more tests in steel (honestly only intended to use the machine for aluminum), but so many suggestions have come in I now want to see if I can tweak it some more. :) Will try out conventional and see how it fares, thanks! I wish I had a better way to measure deflection and rigidity during the cut itself :( Trying to understand what's going on from the cut sound and surface finish feels like a proxy at best... I wonder if a high-speed camera could capture the dynamics during a cut to analyze objectively. Hmm...

[@brianmoore1164]

@@BreakingTaps There are systems that do that very thing, but pricey. Some high dollar cnc machines have it built in, but on my modest budget I find listening closely watching the finished surface will usually tell me what I need to know. I will often put my hand on the machine to feel for vibration. Never forget, everything is a spring.

[@siraig]

Brian has a great idea. If there's any play at all in the travels, climb cutting is disastrous. But this thing seemed to be doing okay, seemed more like rigidity issues to me.

[@nottelling6598]

Using an indicator you don't mind rattling around on the frame of the machine with a camera trained on it can help you figure out if there's a specific frequency that it'll resonate at. It can pick up vibrations you can't easily hear, so you can gather quite a bit more data than most would think just judging vibration by ear.

[@lordlorz]

I was fairly concerned about machining steel with my diy gantry CNC, but your feeds and speeds worked excellent as a starting point. Thank you! If it weren't for videos like this, I'd most probably have a couple of broken endmills lying around ;)

[@BreakingTaps]

That's great to hear! Happy that my feeds/speeds help get you up and running :)

[@JohnHoranzy]

Well considering you have a $3,000 spindle..... and maybe we could reach a better conclusion ourselves if we actually saw the whole mill. But lots of good info the speeds and feeds. Thanks for posting.

[@iopfarmer]

great try-out video!

[@jongrimm7767]

I have to say that I am impressed with the results achieved. We are a big fan of 3-flute endmills to avoid chatter, and you should definitely spend the extra money and use 1215 or 12L14 when practical. I have zero experience with adaptive clearing and can't wait fast enough.

[@brukernavnfettsjit]

wow, this is great!

[@HSMAdvisor]

Amazing video! You are absolutely correct: HSMAdvisor does not consider the rigidity of the machine, but instead assumes there is enough of it for the spindle power. It will actually suggest lighter cuts when there is not enough HP. This works perfectly for the heavier machines, but for such light machines it sometimes may indeed turn out overly optimistic. Still HSM machining strategies are preferred for cases where there is not enough hogging brute strength.

[@BreakingTaps]

Oh awesome, thanks for stopping by @HSMAdavisor! Really enjoy your software, as a newbie it has helped me find good starting points even if it needs tweaking afterwards. Appreciate the confirmation that my understanding of how it works wasn't way off base. I wonder if there is a good way to "de-rate" the estimations that HSMAdvisor gives to compensate for smaller machines? Set the spindle HP lower so it doesn't give as aggressive of cuts? I find with the 3HP spindle that even with the finishing slider maxed out it can still be too aggressive. Perhaps some kind of "low-rigidity" mode could be toggled that has different set of assumptions? Dunno, might not be possible at all since the variables in a "low rigidity" machine are so much different and probably not consistent. Anyhow, thanks again for the software!

[@HSMAdvisor]

@@BreakingTaps I made an analysis of your video on my blog: zero-divide.net/?&article_id=5258 Basically the solution to prevent the power of the spindle exceeding the rigidity is to Dr-rate the spindle using "Warning At" field in the Machine Profile dialog.

[@BreakingTaps]

Very cool, thanks for the writeup/analysis and the tip! Will try that on future cuts.

[@gmack4097]

@@HSMAdvisor Isn't it more about cutting force (which is inversely proportional to spindle speed and endmill diameter) than spindle power for these types of machines? Maybe a "Warning At" or "Maximum/Target" cutting force = *** for these types?

[@HSMAdvisor]

@@gmack4097 I agree. There probably should be a "Max cutting force" value in the machine profile. I will add in the future updates.

[@revenger2111]

Now you have a ballnose endmill XD

[@kanedadry7642]

Wow sooo helpful to me, thank you so much !

[@northernsmith]

I found on my mill putting a 1 degree wall taper on the plunge keeps the side of the end mill from dragging and really improved the tool life and chatter.

[@BreakingTaps]

Ah that's a good idea, will give that a shot next time.

[@MHZizzi]

Great stuff. I'm interested in seeing what all went into getting the S30 wired up to the avid plug-n-play system!

[@BreakingTaps]

Thanks Will definitely post a wiring video at some point. Few odds and ends to finish up before then: need to finish enclosure (~80% done), wire in the low pressure fault sensor and wire in that drawbar interlock. Think those are the last things that need doing, then I'll put together some diagrams of the wiring and pneumatics (and extra parts that are needed).

[@thewoodologist8176]

Got the same setup, s30c spindle and avid cnc. I'm on my 3rd vfd and the delta vfd from cnc depot is the best one so far to work with the avid electronics package. Awesome setup, would highly recommend

[@NeoQJ]

Amazing for this small machine to cut steel at this speed👍🏼👍🏼👍🏼

[@denpepp7622]

Looks good. A lot of things we take for granted. 1/4 endmills are cheap. Accupro TICN coated are $15 from MSC. You should be able to run 4500rpm and 50-80 ipm with a .003-.005 stepover @ .5 depth. Good video.

[@DanielH]

Awesome machine

[@hamdicanozdemir5760]

Perfect video I ve ever consulted !!!!!!!!!!!

[@mindfulmunchkin1215]

Awesome thanks for this ! will try and blow my spindle up later this afternoon 😀

[@smellsofbikes]

I've done the same thing with clamping an ER collet the first several times. Whoops!

[@ogt92fromthe1step9]

I as well and I learned the best way. I ordered a set of er32 collets off of evil Bay and was not familiar with them cuz I was used to using r8 or 5C so I brought it over to my local machine shop and ask the guy he could turn it down on his lathe I didn't have my lathe at the time and because it wasn't seating properly. And his response was a very good laugh at my stupidity 🤣 but by asking he did then showed me how they properly seat. Live and learn 🤟🤣

[@lukejohnson835]

Got a kick out of the "Subscribe" message on the Jo-block (10:47). Very ToT of you!

[@BreakingTaps]

Hehe, definitely lifted the idea from ToT. I love trying to find the hidden "Subscribe" in each of his videos, like a machinist-youtube-where's-waldo :)

[@Bianchi77]

Nice video, keep it up, thank you :)

[@flyingmonkey3822]

I hit like right when you dropped the chuck 😂

[@iheart3dprinting951]

I was ready to buy this machine when I had the cash, but the sales person couldnt really give me any confidence in what it could do and they seemed annoyed. Had a video like this been out in 2018-2019 I would have purchased the complete kit. :(

[@BreakingTaps]

Yeah, I get the impression they aren't used to these machines being used for metal. I asked some questions and they were helpful to a degree but didn't have specifics regarding metal, tolerances, etc. They have been great in answering other questions regarding pinouts, etc. Although I've also been talking to internal support engineers and not sales reps, so that probably helps too

[@glenndwyer5786]

Yeah man sounds good

[@azizrizki1664]

good job

[@djoertel93]

Never Drop the rpm ! I stay allways 20-30k rpm and just modify the parameters till iam happy

[@trevorlahti569]

Yes sir. Keep that chip load down! I agree. Keep that spindle speed up there.

[@akren2482]

Your 2 videos convinced me to purchase the same setup you have! Definitely the best performing gantry cnc I've seen so far. A few questions if you have time: 1. Were there any other gantry mills on your shortlist? 2. I saw you claim +/- .001 tolerance in steel, is it possible you just got lucky on that part? Thats about what tormachs can do reliably. If you have time, could you machine a test part twice in each aluminum and steel to get some feel for consistency? Something with a bore, contour, and slot? Would be happy to send $20 to help cover materials. 3. Looking forward to your spindle wiring video. 4. Could you test the low rpm torque with a drill bit test in aluminum? Maybe like 3/8" or something? Not sure what a realistic maximum is for that spindle. 5. Is the low speed rpm consistent enough to use with a floating tap head? Sorry for the laundry list, any insight is appreciated before I spend $10k! High quality videos for a casual youtuber as well, cheers!

[@BreakingTaps]

Happy to help! I'll see what I can do for some more tests, I was wanting to try out a few different end mills anyhow (and all the suggestions in this video). Unsure when I'll be able to get to it though, just a nights/weekend hobby for me right now :) 1. I briefly looked at the Stepcraft lineup (since they have ATC), but wasn't impressed with the v-wheel style motion system, and read some poor reviews on them in general. Also considered the wide variety of 60xx chinese routers (the larger 6090s, etc) but they are tailored for wood and also hard to know what you're getting, dodgy QA/support/etc. Tormach didn't have their router at the time, but I think I would have passed since it looks geared more for wood too (and expensive) The other machines I was seriously considering were "mini VMCs", like the Tormach 1100mx, Syil X7, SkyFire SVM2, etc lines. And maybe a Haas MiniMill on the upper end. 2. Very possible :) It's also better than Avid specs the machine, so it could be luck (or conservative specs on their part). I didn't do rigorous testing mainly because I hadn't done any tuning yet. Just tuned the steps this weekend, need to re-tram, fiddle with CV mode, etc. I'd also like to do some repeatability tests with indicators, etc 3. Hopefully soon, once I work up the motivation. Been putting it off because I need to unwire some stuff to put in a proper enclosure 4/5. Unsure, I haven't run it slower than ~8000rpm so far. Max torque for my spindle is ~18k based on the spec sheet, so I suspect low-end torque to be quite low. There is a torque boost setting on my VFD but I haven't played with it yet. I was planning to threadmill rather than trying to get a tapping head to work (also because they eat a lot of Z and there's only ~9" to work with)

[@akren2482]

@@BreakingTapsI'll stay tuned, thanks and good luck!

[@StepcraftInc]

@@BreakingTaps Stepcraft does not use a V-wheel in our systems. If you would like to ever discuss I would be happy to talk [e-mail]

[@BreakingTaps]

@@StepcraftInc Sorry, should have been more precise in my wording. By "v-wheel style motion system", I was referring to your steel rollers on round rails (i.e. www.stepcraft.us/web/image/74255/allsteelmotion.jpg). I wanted something with linear rails so this ruled them out.

[@rodfrey]

Gutsy experiments! I never would have guessed this format of machine could perform so well in steel. Really makes the case for the machine if you're a mostly-aluminum-sometimes-steel person.

[@BreakingTaps]

100%! I don't think I'll be doing steel very often, but it's nice to know I could knock out a part without having to fall back to like 10ipm to do it :)

[@richardfarwell6759]

This is really impressive! I have the Avid 2x2 but never considered doing steel. (I've got the smaller nema 23s and a variable speed router vs spindle.) Would using a two flute or even O flute bit help with feeds and speeds? I look forward to watching what you do with this machine.

[@BreakingTaps]

Thanks! I also have the NEMA 23's fwiw... the Avid folks mentioned the larger NEMA 34's wouldn't be useful to me because their higher torque would mainly be useful at higher feeds, but higher feeds would also start to induce whip in the ball screws. Might be less of a problem on the 2x2 though, since they have a smaller y-axis I'm picking up some singlue flute "O" end mills to play around in aluminum, but I don't think they will be helpful in steel. Having such a large gullet is helpful in removing chips (which helps prevent welding in aluminum), and also logically helps keep the feed rate down. But it also weakens the end mill due to so much material being removed, which can be a liability in steel. The extra deflection caused by a less-stiff end mill can start to chatter/resonate when hitting the harder steel and leads to failure. That's why most end mills for harder materials are 4+ flutes. Recutting chips is still and issue, but since you don't have to worry about welding it's less of a driving concern and more of something you keep in mind.

[@davidlong2691]

We used to run flush and thru-spindle-coolant with carbide tooling on steel and stainless steel parts all the time. I don't see an issue. Note, however, that the efficient flushing/removal of chips is one really good reason to use flush coolant instead of just lubricated air. On aluminum where chip re-welding becomes a huge concern the liquid flush at high feed rates to cool the part/chip and remove the chip is absolutely necessary.

[@jimmyjones001]

All things considered good job. Some advice use only air to clear the chips depending on your budget look into anti vibe endmills. They are extremely expensive though. Our standard 3/4 and mill we use is 60 bucks. The anti vibe that we use is $386.00 so you have to justify the cost. For a hobby you can't justify that slow things down take your time and have fun with it .

[@accidentaltradesman5139]

Awesome video! I’ve got an avid pro on the way for my second machine! Any tips? Ive been running a routakit HD for the last couple years to my dismay.

[@BreakingTaps]

Hmm. I got bit by step calibration because I only did it in one location... so if you calibrate make sure you repeat in several locations, and try to calibrate across large distances if possible. Otherwise, a sturdy table is really needed. Once you get the machine moving fast, it has a bunch of inertia and can throw the table around if it isn't stout (which then causes issues in the cut because things are waving about). Otherwise I've been pretty happy with it. Goodluck!

[@accidentaltradesman5139]

Breaking Taps I’m using my own electronics so I’ll have to calibrate on my one but I appreciate the heads up. I doubt I’ll be cutting any steel.....other than clamps!

[@an1ma169]

I wonder what cuts like those do for the long term life an accuracy of the machine? I'm currently putting a 4x8 machine together, primarily for wood and ally, but may be tempted by some MS cuts, I'm just anxious that each one would be accelerating the wear and tear on the whole setup

[@BreakingTaps]

Yeah, it's a fair question... not sure! I guess we'll see in like a year :D Most of the machine components (on my benchtop version) are pretty robust. E.g. the ballscrew bearing supports, the gantry beam, the linear slide attachments, etc. I am keeping an eye out for bolts slowly loosening over time due to vibrations though. No indication this is an issue yet, but I could see it causing problems in the future and might need some threadlocker to remedy.

[@OGmolton1]

nice machine, what kind of stepper motors you got on that little beast?

[@BreakingTaps]

420 oz-in NEMA 23 steppers, although I do wish I had splashed out for the larger Nema 34s instead. Or just gotten servos. Oh well :)

[@OGmolton1]

@@BreakingTaps that's exactly what I wanted to hear. Thanks. I just ordered some nema 23 motors and that looks powerful enough for my needs, gotta redesign the whole machine to make them fit but it looks like they'll be worth it. My Nema17's lose steps when they need a little lubrication, even while not cutting anything. Squeaking is one thing but losing steps is another

[@albertodalmaso8896]

On steel try High feed mill cutter and the standard end mills for finishing

[@scotia3d263]

thanks under 3mm endmill is fine in bath but 6mm shoots large droplets rapidly near some electric stuff, rrecomend mist by tiping say inch of water into air compressor tank, or spraygun.

[@Madkite]

As someone who has been chewing up steel since he was 8 on mills a d lathes. Most small mills are not that rigid. More that 1 or 2mm depth cut on a 10mm end mill in steel would be considered rediculous. Though the mill is turning almost always well under 1000rpm. So each cut is a lot larger. But you get a feel for manual feeding. Which is what I need to translate in to CNC. I'm just setting up my first CNC router and it's not as good a model as that. But I still think it will cut steel. As long as the tool is not to large and the cuts light I see no reason why not. That will wear tool more, but unless it's a huge CNC milling machine it's the compromise you make. And a good note is CNC mills are huge, but compared to the footprint, the working aria is small. That's how it gets strength. Franky I'm amazed it even did the first cuts I watched. I would have been way way more conservative and worked my way up to its limits. Also, taking small cuts and working bigger is the advisable sequence. You tend not to break things that way.

[@desktoplathes]

Good video! Question on the ER collets... were you loading them incorrectly on the Taig mill when testing it out? Lots of folks are confused by them... often thinking the closer is deformed. I bet pulling the collet out with that taper without help from the closer was a bear.

[@BreakingTaps]

Thanks! My taig actually has the old custom collet system before they switched to ER, so it just "sits" inside the closer without any snap fit. So, theoretically, those were loaded correctly :) And yeah, it really was a real bear haha. I felt pretty foolish after discovering I had been using them incorrectly... in retrospect it definitely messed up some of the tests I ran on the first aluminum video without me knowing about it. Serious facepalm moment for me :)

[@desktoplathes]

Breaking Taps I commend you for sharing the collet experience - most learn more from a mistake, I know I do anyhow. Let me know if you want to upgrade that Taig to an ER spindle! I’m working on some Taig CNC mill tutorial vids now. Keep up the great content!

[@pnt1035]

@@BreakingTaps Is the original collet chuck on a Taig similar to the original E16 collet chuck, or completely different? Pictures I've seen show weird collets similar to but not the same as ES16 (an early, compatible, derivative of E16). I have an original E16 collet chuck for my Unimat but only a few collets. ER16 collets have the same taper angles as E16 but are slightly longer, so they fit, but the nut doesn't screw on far enough for safety. But... On my E16 chuck, the nose thread is 20mm dia x 1.5mm pitch. A standard ER16 nut is 22mm x 1.5mm. It turns out 20mm helicoil is a perfect fit in an ER16 nut and it made a very effective conversion. A friend of mine adapted a collet block to fit the spindle nose on a Taig.

[@BreakingTaps]

@pnt103 The original Taig collets appear to be their own creation, probably wouldn't fit E/ES16. The ones I have look like this: www.soigeneris.com/taig-lathe-collet-set-1040 Notably, the collet closer/nut pulls down tight against the flat on the collets, which makes me think they wouldn't be compatible with the top taper on an E/ES16. I can grab some dimensions later today if that'd help. At some point Taig switched over to standard ER collets if I'm remembering correctly, so it probably depends what year/make you find.

[@pnt1035]

@@BreakingTaps Yeah, that's the sort I've seen in other pictures. So unless the Taig back taper matches the ER16 back taper, and the nose thread is compatible, allowing you to use a new nut, my trick isn't helpful.

[@ken481959]

I may have missed something, but which model and set up, specifically, are you using, as well as the pricing for it. Thanks. Great video.

[@JamesTorrey]

I've got a pro 5x10 fully upgraded but use it for wood. Was thinking of getting into some aluminum, but had no idea I might be able to cut steel. Is your machine similar to mine?

[@BreakingTaps]

I have the (much) smaller benchtop version, only 2x3. The Avid support folks said the benchtop version would handle metal better, since it's a lot more rigid due to small size. So the fullsize version might be able to handle steel but it'd probably have very different cutting parameters, and is probably less rigid overall due to all the extra travel. That said, plenty of folks have cut aluminum on their full size machines (Robert Cowan comes to mind: kzbin.info/www/bejne/n5qaeYWdi5KqmLs)

[@Zebra66]

Use Gwizard for feeds and speeds in metal on a cnc router. Most other calcs are made for mills. .25" deapth of cut is too much for steel on a router with a thin tool. No wonder it sounds bad... I'd start with 1mm and go up from there. That finish is poor which means you're gonna destroy your bearings if you keep ignoring the warning signs.

[@jeremymorrell]

As another Benchtop Pro owner who hasn’t had a chance to really dive in yet, thank you for this! I wonder if there are aluminum pieces in the frame you could remake in steel using the machine and bootstrap a stiffer machine? 🤔

[@BreakingTaps]

Hehe, it has definitely crossed my mind :) The upright L-shaped gantry supports would be an easy candidate for conversion. Simple part, doesn't need careful alignment, and could replace without disassembling the entire machine. Deflection of the z-axis forward/back when the spindle is extended, and torsion of the x-axis (caused by pushing the z-axis forward/back) are probably the main modes of deflection on the router, so replacing parts on the gantry assembly would be the next best thing to do. Would require more work since you'd be re-aligning the ballscrews and linear rails. A steel table (or even a big chunk of aluminum) would be a nice upgrade too. That's probably going to land on my todo list at some point. Would be nice to replace the t-slot extrusions with something solid and flat.

[@captainmcderpyderp]

Stiffness isn't the primary parameter for stability in cutting machine tools, damping is, and steel is not much different to aluminium in that respect. That's why cast iron (or sometimes epoxy granite) is used. Stiffness can be achieved by geometry rather than materials selection to the extent that it is required.

[@BreakingTaps]

Hm fair. I might break out some indicators and try to measure deflection at rest (e.g. push on various parts of the machine while the motors are engaged to see how much different components move). Would give a better idea where stiffness is needed, and where it's just poor vibration control.

[@operator8014]

Ooof. Those collets. I feel your pain man.

[@signzonepr]

Awesome. CNC router aluminum frame its not for steel but the important its possible make non precise parts like welding plates, engine header plates, exaust spacers etc. the brand of the endmill and more hp its important. you need make sample with 3 flutes endmill Kennametal Brand.

[@MVPartStore]

Where did you get your endmill and do you have a part number?

[@silent_tofu7921]

Typically with adaptive toolpaths you want to stick to about 10% of cutting diameter with radial depth of cut. When I went to Sandvik's Metal Cutting Technology class they said you should try to run dry wherever you can. I think you should keep the air blast but try cutting out the MQL oil. Having a bit of oil may make it harder for the chips to get out of the pocket and you'll recut chips increasing your chances of tool failure. Also, you may want to try high feed end mills. They have particular geometries that are designed to send more of the cutting forces into the positive Z direction. I've seen this approach outperform adaptive toolpaths in MRR. It would be interesting to see if those tools work in a router

[@BreakingTaps]

Oh that's very interesting re: Sandvik... I definitely trust them to know what they're talking about! And I have for sure noticed chips sticking to walls due to the mist of coolant. Seems like it provides just enough stickiness that the airblast can't always dislodge it. Funny you should mention high feed mills, I picked up a few the other day. Just small, solid carbide ones to start. But if those look interesting/promising, I wanted to investigate the insert variety (Kyocera Raptor, etc) because they seem easier to get in a variety of sizes, and should help my wallet a bit. Will post a video eventually when I get around to testing them! Really interested as well to see how they perform on the router. Since they put most of the force up the spindle, it seems like a perfect match for less-rigid machines.

[@philipsommerton4280]

@@BreakingTaps interesting...did this video get made?

[@BreakingTaps]

@@philipsommerton4280 yep! I tested a high feed mill in kzbin.info/www/bejne/nHatYa1nqtqhn5I

[@pro3ification]

for hardened steel only use airblast, for regular steel use water+oil

[@Z-add]

What about the endmill? What role can a high quality endmill play?

[@tobiastho9639]

What is the machine standing on? It also affects sound so much! Try a big slab of stone for example?

[@berendlucasvanderweide]

Try it again with the machine clamp as far to x0 as possible. The machine has more stiffness at the outer edges by design. Yes, steel can be machines without coolant. It's a lot more forgiving than aluminum. And the machine will probably behave different in terms of stiffness in X and Y direction.This machine uses moving carriages for the Z axis instead of moving rails.. Although it is convenient for the Z's travel, stiffness has to give in a bit. ER32 nuts are normally tightened with 120Nm of torque. That's a LOT. Righthand tools can come out when the nut isn't tightened good when pushed from the sides relative hard (normally the case with adaptive clearing)

[@BreakingTaps]

Ah that's a good idea, will try closer to the edges of the machine... and definitely thinking about getting an adapter so I can use a torque wrench on those tool holders :)

[@GraphicManInnovations]

why you drop down the rpm when you increase the WOC?

[@strongheartwsi431]

Tell us more about tool changing macros

[@unknownplayer7127]

For the speeds & feeds use the website from the producers of the endmill, like when you have Walter Tools use Walter GPS they give good data and also tell you if you should run it with or without coolant. When you do trochoidial cuts (depends on the material) you shouldnt use coolant. For Helix I did recommend using about a 2-3° angles and or about 0.5-1.25 mm per depth, High RPM and low Feedrate works fine I did say try with Vc=110 M/min and Fz= 0.01 mm (those are for low rigidity so they might work pretty good)

[@jeetenzhurlollz8387]

there are these router collet extenders, very cheap for extending router bit by 1 inch or so. What do you think of them for milling ?

[@Z-add]

Best upgrade would be servos, like clearpath ones.

[@TyberCusaa]

I have a question, can I use a desktop CNC to make a stamp in steel? you know, a stamp of those that are used to "stamp" metal

[@AlfredLarsson]

would you divide the feed by 4 if you used a one flute end mill?

[@BreakingTaps]

Generally, that's correct! Feed rate is mostly tied to number of flutes and the chipload (which is a combo of width/depth of cut and material). But you wouldn't want to run a single flute in steel for example, because the tool wouldn't be rigid enough... that's why 4+ flutes is generally recommended in steel.

[@Seadogstudio]

Mannnnn. I have been loading my er11 collet wrong toooo. Thanks

[@shyowl3453]

I mean I know it’s very different but in preparation for building a mostly printed cnc I’ve learned any metal cutting is best done slow and shallow, now obviously your machine can cut steel where a mpcnc without upgrades can only reliably do aluminum and that slowly but maybe starting from a slow and shallow point and going bigger rather than working backwards would show results a little clearer

[@snapo1750]

would a rough milling cutter not be better on strong materials with so little power??

[@roswaytv9172]

Carbide loves the heat to a certain extent so an airblast system keeps it there with chip removal and no rapid temp changes that could weaken tooling, seCURE UR ER's

[@matejogrinec4111]

Is there any video of the router cnc? Is it home made?

[@comanderiz]

maybe Im too late for this, but use rubber mallet to completely set the material in the vice, and then do the final tightening turn

[@panossimm955]

What kind of cooling do you use?

[@naoufelmelayh240]

hi sir sir thanks for videos , any helps please need to purshase one router for metal ,

[@techniccreator67slegotechn25]

Can you please try a high feed from lakeshore carbide? Their geometry results in almost entirely alxial cutting forces rather than mostly radial forces. You can only take shallow cuts with them but you can run higher surface feet per minute and your feed per tooth because of their geometry is really high. So you end up dancing around the part putting your cutting forces up into the spindle with feeds in the hundreds of inches per minute. Such high feeds in steel with stepper motors may be an issue though. Mainly asking because I want to get approval to try a high feed mill in steel on a robotics teams CNC router.

[@BreakingTaps]

Already picked two of those up! I grabbed the 0.240 and 0.120 high feed mills a few weeks ago, but haven't had a chance to test them yet. Was thinking the same as you: the high axial load should be better for relatively non-rigid machines like routers. The high feed rate are what have given me pause so far, mainly because really high rates tend to throw the machine around. But I've been dialing in the acceleration so it doesn't jerk the machine quite as much... feeling more comfortable with higher feed rates now. I'll try to get them tested sooner than later!

[@Rough_cut613]

A lot of good comments here but the best advice is to switch to conventional tool paths and use HSM DOC so 1/16 of the diameter for DOC. If you take these steps I'm sure you can increase your feed rates considerably w good finish and dimensional results.

[@scotia3d263]

my 800 watt air cooled spindle blowes out the bottom and im wondering if bath water would splash from endmill into spindle, please advise me someone, thanks in advance top video.

[@BreakingTaps]

If it is blowing air out of the bottom it is probably similar to mine: that air pressurizes the spindle case and keeps debris/liquid out of the labrynth seal around the spindle nose. I wouldn't submerge it or anything, but it should keep chips, dust, mist, etc from getting inside the spindle. I have mine pressurized to around 30psi...not sure the optimum pressure but since I won't be working with dust (wood) it seemed a reasonable value.

[@scotia3d263]

@@BreakingTaps thanks its very solid little 6040 cnc, been cutting slate stone plaques with good results. But may upgrade to cheep 1500 watt aircooled spindle to try steel.

[@Frajmando]

What endmill is that? Seems like very high RPM for steel

[@skreech01]

4:05 is that endmill for aluminium and u use it for steel ?

[@BreakingTaps]

Nah, just shooting b-roll after the main cutting was done and it was the end mill in the holder at the time :) I used a 4fl variable for all the cuts in steel in this video

[@skreech01]

Breaking Taps okay

[@diditwork370]

Whenever I don't like the sound of my machine I just put on hearing protection. Edit - just watched the end and carbide endmills are always slightly undersized. I always have to offset my final pass. This is assuming your tool is running perfectly concentric though.

[@ReevansElectro]

Watch "This Old Tony".

[@tarehjernetarehjerne4082]

8:59 you set your stepover to .99? One inch? I hope you meant .099 lol For less rigid setups i find shallow depth of cuts with very high feed rate to be optimal as you still form a chip. Good video as always

[@BreakingTaps]

Err, definitely mispoke :) My machine would explode if it tried 0.99" stepover :)

[@tarehjernetarehjerne4082]

@@BreakingTaps i have a 2.2kw watercooled high speed spindle from AliExpress and it can do 12mm DOC with 1mm stepover in steel (was probably doing 0.3mm feed pr tooth) and it powered through it without issue. It was on a mill, not a router. Good luck finding your perfect speeds and feeds.

[@timeckelmann1196]

Thermal shock would not be an issue with Carbide, only with CBN and fully ceramic inserts. To reduce the chatter use a combination of a smaller diameter end mill a lower axial depth of cut and a wider width of cut. Also more flutes. Get a GOOD NAME BRAND VARIABLE PITCH END MILL. I would recommend Helical Solutions. They account for 90% of the end mills in my machine shop. Low radial high axial tool paths require a rigid machine and setup.

[@stephanbrunker]

I would say otherwise. You can see in the finish of the bottom of the last completed cut that the corners of the mill were already damaged. They just did break away on the last one. My attempts to cut 3 mm (0.112 in) steel plate with a 3 mm mill failed similar, after one or two feet of machining the edges crumbled, started to glow and then the whole mill broke off. So your results were far better than mine. There aren't that many possibilities for the damage to the edges: overheating or thermal shock. To high cutting forces would break off the whole mill. Because the coolant only partially and intermittently reaches the lower edges, I'd think of thermal shock because some of these mills can even used dry or with air. Because I feared overheating, I tried to keep my cutting speed much lower, you are using about 750 ft/min (250 m/min) which is way above the mills I could get here in Germany. Most are rated with 100 m/min in mild steel which means only around 5000 rpm for a 6 mm (1/4 in) mill, and all the spindles I know lack torque and/or a torque steady for a full rotation for these low speeds. You would need something geared which simply doesn't exist.

[@chuljinbaek7937]

How do I adjust the RPM when the tool is 1mm? What rules are there for RPM control when the tool blade changes 6mm 3mm?

[@cookie191]

What types of water cooler is that?

[@donochetti2177]

2:36 The tripods are attacking!

[@ipworks99]

Strong spindle sir

[@greeceuranusputin]

This video left me wondering, what is a gantry router?

[@lelearmi6186]

HI . Could you do the same with a 3mm tool?

[@denis213]

What model of avid cnc you have?

[@BreakingTaps]

Benchtop Pro 2x3

[@nicktohzyu]

am not a machinist, but how do you keep WOC and rotation rate and load per tooth the same while changing the IPM?

[@BreakingTaps]

Width of cut should stay constant, as that's a function of the axis motors positioning the endmill relative to the work. Rotation rate should, in theory, remain constant as well. In practice it'll slow down to some degree depending on how heavy the cut is (the spindle controller has some rudimentary feedback control to sense RPM, but it's not super high resolution). Assuming those two variables stay constant, load-per-tooth will change as the IPM changes. E.g. you can see the IPT doubles between the first and second test because the IPM doubles, but all the other parameters were held constant. Usually you aim for a certain load-per-tooth range and then adjust the other parameters to suit (subject to limitations like spind speed or horsepower or machine feed rates)

[@nicktohzyu]

@@BreakingTaps Ah, I see, thanks. I thought load per tooth was being kept constant because you didn't colour it haha

[@OG-Insomniac]

What's the largest pice of material you can work with that set up?

[@BreakingTaps]

Pretty much the size of the table if you're creative with strap clamps and pre-drilling holes to fasten to the table. So a bit less than 24x36" sheets. Z height is limited to around 8" however, much less if you're using vises or it's off the table.

[@ham-handeddesigns5252]

Why drop the spindle RPM for a greater WOC?

[@fpbibi]

As other said. Conventional milling for low rigidity machine is better than climb milling. From what I see with your machine you'll get mirror finish in the other direction.