Fixing the Z axis on my CNC machine!
ฝัง
- เผยแพร่เมื่อ 30 ก.ย. 2024
- While getting started with working on my new CNC machine I discovered it had a big problem! Lots and lots of lost motion (backlash) in the Z axis. In this video I show how I went about diagnosing and fixing the problem!
I also talk about what a ballscrew is, what the basic axis of a CNC machine looks like, and lots of little tips and tricks that make working on a machine like this safer and easier!
If you have any questions or suggestions please feel free to let me know in the comments! If you learned something from this video and would like to help me make more like it, please consider becoming a Patron:
/ goughcustom
Thanks for watching!
-Aaron
Seeing you go from making a knife by hand 8 years ago to now being a proper CNC technician in order to make the best knives possible is just incredible. It makes me even more proud to own a Resolute Mk III, that I bought when you had to replace your spindle 5 years ago. Thanks for the knife and taking us all on the path with you.
Thanks for your support mate, and for continuing to check out my videos! Very cool to get to share the journey with awesome people like yourself!
Yeah he’s good at this . All nice and clean equipment and workspace . With care too .
I once had a similar issue. I baught a Mill, cheaply and the guy I baught in from forgot to put a spacer bushing back into the spindle. when milling everything looked fine but once you would drill something, the spindle would overheat big time because the spindlenose was rubbing on the housing.
5 minutes on the Lathe and some scrap seel tubing did the trick.
Amazing the things that get lost when you take a machine apart! I'm sure we've all had an 'extra' screw or two after doing a project... This was not the only thing that the previous owner had done incorrect on this machine though unfortunately... When I got the machine the 15 HORSEPOWER spindle motor was held in place by only a single bolt. 🤨
lovely stuff as always!
Thanks very much mate!
Naive question: For the retaining bolts, would it be reasonable to use thread-locker?
Not naive at all mate, good question! I think a weak threadlocker would be fine, I wouldn't want to use a strong one though, too much risk of causing damage when trying to undo the bolts in the future. That said my other machines have not had threadlocker on these bolts and I haven't seen one come loose yet!
I use the blue Loctite 243 glue stick on everything unless I know it will be undone regularly. When it arrives, I plan to use a torque wrench on important bolts (plus 243)
Hola, nosotros en lo personal usamos loctite anti aferrante C5-A, nunca no a dado problemas aun cuando lo usamos en maquinado con refrigerante liquido y como dice el compañero siempre respetando los torques, espero le sirva, saludos.
I remember being a bit disappointed when the CNC arrived.
I felt : After mastering handmades, he's going to get MIGHTY bored watching a machine make them. Like watching paint dry.
How badly mistaken I was !
The excitement hasn't reduced, it's multiplied hundredfolds shifting from the knife-edge to CNC !
I just realized, you don't FIND excitement; you CREATE it by going where you hitherto haven't and most wouldn't ever dare to.
Thanks for a very interesting & inspiring video.
Thanks for the great comment, and for continuing to watch even after I got the CNC! :) Having made knives both by hand and with the CNC I can tell you that making them with the CNC is far more challenging to get right, though less labor intensive when things are going smoothly.
I think it's a good balance for me personally, it tends to put the emphasis on working out processes and fine tuning details, rather than repetitive manual labor. Personally doing low skill labor again and again really takes the joy out of the process for me, so I am working to reduce that!
-Aaron
The only person happier than a man who had saved a hundred bucks is a man who had saved a grand.
Very true Yan!
Always nice when stuff works out like that. Smart checking the bearing while you had it apart. Hopefully no hidden damage from it being loose. :)
Hey Bert! I've been a bit slow posting this video, filmed it kinda early last year (around April) and the machine has been running great since then, so it seems like no harm done! I actually keep a spare thrust bearing on hand (as well as a bunch of other spares for the machines) so if it does end up going it will only be a few hours of downtime to swap it out... Downtime is definitely a risk with these older machines so I try to keep common stuff on hand to mitigate that!
Good stuff. I learned some things today. I must do a backlash test on the big old mill I sometimes run at work.
Glad to hear mate! If you do a backlash test, make sure to add whatever backlash compensation is set in the machine to get the real numbers. If you're comfortable doing it, the best way is actually to zero out all the backlash comp before doing the test.
I see Vicky is still sweating out all the graphite she ate in her previous life...
Haha yep! This was actually filmed right as I put her into service, early last year (april) she's been running great since then and the oil runs clear now! :)
I have no idea what I just watched but...
1. I love it.
2. Yes.
Haha well I'm glad you enjoyed the video Dan!
Buen día excelentes videos tengo un problema Fadal 2216 al hacer semicírculos en X y Z me deja un plano abajo puede ser lo mismo de tu máquina ? Gracias saludos
I really admire your mastery of your tools. I know literally nothing about cnc and yet I was interested the whole time simply because you knew exactly what you were doing and you explained it so clearly
Really glad you enjoyed the video mate! It's definitely somewhat hard to present things like this in a way that will keep people engaged, I cut out about 95% of what I actually filmed lol. Hopefully you now know some stuff about CNC! 🙂
@@GoughCustom I think you should do a fully unedited video for us who like the information and or just listening to explanations lol
hi i have the same fadal. I want to replace the ball screw x and y. but I live in Poland and it's hard to find parts for the fadal here. there is a company that makes such ball screws, but it needs a drawing.
The important stuff. Tell you right now it’s the bearings ?
Hi. I have a cnc machine and it didnt want ti go back to zero. Then I done ref. home and it went ok. What could it be?
After watching your CNC videos I had a dream in which I bought a CNC and repaired it.
Sounds like an awesome dream!
suuuper awesome. absolutely bea-yoooouuutube-iful.
I'm surprised this didn't recommend torque wrench tho
Thanks mate! I'm honestly not sure if there's a torque spec for the thrust mount bolts, I guess I should check the maintenance manual next time I have to do this job!
this was a great watch!!
Really glad you enjoyed it Mark!
How many hours of work was this? haha
This was actually not too bad! I think the whole thing was done start to finish in less than a day, maybe 6 hours or so?
You lucky sob! Awesome!
Cheers Russell!
9:49 So when are you machining that set of Beskar armor?
Good one but thought he should first must contact Jorek Byrnison for some forged sky iron to prototype with. ;-P
@@pjhalchemy That reference went right over my head xD
Perhaps once my signet has been revealed...
Nice video, I think that the nut in the ball screw is a pre-load for the bearing, in that case it's not a very good a idea to thigthen it so much, because that's make the ball/rollers squeeze inside the bearing. Maybe a locktight it's a better solution.
Keep going I love your knifes!
Hey Nicolás!
The preload on the thrust bearings is actually determined by a thin metal shim in between the inner races of the two thrust bearings. So tightening the nut that retains them does not affect the preload which is great.
I have seen some designs, especially in spindles, where the preload is altered by the torque applied to a retaining nut and it tends to be a very fiddly and generally poor design, thankfully they didn't do that in this case!
-Aaron
My vmc15xt has some backlash on Z axis I went ahead and purchased the thrust bearings only problem I can't figure out is how to align the ball screw any ideas???
Install the ball-nut bolts but leave them a bit loose, same with the thrust bearing bolts. Move the Z axis all the way up, then tighten up the thrust bearing bolts, then the ball-nut bolts. The thrust bearing and its mount should determine the alignment, then you just tighten the ball-nut in place to maintain it...
Run the Z axis all the way through its travel with a cordless drill or by hand to make sure it doesn't bind up or get tighter anywhere in the travel, and then you're done!
Definitely not a precision process but it has worked well for me so far.
Very good video, loved the methods you used, you did a very good job.
I worked on a machine with the same problem as yours had, it machined graphite electrodes, and the dust destroyed the thrust bearings, the z would move and shake the entire machine.., it weighed 20 tonnes. Its crazy what you see sometimes. I'll have to start making videos on the servicing of machine tools, theres not enough on TH-cam.
Cheers Max! I think it would be great to make machine repair videos, lots of people would love to learn more about the process I'm sure, myself included!
The 7:30 measurement is wrong. There is no bearing anywhere near the tip indicator to keep this ballscrew in its axis of rotation. If you would bore a pipe of external size of a ballscrew + tolerance and bolt it in place...
I'll have to disagree given that the before and after showed that I fixed the problem... It doesn't have to be perfect, it just has to be able to detect the issue. I am not really taking a quantitative measurement here, just a qualitative one. The sudden change in indicator reading when I reverse direction is all I'm looking for as evidence that the ballscrew is moving on its long axis. If the ballscrew is rotating outside its central axis then that would show up as a slow periodic change on the indicator, in step with the rotation of the screw, much like what you see in the 'after' measurement. This does not really hinder this measurement from being effective.
Na kakvom temelju stoji tvoj cnc?
Temelj mora biti jak i težak, da bi stroj pri obradi imao minimalno vibracije. Po mogućnosti, nikakve.
Dobro si primijetio da je prazan hod bilo koje osovine, osnovni problem pri radu s tolerancijama. Osim toga, nadam se da je tvoj cnc po sve tri osi postavljen u nulu.
Pratim tvoj rad i imaš izuzetan entuzijazam za čelik.
Tvoj proizvod to potvrđuje!!
Baš volim tvoju predanost poslu!!
Sve dobro.
Pozdrav.
Hey mate! The floor under the machine is 6 inches of concrete, it's not the best floor ever but it's pretty good. The machine has been levelled very carefully! Thanks very much for the kind words, glad you liked the video!
Great vid love the explanation of the diagnostic process!
Cheers Jef! Glad you enjoyed it!
Grinding that screw flat despot sound like the right way to me either , lol . I know guys like that like we all do . I want my stuff right and to have confidence in my tools personally .
awesome video gough i came in knowing nothing about CNC and learned a lot!
i had no idea that a ball screw had ball bearings that run in the channels, i guess its in the name but never put it together. facinating
Hey mate! Really glad you liked the video, thanks for watching! Ballscrews are very cool, I just wish they were cheaper! :)
ohhh long time no see!!! Fantastic. This is the way
This is the way indeed! Not sure if you saw them but I actually released 3 videos over the last couple of months!
You doing more videos, I like your indepth view and your work
Thanks mate! Yes next video coming on April 1st! Make sure you subscribe to get notifications!
Great troubleshooting info, thanks!!
No worries Chad!
EXCELLENT VIDEO! THANK YOU!
You're welcome!
Thanks for all the information you share. Would you happen to have or know of a reference/guide on how to replace the X/Y thrust bearings on a Fadal (I have similar 2016L)? All the threads I've read get pretty confusing and go into troubleshooting backlash and details about quirks/tips for re-install etc. Kind of looking for a fundamentals of what to remove and how. Also, have you ever considered to reball your screw if you think you may have issues with it instead of having to purchase a new one? Steps seem simple from what I understand, but doesn't seem many try to do this. Thanks in advance.
Hey Sarah! The steps involved in removing the X/Y ballscrew are pretty much the same as what I show in the video for the Z axis, except you don't have to worry about the counterweight.... Remove the servo, remove the thrust bearing mount and the ball-nut mount bolts, remove the entire ballscrew assembly, then you can dissassemble it and re-assemble it as I show in the video!
I have not tried re-balling a ballscrew yet. If your screw is in good condition and has fairly even wear then it should definitely be an option!
@@GoughCustom Thanks for the help. I wish I could have read what you wrote a couple days sooner because I took apart the X ballscrew and didn't realize the ball-nut mount, therefore my tiny balls went flying everything when I backed out the screw. I guess it's a good excuse to go ahead and attempt the re-ball, I went ahead and ordered nominal 0.125 Grade 10 balls as I measured a few of the existing balls to be ~0.1241 - 0.1245 . It's about 5X the cost for non nominal sized tiny balls. In case anyone is attempting also, I estimate about 250-300 tiny balls per ball-nut.
"screw" that problem! 😅
haha seriously!
When zero is the hero.
Well played ✌️
Thanks mate!
Ball screw are cheap on AliExpress
They are yes. Unfortunately the end machining on this screw is not standard which means I would have to pay extra for custom machining, if they even do it. Additionally the quality of AliExpress ballscrews is very variable... cheap ballscrews are fine for a hobby machine or for a machine that you're fine with tweaking, but my livelihood depends on this machine so I would only buy high-end ballscrews for it!
Man those thousands are so confusing, inches and stuff. Looks like you have it figured out though hhaha
Yeah imperial units are definitely a bit silly compared to metric. I grew up with Metric but learned imperial as soon as I started making knives so I'm pretty comfortable with both. I use imperial in my shop (mostly) because all my materials and tooling are much easier to get if I buy imperial...
@@GoughCustom aussies went metric thank f hahah, spent a good part of my life there, but the feet seemed to stay haha
@@draganpastrovic2157 yeah I grew up thinking kilometers for distance and feet for how tall people are lol, bit weird! Using 'decimal imperial' (thousandths of an inch, ten-thousandths, etc...) is honestly pretty pretty straight forward and is the norm in most North American machine shops...
@@GoughCustom yeah just getting used to it I suppose
Great video Aaron and a good tutorial about the possible culprits. Glad you found it and solved it quickly with only one knuckle bust...felt that clear over here. @¿@ Curious how much you can offset in code in each axis? Thanks Much! ~PJ
Hey PJ! Thanks for watching as always mate! Yeah that knuckle hurt, didn't leave a scar though luckily :) You can offset quite a bit in the control, up to about 0.005" I think, however anything over 0.001" probably won't give reasonable results. 0.0005" is about the most I would want to comp in the control before replacing the screw and/or thrust bearing.
I feel like you and I have spent more time fixing machines than making knives haha. Great work mate! Cheers James - Fifty50 Knives
Hey James! Yeah it can definitely feel that way at times lol. But think of all the money we've saved! Especially you with your fancy machines mate! :)
Precision milling is so interesting. We have a severely worn out manual mill at my work, and it literally has 0.050” of backlash in the x axis.
ooof that is a lot of backlash! Luckily it's definitely less of a problem on a manual mill as I'm sure you know... having that much backlash on a CNC would mean a full rebuild or a trip to the scrap heap!
I am awed. Great job.
Cheers Tony! Glad you enjoyed the video!
Thats the great thing about the Fadals - they're relatively simple machines, usually low priced , with great aftermarket parts support, and a huge community who can usually help diagnose any issue that may stump you. If you're trying to start up a shop, and don't need super high speed and feed milling, or are doing fiddly work splitting tenths, they're definitely the way to go.
I totally agree! I am at the point where I'll probably be looking for an upgrade within a couple of years, and even then there are options for Fadals to modernize the control and make them more accurate... My machines have certainly treated me well!
Thanks for sharing Aaron. Do the 88 controls accommodate linear scales? I swear I've seen a Fadal with scales at some point.
Hey mate! Yes I believe there were fadals with linear scales, I have personally never seen one though! There were lots of fadals of this vintage that had chilled ballscrews though, I think that was meant to be their cheaper solution to thermal management... only problem was the rotary unions tended to leak and destroy the thrust bearings!
So nice to find out, only two loose bolts. That is the best result you can find when searching for a potential expensive problem.
Thanks mate! Yes I was definitely very happy with the outcome!
Nice! Thats a lucky break! Glad it got fixed properly
Thanks mate! Yeah always nice not to have to throw money at the problem!
That's so fantastic! You found those two bolts loose. I know how frustrating it is to find what the problem is with a machine tool. And how satisfying it is when you find it and fix it! Good luck Happy machining!
Thanks very much Scott!
Muito bom ! Obrigado.
Cheers Jesse!
Always great when you post a video. Thanks for sharing.
Thanks very much for watching mate!
I love seeing all the minute details. I'm a big fan of the work you put out, especially seeing where you had your start. Great video!
Thanks very much Ashley!
Nice one. Very lucky to get away with that:) I would love larger machine like this
Thanks Steven! It's really nice having the larger machines, though I wish I used Milly more than I do at the moment! If you ever get a garage big enough to fit one I definitely recommend the upgrade!
Absolute quality as always Aaron - Thanks mate 👍🏻
Thanks very much Mic!
Really cool video! Thanks for explaining all the steps you took! I learned a lot today!
No worries at all mate, thanks for watching!
"This Is the way!!"
That doesn't sound like something a Sith would say... 🤣
Graphite is hard on machines not designed to machine it. Good job!
It definitely did a number on the electronics, but I've been surprised at the mechanical condition of the machine so far! That said I know the previous owner put a LOT of parts through this machine. I think all the ballscrews have been replaced at least once each...
@@GoughCustom I've seen just about every major machine tool builder out here struggle with Graphite when they try to just hang an exhaust system around the cutting zone and call it good. Purpose built machines still struggle with the stuff. You did a fine job ressurrecting these machines.
@@terrymoorecnc2500 Thanks Terry! It was definitely a bit of a process! Thankfully I think the final result has been worth the work... This video was actually filmed last April and the machine has been running great since then, making knives every day!
Nice!
Thanks Mark!
Awesome job, Aaron! Great (and cheap) fix.
Only thing missing was the heavy metal 🤘🏻😈🤘🏻
I will make sure to include some in a future video! Thanks again for watching mate!
@@GoughCustom
Defo! 👍🏻
Outstanding content. Thank you
Thanks very much Michael, glad you enjoyed it!
Good to see you back!
Thanks very much Grant! I have actually posted a few videos over the last few months, worth checking out if you missed them!
I have indeed missed them .
Thank you for the heads up.
That’s my evening sorted for tonight.
Take care.
@@grantcook5376 You too Grant! Hope you enjoy the videos mate!
I love it when a plan comes together!
Me too! Especially when I don't have a plan in the first place! :)
What a great result, awesome.
Thanks very much mate!
Gough: that is perfect
Herrera: that is pure sex
Gough: that is *fucking* perfect! 🤣
I love it XD
I love your reaction when it just works out, definitely appropriate you saved 100 CN! It's really nice to see you working on machines that you have gotten to know so well, it's also educational. I've never used a CNC machine but would love to get my hands on one to play around with so to speak. Thanks buddy, really enjoyable stuff!
Hey William! Even better it was USD$100, plus shipping and import duties and everything, so probably closer to $160 CAD!
One really cool thing about these particular machines (Fadal) is that they're actually really affordable. If you're in the USA in particular... I bought these one for $3,900 each though they needed a lot of work. In the USA it's not uncommon to see Fadals in decent shape selling for $8k or less!
@@GoughCustom I'm in NYC but renting so I'd need a place to put them but good to know and even better that you saved 160 CAD.
@@Madlintelf Just chuck one in the living room mate! :)
@@GoughCustom I'm sure the wife would love it! :)
I am wondering if you are getting enough oil to the ball screw nut on the Z-axis ? The oil seems awfully black. Maybe worth checking out the oil distributions block and such ?
Thanks for the concern mate! This video was filmed shortly after I first put the machine into service in my shop, and in it's previous life it was mainly cutting graphite which is why the oil was coming out so black... I've been running the machine for close to a year now and the oil is mostly coming out clear now, just needed time to flush out all that graphite!