It is! Though I did upgrade from the version seen here as the machine started getting into production-like loads and the NEMA23 were not cutting it. Upgraded to NEMA34/12Nm about a month after this video, and to a 10mm pitch screw. The "compound nut pulley" part is still printed nylon. About 0.003"/0.1mm runout was the best I could manage what with thermal expansion and printer tuning (even with turning it on the lathe after printing, the gear teeth are not perfectly concentric to the center of rotation). This creates a little vibration and premature wear on the radial bearings. I would also suggest proper thrust bearings at this point if one thinks the machine would see a duty cycle more than hobby or intermittent. About every 40-80 machine hours I find myself tightening the plates or replacing those to take up slop from wear as the RS type bearings are just not quite keeping up with wear resistance under heavy cutting loads (i'm now running a 5hp spindle and pushing material removal rate as much as I can). The NEMA34 weight also causes the taller plate to want to sag under motor weight, and vibrate additionally, so I will recut the housing to be probably 1" Aluminum 6061. FloweringElbow on KZfaq has a similar design that is cast, I just tried for something quicker and cheaper to build (as I don't do casting here). The ShopSabre commercial routers also use this same drive system and you might find some videos of theirs. The current system runs at over 20,300mm/min and I am throttling it to give myself a confidence interval on reliability. I have run it at over 25,400mm/min with this machine's newly casted 400lb/180kg gantry assembly. So I'd say it's up to industrial standards with some considerations. Thanks for checking back. I'll try to post more updated info when I've organized things a bit.

@@calphis thanks for the reply wizard, I see a lot of people saying it doesn’t work or wears to quickly but your solution seems robust at high speed. A new video with the mods you’ve made would be highly appreciated! I have some bearings ordered and going to print the parts soon

Most commercial gantry mills (metalworking) and high end routers (like ShopSabre) rotate the nut instead of the screw. Thomson Ballscrews for example makes some high end rotating/driven nut systems for industry. They also have hybrid systems where both the screw and nut can rotate independently. What I've shown here is just an example of how one could make such a system at low cost for lower duty cycles and a shoestring budget. But industry can and already has far outpaced what conventional screw-turning systems can manage, by orders of magnitude. But there's definitely a gap between entry commercial and hobby grade machines, and those commercial 20-40HP monsters, where designs like these can live and serve well. Oh, one other thing I will note is that I did eventually have some of the nylon threading start to become compromised. Fortunately I formed all 6 holes and only started with 3 being used so I had some buffer to fall back to. This was due to vibration from aggressive cut spindle feedback. Heavy cuts -- 15mm deep and 8kmm/min feed rate in dense, wet wood. Also had some other looseness in linear bearings that was helping these vibrations resonate instead of damp, so maybe not an issue. But some threadlocker at those interfaces might be advised if you expect heavy loads. I figured the nylon itself would act as threadlock as locknuts are often made with nylon. I used Loctite Blue everywhere else but here and resolved by adding it here too.

@@calphis how did you mount the ball screws?

@@jamieclarke321 the new assembly was too big to fit where the version in this video was. so it was moved to the outside edge of the table, and some flanges drilled and welded to the table frame. one side foregoes the use of the original BK/BF## style bearing block and instead just uses a hole. this corresponds to the side that has the bigger block and the conventionally threaded section for the set nut. That nut is used to clamp the bare ballscrew end in this hole without allowing rotation. The other side has oversized mount holes that line up roughly to the screw holes for the BF## block. Those are oversized and allowed to float during initial fit up. Then run the axis down to the static side, and oversized holes for the entire assembly to the gantry allow that part to be tightened in place to establish spacing between gantry and that center hole. then run the axis down to the floating side and tighten those in place. I find tightening in place like this gives much better results than relying precision cutting parts alone. The only tough part about this technique is you do have to precisely cut at least one dimension. for my setup it was the spacer used for the mount between the driven nut assembly and gantry. so that and the center point on one side are fixed, everythign else is floating and tightened in place. wish KZfaq would let me post pic links here.

20mm

in this video it was GT3 with NEMA23 steppers. but now I'm using NEMA34 and HTD 5M. 10mm pitch screws but would work much better with 20mm pitch

I currently have mine set to 180ipm (about 4600mm/min). That's with one screw slightly bent, poor alignment, and one side has a driver that got printed with missed steps on the flange part so its out of round. Testing each axis independently of those issues I was able to get 275ipm (around 7kmm/min) without too much fuss. That's with 3Nm NEMA23s. ALso, my screw alignment is very very poor right now. I suspect with 4Nm motors, good tuning, you could easily get into the 400ipm (10kmm/min) and up region.

@@calphis that’s awesome dude thanks so much for sharing. I’m looking to add the rotating ball nut to the printNC design and get officially accepted as a mod to allow for 4 x 8 machines with that design so gathering as much info from other makers as possible and you’ve been the most helpful person I’ve found so far so thank you

@@jamieclarke321 That sounds awesome! Glad to help. The community has made a lot of information freely available and I've been able to use it to accomplish everything I've done so far. It just fits that we contribute back to the pool when we make something new, when we can. By the way, just posted another piece of video data on the same configuration milling aluminum, so the driver part being printed nylon is not a concern i think. On most machines it will be far from the weakest link in terms of rigidity. kzfaq.info/get/bejne/n86Zqbdhy5_Nlok.html