In this video I attempt to make a leadscrew nut from acetal (Delrin). All you need is a 2" L x 1 1/2" Dia piece. Local machine shops have tons of leftovers.
That is an interesting way to make a new lead screw nut. Ironically, I had to replace my X-axis lead screw and nut 7 months into using my new PMD-30. I did check the y-axis nut while it was apart and it still seemed OK. It took about 6 weeks before it was all sorted out with King, but, in the end I have a working mill again. Thanks for the great video. Cheers from SK
Great solution and probably a need-to-know for the rest of us (mill/drill owners) , it looks tight enough to use on a cnc application. Thanks for the vid, cheers Gilles!
Well that’s a new approach! Interesting repair. Hope it last longer than the original. I’d be will to bet that original one was brass and not bronze. Also on my lathe I found they used cast iron as a nut and the hardened lead screw wore out the cast iron with no damage to the lead screw. I would have thought it would have done some damage or wear. But cast is soft so it makes sense I guess. 🍻
Very interesting. Might I recommend using moglice to achieve a similar "type" of result but using the original nuts. Drill holes in the original nuts that can be used to inject moglice, put the threads on the screws, seal up the ends so that the moglice can't run out the open ends, and then inject moglice into the holes you drilled. This will form a perfect thread form around the lead screw, similar to what you did here but doesn't require any additional machining afterward. Don't forget to spray the lead screw with some type of release agent so that you can get it back off after it cures.
After this strenuous exercise I definitely need to get some release agent. Moglice sounds like a great idea. Thanks for your input. A good project for the next nut. Gilles
@@LetsRogerThat I love the stuff, I discovered it about a year ago and have kept it in the shop ever since. It can be used to repair all sorts of things; nuts, slide ways, dovetails, etc etc. And the people who sell it in the states are a great bunch of folks. Devitt Machinery. In Aston PA.
Lithium grease as lubricant with acetal? Seems like my newer import machine has more backlash new than my 50+ year old atlas MFC. As stefan says, these machines should be considered as 1/2 machined casting kits. Good job on the repair.
This is super interesting. I wonder what kind of life you will get out of the acetal. Quite a shame that the factory nuts failed so quickly. Probably just a poor quality bronze.
Thanks. I read a blog from a machinist who made some and they apparently haven’t degraded in years of use. I think I will take a look every 6 months to document how it holds up
Seems chinesium machine quality can be let down by the smallest of parts. On my mill the backlash was excessive from new on the X axis and i mentioned it to the importer at one of the shows we used to have here, they said use the adjusting screw, when i got home i looked for it and found it was missing altogether! We won't even go into the Y nut being loose in the casting.😢 All i can say is thank goodness i fitted a DRO.😊
Excellent .. I have been pondering whether to swap out my lead screws for ball screw ... This makes CNC conversion with lead screws very workable for my mill & lathe ... How are the derin nuts after a few months - do you notice any wear or becoming loose?
Did the factory have the original nuts, with the backlash adjustment tightened to what looks like they bottomed out the split nut adjustment? Seems like a nice fix, Delrin is pretty tough material. I was surprised you got the two half sections to appear to have welded back into a single part. But capturing that inside the bore of your new nut clamp should prevent that splitting apart. I hope there's no follow up of a new problem..... I recently had a similar problem with a harbor freight sawmill height adjustment. They made the threaded jack screw with square threads, I mean real square threads, not acme. So the major pitch diameter was sharp 90 degree edges. The bronze female had acme face angles. That square edge just cut right through the brass threads. This was a 3mm pitch (but a bastard OD thread, 19mm if I recall). I originally got a replacement female part from their support, $80, but it failed within doing the one log as the original one failed time wise (first use, then second use). So I ordered the left hand threaded acme lead screw and bronze nut from McMaster Carr, and modified them both to fit the machine.
Its quite disappointing to see such degradation in such a short time. The leadscrews showed a significant amount of sharp edges, somthing similar to chrome peeling off metal. Very odd. There's little doubt that may have contributed to the nuts wearing down to such an extent. I repaired both leadscrews to pristine condition. We'll see how it works out. Perhaps in the end I'll have to do what you did but for now I'm giving a try. As for the acetal it welded itself very easily. Before finishing the project I clamped it in the 3 jaw to face both end and that thing never showed any signs it would split it welded seems. Cool stuff. Gilles
@@LetsRogerThat I just saw a short where you indicated you're going offline for some surgery. Good luck to you, I hope it's not a cancer you're dealing with, and something not involving a primary organ. I had two colonoscopy's last summer, as the first guy was not a surgeon and saw something weird, so after a CT scan where fistulas, and other stuff was seen (and the radiologist diagnosed cancer) a follow up with a surgeon, now believes this to be diverticulosis scar tissue, but now I have another scheduled for next month, such fun. I want to make it another 29 years to hit 95 if I can. As for backlash in my Wells Index mill, it's over 45 thou, and the DRO enables precision work. Even if new, I bet there was 5 thou of backlash. My lathe has adjustable cross feed screw, I've never seen zero on my lathe that has that. And you know snugging them tight, just wears everything faster. Again, DRO's are the best add-on accessory. Good luck to your health.
@@LetsRogerThat Gilles; Sadly, evolution never expected animals to develop a complex language adaptation, enabling us to comprehend the fatality of our existence. It sucks. At least you weren't eaten by some predator while grazing on fauna.😀
Based on what I've read from others who have done this, longevity appears to be multi year with no observable wear. But I'll have to inspect it at 6 month intervals and see how it performs. Acetal is an amazing product to work with and its lasting power is well documented. Gilles
That is an interesting way to make a new lead screw nut.
Ironically, I had to replace my X-axis lead screw and nut 7 months into using my new PMD-30. I did check the y-axis nut while it was apart and it still seemed OK. It took about 6 weeks before it was all sorted out with King, but, in the end I have a working mill again. Thanks for the great video.
Cheers from SK
You’re welcome. And thank you for watching. Gilles
Thats an interesting approach. Thanks for experimenting and showing.
Great solution and probably a need-to-know for the rest of us (mill/drill owners) , it looks tight enough to use on a cnc application. Thanks for the vid, cheers Gilles!
You’re welcome my friend
Wow, that's a brilliant idea.
Thanks. It was an interesting experiment.
Well that’s a new approach! Interesting repair. Hope it last longer than the original. I’d be will to bet that original one was brass and not bronze.
Also on my lathe I found they used cast iron as a nut and the hardened lead screw wore out the cast iron with no damage to the lead screw. I would have thought it would have done some damage or wear. But cast is soft so it makes sense I guess.
🍻
You may be correct on all counts. So far so good the Acetal nut still has no additional backlash. Gilles
Very interesting!
Never seen this methode before. I think it's very interesting.
And if it doesn't work anymore, just make a new one.
Exactly 👍🏻
Very interesting. Might I recommend using moglice to achieve a similar "type" of result but using the original nuts. Drill holes in the original nuts that can be used to inject moglice, put the threads on the screws, seal up the ends so that the moglice can't run out the open ends, and then inject moglice into the holes you drilled. This will form a perfect thread form around the lead screw, similar to what you did here but doesn't require any additional machining afterward. Don't forget to spray the lead screw with some type of release agent so that you can get it back off after it cures.
After this strenuous exercise I definitely need to get some release agent. Moglice sounds like a great idea. Thanks for your input. A good project for the next nut. Gilles
@@LetsRogerThat I love the stuff, I discovered it about a year ago and have kept it in the shop ever since. It can be used to repair all sorts of things; nuts, slide ways, dovetails, etc etc. And the people who sell it in the states are a great bunch of folks. Devitt Machinery. In Aston PA.
@@DavidHerscher awesome. Gonna contact them and get some. Thanks
Lithium grease as lubricant with acetal? Seems like my newer import machine has more backlash new than my 50+ year old atlas MFC. As stefan says, these machines should be considered as 1/2 machined casting kits. Good job on the repair.
Totally agree with you the old machines are great. Gilles
This is super interesting. I wonder what kind of life you will get out of the acetal. Quite a shame that the factory nuts failed so quickly. Probably just a poor quality bronze.
Thanks. I read a blog from a machinist who made some and they apparently haven’t degraded in years of use. I think I will take a look every 6 months to document how it holds up
Seems chinesium machine quality can be let down by the smallest of parts. On my mill the backlash was excessive from new on the X axis and i mentioned it to the importer at one of the shows we used to have here, they said use the adjusting screw, when i got home i looked for it and found it was missing altogether! We won't even go into the Y nut being loose in the casting.😢
All i can say is thank goodness i fitted a DRO.😊
My DRO is a saving grace
Excellent .. I have been pondering whether to swap out my lead screws for ball screw ... This makes CNC conversion with lead screws very workable for my mill & lathe ... How are the derin nuts after a few months - do you notice any wear or becoming loose?
Did the factory have the original nuts, with the backlash adjustment tightened to what looks like they bottomed out the split nut adjustment?
Seems like a nice fix, Delrin is pretty tough material. I was surprised you got the two half sections to appear to have welded back into a single part. But capturing that inside the bore of your new nut clamp should prevent that splitting apart. I hope there's no follow up of a new problem.....
I recently had a similar problem with a harbor freight sawmill height adjustment. They made the threaded jack screw with square threads, I mean real square threads, not acme. So the major pitch diameter was sharp 90 degree edges. The bronze female had acme face angles. That square edge just cut right through the brass threads. This was a 3mm pitch (but a bastard OD thread, 19mm if I recall). I originally got a replacement female part from their support, $80, but it failed within doing the one log as the original one failed time wise (first use, then second use). So I ordered the left hand threaded acme lead screw and bronze nut from McMaster Carr, and modified them both to fit the machine.
Its quite disappointing to see such degradation in such a short time. The leadscrews showed a significant amount of sharp edges, somthing similar to chrome peeling off metal. Very odd. There's little doubt that may have contributed to the nuts wearing down to such an extent. I repaired both leadscrews to pristine condition. We'll see how it works out. Perhaps in the end I'll have to do what you did but for now I'm giving a try. As for the acetal it welded itself very easily. Before finishing the project I clamped it in the 3 jaw to face both end and that thing never showed any signs it would split it welded seems. Cool stuff. Gilles
@@LetsRogerThat I just saw a short where you indicated you're going offline for some surgery. Good luck to you, I hope it's not a cancer you're dealing with, and something not involving a primary organ. I had two colonoscopy's last summer, as the first guy was not a surgeon and saw something weird, so after a CT scan where fistulas, and other stuff was seen (and the radiologist diagnosed cancer) a follow up with a surgeon, now believes this to be diverticulosis scar tissue, but now I have another scheduled for next month, such fun. I want to make it another 29 years to hit 95 if I can.
As for backlash in my Wells Index mill, it's over 45 thou, and the DRO enables precision work. Even if new, I bet there was 5 thou of backlash. My lathe has adjustable cross feed screw, I've never seen zero on my lathe that has that. And you know snugging them tight, just wears everything faster. Again, DRO's are the best add-on accessory.
Good luck to your health.
@@f.hababorbitz thanks. I had a kidney issue but thankfully it’s gonna heal. It’s important to enjoy every single day. Life is short 😉
@@LetsRogerThat Gilles; Sadly, evolution never expected animals to develop a complex language adaptation, enabling us to comprehend the fatality of our existence. It sucks. At least you weren't eaten by some predator while grazing on fauna.😀
@@f.hababorbitz That made me laugh. Thanks I needed that ;)
Neat technique. What do you think of the durability of POM vs bronze?
Based on what I've read from others who have done this, longevity appears to be multi year with no observable wear. But I'll have to inspect it at 6 month intervals and see how it performs. Acetal is an amazing product to work with and its lasting power is well documented. Gilles
@@LetsRogerThat Thanks for the reply👍