Vevor 250 x 750 Lathe Upgrades

Thanks. Yes, the loading should be less than 20 lbs per bearing, I expect. The aluminum may still deform by a few tenths into a semi-torus shape due to extrusion, but I don't think it will wear appreciably. If it does, I can always tighten the nut a bit. It's a very simple piece. I could easily replace it with steel, if necessary, but I don't think it ever will be.
 
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The handwheel now runs smoothly without any appreciable wobble. This did not affect the backlash, obviously, but the backlash is only moderate, and the feel is much more precise.
 
Job 2 is to replace the handle assembly on the handwheel. The carriage handwheel is quite close to the cross slide handwheel, and its handle is very short. This means it is very easy to accidentally pinch the hand between the grips of the two handwheels. The grip is also a bit inconveniently thin, producing an unnecessarily high pressure on the fingers when turning. Finally, it did not run smoothly when moving the carriage.

I replaced the 8 x 45 + 10 mm retaining screw with a 5/16" steel drill rod, 112mm long, tapped at both ends. The end facing the handwheel was tapped to 6 x 1 mm, to match the threads in the handwheel. The other end was tapped to 10-32. The rod is well polished to limit friction between it and the Aluminum grip, which is also much longer and fatter (3/4") than the old grip. I considered knurling the grip, but since there will be almost no torque applied to the grip when in use, I decided not to do so. The grip was bored its entire length to 8.0mm and tapered to 0.500" at one end. The other (untapered) end was bored to 16.1mm x 19.0mm deep. I inserted a 6mm x 20mm stainless steel set screw into the 5/16" steel rod and added blue locktite to both sides of the threads, screwing the rod into the handwheel. I slid an 8 x 16 x 5.5 mm thrust bearing over the rod, followed by the grip, which was then followed by another 8 x 16 x 5.5 mm thrust bearing. To maintain a proper pre-load on the thrust bearings, I followed the second thrust bearing with an 8mm x 15mm stainless steel wave washer. I machined a piece of Aluminum to 15.25mm diameter x 9.5mm long. I bored the piece to 5mm and then counter-bored one end to 8.5mm x 5mm deep. This bears against the wave washer. A 10-32 button head allen screw holds the entire assembly together.

Now it runs vary smoothly and with no appreciable wobble or slack. The surface finish of any hand-turned parts is vastly improved. No more bruised knuckles.
 
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I know it has been quite a while, but last year I installed James Clough's Electronic Lead
Screw.
 
You have definitely upgraded your machines. Out of curiosity, how long did it take? My homebrew ELS took me, hmmm, let's see, about 8-9 months start to finish. But that's because I wrote my code from scratch and designed a PCB - and I knew little about the subject when I started.
 
Oh, that's hard to say. It's been about 2 and a half years since I bought my lathe and about 2 years since I bought the mill. Of course, in no way have I been upgrading the entire time. Most of the upgrades require taking the machine out of service, so I try not to keep either of them out of service for more than a couple of days. Of course, some of the upgrades are small and don't interrupt service at all. You can see one of them above: I milled two Aluminum bars to fit a pair of bar magnets and screwed them down to an Aluminum plate. I glued two felt pads to the magnets and then screwed the entire assembly to the front of the lathe, and now all the adjustment wrenches for the lathe are right where I need them. It is very hard to overestimate the value of having a dedicated place at hand to keep the tools required by essentially every operation. I also did this:

IMG_1030[1].JPG
 
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The next project on the lathe will be a spindle stop, I think. I avoid getting in a rush, and it has all been fun.
 
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