Just spent 2 hours getting the lifting screw installed.
I’m using some 1/2-8 acme, so I don’t have to turn it a million times to raise and lower the table.
After cutting it to length, I needed to turn it down to fit into the bearings. Since I don’t have a metal lathe, I made a jig to do it by hand. I made this when building my CNC years ago, so didn’t have to waste time building the jig this time.
The jig is a simple plywood box with a 1/2” bearing on each end for the screw to run through. I clamp it to my table saw to hold it in place.
Power is from a cheap 1/2” drill. I put a few clamps around it so it doesn’t slide around, and use a spring clamp on the trigger to keep it running.
I use a grinder to remove the bulk of the material, and finish with a file, checking every minute or so. You get a feel for how much metal comes off in a minute, so you can get it pretty close.
Here’s the finished end, roughly 5/16” to fit through the 8mm bearings.
And a bearing to test the fit. It doesn’t need to be that precise for this application.
I picked up a handwheel on Ebay for $5, with a 12mm bore. I’m mounting it on a piece of 1/2” threaded rod. I actually cut the threaded portion from a carriage bolt I had in the garage.
I chucked it in my drill chuck on my wood lathe, and filed the 1/2” threads down to 12mm, just enough for the handwheel and about 1/4” of threads for a nut to hold it on. I then drilled the end 5/16” to slip over the screw.
Here are all of the parts.
The “adapter” screw in the handwheel, showing the hole that will slip over the turned end of the screw.
And the other side with the acorn nut.
With the screw slid into the bearings, about 3/8” of it sticks out to mount the adapter to.
Add a little JB Weld into the adapter, and carefully slide it on, without getting JB Weld on everything.
The weight of the screw holds it in place, but I added some tape to be safe. And some tape to hold the adapter on the outside.
Tomorrow I can add the handwheel, and then move on to making the nut from a piece of Delrin rod.
Not sure how far I’ll get as I have to work tomorrow morning, and have a lot of yard work on this 1st warm spring weekend here.