Millrite X-Axis power feed install

[Tim9]

Well, for the last two weeks I’ve been installing a power feed for my Millrite MVI milling machine. I took a number of pics of the install so I’ll document my installation in the next few days. For reference I looked at a couple of instructions on the net, including one on groups.io site and Bob Korves installation on this site.
Bob removed the x-axis lead-screw for his installation and although I too felt this might be the best route in order to drill and install an extension, I thought I could avoid this step by going about it differently. The risk with my method is that there was a chance of ending up with an extension off center. Bobs install shows how he mounted a slightly oversized extension and then turned it true to the shaft on the lathe.
Call me lazy. Take your pick. In all honesty his method is probably best. But I didn’t want to go through that much trouble. So I’ll soon be posting some pics and showing how I went about it.

 

[MAKEITOUTOFWOOD]

Look forward to it. I am in the near future going to retro fit a feed on my Fray mill. Just finished up with a 3 axis dro install.

 

[Tim9]

First thing I did was clean up the Millrite end cap where the surface isn’t square. It’s just a rough casting from the factory but to mount the power feed the surface should be flat and square. I didn’t have my rotary table here.... it’s still at my old place. So I mounted the cap on a diy arbor. Stuck a collar on it but it would not tighten up enough so I loosened it....super glued surface and tightened it up. Mounted in lathe and since it was so out of balance I set lathe to back gear low speed. Cut it lightly @ 100 rpm.
I had to move position of QCTP to take two cuts. One at outer end of circle surface and then reposition tool post to cut the area around the center bushing

 

[Tim9]

I then cut an aluminum spacer to fill in that recessed area of end cap. Drilled a 1/4” hole about a half inch from edge. Fitted it into end cap and used a transfer punch through the hole to mark end cap. Tapped and mounted spacer. Then drilled an oversized hole to accept the center end cap mounting bolt. I also mad a bronze bushing which fit over the lead screw and fit inside the supplied bushing included with the power feed

 

[Tim9]

Next I drilled those two holes to mount the power feed. I mounted the feed on the bushing and rigged a clamp extended which held it in place while I used a transfer punch to mark positions of the two mounting bolts. That last picture tapped holes

 

[Tim9]

I then made an oversized length extension 5/8” diameter in which I just measured the total length needed for gear and handle once the feed is installed, and added about 1/4” length to it and pre drilled it while in the lathe so I knew hole would be straight and centered. I then used an oversized length drill bit I had.... about a 12” long 0.237” bit.
This extension was now my guide to drill the lead screw. It would act like a drill bushing. The way this worked is that the bevel gear of the power feed is a 5/8” bore gear. When I slipped the gear which is about 2.5” long it acted as a guide in which I could then slide the extension inside and this acted as a center guide for drilling the lead screw. I did have to add a .002 brass shim around both the screw and the extension so there was no play and then drilled the lead screw using that 0.237 drill bit to drill about a 3/4 depth hole in the screw. Sorry, I forgot to take pics of this.

 

[Tim9]

No pics of me drilling the lead-screw but the above pic I posted shows the extension once I had drilled the lead-screw. I then mounted it back in the lathe and drilled it to final diameter center hole 5/16”
I then free-hand drilled the lead-screw for 5/16” threads. Since it was already drilled 0.237 , I only had to enlarge it for a 5/16”-18 threads tap. Used plenty oil and took it easy but wasn’t much to it. Used taper, plug then bottoming tap to thread lead-screw. I then mounted a long 5/16-18 rod threaded at one end and marked other end after installing all necessary items.... extension, handle etc. FWIW...I did have to make a few step keys for the extension as shown in above post pics.

 

[Winegrower]

This is heroic. It took about 30 minutes to install a power feed on the Bridgeport X-axis. That was because I work slowly.

 

[Tim9]

If you read the first post, it took me 2 weeks. I wish I could do it in 30 minutes.But in my defense the power feeds are designed for Bridgeports. Millrite is another animal.

I also wish I could document every step and post pics, but when doing the installation I was pulling my hair trying to figure out everything. And the Chinese instructions which came with my 120.00 EBay power feed suck big time.
Anyway, I got it on and it’s working good. Still need to mount micro switch safety stop. Still need to work that out.

 

[Bob Korves]

Make sure you constrain and adjust out the end thrust on the lead screw. Does the 5/16" rod need to be that long, and for what?