8x30 Power X-Axis Power Feed

[Radials]

I've had an 8x30 x-axis power feed modification on the back burner for quite sometime now and I'm getting close with the project being complete. A goal of this project was to also replace the leadscrew bearing blocks on either end and align the leadscrew which was not parallel to the table. The original bearing blocks attached to table ends with just two M6 SHCS and this seemed just a little undersized so I wanted to upgrade those in the process. Unfortunately I didn't photo document the whole process but got enough to show the project. The first step was to determine the location of the leadscrew relative to the table to be able to design the new end bearing blocks. This really wasn't a hard step and just involved some indicators on either end of the leadscrew to determine it was straight passing though the lead nut. With known dimensions I modeled the table up in CAD and designed the power feed add-on. Because of how my mill Y-axis DRO scale and one-shot oiler are mounted I had to mount the power feed further off the table end for interference reasons.

Here's the start of the new bearing blocks. The actual bearing bores were done on the lathe since my mill doesn't have power down feed on the quill. That'll be another modification one day. I added some tapered features to these later on but didn't take any photos of that step.

Next the power feed standoff was made. This is to provide clearance so the power feed doesn't strike the one-shot oiler on the side of the knee.

Just a couple shots of that process. The boss shown in the turning picture registers into one of the new bearing blocks.

 

[Radials]

The leadscrew shaft extension was made from two pieces. I first bored and thru broached a slug then welded it to a rod with material still needing to be turned. (Not pictured) I did this since I didn't want to have to come up with a way to blind broach the end. After that I dialed it in the 4 jaw and turned the rest of the shaft.


I turned a short section of shaft and milled it for a key in a collet block so that the new leadscrew extension could have it's internal keyway timed to the new external ones.

The screw extension shown here being timed for milling the new keyways.

The completed leadscrew extension with keyways and setscrew holes.

 

[Radials]

In order to accurately drill the new mounting holes in the end of the table I made a fixture that could be mounted to each end for doing that.

The fixture has the four hole locations and bushings that are used for drilling and then tapping.

The 4 new holes are 3/8-16 and were placed to miss the original two M6 holes on the table ends. The drill/tapping fixture worked excellent.

 

[Radials]

The power feed side new bearing block and leadscrew extension attached. A couple steel spacers were made so that the original threads on the bearing castle nut could still be used. My new bearing blocks are skinnier that the original ones this mill came with so the bearing moved towards the table more on both ends. The only modification to the leadscrew was done because of this and that was to extend the bearing shoulders by turning off a few threads on both ends.

This is the bulk of the parts made for this project. Since my mill was missing all the dials when I got it I made some stand-ins to make it look more complete. I won't take the time to actually make these into dials since there is a DRO on the mill.

The power feed unit fitted on the end of the stand-off.

 

[Radials]

Here is the nearly complete powered side of the assembly. I still have a spacer and a cap to make which will be located on either side of the crank handle.

Here is the tail side of the assembly complete.

Y-Axis dummy dial for aesthetics.

This is as far as I am with this project now. I have yet to figure out how to mount the feed stops with the X-axis DRO scale being mounted on the front of the table. Or where to mount the feed kill switch as well. Details...


Here's a close-up of the Y-axis DRO scale and one-shot oiler to better understand why the new power feed was mounted on a standoff.