Power feed for the Y axis, complete.

[mixdenny]

I recently installed a power feed on the Y axis (cross feed) of my 2001 Eldorado. I have written up the installation on my Shoptask web page. I also have a section on an extended milling table, 24" instead of the standard 18", although that is a future project. Maybe after I finish my FR-F1 sniper rifle replica!

http://home.wowway.com/~dthompson4389/Shoptask.html

Dennis

[sharpshooter90]

Dennis,
Thats a nice project- I was going to build a stepper motor control for my machine, but yours looks better and cheaper-
Could that controller have been adapted to the front of the carriage with a shaft passing through to the original handle?
It looks like you could make a remote connection from the front with a couple of rod ends and another lever so you wouldn't have to reach across to engage it.
On that table extension, how do you plan to attach it and align the dovetails? how much did shoptask charge for the piece?

[mixdenny]

Hmm, I hadn't thought of a linkage. It would end up about 2" off the right side of the table, so it would hit the tailstock. And the speed control knob and fast traverse button would still be on the back. It isn't as cumbersome as it might seem, especially for milling with the tailstock removed. I was making a face plate on the lathe a few days ago and had the tailstock in position. It was such a joy to watch the chips spiral off while facing under power I never even thought about having to reach back. You do need to be careful, of course, but the benefits far outweigh the ergonomics.

I am going to go ahead and design a new mount for the front of the table where it belongs anyway.

I forget what JT charged for the section of a milling table, it wasn't much, $25 or something. To attach it, I plan to use shoulder bolts bolted through the extension and threaded into the existing table. The shoulders will fit tight in reamed holes in both pieces. Once the basic holes are drilled, the final reaming can be done by hand with the extension tightened in place on the machine, so it is properly aligned.

There is room for 1/2" shoulder bolts in the meaty portions of the table towards the outside, and places for smaller bolts (5/16" or 3/8") in the smaller sections on the lower part of the table.

The extension is pretty much the same size as the existing table, within the tolerances of each individual table. When the far dovetails are pushed together, I can make up the slight difference in width between the two dovetails with a custom gib where the extended portion will be a different thickness, or simply have shims attached if required. It is the far side dovetail that is the reference surface and that will just be pushed tight by the custom gib.

On the section of the table I have, it ends up a bit thicker than the original, so when all is assembled, it will need to be ground down to match the existing table height, then a final pass made across the whole new longer table, I'll have to farm that out. It is technically possible to make the cut in place using its own milling capabilities, but it would require a flycutter with a 10" diameter to reach the far corners of the table!

Actually, I don't know why the factory doesn't design a longer table. Heck, 18" travel in the Y axis would transform the machine.

Dennis

[smallblock]

Dennis,
I asked JT about the longer table when I had my older machine. His explanation was that in order to do it right, they would also have to make the lower carriage larger to keep a reasonable amount of support under the table at full extension, and of course the lead screw would be longer as well. He had no objection to customer modifications as long as they understood those issues. He had cut up a spare table to supply parts to a few people. It looks like he kept our comments in mind when he designed the patriot, as the new machine has a larger lower carriage and the cross carriage is about 50% larger and power feed is standard.

[mixdenny]

Yes, the stiffness is an issue. But I measured the small mill/drills with the 22" tables, and their V ways are not much longer than what this has. They have 16" of travel with 8 1/2" of support, the Eldorado has 8". I thought of making a 1 inch extension on each end of the under carriage and making longer gibs, but it would be a lot of fitting to get right, and you lose 2" of travel. Still, it would be a lot better than the 10 3/4" Y travel it has now, it would end up with nearly 15" of travel. It's more of a fun problem to solve and have a unique machine rather than a factory-type solution.

I didn't realize the Patriot had the enlarged lower carriage, that should stiffen things up. The other thing I would like to see done would be increasing the spindle bore to utilize a 5MT taper and enable the use of 5C collets directly in the spindle with no need for a collet chuck. It would take an increase in the spindle bore from 1 1/8" to 1 7/16", I think. But I realize it would require all new head castings to fit the larger bearings, so it would be a complete redesign.

On another note, (for those who are always wondering how accurate a Shoptask is) when I was machining the adapter shaft for the power feed, I carefully tried to see how good I could make the diameter of the 5/8" shaft. For a 6" long shaft I held the diameter within .0003" from end to end, and could have done better with another tweak or two on the tailstock offset.

I often read people mentioning that carbide tools don't like to make small cuts, especially on lighter weight machines, but I had no problem making cuts less than .001" with a cemented carbide tool. I liked the finish better than what I was getting with an insert tool.

Dennis