[fritts]

Have an Enco 100-1427 turret mill with 2 speed & pulley speed change head. Started seeing issues in fly cutting and and increase in noise from my spindle. Pulled the top end off to check bearings, pulleys and gears. One item I noticed that concerned me was that the sleeve around the quill does not appear to be fixed in place and can be moved up in down the quill with some force from the top end, sorry should have taken pictures will add tonight. Based on the manual I can't tell where and what holds the sleeve in place. Spindle bearings don't sound bad either which was my first suspect. Though the splined spindle appears to have some wear on the splines. Any thoughts on these issues? What are the standard failure items on these type of mills?


Thanks

[Jim Dawson]

The sleeve floats in the housing, it's purpose is to keep chips out of the works.

If the bearings sound good, they could be just a bit loose. The preload nut is on the top of the spindle. But you have to pull the quill out to get to it.

[fritts]

Thanks for the info. Had MSC quote a few of the parts including the skirt. Looks like I could buy a used Bridgeport for the money the want in parts.

Got stuck in my disassembly again. The quill feed take off from the spindle doesn't want to slide up off the vertical crown gear shaft. Removed the nut from the crown and bolt from the pinion but can't slide the assembly up and off the shaft. Am I missing something?

[Jim Dawson]

If your goal is to get to the spindle bearings, then you need to drop the quill out of the bottom. On some machines the quill rack is machined all the way up the quill, thus you don't have to remove the quill pinion shaft. On others, you do have to remove the quill pinion shaft. In either case you need to remove the quill return spring.

If you need to remove the quill pinion shaft, then you also need to remove the quill power feed clutch assembly and associated gearing on the left side. Don't lose the shaft keys, they fall out, hit the floor, and you never see them again. The pinion shaft comes out the right side.

Support the quill while doing all of this, it weighs about 20 lbs or so.

[fritts]

My other reason for removing the quill feed is that I'm working on a cnc conversion of the mill and figured I'd remove the top end drive as well.

Thanks

[Jim Dawson]

I think that assembly comes out through the side, but I don't remember if the quill spline is in the way. I can take a look later, I have a head torn down in the shop.

If you are interested, here is how I did my Z-axis. Holds 0.0001'' consistently.
http://www.cnczone.com/forums/knee-v...ml#post1977204

[fritts]

I had read through your conversion on the z axis. Like the idea of manual/cnc conversion with ease of using either. One thing I was wondering about it was the force required for preloading the column like you did and if it needed to be higher due to odd cutting forces that might pull a bit into the work piece. Definitely a very nice solution for the Z axis though compared to the ballscrew solution.

[Jim Dawson]

One thing I was wondering about it was the force required for preloading the column like you did and if it needed to be higher due to odd cutting forces that might pull a bit into the workpiece.

Thank you for the kind words.

The up force is adjustable, I run it at around 30 PSI. But could go to 120 or more if needed. The only time I had a problem was with a 3/4'', 4 flute endmill taking heavy cuts in steel. I just cranked up the pressure to around 90 PSI and ended the problem. Most of my work is reasonably light, so lower pressure works fine. I can walk through a 1'' DOC with a 1/2'' rougher in steel with no problem.

I would be happy to give you the drawings if you're interested.

[Jim Dawson]

I took a look at the head, the bevel gear has to come off with the assembly. It should just pull up, but may need a little persuasion.

[fritts]

I would absolutely love to see drawings or models if you would. I work in SolidWorks/Fusion360/Autocad but anything works.

[Jim Dawson]

I'll send you a PM with a link