The Home Machinist!

I have a GMC Chaiwanese mill from Quality Machine Tools. The x dials started slipping after a while, and now they barely do anything. Yes, the gibs are unlocked. I noticed there are nuts on the ends of the feed screws, and they were pretty far out on the ends, so I wondered if there were clutches attached to these things, and I tightened them a little. No change.

Can someone tell me how to make this crazy thing move again? I can't find this issue in the manual.

It's a Bridgeport-style mill with an x power feed.

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People who say, "Google is your friend" need to talk to a Chinese dissident.

On my B'port knockoff, I have power feeds on the table. As I remember, they drive through a bevel gear, and a dog clutch that releases when it's not engaged. Assuming it's the power feed, can you post a picture?

I'll look around and see if I have the manual for my power feed.

Dave J.

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Every day I ask myself, "What's the most fun thing to do today."
9x48 BP clone, 12x36 lathe, TIG, MIG, Gas, 3 in 1 sheetmetal.

I don't know if this makes me stupid or what. Here is what I learned.

When I was studying videos and so on, learning how to use a mill, they explained how the little knurled rings on the dials worked. You tighten the ring, and it moves with the screw so you can use the micrometer markings. That's about all I learned about them.

Today I found that when the rings are very tight, the table doesn't like to move. I suppose everyone on earth knows this except me.

Anyway, it seems to work now, but I think I burned up my power feed before I learned all this. I'll have to take it apart and see.

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People who say, "Google is your friend" need to talk to a Chinese dissident.

Not on my machine. The dial locks do not affect the screw drag in any way.

Dave J.

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Every day I ask myself, "What's the most fun thing to do today."
9x48 BP clone, 12x36 lathe, TIG, MIG, Gas, 3 in 1 sheetmetal.

Man, I don't know what's going on. I'll keep poking it.

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People who say, "Google is your friend" need to talk to a Chinese dissident.

I don't really know what you have, but with a servo type table feed there are shims between the gear and bearing. (A new power feed comes with a shim assortment.) If you are not correctly shimed then over tightening the dial can jam the gears together. This isn't good and have have expensive results. The dial acts as a dial and also as a dust cover for the gears. I adjust the shims with high spot blue and look at the contact pattern. Not enough shims and there is no gear back lash. To many shims and the gear contact is on the outside edge of the teeth where it shouldn't be.

This may be of interest to see what I am talking about.

http://www.servoproductsco.com/specs/0206_NEW_80092.pdf


Richard W.

Man, that sounds exactly like my situation. I wonder what "expensive" means. I'll bet there is no one around here who can fix it.

Thanks for the help. You may have saved the day. I'll try to get a grip on that document and use it to diagnose and/or repair the mill.

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People who say, "Google is your friend" need to talk to a Chinese dissident.

The bevel gear does have to be shimmed for mesh. And then the dials need to be shimmed for clearence with the housing. I just installed a Knee power feed and had to rob shims from another mill I have. You can make your own shims by stacking shim material between some scrap-bin waste and turning the od on the lathe then cut the hole on the mill. Don't remove whatever you use to hold the 'stack' on the lathe untill you have said 'stack' clamped on the mill. I've done this at a place I worked before, many times. Stack a variaty of thickness's so you can adjust the clearence.


Krutch

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Krutch

Mentally confused and prone to wandering!

I am returning to this problem.

The mill is still screwed up. The power feed is an Align 300SX, presumably Chinese. Here are the symptoms.

1. The dials catch when you apply horizontal (inward) pressure as you turn. Over time, it took more and more pressure to do this. Now they don't engage at all, so the table just sits there.

2. I can move the table by turning the lock nuts at the ends of the screws with a wrench, but every so often, it catches and stops. I have to wiggle the wrench back and forth, and eventually the screw comes loose again.

3. The power feed powers up, but I hear no sound from it, and I don't feel any vibration. I don't think it's doing anything.

I'm trying to get the power feed off the mill, so I can see what's going on, but after removing the four hex screws holding it onto the side of the table, I can't get the feed off. I think maybe I need to take the lock nut off the end of the screw, but I can't do it, because the screw turns when I turn the nut. Advice would be appreciated. I have an email in to the Align people.

I'm wondering if I've had the gibs too tight. When I move the table, I don't open them way up. I just turn them until they hang loose. Is that the wrong way to do it?

I found some documents at the Align website:
http://www.bestlinepro.com/prod01.htm[url]
http://www.bestlinepro.com/Most_Common_ ... arts_N.pdf [/url]
http://www.bestlinepro.com/Most_Common_Replaced_Parts_N.pdf

I found a really bad installation guide here:
http://www.elrodmachine.com/PDF/ALign%20Power%20Feed%20Instruction%20Manual.pdf

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People who say, "Google is your friend" need to talk to a Chinese dissident.

You will probably find the power feed has 2 dowel pins in it as well and this is making it hard to get off.
I am not 100% sure without looking but I think I remember they have a reset button on them, I ran my Y axis to far one day and remember thinking I had stuffed it up, but there was a reset which saved me.

I would suggest taking it all apart so you can see how it all works to familiarize your self with it. If it come factory fitted you may need some extra shims as this could be the problem, I am sure the Align people would have them in sets.

As for getting you nut off the end, use an adjustable grip wrench (with something like aluminum sheet or something similar) over the screw to protect it right at the end near the bracket, as that part of the screw gets no use anyway. You might find there is no thread on that part anyway.

I am not sure what you mean about the gibs, they usually have a screw at each end and you adjust both one way or the other to get a slight drag on that axis. You don't want to tighten the screws against each other of it will put unneeded pressure on the gib and could bend it slightly in their or burr the slot it sits in.

I just re read you reply and see the motor is working, you have probably done the lower (Zytel) "spelling" plastic gear at the bottom. Some have a screw to take the bottom plastic cover off where others just clip off. If there is a screw it is usually in the centre of it.
These are a normal thing to go and are a built in fail safe so nothing else inside gets damaged. You can pick them up on ebay for around $30 each, but some power feeds come with a spare in the bottom cover you take off to get at it. They all have a provision for a spare in the cover but only some brands come with one.

Dave

I will try to put that advice to work.

I don't know what screwed it up in the first place. That's one of the annoying things. I did crash it once, but there was no change in the function afterward.

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People who say, "Google is your friend" need to talk to a Chinese dissident.

I just found out Servo sells import power feeds. The reason I point this out is that they are probably mighty similar, and Servo has installation PDFs which could conceivably be helpful to other people with power feed issues.

http://servoproductsco.com/specs/D-1000-9508.pdf
http://servoproductsco.com/specs/dynamo_exploded.pdf

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People who say, "Google is your friend" need to talk to a Chinese dissident.