installing quil on mill drill

[elewayne]

I have a ZAY gear head mill drill that i have been rebuilding. It was neglected for some while before I got it and was covered in rust.
Houston, should be all I need to say. I took it apart and removed all the rust. Re lubed and put most of it back together. when I put the cross shaft in,that controls the quill up and down, if I tighten the bolts then the shaft is too tight. If I loosen the bolts, the ones on the small casting on the side of the head. The shaft turns freely. Is there a utube on this somewhere? or some instructions with photos?

[pete]

I'm guessing you mean the pinion shaft? And bolts or nuts on the end of that shaft? I don't know much about that exact machine, but generally on quill equipped mill / drills there's a large coiled main spring on the left end of the pinion shaft. Without some pictures or a better description it's real tough to figure out what your issues might be. Do you have a manual for the machine? Posting a scan of the correct page or a link to the whole manual and then using the manuals part names or numbers would help a lot.

[elewayne]

I'll try to get a picture up and no I don't have any Manuel, of course.The bolts are on the casting that the micro feed wheel comes out of. When they are tight the pinion shaft will no longer turn, something is binding at that point. I was hoping someone was familiar with the mill drills. The quill went in easily and slides up and down just fine.

[pete]

OK that makes a bit more sense. Those bolts are for cover that would be over the worm and worm wheel that's used to micro adjust your spindle Z height correct? Were or are there any holes in the main head casting and in the cover that might have taken dowel pins used to set the correct alignment of that cover? Only a guess but it sounds like the worm is being misaligned with the worm wheel as those bolts are tightened and that's causing your binding issue. All these geared head mill / drills are pretty much the same and copied from other far east manufacturers. And if Zay is still in business it shouldn't be hard to get a manual for your exact machine if you provide them with the serial number. That number is probably stamped either on a placard attached to the head casting or more rarely stamped somewhere on the side / end of the table.

[Lewayne]

Thanks, I do have a couple expansion pins still on the bench. I was wondering where they went. That makes since and would explain the issue. I’ve tried several sequences of reassembly to maybe get the alignment. I’ll try that tomorrow.

[elewayne]

Well the pins I had, went to the levers on front for the gears. So my problem persists. If I loosen the two bolts on the cast housing where the shaft goes through. The micro adjust wheel, in front, spins and cranks the quill up and down freely. but if I try the three handle drill press lever it is very stiff.They are the same thing though, unless there's something I don't understand about how the two things work.

[spro]

If the fine/ micro adjust feed is operating, it is moving the quill via the worm and worm wheel. The older m/d s had a knurled sleeve between the levers' hub and the micro adjust. May be tight but it should turn a few times to fully engage the micro adj OR lever feed.

[pete]

Since I don't know that mill this might be worthless. But some of them were set up so the worm either pivots into or out of engagement. To use the fine feed then the worm has to be in engagement with the worm wheel. To use the down feed on the quill like a drill press then that worm has to be swung out of engagement. With the worm engaged then that 3 spoked quill handle can't be used since the worm is preventing the worm wheel from rotating.

[spro]

Even disconnected from the fine feed, the fine feed shaft is able to be bent.

[spro]

I talked with a friend who has a different Asian mill/drill. This is an unusual type with the swivel table. His "lock out" of the fine feed is by a knob in center of the levers' hub. It is pulling a pinion out of contact with the fine feed, someway.The worm shaft is 8 5/8" long with only 1 1/2" of worm x 7 threads of near 25mm OD / .978" . This long shaft is apt to get bent and either break the housing or warp it by collision. The bend is just behind the worm where the shaft is 16.2 mm meeting 25 mm for the bearings. Of course there is also bend at the shattered hand wheel end.
Anyway, that mill may have had whack right at it's fine feed and bent things.

[elewayne]

Yes, I've been wondering if one of those shafts was bent possibly. I don't know if it was working when I got it. So much rust. It had been moved a couple times and weighs about 1700 lbs, so anything is possible. I was thinking about trying to mount them in my lathe chuck and checking for run out. I really don't understand just how it's supposed to work though. Maybe I'm just not doing something?

[Harold_V]

If the pieces in question have center holes, that's the way to determine if they are not straight. Place them between centers, and hand turn them. If they're bent, it will be obvious, although a DTI can be incorporated to determine their exact status. Gripping in a chuck isn't the most reliable, although it would be acceptable if there are no center holes.

Assuming you determine that the part(s) need straightening, you can use this setup to determine where, and how much. Use a grease pencil to mark the highs and lows, so you know where to block the part for straightening. An arbor press would be invaluable in this instance, as would the use of aluminum blocks. They prevent denting of the steel components.

I am not a fan of rusted machines. Any rust that is removed is metal that played a role in the making of the machine tool. If it is removed from critical surfaces, there is damage that most likely can't be repaired, although a rebuild, where the surfaces are re-scraped, may alter that scenario.

H