HF 44142 Newb Question - Need help

[RetroWoody]

I have had a HF44142 for a few years, uncrated, but never mounted or run. After moving, I am putting it in service but am having a few issues. I am not new to metalworking, but this machine is challenging me. I need help getting this machine going.

First off, it is all clean of cosmoline on the outside, gearbox lube has been changed, and the balls oiled. The ways are clean and lubed, tailstock is ready, etc.

The motors both run when disconnected from the belt system, so I know they are fine. Low, low noise, I was surprised.

The issues are 1) mill/drill assembly seems "locked" and doesn't rotate. I have loosened all of the locks that I found but when I move the pully on top, it moves just a degree or two (backlash?), but makes a solid "clunk" at each swing of rotation. It doesn't seem "gooey" or just stuck. What am I missing? The power is off and unplugged, so even if there were an interlock, it wouldn't be energized. Downfeeds work fine and smooth. Quill Lock works too.

2) The lathe chuck experiences a similar phenomenon. I have disconnected the gears/power feed, so there is no load on the gearbox. I have been all over the diagrams for the assemblies, but I don't see what could be causing the problem.

It was late when I was working on it and I was tired, so it might all make sense today. I can send pix if necessary to help outline the problem. Any help would be appreciated.

[Torch]

The issues are 1) mill/drill assembly seems "locked" and doesn't rotate. I have loosened all of the locks that I found but when I move the pully on top, it moves just a degree or two (backlash?), but makes a solid "clunk" at each swing of rotation.

The pulley rides on it's own bearing and engages the spindle via the splined shaft. The splined shaft rides on a pair of tapered roller bearings. There is no spindle lock to prevent rotation. Does the shaft move at all, or is your motion just the pulley movement just reflecting the lash in the spline? I suspect the spindle bearings may be seized -- hopefully just congealed grease after many years of sitting.

I can't guarantee specifications did not change over the years, but the spindle bearings in my machine (an HQ800V, one of the several clones like the Grizzly 9729 -- all are made in the same factory: Anhui Chizhou Household Machine Tool Company Ltd., China) are 32007X (lower bearing, 35mm bore, 62mm OD, 18mm thick) and 32006X (upper bearing, 30mm bore, 55mm OD, 17mm thick) high speed tapered roller bearings. They are a tight fit on the spindle, and it required a fair bit of force to drive the spindle out when I changed them.

2) The lathe chuck experiences a similar phenomenon. I have disconnected the gears/power feed, so there is no load on the gearbox. I have been all over the diagrams for the assemblies, but I don't see what could be causing the problem.

Does the lathe chuck move at all? Like the mill pulley? There are gears in the headstock and they serve to splash gear lube up on the lathe spindle bearings. If the chuck rocks, then I would suspect something in the gearing -- careful, two of them are plastic. If the chuck is frozen solid, then I fear corrosion. The gearing is accessed through the cover on the rear of the headstock. Some of the shaft ends are covered by blind plugs. (It's a tight place to work, especially if your machine is mounted near the wall, like mine is. However, I did successfully squeeze in there and change the plastic gears for a pair of shop-made aluminium ones, so it can be done )

I have not changed mine, so I cannot verify the dimensions or part numbers, but the lathe bearings are listed as 32009X (45mm ID x 75mm OD x 20mm thick) and 32008X (40mm ID x 68mm OD x 19mm thick) high speed tapered roller bearings. I did check the adjustment on mine, and they were not nearly as tight on the shaft as the mill bearings, but still required some tapping with a block of wood to move the shaft.

BTW: the Grizzly 9729 manual is available on-line and is much clearer and more extensive than the HF version.

[RetroWoody]

Thanks for the reply. I already use the Griz manual. It is better, but not quite enough of a manual to suit me. I am getting to know this machine quite well, though, by having to take it all apart.

I will check for shaft movement tonight on the mill head. Are the bearings available from a bearing supplier? I would hate to have to order them from China. Given that the other parts in close proximity move smoothly and have a nice coat of oil/grease on them, I am surprised if it is a seized bearing, but I have been surprised before. Perhaps I can just wash out the old gunk and regrease?

The chuck rocks a few degrees. I never considered something in the gearbox.

I just drained and filled the reservoir, so I hate to dump it again, but that is the way it is, I suppose. It is on a table in the open so I have all of the access I need.

Any other ideas until I get another look at it tonight? Any Mill head takedown procedures/suggestions? How long did it take you to get it apart?

[Torch]

Mine is probably slightly different at the pulley, as it is the "V" model (1.5hp Variable speed drive). But I'm sure the principle is similar.

To avoid damage to the spindle, I took a trailer brake bolt, which is nicely tapered on the shoulder side and drilled a small dimple in the centre for the puller point.

(continued next post)

[Torch]

I found it was not actually necessary to remove this circlip...

For the simple reason that I didn't have to remove this bearing either. Of course, I didn't discover this until after I removed it... :

Continued next post...

[Torch]

Now, at this point I lost a bunch of my photos in a hard drive crash, but basically, it's hammer the sucker out with a dead-blow hammer. It's in there good. The bearings were readily available at Canadian Bearing Supply, so I replaced the Chinese bearings with good ones (those numbers I gave you are not Chinese bearing numbers, they are NTN or SKF, IIRC). I figured it was a good idea after all that hammering.

However, I do still have the original MT3 spindle (the reason I was in here was to swap it for an R8 spindle) and one of the bearings. I'm not sure what I did with the upper bearing. Oh well...

This is how the lower bearing was oriented. The race was pressed on the shaft and the cup was pressed into the quill. It came out without a fight.

The upper was oriented the opposite way, so tightening the retaining nut (with the tab washer) increased pre-load. I polished the spindle shaft with sandpaper in the lathe to ease the fit a bit. I really didn't like how tight it was. The other option of course would be to warm the bearing and freeze the spindle.

I could not get good numbers for pre-load torque from anywhere. I even contacted the factory. Several times. This is the most intelligible answer I got out of them:

"After i confirm to our productive department ,the detailed procedure as following :

1)Pls preloading the item #532 amd #533.
2)Take the feed wheel at the end of place.
3)Pls preloading the #581 and #582 and knock it .
4)Preloading the item #578,now it's ok.

If you still have doubt ,pls inform me."

I think she really liked the word "preloading". It was her new English word of the day.

Anyway, in the end, I treated it like a lathe bearing: take up all the slack, overtighten to the next tab that can engage and run it at high rpm for 5-10 minutes. If it doesn't noticably heat up the spindle, tighten it to the next tab stop. When I got it to that point, I locked down the tab washer.

After a few hours use, I had to do it again because it had loosened up some. Then a few weeks later it needed another snugging. I think the final one was about 5 or 6 months after that, but it's been stable ever since. It seems even with the sandpaper treatment, that bearing is TIGHT on that shaft! It just didn't want to snug down that last few thousandths.

Hope this helps. Good luck.

[RetroWoody]

You are correct. I have the step pulley on the front spindle. I also was not sure that circlip needed to come out when I looked at it. Thanks for all of the pictures.

I think her instructions make perfect sense!

I will go out in a little while and see what I can do.

[RetroWoody]

I went out for a few minutes last night and saw that, while the step pulley moves a few degrees, the spindle also moves a couple of degrees. The clunk is the pulley hitting the shaft splines. I hope to get enough time tonight to pull it out.

Once clarification, though. When you say hammer it out, do your mean up or down? I assume down, but wanted to be clear before I picked up a hammer.

[Torch]

DOWN!

That's why I blocked up the quill with wood in the one picture.

The nut draws it back up. Eventually.

[RetroWoody]

Thanks. After looking at the photo again, I see that I first thought the wood was leaning against the wall. I didn't see that it was blocking up the quill.

[RetroWoody]

Hey, Torch, did we scare everyone off? It's pretty quiet around here. It must be me, because your post count is too high for it to be you!

I broke the pulley loose. A few tugs on the pulley with a short cheater bar and it popped loose. It sounded grainy inside when I turned it. After pulling the pulley, I could tell the top bearing is fine. It spins easily and smoothly. I put penetrating oil down the shaft splines and it began to move much more easily. One of the hex nuts holding the collar down stripped the insides, so I have to get a pair of visegrips to see if I can break it loose. It is soaked in penetrating oil for a while, so we will see.

Overall, not much in the way of lubricants, but where it is, it is working. I hope the bearing just needs greasing.

More to come when that hex bolt comes out. (...and yes, I do have my quill blocked in the up position. Thanks)

[RetroWoody]

After getting the stripped hex bolt out, I pried up the block like your photos. Penetrating oil does wonders! I cleaned the bearing our with a toothbrush and more Pen oil. It runs pretty smoothly now, even with no grease. I ran out of time, but am considering if I need to continue and remove/clean/regrease the lower bearing. I know I probably should.

Everytime I think about not doing something like this, I regret not doing it. If I do it, it will be done right, and I won't worry about it anymore. So there it is.