Question for any machinists ro anyone for that matter

[Brendan Zimmermann]

The background

I recently got a shelix head put back into a 12" Fay and Egan jointer that I have been trying to get into service. To do the shelix mod I also had the babbit that was still supporting one side of the head replaced with a bushing to match the drive side. When I got it back from the machinist (this was kind of a back door/under the table deal otherwise I'd ask him but that option really isn't available) he said the fit is a bit snug but it woudl wear in.

I was surprised by how snug it was, I installed a new baldor 5 hp 3 phase motor on it and it turned over a few times before it blew a 30 amp breaker the first time I started it up. So I checked the motor with no belts on it that seemed to work just fine. Then I reinstalled the belts and lossened the cap bolts holding the split bushings a tad until the head spins a bit more freely.

When I fired it up again the thing hums right along so I let it run for about 10 minutes and then checked it. This time the bushings seemed quite warm, no smoke coming out but they were hot to the touch. There seems to be plenty of grease and there was no odor so I'm pretty sure they didn't overheat.


The Question

Is it alright to run the thing with slightly loose bolts holding the caps on the split bushings (4 bolts each side) or should I install a thin piece of brass shim material between the top and bottom caps there is already a shim piece there but if it were a couple thou wider could I tighten the bolts and not worr about the head flying out (wouldn't that be exciting). Or will it just break in and I can slowly tighten the bolts as the shaft seats in the bearing.

One way or another I've got to start using it because the 6" powermatic that I traded for this beast is going to its new home.

Thanks
Brendan

[Kevin Groenke]

I'm not quite a machinist, but was a journeyman for some time (I suppose I still am). From your description, it sounds like you replaced the babbitt with a bushing only? I'm surprised a machinist advised you to do this. Is it just a bronze bushing in a split pillow-block arrangement? If you're going to run it like this, I would suggest shimming the blocks rather than leaving the screws loose, but ultimately I would try to get babbitts or ball bearings back in there. I think you'll find the bushings wearing and getting sloppy prematurely.

Sorry, but that's my .02.

-kg

[Chris Bruno]

Hi Brendan,

I DEFINITELY would not run it with the bolts loose. God forbid if one came out and you have a shelix head flying around.

Regarding the bushing... If it were me, I would have tried to fit a bearing with an appropriate support design. However, I don't know quite what it looks like and maybe that wasn't an option.

If you do need to stick with the bushing, what material did the machinist make the bushing out of? If its a steel similar to the shaft on the shelix head, then your going to have problems. Hopefully it isn't - and you will want to try to keep a lighter oil in between the shaft and the bushing - not a grease. Grease is much to heavy for the RPMs that the jointer spins. You may even consider drilling a hole in the top side of the bushing so that you can oil it regularly. There are even reservoirs available where you could fill a little reservoir with oil to keep the bushing lubricated longer.

Hope this helps,
-Chris

[Stephen Pereira]

One thing that struck me immediately is that your say your old Fay&Eagen jointer had/has babbitt bearings. If I understand correctly babbitt bearings were not designed to run at high RPM's. If the bushing your machinist installed is massive enough AND if there is a constant supply of lubricant you might come out OK.

I would slow the RPM's down and install more shims. Installing extra shims is not ideal as your split bushings are no longer round but in this instance there isn't much more you can do other than line bore and install modern bearings.

Steve

[Phil Thien]

Can you describe the bushing in more detail? I am familiar with using oil-impregnated bushings but you said grease is being used. Do you have some sort of reservoir to feed the bushing?

I wouldn't run the bolts lose. I'd make some shims (use aluminum foil or cans) and crank the bolts down. Run it for a while and then re-check. If you are not using impregnated bushings I'd remove the head and check the shaft for any scoring.

But let us know more details on the bushing contruction. Photos wouldn't hurt, either.

You may also want to head over to the Old Woodworking Machines site and get some expert help over there.

[Brendan Zimmermann]

check out this site it has a few shots of the non drive side of the Jointer assembled and disasembled. looks like it already has a thou brass shim in place so maybe I should just cut a thicker one then crank the blocks down and see what happens. Looks like a brass or bronze bushing, I'm no expert though. It also looks like there are paths for lube thru the bushing. That must be a good thing. Cutter is a 6 wing and it has to be 6-8" diameter so I'm guessing the RPM's are a lot slower than the powermatic 6" it replaces.

http://www.stonehousetap.com/boom/shop/jointer/index.html

Thanks for all the replys so far.
Cheers
Brendan

[matthew Roberts]

I'm not a machinist but I have worked with a lot of high speed machinery. Like the others have said do not run it with the bolts loose, it may work for a while but bad things could happen. Hopefully your machinist made the bushing out of oil impregnated bronze at least there are also other bronzes that have lubricating materials in them. Using the shim in the split will work but I think there may be a problem with consistent support around your bushing.

If you have to leave it as is, constant lubrication is imperative

Hope this helps...

[Chris Bruno]

Brendan,

That does like like a brass/bronze bushing, so materials wise, you should be OK. I still think the grease is not quite the best lubricant to use, but if you must, I would use the lightest you could find. Your idea of using a thicker shim is perfectly legit - you want just enough clearance so that the lubrication is actually 'supporting' the shaft - there should be no noticeable play in the shaft when its warm, but it should not be at all stiff to turn over without belts in place.

Let us know how it goes!
-Chris

[Pete Bradley]

I'd take this question over to the forum at www.owwm.org. You'll find a lot more people there with firsthand knowledge of this jointer as well as various mods to babbitt setups.

Pete

[Stephen Pereira]

I'd take this question over to the forum at www.owwm.org (http://www.owwm.org). You'll find a lot more people there with firsthand knowledge of this jointer as well as various mods to babbitt setups.

Pete

Brenden,

I would take Pete suggestion, discussion groups are a wonderful resource.

Why did you have the machinist replace the bushing in the first place? From the pictures you posted it appears as though the brass was poured in place as I suspect the original babbitt was. Poured in place babbitt was hand fit to the shaft is supports.

I have a little experience with this sort of thing, I have a 1906 Lodge&Shipley 16" swing metal lathe. The massive babbitt bearings in the headstock had worn to appx .010 clearence...way too much. I had the opposite problem as you, I had to remove shims. After a bit of fussing around using plasti gauge to check clearences I ran one of the journals with the bolts a TAD loose. After about one year of use I tightened the bolts to a torque commensurate to the bolt size. Of course, my lathe and perhaps your planer was designed to run at 600 rpms.. tops.

I'd be interested to hear what you find out from folks more knowledgeable than I.

Steve