Delta Drill Press Mystery Noise

[Rick_Br]

I'm working on a Delta DP-600 17" drill press from 1945. It has a mystery noise you can hear in this video - starts about half way through and is most apparent near the end.

I describe it as train wheels clanking on tracks noise. I'm running an AX53 belt on the slow speed delta pulleys. Noise occurs regardless of belt tension. The motor has new bearings and the noise does not occur on the unloaded motor. The spindle bearings are new as well. The noise occurs with or without the quill installed. To me it is coming from the spindle pulley area. The noise is intermittent (comes and goes) with no apparent pattern. It seems to occur when different pulley steps are used or the frequency is reduced. I'm sure there is information I am forgetting but I am, stumped. I've included the delta document which shows the spindle pulley construction - there is not much there - two bearings, the pulley, two washers, a lock washer and a nut.

 

[Davefr]

The first thing that comes to mind is pulley planarity. Place a straight edge on both pulleys and the leading/lagging edge of both pulleys should be on the same plane. (ie no gaps under the straight edge.) Test this on several speed positions. (see below)

The other thing to check is that the pulleys are not damaged or bent.

Lastly, is your belt brand new? Older belts can deform (take a "set") over time.

These old DP600's are wonderful machines but I would not call them particularly quiet. (6 ball bearings)

Also, is your upper spindle centered properly. You adjust a nut to get it's bearing centered into it's position in the head casting bore and the upper part of the spindle shaft should not rub on the top cap/cover.

P.S. And are both pulleys tightened. Two set screws per pulley and key stock in each.

 

[WillyBoy]

One possibility is wear between the spindle splines and the pulley splines. Remove the belt and hold the spindle and try moving the pulley back and forth. Some amount of wear can be silenced by a coat of grease on the splines but it's not really a repair.

 

[Rick_Br]

One possibility is wear between the spindle splines and the pulley splines. Remove the belt and hold the spindle and try moving the pulley back and forth. Some amount of wear can be silenced by a coat of grease on the splines but it's not really a repair.

There are no splines on the spindle pulley on this machine. The spline connection is between the upper and lower spindles and the noise occurs with and without the spline connection

Rick

 

[Whitworth]

AX belts are cogged. My guess is a harmonic is happening at various rpm's, leading to a chugga-chugga-chugga noise.

But it doesn't seem all that loud to me.

 

[Rick_Br]

I have reached the end of the line I believe. Over the last few days I have tried

1. Insuring the front and rear pulleys are aligned both vertically and horizontally
2. Tried different steps on the pulleys - doesn't seem to make a difference - although the noise seems to be related to noise. The noise is present at pretty much all speeds but is more apparent at faster speeds.
3. Changed upper pulley bearing (bearing with the snap ring)
4. Cleaned the bearing seats
5. Tried different belts
6. Changed the spindle pulley
7. Checked interference of the pulley with the head
8. Checked interference of the spindle top with the bearing retainer cap
9. Let it run for an hour - noise didn't get better or worse
10.. Checked for hot areas - nothing except motor stator shell got warm after the hour
11. Still think the noise is coming from the front of the head
12. Checked the top bearing for spinning - none
13. No way to check the bottom bearing while operational. See question below.
14. Tried some grease on the spindle where it goes through the pulley.

None of this made a difference in the noise - except speed as noted above. I've attached a video from about 3 or 4 feet in front of the machine - although I don't think it is adding any new information. I'm out of ideas except for changing the head - I do have a spare head I could clean up and use.

Does anyone think the noise could be related to the lower spindle bearing rotating - it seems awful loose in the seat - pretty much drops out. The intermittent change in noise level is perplexing me. Something has to be moving but I certainly can't figure out what. The pulley has no movement - either vertical or horizontal. It is trapped between the bearing races and keyed to the spindle. I can't physically move it manually. The top bearing is held in place with the retainer cap. With the spindle keyed to the pully and the top lock nut it cannot move. it is clearly a mystery.

Also - thoughts on trying a different head?

Or should I just move on?

Rick

 

[Davefr]

I have reached the end of the line I believe. Over the last few days I have tried

1. Insuring the front and rear pulleys are aligned both vertically and horizontally
2. Tried different steps on the pulleys - doesn't seem to make a difference - although the noise seems to be related to noise. The noise is present at pretty much all speeds but is more apparent at faster speeds.
3. Changed upper pulley bearing (bearing with the snap ring)
4. Cleaned the bearing seats
5. Tried different belts
6. Changed the spindle pulley
7. Checked interference of the pulley with the head
8. Checked interference of the spindle top with the bearing retainer cap
9. Let it run for an hour - noise didn't get better or worse
10.. Checked for hot areas - nothing except motor stator shell got warm after the hour
11. Still think the noise is coming from the front of the head
12. Checked the top bearing for spinning - none
13. No way to check the bottom bearing while operational. See question below.
14. Tried some grease on the spindle where it goes through the pulley.

None of this made a difference in the noise - except speed as noted above. I've attached a video from about 3 or 4 feet in front of the machine - although I don't think it is adding any new information. I'm out of ideas except for changing the head - I do have a spare head I could clean up and use.

Does anyone think the noise could be related to the lower spindle bearing rotating - it seems awful loose in the seat - pretty much drops out. The intermittent change in noise level is perplexing me. Something has to be moving but I certainly can't figure out what. The pulley has no movement - either vertical or horizontal. It is trapped between the bearing races and keyed to the spindle. I can't physically move it manually. The top bearing is held in place with the retainer cap. With the spindle keyed to the pully and the top lock nut it cannot move. it is clearly a mystery.

Also - thoughts on trying a different head?

Or should I just move on?

Rick

Remove the quill/lower spindle assembly. Does the noise go away?

 

[Rick_Br]

Sorry - I forgot to mention that - noise,is fhe same with or without quill/lower spindle installed

Rick

 

[Whitworth]

You could try setting the lower bearing in place with a drop of Loctite

Again , it doesn't sound that loud to me.

 

[Davefr]

Sorry - I forgot to mention that - noise,is fhe same with or without quill/lower spindle installed

Rick

Then it pretty much has to be one of the two upper spindle bearings assuming the motor runs normal with the belt removed. Or Is the upper spindle bent/deformed.

I guess it could also be a head casting defect or damage where the bores for these two bearing are not in perfect alignment or a sloppy fit with the bearings. Are they OEM bearings?

 

[Rick_Br]

They are new bearings in the qill, upper spindle and motor. I don't think the spindle is bent but I do have a few others i could try. I also thought about the head casting bearing seats machined incorrectly.

Rick

 

[Rick_Br]

Then it pretty much has to be one of the two upper spindle bearings assuming the motor runs normal with the belt removed. Or Is the upper spindle bent/deformed.

DING DING DING! Thanks Dave

I initially didn't think so but decided to replace the spindle as a test. I have several of those spindles sitting on the shelf. In the following replacement = spindle on shelf and new/original = the spindle and bearing I started with. I grabbed an old greasy grimy one with a crusty lower bearing (the bearing turned nicely by hand - just grimy). Slapped that in thinking if it worked in its grimy condition then maybe I would have a path to follow. Lo and behold it worked fine - no clanking at all. So I put the original (new) bearing on the replacement spindle (after cleaning it up) and the clanking returned - ah ha the bearing maybe. I put the replacement bearing on the original spindle and no clanking! I have to conclude the new bearing is faulty.

I noticed a difference in the lower bearings - both were marked as 87503 and measurements confirmed they met the spec for an 87503. The new bearing, purchased from Accurate, had extended races both sides (as specified in their catalog). The replacement bearing had an extended race one side and a thicker outer race. Comparing measurements both bearings have the same overall thickness. Even though they are different configurations I think I have to conclude the new bearing is bad.

So now the question is purchase a new 87503 bearing or just use the replacement bearing - after a little more clean up. Any thoughts?

Rick

 

[Jlanciani]

Extended race on both sides is the wrong bearing.

 

[Davefr]

So now the question is purchase a new 87503 bearing or just use the replacement bearing - after a little more clean up. Any thoughts?

Rick

Glad to hear you found the problem.

I've rebuilt 7 of these DP600's and always strive to re-use the original New Departure bearings. They were top notch bearings and I've never seen one worn out. A DP has a low duty cycle and they usually run at low RPM. The only problem is dried up grease.

I take apart the ND bearings, clean them thoroughly and repack with Mobil Polyrex EM grease, test them and then reinstall them.

They're superior to new Chinese bearings.

Taking them apart is kind of a PIA but it's do-able.

New Departure Bearings - How to restore tutorial

In the Delta vintage grinder thread some guys claimed New Departure double shielded bearings couldn't be restored. I told them they could and they asked for images. I have a new project with these bearings and here's how I restore them. IMHO they are among the finest USA bearings I cringe...

www.garagejournal.com

 

[Davefr]

Extended race on both sides is the wrong bearing.

The New Departure OEM bearings had extended races on both sides. I doesn't matter because the lower spindle spacer makes contact with the outer race only at least for the MT2 drive. The J33 collar mount style spindle might be different.

 

[Rick_Br]

I think we are mixing up bearings - I'm talking about the bearing under the spindle pulley on the upper spindle. See the delta document in my first post

 

[Rick_Br]

I finished this machine up today and thought I'd share some pictures. Thanks to all who offered suggestions and ideas.

Rick