old drill press bearing replacement, help?

[Vintage Veloce]

Ok, so taking apart my old drill press was much harder than I expected.
Everything is cleaned up and I am beginning assembly.

I replaced the bearings in the motor and the spindle/quill without too much drama.
However, I'm not sure how to reassemble the bearings above the spindle.
Here is a picture:
View media item 77166
My basic plan is to put the pulley in gap of the cast head. Then to drop the tube through from the top into the pulley, and bang it in to the proper depth.
But then... the bearings are more delicate. And pushing either on can shift the pulley on the shaft or the other bearing.
Note that there are no "stops" in the cast head where the bearings fit, they can be pushed right through.
I'm thinking maybe the best answer is the shim the pulley in the centered in the cast head's gap. and then to press (carefully) the top bearing in place, somehow holding the tube from the bottom. Then to put the cast head on a table upside down, and to press the bottom bearing in somehow.
There has got to be a better way...
Ideas?

 

[lilredex]

I'd put some stops in that CI head and gently push in the bearings up to them. Much like these thread stops shown below.

Edit: If you feel uneasy about trying to reform CI, you could drill into the side of that bore and install a drive screw as a stop. Grind off the side of the head if need be to gain more depth and if that does not work out you can easily remove the drive screw with a punch (shearing side blow).

 

[Vintage Veloce]

lilredex... hmm I guess that might be possible. I could try and put those in for the lower bearing, and then try and press everything in from the top. Not enough room for stops like that in the top.
I could also just use some bearing retaining compound, ore sleave retainer, and "glue" the lower bearing in place.
Still, you end up putting a lot of force on the lower bearing when you press in the shaft and the top bearing.

I just tried freezing a bearing, hoping the outer race would just drop in the head. No such luck! And I don't think my wife would let me put the whole cast head in the oven... that's for the turkey...

Other ideas?

(PS what does CI stand for?)

 

[Vintage Veloce]

Oh, another angle on the tough spot in the head.
View media item 77172

 

[Vintage Veloce]

Hmm.
At the moment,
I'm thinking:
1) I press the bottom bearing into the head.
2) Then I machine an 8.5" (approx.) long cylinder to be a die/anvil to support the bearing in the head from below (well supporting the center race).
3) Then I put the pulley in place, and put a temporary shim under it to space it in the gap.
4) From above, press the tube through the pulley into the lower bearing. It should stop against the special die/anvil.
5) From above, press the upper bearing in over the tube and into the top of the head. Might need a special top die to do that without hurting the top bearing.

 

[Vintage Veloce]

Hmm, the plan in my last post will not work. Not enough space to get a temporary shim below the pulley in and out.
View media item 77175
I think I'll have to do the reverse, and put the lower bearing in last:
Plan B:
1) I put the pulley in place.
2) Press the top bearing on the top of the tube.
3) From above, press the top bearing - tube assembly through the pulley. The top bearing seats in the cast head. Might need a special top die to do that without hurting the top bearing.
4) Then I machine an 8.5" (approx.) long solid cylinder to be a die/ram to push the lower bearing on from the bottom side of the head.
6) Press the bottom bearing into the head from below (arg!). Probably invert the head for this.

That looks ugly, There has got to be a better way.

 

[larry_g]

Am I seeing a couple of groves in the bore for a retaining ring?

Are you dealing with the arigional pulley or something that has been installed at a later time?

You say that you cannot get a shim in or out, can you use something like cardboard that will flex and tear out when done?

Am I correct in assuming that the the shaft is press fit into the bearings and the pulley or is the pulley held with a set screw? My old buffalo like that uses the top cap as the bearing retainer does yours or are you strictly relying on press fits to hold things in place?

It would seem to me that you would install the lower bearing, press the pulley through the pulley and lower bearing then install the upper bearing. I'm also thinking that there should be some slip fits here also. It's not good practice to have a press fit on both inside and outside of the bearing as it can close up the bearings clearances and cause problems.

lg
no neat sig line

 

[Vintage Veloce]

Am I seeing a couple of groves in the bore for a retaining ring?

Are you dealing with the arigional pulley or something that has been installed at a later time?

You say that you cannot get a shim in or out, can you use something like cardboard that will flex and tear out when done?

Am I correct in assuming that the the shaft is press fit into the bearings and the pulley or is the pulley held with a set screw? My old buffalo like that uses the top cap as the bearing retainer does yours or are you strictly relying on

No grooves for a retaining ring, that just marks from the bearing being in place 50 years. ;-)

Original pulley.

It would be really tough to get anything under the pulley.

Shaft is press fit into the bearings AND pulley. The shaft is actually knurled for the pulley. There are also additional set screws for the pulley.

I'm thinking this was originally assembled with a press with special dies on both ends.

 

[Vintage Veloce]

It would seem to me that you would install the lower bearing, press the pulley <I think you mean shaft> through the pulley and lower bearing then install the upper bearing. I'm also thinking that there should be some slip fits here also. It's not good practice to have a press fit on both inside and outside of the bearing as it can close up the bearings clearances and cause problems.

Exactly. But I'll need some special support/die/anvil on the bottom, inside the head. Otherwise the bearings may be crushed between the races.

 

[Vintage Veloce]

Tight fit:
View media item 77222There is a bit of clearance once it is all the way on there. But the pulley is like a hat, and hangs little over the bottom casting.

Close up of the shaft, showing knurling for the top of the pully. Also note it is long and protrudes through the bottom bearing and has a shoulder for the top surface of the bottom bearing.
View media item 77223

 

[FrankLee]

Another option...

I'm not sure how far below the lower bearing the shaft sits, but...

• get one or two pieces rigid tubing (copper?) that just fits over the shaft
• get a long piece of threaded rod just small enough to fit inside the shaft
• get large fender washers and nuts, maybe jam nuts for the bottom
• press the upper bearing onto the shaft
• assemble pieces so that tightening nuts will press pieces together

 

[Vintage Veloce]

Another option...

I'm not sure how far below the lower bearing the shaft sits, but...

• get one or two pieces rigid tubing (copper?) that just fits over the shaft
• get a long piece of threaded rod just small enough to fit inside the shaft
• get large fender washers and nuts, maybe jam nuts for the bottom
• press the upper bearing onto the shaft
• assemble pieces so that tightening nuts will press pieces together

Oooo! I've done something very like this with motorcycle steering head bearing cups! This might be possible. Probably still tough on the bearings, but probably better than banging...

 

[rsanter]

I suspect that the lower bearing was installed
then the lower bearing was supported as you are thinking of doing.
then I also suspect that the bearing was already on the shaft and that the shaft and bearing was pressed into the assembly with a die that pressed on the bearing and the shaft at the same time

bob

 

[FrankLee]

Note that there are no "stops" in the cast head where the bearings fit, they can be pushed right through.

What I can't tell from the pictures is... what is preventing the whole pulley assembly from dropping in the head frame and scraping the inside ribs of the pulley?

There is a spindle cap that likely prevents the assembly from lifting, but what holds it up so the pulley floats between the casting?

 

[Vintage Veloce]

What I can't tell from the pictures is... what is preventing the whole pulley assembly from dropping in the head frame and scraping the inside ribs of the pulley?

There is a spindle cap that likely prevents the assembly from lifting, but what holds it up so the pulley floats between the casting?

Shaft/tube is knurled and fits tightly to the pulley. There are also 2 set screws on the pulley.
Shaft is press fit inside bearings which are press fit in the head.

It was incredibly hard to disassemble, if it fits that tightly back together, it isn't going anywhere.

 

[kansei]

If the shaft is hollow, FrankLee has the solution. I too would install one of the bearings on the shaft, though only just (not necessarily pressed on all the way to its final resting place). Threaded rod long enough to extend past the top and bottom of the shaft, with plenty of extra length to accommodate thick fender washer(s) just large enough to fit over diameter of shaft, followed by a nut. Feed threaded rod through casting, pulley assembly, etc. Slide top (or bottom, whichever you didn't start with) bearing over rod, and tap it on to shaft (just start it) with a brass hammer or plastic mallet (best to use a deep well socket the same diameter as inner race)- just start it on the shaft to ensure it is square. Install final fender washer(s) and nut on this end of threaded rod, and slowly work second bearing onto shaft, holding opposite end's nut and threaded rod still. Then you can hand tighten both nuts (at the opposite ends), which should compress entire assembly together evenly. Don't use an impact or any power tools. Two combo wrenches would work well and let you "feel" if anything begins to bind. Once everything is seated where you want it, undo the nuts, remove the washers and threaded rod, and voila, you're done. I've used this method many times on different projects. Hope my description is clearer than mud...

As a side note, heating the casting would help. Since the wife wouldn't like the use of the oven, if you have access to a propane tank torch, use it to gently heat the casting up a bit before beginning the whole ordeal- may help the bearings go in a bit easier, and would be better than trying to freeze the bearings, as that may negatively affect the lubrication used in their construction.