How to remove SX2L R8 spindle screw (while converting to tapered bearings)

[iafilius]

Hi,

I'm half-way (hopefully) of converting my Sieg SX2L R8 mill to tapered  bearings, but one screw holds me to go any further at this stage.

While converting to tapered bearings, they need more space, and basically my plan was to turn the spindle a little bit off on the lathe (4mm) (which is the extra space the lower bearing takes. ultimate plan is to keep pulley at the same height, as there is not much room to adjust.
The crew cap is only about 3mm from the bearing shoulder 9see photo's) , and not knowing how hard that screw is, i want to get it out before i start on the lathe.

I'm afraid the screw may be glued, as there is no way to get grip on the screw (it's turned off before putting it together it seems)

Has any of you done this before of perhaps any idea's?

Regards,

Arjan

[Stilldrillin]

Hi Arjan.

The "screw", is a pressed in plug. I levered it out, from the bore........

Have a look here....... http://madmodder.net/index.php?topic=4754.0

Good luck! 

David D

[iafilius]

David,

Thanks a lot for your swift information.
Until you pointed it out i didn't find any r8 taper bearing mod before.
Good to see i'm on the same path by turning the r8 spindle off.

I'll have a little thinkover on how to press the peg out without damaging the r8 spindle.
Regards,

Arjan

[velocette]

Hi Arjan
Have you considered Angular contact bearings instead of taper roller bearings.
A straight swap no machining or fabricating shields or seals.
By what I have read this is an excellent modification.
It is possible to have the inner race on the taper roller bearing ground shorter to fit correctly.

Eric

[iafilius]

Hi Eric,

Thanks for your suggestion, I did consider angular contact bearings, the type i needed for lower 7007 (62x35x14mm) in precision class costs around 150 euro's although you can get 7007's for 16 euro's as well.

Having thought over life expectancy/stiffness/allowable load my choice was to have it tapered bearings, with the knowledge i wasn't a just a bearing swap. Actually the outer bearing races (upper/lower) are already pressed into the milling head.

I may change my mind, I ordered even a spare R8 spindle in case i want to go "original" (read messed-up the old spindle) , but at this stage i still want to go for tapered.

Thanks,

Arjan

[iafilius]

Hi Arjan.

The "screw", is a pressed in plug. I levered it out, from the bore........

Have a look here....... http://madmodder.net/index.php?topic=4754.0

Good luck! 

David D

David,

Started to make some tools for levering it out, see photo's, but I felt just lucky, noticing on my spare R8 spindle which arrived today the loose peg, which i could grab with my fingers.
photo's contain an aluminium tool and POM tool for helping levering it out, which i didn't (successfully) use in favour of the loose peg of the new spindle.

attached a photo of the 2 R8 spindles together (and loose peg), and I noticed the blackening  halfway on the outside (but halfway on the inside as well)
I wonder is this any good?

Regards,

[Stilldrillin]

Arjan.

I think, I removed my plug, using a Morse taper extractor. "Seesaw", rocking it on an old copper coin.

Gave it a clump, with a lead tup. It levered out, no problem! 

Is your 2nd spindle, second hand? Someone's given it the heat treatment. Probably, while it was rotating........ 

Provided it spins true, all will be well. Probably! 

David D

[iafilius]

Hi David,

Bought the "spare" spinde as new from the same shop as i got my sx2p in your country (not sure i may mention names, but you don't got many options to guess).
Did not notice any blackening on my original spindle.

Here's the result (photo) after centering the spindle on the lathe and turning 4mm off, polished the upper bearing location, and tested it with the old bearings.
Next need to grind a little bit of the peg it's cap (1mm only), and start putting it together. Possible need to shorten the drive pulley wit 1,75mm (extra upper bearing space), or maybe it just fits without.

[iafilius]

Hi to finish the story started halfway with the peg.

I'd put the peg on a grinder to make sure it won't touch or lift the lower bearing and pushed it in on a bench after deburring some sharp edges around the peg-hole on the spindle (wich i touched while tuning 4mm off)
See photo.

Pressed on the inner part of a 32007 X/Q .
Noticed the cage holding the roller tapers slightly longer then the inner race, and would probably damage it while using a regular bearing puller.
Created a POM ring with a 40mm outer diameter and 35,5mm inner diameter, to press the bearing on the inner race. See photo, white ring.

Put the spindle in place and pushed the inner part of the upper bearing (30206 j2/q)  in place with some custom pvc pipe /pom adapters.
Due to polishing the upper bearing location on the spindle this was a light task, and helps easy bearing preload adjustment.

The key (for pulley) didn't fit the new spindle, after a slight grinding it fitted and put everything back.
I didn't do any correction for the about 2mm added by the upper bearing, hoping it would just fit. And the sx2p seems just tolerate it.

Did an easy idle run for some hours and the head feels slightly warm, which is perfectly fine i guess.

Some leftovers on the upgrade to tapered bearings path:
1) Lower bearing seal (high prio before any work on sx2)
2) upper bearing seal (low prio due to dust cap)
3) modifying/changing the crude spindle nut set-screw mechanism which damages the spindle thread. I saw a nice made nut which solves my problem damaging my new/modified spindle thread. (Foto attached) anyone created such kinda nut?
4) r8 drawbar seems to whobble a lot (upper side) this may or may not cause any problems, but i think i should have a closer look at it. Of course i didn't look at that with my original spindle. Anyone noticed this? Or just centered nicely?


Regards,

Arjan