Doing NEQ6 Belt Mod - Advice Needed on RA bearing

[IanL]

After sitting at the bottom of my to-do list for a while, I had a day off work today and decided to make a start on fitting my Rowan belt mod kit to the NEQ6.  It's gone pretty well so far, but I am at the point of re-fitting the RA axis to the mount base and have run in to an issue.  Below you can see the RA shaft with the upper bearing still attached (the silver one just to the right of the brass barrel).

I cant get the RA axis back in to the mount base square just by dropping the whole assembly in as it is shown above.  I think what is happening (hard to see) is that the upper bearing is not locating squarely in the base, and that throws everything out so the brass barrel will only go in about 2/3rds of the way before getting jammed due to being off centre (indeed the bottom end of the RA axis where the taper bearing and retaining collar go are way off centre when the brass barrel is in 2/3rds of the way).

Consulting Astro-Baby's stripdown guide, it suggests that the upper bearing should be separated from the shaft and inserted in to the body first and tapped in to place so it is square and fully home.  Makes sense to me, but the problem is I can't get the bearing off the shaft - it will slide up as far as the left edge of the silver piece of the shaft on the right as shown above (which is where the taper bearing would locate I think), but it won't actually go over it.

I don't want to apply any excessive force here, and indeed there doesn't seem to me to be any way to get a grip on the bearing or to tap out with a wood block or mallet. The silver bit  of the shaft looks OK, no burrs or unexpected ridges there, but it is ever so slightly wider than the black part of the shaft.

My thought is to get a gear/bearing puller from ScrewFix (about 15 quid) as that should allow me to pull the bearing off the shaft nice and squarely.  I'd just need to block the open end of the shaft by bridging it with a bit of metal or a wood block so the central screw of the puller has something to bear on.  Does this seem feasible?  Has any one else had similar issues or any other suggestions?

Thanks all.

[1parsec]

Hi Ian,

The very small clearance between the shaft and bearing bore means the bearing will tend to lodge at an angle if every thing isn't exactly in line when trying to assemble.

The bearing shouldn't be too difficuct to move again and I don't think you will need a bearing puller.

If you gently tap the inner race with a soft aluminium / wooden dowel it should get the bearing square on the shaft again.

I usually put the bearing in the main casting first and then feed the shaft through it using a small 'circular motion' to help stop the jamming.

Also giving the shaft a light smear of oil / grease helps fitting too.

Cheers, Dave.

[Demon Barber]

Hi Ian,Dave is spot on i had exactly the same problem last night,you could try holding the unit between two blocks,get someone to hold/support unit and using a rubber mallet hit the shaft this worked foe me,just be patient and go in small steps,

Regards

Mike

[IanL]

Thanks guys, managed to get it moving again with a few taps and then pulled it over the sliver part with really tiny movements.  Once it was on square a fraction of a mm it just slid off no problem.  Have now re-assembled everything; fitting the idlers and motor pinion to the belts turned out to be a lot easier than I feared it would be.  Decided to give it a break for today and will test how it runs tomorrow and do the worm gear mesh adjustments when I am fresh rather than rushing it now.

Cheers for the help.