Need advice for dismantling shaft and searching for bearings for Kity 637

[Niall Church]

Hello everyone,
I'm reaching out to you today because I'm facing a bit of a repair challenge with my Kity 637 planer-thicknesser. After identifying a problem with the ball bearing, I'm getting ready to replace it. However, before I can go ahead with purchasing and replacing the bearing, I need to dismantle the shaft it's mounted on, and I must admit I'm not entirely sure of the best way to proceed.
I'm therefore seeking your advice and tips on:

Safely and efficiently dismantling the shaft's screw (photo attached). If you have any specific recommendations on tools to use or particular precautions to take, I'm all ears.
I've tried using an Allen key and a lever arm, applying penetrating oil + heating, but nothing moves, both clockwise and counterclockwise.
Knowing that I've already heated the screw, given a few punches with a drift pin. Attempted to turn in both directions...

Dentifying and finding the right bearing for my Kity 637.
If you've ever had to make this kind of repair or if you know of any resources, tutorials, or reliable parts suppliers, your help would be greatly appreciated. Additionally, if you have any general advice on maintaining this machine or recommendations on practices to ensure its longevity, I'm all ears.
Thanks in advance for your time. I look forward to your responses and advice.
Best regards, RémiView attachment 178026View attachment 178027

You could try scheppach they do bandsaws based on the kity series,and also [email protected] they also do spares for kity machines!

 

[Rémi52]

I have no proof but believe the pulley might be threaded onto the shaft. Know anyone with an Xray machine?

Pete

No

You might try this company [email protected] they're french but also english speaking also try scheppach they do kity spares, I think!

You gave a good lead with the site https://www.probois-machinoutils.co...-et-scheppach-bestcombi-50-4014915135524.html where we can see a Kity 1637 shaft (I think it's the same shaft). I'm going to contact them to see if they can give me some guidance.

Steve Maskery, who used to post here and I think is still active elsewhere, has a Kity 637. He's super helpful and may know if this is a screw or simply a hex hole.

I sent him a message

I assume that is taken off somewhere else on yours?

After reading your advice and trying again with a clear head, I think there is indeed a screw holding the pulley in place

If it turns out to be an interference fit then personally I wouldn't bother trying to get it off yourself. Take it to a local car repair shop. They will have a variety of pullers, and probably a press. To buy something suitable yourself is going to cost far more than a replacement pulley and, if my experience is anything to go by, may still not get it off without having to destroy it in the process. Please don't be tempted to use some cheap puller from e bay or similar. You will need a proper one to have any chance atall, and they are hundreds of pounds. And don't let them just pile on more and more pressure. Sure if you put it in a 20ton press it will get it off, but may wreck the shaft in the process.

The reality is that you are looking at a piece of Aluminium alloy that has been sitting tight on a steel shaft for what, 40 years? They may as well be welded together. If it won't come off with reasonable force then you may have to accept that the pulley is expendable, and cut it off. You can make another pulley quite cheaply, but not another shaft.

As to the pulley itself, if you look on for example Gates web site you will find all the measurements for the grooves for all the normal poly v grooved belts. Anyone armed with that information, and a decent metal working lathe, should be able to turn a new one in less than an hour. The only really critical measurement will be the bore. To get that right they will need the shaft, so it can be measured accurately and the pulley bore made to the correct undersize.

I did this myself, so it cost me the price of a suitable piece of round alloy bar, about £10. No idea what a machine shop would charge you, £60 ish maybe?

Given the age of the machine I think you would be very lucky indeed to find anyone who actually has the part.

actually I think it could be a last resort solution.
In any case I am not going to buy a press or another machine
If that doesn't work, the next steps will be:

1) Impact wrench
2) Drill the screw and rethread or cut the pulley if I find someone who can do it again for me

I'll keep you posted.Thanks again to everyone.

 

[Fergie 307]

I would urge to not to drill it or use an impact wrench unless you know for an absolute certainty that it is a screw, other wise you may wreck the shaft. Please, contact one of the spiral cutter suppliers. Their product will have exactly the same arrangement, and so they will be able to tell you for sure.

 

[Fergie 307]

I think Pete is right that the hex is in the end of the shaft, rather than being the head of a bolt. Only really two possibilities there.
One it is for positioning the shaft during the production process, during balancing for example.
Two the pulley is threaded into the shaft, and the hex is there to hold the shaft in order to unscrew the pulley. If this is the case then the pulley will unscrew in the opposite direction to its normal rotation. if this were the case then I would have expected there to be some provision for the pulley to be unscrewed, for example a hole for a peg spanner or flats in the pulley for a spanner. In fairness this is not always the case, and you might have to use a strap wrench or similar.

But is it threaded ??

Looking at the various spiral ones it looks as though the shaft with a threaded end is much longer than yours, and also long at the opposite end as well. Maybe a version intended for use with one of their combi machines? Also the threaded section is short, suggesting a nut or similar, rather than the pulley itself being threaded.
The one that looks to be the best match has a smooth shaft, suggesting an interference fit pulley like the 636.
As Chai Latte has said frustratingly I can only find images of two of the allegedly three options.

Again I would urge you to contact one of the manufacturers of these, they WILL know the answer.

I think you misunderstood my comment about the screw in the end of the shaft on the 636. The point I was making is that yours is NOT the same.

 

[Rémi52]

Hello,

I wanted to give you an update. I saw an agricultural mechanic three weeks ago, and he just returned the part to me today. He explained that with his press, it was a piece of cake—it just needed some force-fitting.

Thank you very much for your messages. I hope this can be useful to someone. See you soon

 

[Fitzroy]

Hello,

I wanted to give you an update. I saw an agricultural mechanic three weeks ago, and he just returned the part to me today. He explained that with his press, it was a piece of cake—it just needed some force-fitting.

Thank you very much for your messages. I hope this can be useful to someone. See you soon

Was there a screw holding the pulley on or just a friction fit?

 

[Rémi52]

Just a friction fit