Removing bearings?

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Christoffer Ahlfors
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Removing bearings?

Post by Christoffer Ahlfors »

Dear forum,
your expertise is needed. I have enjoyed my tiger 1 for fourteen years now and had it driving in all kinds of conditions. However, A very muddy and grassy Overloon this year, made the road wheels squeak afterwards and it has been necessary to do major overhaul. Some bearings need replacing.

However, I have glued them in place as per the instructions (back in 2010...). I know that superglue can possibly be loosened with heat, so I tried the hot air gun to the hubs to no avail.

What would you say - do I need to take the wheels apart and torch the hubs? I would really hate to do that. Does anyone have a smarter solution?

Next time I will not glue them in place, to ease in replacing if necessary.
A little too much is about right...

Gian Marco Menozzi
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Re: Removing bearings?

Post by Gian Marco Menozzi »

HI Christoffer,
You need an internal bearing puller,
like these:
https://www.ebay.it/itm/373263211415?_t ... 2PXDZYWR4F

https://www.ebay.it/itm/253224103718?_t ... KNYZABN371

these are just 2 examples.
Ciao
Marco

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Jerry Carducci
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Re: Removing bearings?

Post by Jerry Carducci »

Yes I was going to suggest an internal bearing puller. I purchased one when I needed to pull bearings from blind beaaring pockets
for small electric motors and hand electric drills. Very handy tool to have.

I would still heat the bearing pocket up as best you can before trying the puller. Hopefully your hot air projector has a good high temperature.
Wouldn't use a torch. Aluminum gives little warning when it's about to fail.

Jerry
http://tanks.linite.com/ - RC tanks: stay home, build a tank and save a life!

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Armortek
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Re: Removing bearings?

Post by Armortek »

Heat and a gear pulley is pretty sound advice.

If you have time on your hands you can even make your own :-)

Armortek

Christoffer Ahlfors
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Re: Removing bearings?

Post by Christoffer Ahlfors »

It turns out that the problem is not the glue, so far at least. If there is any glue. The reason for the problem was totally different.

My tiger1 is from 2010. In 2012 or so, Armortek showcased their brand new machinery, factory new, higher capacity, new functions and with finer tolerances. In other words, my kit was manufactured with the soon to be retired machinery, with its potential tolerance issue. The way these wheels are constructed, the bearings are inserted in the hub and the wheels then mounted on the hub. The wheels have a hole the same size as the hub, so it looks like the bearing should come out of there, but it didn't. The wheel hole fouled it! As soon as the wheels were off, the bearings came off effortlessly. At least on the first three wheels.

The reason I didn't want to take the wheels apart, are those tolerance issues. Well, for the labor too, of course. When I first mounted them, they were so wobbly, that they interfered with each other. If you have seen old videos of models, you can see how wheels sometimes turn backwards. That's when a rubber ring hits the hub of the next wheel and is forced the other way. They way I managed this problem was to sort all wheels and hubs in tolerance groups from good to bad and then assemble them in an orientation where the wheel wobble canceled out the hub wobble as much as possible, instead of adding up. I would really prefer not having to do that job again... :|

So, all I have to do now is to disassemble all the wheels, carefully mark the orientation of the parts that were mounted together, clean everything carefully, fix the paint, glue some rubber rings, clean and relubricate all the bearings, replace as necessary and reassemble. Oh, and this would be a good time to install scale fasteners where visible. Something I have wanted to do since I built it. And possibly backside detail on the first wheel...

Somehow, this job is getting bigger as I chew it... :P

It's a dirty job, but someone has to do it! :D
A little too much is about right...

Christoffer Ahlfors
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Re: Removing bearings?

Post by Christoffer Ahlfors »

A few pictures to illustrate.

First, here you can see clearly why mud and tall grass is a bad combination. It gets the worst on the inside where there is an axle to wrap around:
20241024_135811_RESIZE.jpg

Next, you can see how the holes in the wheels stack up. Looks like the bearing should come out of there, doesn't it? Sometimes yes, and sometimes no.
20241027_132334_RESIZE.jpg

I stamped the parts for easy alignment when reassembling:
20241027_134120_RESIZE.jpg
//
A little too much is about right...

Didier Molard
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Re: Removing bearings?

Post by Didier Molard »

hello
if glued with superglue, you can use acetone or nail polish remover (a bit less effective )to remove the glue
it may take a bit of time, but avoids having to disassemble everything
you'll probably need to put some cotton wool on the beraing and regularly poor some acetone on it as dry superglue is hard to dissolve
regards
Didier

Robert Tanzer
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Re: Removing bearings?

Post by Robert Tanzer »

Hello Christoffer
Now I understand your problems after looking at your pictures.
It is obvious why this problem occurs.
You haven't painted your models, with the special protective paint called Camoflage. :P :P :P

Have a nice day my friend.
Robert

Christoffer Ahlfors
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Re: Removing bearings?

Post by Christoffer Ahlfors »

:P :P :P
It's hard to believe, but there is a clear coat applied! The only downside with that is that you can't see when it fails! With any other paint, it would be obvious when something needs to be done.
A little too much is about right...

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