Removing the one way bearing

[irresponsibility]

I have a fair amount of spare parts that came with a used TDR I recently bought (enough it seems to make a sizable push towards building a second, but I need to show some restraint here) and I have been picking through the pile, throwing away damaged items and repairing the salvageable ones.

One of the pieces that I want to fix up is the one way hub. The spare has much more resistance in it than the good hub which is currently on my helicopter, and I would like to try a swap out. I bought the TDR all-in-one bearing pack, and it came with one... so I'm assuming it is possible. The assembly, however, doesn't seem to want to come loose, even in the oven. The radial bearings on the top and bottom fall right out, but not the one-way. Is this part smashed into place with a press? Or is it simply not replaceable at all?

[Mercuriell]

Makes sense it would be a tighter fit than the radial. Did you try your oven at 130'C/300'F. It it didn't move then may be Loctited. Find a suitable drift and then heat the hub evenly as possible till some smoke starts coming off the bearing area then try drifting it out. Alternatively make up a bearing puller from a suitable sized nut and bolt. Must be remove able!

[irresponsibility]

I'll have to rig up a puller, I was expecting it to be secured with a grub screw or something of that nature (seems odd to have all the power of a drivetrain being held in check by an interference fit, but it obviously works quite well)

I will probably craft something up tomorrow and see how it goes.

[DT75]

The one way bearing is "just" pressed in.

After a crash about two years ago, I ordered only the OW hub, without the OW bearing (and a lot of crash parts), thinking it was an easy swap...

The outer housing have slight angles, think octagonal, probably to achieve a very tight fit.
The bearing rollers are held in place by some kind of "synthetic" holder, definitely not metal, so be careful that you don't heat it too much.
The OW bearing is manufactured by INA, BTW.

I used a hammer and a fitting socket, in combination with some careful heating, in order to get it out, and into the new hub again. Took a lot of sweat and force...

So it is possible to press it in and out, but I would recommend you use an arbor press or a drill press or similar, and a drift that fits snugly in the OW hub, combined with moderate heating.

It's got about 300 flights on it after the swap, and is still going strong, even after the abuse it got from the hammer.


EDIT : How the bearing / clutch is constructed, explained by INA :

http://www.ina.de/content.ina.de/en/branches/industry/sports_fitness/prod_sports/drawn_cup_r_clutches/drawn_cup_r_clutches.jsp

[irresponsibility]

Very interesting, thank you for the information. I did have the assembly in the oven at a higher temperature for a bit, perhaps that is why the old one-way is a bit stiff. I haven't yet had time to rig up a bearing puller, but I am thinking a nut and bolt through a hole drilled in a plate will do the trick.