krazy4planes

Need some help, crashed, flattened needle bearings on lower connectiog rod/crank, the pin the bearings/cage ride on has a flange and is press fit into crank so the bearing/cage assy won't just slide off, tried Troybuilt and the DLE web site but they don't seem to know what i am talking about, I have new bearings/cage to install but don't know wether to heat or to cool the part to get the pin out of the crank, I would like to know how the factory installs thebearings and removes them, also is there a special press I can purchase to prevent damage to the surfaces durring removal..

BarracudaHockey

My Feedback: (11)

Had the same thing happen to my 55, I just ordered the crank and rod. A guy that rebuilds racing engines flys with me and wouldn't mess with trying to get it apart.

krazy4planes

Thats the jest of what I'm hearing, well I ordered a new crank, won't be in till mid july, wanted to get in some flying before than, I'll do some exploring with this crank and pin and post my findings with the results...

Lnewqban

According to what this picture shows, I believe that neither heat nor cool will do the trick.

http://www.rcpower.com.au/product_in...products_id=53

It seems that the extreme of the crankpin is deformed like a rivet head after the cage is in position, probably in cold state rather than hot.

May be grinding that step down would be the only way to pull the needle bearing out, better is done centered in a machine.

However, reproducing something similar after the new cage-bearing is in is going to be difficult, due to the hardness of the crankpin.
Welding is out of the question, being a precisely machined surface.

krazy4planes

I can appreciate your ideas on this subject, I guess the fact that I was able to aquire the bearings from a large online hobby store with no way to install them seems defeating as a customer, at the least the store could have informed the customers that this part is not replaceable without major rework..

krazy4planes

P.S. even the RC web site you sent sells the same bearing set...

scooterinvegas

My Feedback: (1)

Maybe if you put the crank in the freezer and the bearing the the oven??




That my friends....was a bad joke.

krazy4planes

That was a good one, I wish I would have thought of that.. I'll get that sucker apart without any damage, install my new bearings, then I'll have a newoccupation..The wind here in Kansas has all but stoppedthese past few days and I am jones'n to fly my Extra..

BarracudaHockey

My Feedback: (11)

Where did you try for the parts?

Valley View RC, Tower Hobbies, and TBM (www.troybuiltmodels.com) would be my first stops.

krazy4planes

Yes they all sell the bearings but they don't offer any instruction on removal/installation..

Lnewqban

Nice bird!

I should have said that heat or cold cannot be a separate application for each part, since they are together while assembled.

I have not tried the repair myself; that is just my opinion from looking at that picture.

It may be still possible if the needles can move out enough inside the cage and all at once; hard to know without messing with it.
Keeping all the needles as spread out as possible is key.

Actually, a huge step would not be needed to stop the needles from moving axially, once they are tight against the crankpin by the connecting rod.

I would destroy the old bearing and try the new one slide over the step.

If you see that it is almost sliding, then cooling the crankshaft and heating the bearing may do the trick.

Best luck, my friend.

krazy4planes

I am back to report that I was able to remove and replace the connecting rod bearing on the DLE-20 crank, I am including photo's, once I had all the items I needed to perform this task it only took 20 minutes to complete...

ton2di

My Feedback: (182)

krazy4planes,

Were you able to remove it out from the crank without heating it? Oo do you need to heat it first? Does the pin go in with the bearing easily?

Thanks,
Ton2di

krazy4planes

Hey ton2di, to answer your question I did have to heat up the crank around the pin, and it slid back on like butter (The pin was still hot, off and on in less than 30 seconds), also the bearing that is shown on the crank pin is actually the piston connecting rod pin that is available at Tower hobbies, this is the wrong bearing,I was able to aquire thecorrect bearing through RCPower out of Australia for around $22, Cody at RCPower really helped me out the bearing was the right one and it came with a new pin too. Be advised he had to special order it from the manufaturer and I just recieved it two weeks ago so the price for a new crank may not be so bad, I just have a good crank and wanted to salvage it for later use. Just an added appreciation to Cody at RCPower.. none of the dealers hear in the states seemed to know how or want to even mess with getting what I was needing.. Thanks RCPower..

krazy4planes

I will have pics of the correct bearing soon..