Align main shaft bearings don't last long

[Helirob]

I was very tired of replacing the main shaft bearings in my 700's. Even if you don't crash the main shaft bearings get notchy. Lots of collective pumping with 8717 servos must put massive loads into the bearings.

I just bought some KDE Direct main shaft bearing blocks that have thrust bearings built in. Finally, no more notchy bearings and they fit perfectly in my 700's.

[jrumer]

Looks good, I got the Kasama bearing blocks and it seems so much smoother than the stock ones. I bet that set you have is real smooth as well. :thumbup:

[Helirob]

Yes, all the bearings are really high quality along with the machine work. The radial bearings fit perfectly in the bearing blocks (just a light slip fit so the thrust bearings will take all the axial loading).

Kasama makes nice bearings blocks also, I just like the look of the KDE Direct machine work. In my opinion, the TREX 700 kit should have come with thrust bearings on the main shaft since the radial bearings get notchy so fast.

[LoveMyTrex]

have you noticed a difference in power with the thrust blocks? or more float on autos?

[nwolsink]

IMO the bearings on the 700 are quite good, I only replaced the top mainshaft bearing after 30+ flights and this one wasn't shot 100% just a tad notchy.

On the 600N it is a whole other story with the stock bearings :(

[HeliSmith]

1st crash = Took out main shaft bearings 100% (About 70 or 80 flights)
2nd crash = Took out only top ceramic bearing (About 90 flights)

Didn't make it enough flights without crashing to know how long they last... :(

[jrumer]

Man I don't get that many flights in a year here our weather won't let me you lucky dog you !!! I guess I need to move to California :P

[KDE Direct]

Hey Helirob, thanks for the picture, the bearings look great in your setup. You mention running these in your 700s, how many do you own? Overall, great looking setup. :)

[HeliSmith]

I own a set! Thank you Kevin!!! These are sweeeeeeet!!!

[Helirob]

Kegerator,

Thanks for the making the new 700 bearing blocks, they work great. Everything is very high quality. The bearings fit perfectly in the blocks.

I own three TREX 700's, two set up as nitro and one electric. I bought one set from you and they worked so well that I ordered another two sets for the others.

Thanks for making so many good upgrades. Keep them coming.

[rcer04]

Hi all
I have just ordered the KDE main bearing blocks for my 700 they sure look impressive, is the radial bearing the same size as the original?.

[TooLy]

Thrust bearings blocks are a must upgrade in the 700.
The stock bearings are fine but the side loads to big for them, they become notchy after 10 flight (3D).
I have the kasama blocks with around 22 flights so far, the bearings running smooth like new...
When I shut of the engine after a flight, the rotor keep spinning and spinning......

[HeliSmith]

Just installed these we will see how they are. I sure am impressed with the tolerances and quality, I used green threadlock on the radial bearing as I would prefer. It went together so easily. The installation manual on the kdedirect.com is very easy to understand.

[Helirob]

I measured the stock align bearing and the KDE direct bearing; they are both the same exact size.

I would not use loctite on the radial bearing; you want to make sure the radial bearing floats in the bearing bore so the thrust bearing can do its job. I have not had any problems with the radial bearing spinning in the bore since the slip fit is perfect. Just a small amount of radial load locks the outer race in the bearing bore anyhow.

All our aluminum transmissions at work have slip fits on the outer race of the bearing. When they get hot (250 deg F) the bearings get really loose in the bores yet we have never had a problem with the bearings damaging the bearing bores.

Just my two cents

[HeliSmith]

I thought about that after I posted the post. I was waiting for someone to come and confirm I shouldn't have thread locked those bearings... I will redo them...

Edit:
These aren't ceramic bearings Kevin gives us is it? I wanna get spare bearings in case I nuke those ones getting them back out. Stock Align ones are good?

[KDE Direct]

The stock radial bearing from Align will work in the bearing blocks just fine. Soon I will have replacement bearing kits available from the website so people can quickly replace these when needed, as I know how frustrating it can be when the bearings are hard to find. :)

[HeliSmith]

Ok I beat them bearings back out. I have to hold the bottom bearing from falling out while I am installing the main gear and then main shaft. I can't imagine how it would work as a thrust bearing using threadlock but the installation diagram says you can if you wanna. I will just let it all be free.

[Gscott]

For future reference you should be able to heat up the blocks in an oven and the bearings should almost fall out on their own. Done this numerous times on a Knight 3D and OS Hypers.

[HeliSmith]

I didn't want to de-temper my race bearing retainer. Have done it before then the little balls fall out.. So I use a 450 main shaft to catch the edge of the bearing and tap the main shaft on a block of concrete. I take my time and work my way around it. In no time you have the bearing out, actually the bearings were still good but I replaced them on GP.

[Phillips942]

I should have posted a picture of my set. On one of the blocks that i received one of the balls came out of the race on the thrust bearing with ease. The cage was ever so slightly warped but i didn't think it would harm much. I haven't flown it yet though...


KDEDirect!!! What do you think?? Should I take em out and replace them or should they be fine.

[KDE Direct]

I should have posted a picture of my set. On one of the blocks that i received one of the balls came out of the race on the thrust bearing with ease. The cage was ever so slightly warped but i didn't think it would harm much. I haven't flown it yet though...


KDEDirect!!! What do you think?? Should I take em out and replace them or should they be fine.

Hey Phillip,

I've simply put the ball in the thrust bearing container back many times before (using Align bearing sets with my 500 and 600 main blade grips) and had no problem (the ball relocate itself in the container and stays there once the races are mounted on top/bottom), but I can replace the bearing for you if you are concerned. This is a common issue with ball-bearing thrust bearings, as they are designed to merely keep the ball in location laterally and don't do a whole lot for vertical play (this is the design intenet, same as heavy-duty versions also for car transmissions). The bearing designers try to keep the friction between the balls and the container shell at a minimum, so this sometimes allows the balls to come out when the races are not sandwiching the container due to the relaxed tolerances to provide smooth and frictionless play. I instructed manufacturing to use brass ball containers and minimal-friction tolerances for the thrust bearings to optimize performance, so this does allow the bearings to float as best as possible. :thumbup:

[KDE Direct]

The King of HeliFreak reviews, Finless, just finished a rather hilarious and entertaining review of the T700N and T600N Aluminum Thrusted Bearing Blocks in his Tech Room at:

NEW - KDE Direct's Thrust Bearings Kits for 700 and 600N - HeliFreak


Make sure and check it out, and a BIG THANKS to Kevin for the hard work in crash testing. :Bang