Bearing fit on crank

[Jack ODonnell]

Well got some good news found a full complement bearing and sent it to Greg Settle to check out.

Looks like we got a winer. Thy checked out real nice and reballed with ceramics seam to be the ticket.

Now on to the front bearing for the same thing.

You may want to check the RPM rating on your full compliment bearings

 

[dwilfong]

Don't know what the rating will be for RPM. None was stated for the bearing in its stock form.

Really was just looking for races that had little or no run out and made from good steel with the groves cut for full complement build up.

Greg has checked many bearing in his day and he was impressed with this bearing. http://endurobearings.com/product/max/

It is a good base to work with.

Theses inexpensive bearing turned out better than most high dollar ones.

The balls that came with them are grade 10 not very good for RPM. But with the grade 3 ceramics installed and the radial clearance adjusted thy are very true.

RPM? will see?

 

[brad nichols]

Are the new crank shafts coming out at different measurements? If so this should be their machining tolerance problem? As far as RPM of bearings, most manufactures will tell tell you the speed rating with grease or oil bath,

Brad

 

[dwilfong]

Brad these bearings are custom built from just the races of a standard bearing. So there is no rating them thy are what thy are.

If you think stock bearing are all going to perform to the specks you have more faith than most. The tolerances are all over the place on production bearing. Unless you spend buku $$$$ for a high tolerance bearing. then the radial clearance is not what is needed for what I have planed for them.

On a stock or lightly modded Eng this is not to much of a big deal. But I am going to a place that this Eng was not designed for.

As far as the tolerances on machined parts there is a high and a low. Get a bearing that is on the high side and a crank on the low side and it will be lose fit. get it the other way and it will be good. luck of the draw is all it is.

Remember we are talking toy boat Eng not the space shuttle.

Then there is my Waco Eng. :blink:

 

[tnrcboatracer]

Full compliment bearings are rated for much lower speeds than bearings with retainers. This is due to the rubbing at the contact point between the balls. BUt perhaps the ceramic balls will not be affected in that manner. Good luck. In hte future you might also want to consider angular contact bearings. Almost all hight speed spindle applications use these, but htey may not be right for the pounding load that our motors produce.

I will patiently await the results of your experiment.

 

[dwilfong]

I was looking at the angular contact bearings for the front of the crank as Enduro also make them in the size I need.

May see about getting one done to test.

Will be some time on this project need to try the crank plating next.

Then I am going to give balancing the crank a try.

Here is a sample of a bearing full complement angular contact.

http://www.bocabearings.com/bearing-inventory/Angular-Contact-Bearings/4283/10x26x8-D6000602C

look at the RPM rating with grade 5 balls 100,000 RPM

so how many RPM can a full complement bearing run with grade 3 balls set up with the right radial clearance?

 

[tnrcboatracer]

Angular contact are great on the front end, as they can take more of a thrust load. But you will need a way to shim them, as they are fitted for axial length.

 

[dwilfong]

Yes I have bin running this threw my head. Have had some discussions on this and how the case and crank expand differently and have bin given some good schooling on this in the past few weeks.

Here is a link to some interesting information.

http://fiorimet.home.xs4all.nl/dissas.htm

 

[dwilfong]

Here are some pics of the bearings I had made for my VAC 1.05 build.

Thy are full complement with the radial clearance adjusted with the proper fitting balls.

There is a big difference in the feel of this bearing. Thy seam like thy will spin forever.

I was surprised how much the center race will pivot in the bearing compared to the original bearing.

This is the first step in the project.

Next I will get the plating setup from Caswell that lohring recommended and try some hard nickel plating to size the crank.

Thanks to Greg Settle for taking a interest in this project and all his help with the bearing design.

 

[brad nichols]

If you are worried about thrust load on the front bearing why not go to square drive to eliminate that problem?

Brad

 

[dwilfong]

I have a square drive on my 21 rigger and it works good.

But it has some things I don't like. the strut bushing is brass that come out with the shaft.

It will not slide over the square end.

I use led Teflon bushings in my ss Octura strut and like that set up. No wear at all and silky smooth.

If a bearing will solve the problem it will make it much easier than redoing the whole drive system.

 

[Michael Caruso]

I have looked at the Loctite info for 640 and 680.

What success has any one had using this?

Will it last till the bearing change is needed?

Loctite will work fine .... the magic to making it work is using the clean and prime. Try it yourself once with out the c&p and then with you will be sold.

 

[Tom Foley]

I have a square drive on my 21 rigger and it works good.

But it has some things I don't like. the strut bushing is brass that come out with the shaft.

It will not slide over the square end.

I use led Teflon bushings in my ss Octura strut and like that set up. No wear at all and silky smooth.

If a bearing will solve the problem it will make it much easier than redoing the whole drive system.

I'm thinking with that engine and prop combo you will be eating that thrust washer crap up quick . Never know till you try , if it saves bearings it might be worth it .

 

[dwilfong]

ya the strut thrust washer is the ? in the setup. that and the cable has to be custom made.

Still on the fence will see how the new bearing work first.

 

[dwilfong]

Going to give the 6000 full complement bearing a spin here real soon and see how thy work.

Have a race coming up in two weeks.

Thy are the same size as the front on my EVO 77.

This should be a good test as this eng Revs real good in my mono.

This should be a good test for prop shaft loading at high RPM.

 

[dwilfong]

Ran the 6000 full complement bearing to day in my EVO 77 Got 5 tanks on it and it looks and feels real nice. the reves where over the top with this setup.

This is a good indication on what it will do as the EVO 2 pice cranks have only a needle bearing on the back side.

The front bearing dose most of the work. this was also a problem child in the front bearing eng.

will race it next weekend and see how it holds up.