levans498

welding a one way bearing in a socket & using a drill to start it ? I have a small but STRONG & FAST cordless drill that would work awsome . I can use the one way bearing in the easy start when I take it off .

SAVAGEJIM

What do you mean by a socket? Is that the hole on the engine back plate where the engine crank goes into the back of for a pull start?

As for starting some of my RCs, I have used a drill on reverse to start roto-start engines. And my drill is 10x more reliable than the sorry way overpriced handheld roto start units.

levans498

yeah trough the back plate . I will work on it tomorrow

SAVAGEJIM

I assume you want to do this mod on your TRX3.3.

What I would do is buy a Traxxas pullstart, and mod that instead. Remove the spring and pullstart handle, and remove the pullstart spring. If you can rig up a part to grab the spool to spin it, it will start up the engine. The pull start assmbly already has a one way mechanism in it so a OWB being welded to the back plate is not required.
(You dont want to weld to alum alloy anyways, you will destroy the temper treatment, and the taiwan alloy of TRX engines will not stand up to the welding of steel to it)

levans498

no I was saying weld the bearing into the socket . You should NEVER weld on a motor

fabrimacator21

Welding on the backplate?

He's talking about welding a Owb to a socket. That way you can just put the owb on the start shaft. Start it and pull it off. No more parasitic drag from the owb while running.

You can't weld aluminum alloys to a steel, just won't stick, not to mention cast iron...


I'd be worried about dirt getting in though.

SAVAGEJIM

Oh, when you said socket, I was thinking about the recess in the backplate of the TRX engines.

Year, I am thinking dirt would be a problem too.

RCCanuck

nope.......cuase its a bad idea LOL.

gonzobot

if its a trx engine it wont work they need a back plate in place due to the crank case being open with the oneway bearing (oneway way bearings need oil)

ridikt

it works. ive done it but its not very conventional. dirt really wasnt the problem just the oils getting everywhere. if you could make some sort of plate to go over the bearing but still have the shaft sticking out it would work pretty well. it wouldnt be that hard to make the plate either. and if the owb isnt on the engine when its running, it doesnt need oil cause it isnt constantly spinning, just used to start it. this method does increase the life of the owb, but i really wouldnt say its very safe. i would just get the rotostart and use your drill with that.

gonzobot

i does need oil. just because it not constantly spinning doesnt mean the bearing isnt still in contact with the starter saft. oil isnt absolutely necessary but it wont be good without it

keithinspace

The crankshaft to the engine goes through a bushing on the starter side of the engine (the non-flywheel side). Taking the engine apart, there is a hole to feed fuel (lubrication) to that bushing using positive pressure in the crank case. I presume a small amount of this weeps over to the OWB.

I would be very, very concerned, not from contamination of the OWB from dirt (you're using it so infrequently, relative to what its normal duty is), but from contamination of that crank bushing from dirt. It will be wet with fluid by definition, attracting dust. A little bit of that dust in the bronze bushing will eat it quickly.

That's why folks who don't want the drag of a OWB use a starter box acting on the flywheel and seal up the back end of the engine.

I think it is a nifty thought and the OWB itself will be fine with a little bit of care, but is a quick path to ruining the rear bushing of your engine.

lean is mean

does the owb really drag the motor down that much to justify a bump box?

matts6887

Well, imo I think its the reverse, i think the bump box is more of a pain in the arse than a owb is simply because using a one way bearing to start it via a pull start or other electric start; u really dont have to worry about lugging around the starter box everywhere u go; and imo i would much rather deal with a pull, roto, or ez start with a owb than have to deal with a starter box.....just my .02 here....

twomanytoys

I dont care who you are you will NEVER NEVER notice any power loss because of a OWB. The drag is so minimal. Biggest reason race engines dont have them is because of convenience. A bump box is fast and powerful. Pull starts and roto starts are not reliable. One day you have a big race and the pull start breaks or the one way bearing for the roto start goes out then you are done for the day because you cant qualify. Bump starts are direct with nothing in between. I had a roto start in my truggy and used it for about half the season racing then I went to bump start the rest of the season. My lap times did not change and it was just as fast with the roto.

fabrimacator21

Well... that is different... bump start motors aren't spinning the start shaft that the owb spins on. Pullstarts, roto starts, etc, have the extra drag from the owb AND the start shaft. Non pull start motors might have a little better throttle response because of this, but the power difference would be un-noticable.

But some non pullstart motors are turbo head while the p/s version isn't and the non pulls have a little more power due to timing in the crank and the turbo head. The picco p3 .28 is one of em.