RE: Saito 125 engine bearing failure
Hobbys,
if the roller bearing in the engine is flat like a wide wedding ring then it is just a roller radial bearing. Is it a one piece unit like a standard ball bearing? What I mean is there a seperate outer race and seperate inner race with tapered rollers caged to the inner race? If the outer race bearing surface is angled so that the inner race w/rollers is held in with pressure from the axial load then it is of a dual purpose. Both radial and axial. I would doubt that the front bearing, if smaller would be a thrust type bearing. It could be a ball bearing that is taking up the the thrust though. Years ago they experimented with all types of bearings trying to find what would work best. I think in the early years they got hung up on the thrust thing and followed the rule of the proper bearing for the proper application. I think you're right and you might find the crank held itself in like the old bushing engines. Those small caged roller bearings tend not to be that good. Hope your's are holding up fine.The normal axial load of a prop is light enough that it really doesn't put much load on our radial type engine bearings. If there is something else wrong in the engine though all hell can break loose. Mike, I actually assemble ARF's for my LHS and lately the customers are coming direct to me. I have now built just recently 5 Kyosho P40s including one for myself. I have bashed mine and this last one somewhat and will do more on mine over the winter. I will be stripping mine and recovering with aluminum monocoat then painting. I intend on putting split flaps and painting it like the one captured by the Finnish. It should be the only one around our local fields with German markings. This plane is powered with a Saito 62 and it flies absolutely the best. I might do a build thread just on the custom touches. For the money and the ease of handling for transport it can't be beat. As you can see in the pics it could use a lot more bashing but right now I'm flying it. The last pic is of the customer's with a OS70. You can see the home made gear struts and the zinc chromate green in the cockpit. Half a day and it will be done.