This whole grinding a notch in the crankshaft wouldn't have happened if props and spinner holes fit properly. I'm open to suggestions of what you all use to remedy this problem. Also how much slop is rejectable with spinner and prop holes being slightly oversized?
Thanks.
It can tolerate a fair bit of slop, if you had .010 clearance, it would be perfectly fine. Not that I would recommend it but I have seen people run props with 5/16" bores on 1/4" shafts and just eyeballing the centering.
But far more to the point - I have never seen one of those rings get more than slightly tight, well within "prying range" with a small screwdriver. And I am pretty sure they do not shrink once they get on the shaft, so if it seem tight to the point you have to use more than a slight finger push to get it on, do something (like debur the edges or slightly sand the bore) so it takes at most a very light push.
But, suppose it does get stuck? The ring is aluminum, the shaft is steel. Just touch the ring with a hot soldering iron, and it will expand immediately and probably fall off. Failing that, or in the field, you can take a small file or a zona saw and file/cut through it, gently, until it is thin enough to split when you pry on it. So you should never have to touch the steel itself. Even if you do, a zona saw will just skid across the crankshaft surface with no damage while dulling the saw. The file may be able to bite it a bit, but you don't need to apply any real pressure to get through the ring. Even if there is slight damage, it be <<.001 and smooth, which doesn't affect the crank in any significant way. In either case, you go carefully and gently using just enough effort.
A Dremel cut-off wheel is a vicious tool that will cut through anything you have in your house, it chops spring steel music wire like butter, and they are notoriously hard to control. It is very useful and irreplaceable for a small subset of modeling tasks, I use mine about 3x a year for various things.
All that is required in this case is to cut through .032 x1/8" aluminum. Push comes to shove, you could probably carve the aluminum away with a good pocket knife or a wood chisel. Using the cutoff wheel, it is utterly inevitable that something like what happened will happen. You have fairly deep cuts with sharp edges in what is probably a case-hardened or induction-hardened peice of steel, right at the base of the thread relief, so the chances that it will crack is pretty high, which is why Doug, me, and others suggest you just get a new one since they are <$30. My guess is that it would *probably* work for while, but its spinning 11000 RPM with a razor sharp blade and you are right in front of it, that is a chance I would not take.
No one is trying to "pile on" here, but this is a classic case.
Almost nothing good can possibly come of taking power tools to a model engine, drills, grinders, etc, are not necessary to operate one. The exceptions already know who they are and if you have to ask yourself if you are one of them, then, you aren't. That means everyone reading this now, and I include myself. What usually happens is what happened here, the solution is the same in most cases - replace the damaged part with a new one.
Brett
p.s If you think getting stuck is an on-going problem, Zona saw, the miracle tool, solves the problem in 5 seconds. Tru-Turn 3/8-5/16 bushing (that someone, NOT ME, tried to get off with a pair of water-pump pliers before I came along..), diagonal cut through with thinnest Zona saw:
Topic: How to remove a crankshaft from OS LA 46? (Read 4631 times)