bigR

My Feedback: (2)

Hi,

Not really the crankshaft, but how do you take the drive plate off the crankshaft? Or how do you put it back on? The instruction sheet exploded view shows the crankshaft, drive plate and crankcase as one part number but 3 separate pieces. Something like a gear puller or ? I would guess. I see lots of articles about polishing the crank but how do you get it out of the engine?

I would like to disassemble some reed valve 049s and Pee Wees so that I can install a thrust washer between the drive plate and the front of the crancase. I have a good running Pee Wee that has a lot of back and forth slop. Doesn't seem to bother it but I know that something is going to give sooner or later. Has anybody installed a thrust washer? If so, what material and dimensions?

Thanks in advance,

John in the PRC

BMatthews

With the engine apart other than for the crank put the prop screw into the crank quite a ways or even until it bottoms out. Then LIGHTLY and squarely rap it with a hammer to tap out the crank. The crankcase should be sitting on a piece of wood as you do this to avoid putting dings into the case to tank face.

Or better yet. If you have a vise in your shop put the crankcase with the prop screw between the jaws with a bit of thin wood to protect the back end of the case again and use the vise to push the crankshaft through.

To reassemble you just push it on with your fingers to start it and then use a prop with the prop screw to pull it back into place.

You won't hurt anything with that end float unless you're using an electric starter or are running the engines as a pusher. In any case you STILL want to make sure that there's about 10 to 15 thou of end float at a minimum. The aluminium crankcase expands faster and a bit more than the steel crank and if the end float is less than that the crank may bind.

If you are running the engine as a pusher or use the electric starter a lot then either brass shim or a very thin steel shim will provide a better bearing surface.

XJet

When I disassembled my Black Widow recently, I found it much easier to remove the prop driver by placing the crankcase on a block of steel rather than a block of wood.

When using wood as the backstop, it absorbed much of the shock from the hammer and the driver wouldn't come free. By placing on a block of steel I could use much lighter blows and it came off really easy.

bigR

My Feedback: (2)

Thanks, guys.

It was too easy a solution; think I was looking for something more complicated. When you reassemble the motor and tighten the prop screw does the thrust plate bottom out at some point. I mean is there a step on the crankshaft?

Yes, I am using an electric starter. The spring doesn't always fit the various props that I use and/or gets in the way when the motor is running. This is more of a problem on the Big Mig Norvels. Also, when using big props *** is harder to get a quick enough flip. I'm using 9 inch props on the 049 and 7 inch on 020.

BTW, I was clipping on to the nicad pack attached to my Sullivan starter. That old Astroflite starter really spins up on 12 cells, about 14 volts! Too much so, in fact. I am now using only one 6 cell car pack. I measured it at about 4K RPM. This works real well.

I can't wait to get home and take apart some motors. Now, does anybody have a method of making those thrust washers? The Pee Wee has so much slop I may be able to use a regular off the shelf washer, any harm in this?

Thanks again, John in the PRC

DesignMan

Yes, the crankshaft will bottom out correctly. And, you can make a washer out of .005 shim brass to take the loads of a starter. Doesn't have to be terribly neat, just make sure you burnish any burrs flat.

bigR

My Feedback: (2)

Thanks, Larry. That's what I wanted to hear. I was afraid of the crankpin contacting the reed retainer, especially if I use the "lapped crankcase and tank no gasket" mod.

I'm really having fun seeing how big a prop I can use on these engines. My main problem from before in Texaco was breaking the crankshafts. These are free flights and tend to nose over or worse on landing. The use of the more flexible electric props may help. I'm not about to use those slow flyer super flexible orange ones though, that's going too far!

Still prefer the Norvel Big Mig for durability and resistance to abuse and dirt, but C*x engines are sure a lot cheaper, like free when you clean out the garage! Now, if I had to buy glow heads or a new motor that's another story.

John in the PRC