franchi

Hi Gang:

I recently bought a Uctkam .15 Diesel and it has one small problem. The problem is that when the prop is snugged up on the crankshaft, the prop drive is driven into the crankcase to a point where the shaft will not turn. The prop drive has a taper on the inside that fits over a split tapered sleeve that is supposed to get tight on shaft to prevent the prop from slipping on the shaft. However, when the prop is tightened. the prop driver is pushed into the crankcase thus prohibiting the prop from turning.

The split tapered sleeve is made of brass and has a recess cut into the rear face of sleeve to allow it to butt up against a shoulder on the crankshaft and prevent it from coming in contact with the crankshaft. However, this is not happening.

My question is this : Should I file some material off of the nose of the crankshaft, file some material off of the rear of the tapered sleeve, file some material offo the rear of the prop driver or all of the above?

Any suggestions as what to do to solve this problem?

Thanks,

Franchi

soarrich

My Feedback: (98)

I'd take it off the back of the propdrive.

gkamysz

My Feedback: (19)

Make sure the crank (and bearings if it has them) is seated correctly. I like to modify parts I can easily make. So trim the prop driver, and save the crankcase.

Which engine is this exactly? Do you have a photo or a link to one?

franchi

Hi Gang:

I solved the problem. I tried filing .005" off of the rear of the prop driver and that did not help. I then took off .002" of of the tapered sleeve and all was well! I used the smoke from an oil lamp to help me spot tin the parts that were binding.

This engine as the model that has a front intake with a small exhaust that is flush with side of the fins. It has three transfer ports and one exhaust port. It also is a plain bearing model sans ball bearings. The backplate is the screw off type. All in all it appears that it might make a good sport engine. Does anybody out there know what this is good for, use, history etc?

Thanks for all of the help!

Franchi




Thanks for

gkamysz

My Feedback: (19)

http://www.rojobcn.com/technic/avion/uctkam25.htm

I have several Russian engines, but I don't have one of these. I don't know anything about it. They aren't that common. I'm glad you got it figured out! Let us know how it runs.

qazimoto

My Feedback: (1)

It's unlikely that it will be much use as a sports engine without a lot of attention by a skilled engine man. I wasn't aware that they came in a plain bearing form. I have a glow version which I believe is TBR. It has been a good source of parts for other engines.

I had a similar problem with an engine once, and solved it by placing a glowplug washer between the front of the bearing and the prop driver. That is space the tapered collet away from the step in the crank. It's still working! I'd guess that your motor would have a 6 mm diameter crank at the prop driver so one could have solved your problem as well. Good luck with it.

Ray