Sheer pin fix...

[heliboy1023]

As many of you know, the stock cp's sheer pin (or Jesus bolt in other heli's), doesn't do its job in protecting the main shaft, and head by breaking during a crash. Also, as for the ones who have broken/ bent/lost them, it has put these people in an odd problem. Well, I've found a great fix for it, and have 100 flights logged using my method (10 crashes too).

Basicly, I went to office max, and bought 500 small paper clips. After doing some experimenting, I've found that if you pull off the rubber coating, they are almost the exact correct thickness of the whole, just a tad smaller. Cut of about 3/4 of an inch of a paper clip, and insert it in the whole. Then just bend the two sides that hang out to the sides. You will have a little bit of play in the head, however it will be fine for all type of flight. (Yes 3d too, as it has held up to my not so smooth rolls)
Also, in my 10 crashes I've had with it, it broke everytime. Only once had I needed to replace the main shaft, and feathering shaft. (I did replace the blades everytime since I figure any internal crack I can't see can still be there, and would rather be safe than sorry though the blades faired pretty well).

So, if you are looking for a very cheap way to fix this common problem, just paper clip it like me. If you want pictures, just pm me.

[WayneBrown]

I used a long shank #4 fishing hook. Just cut off the eye and the 'J' bend and trimmed a bit to fit.
Worked pretty good, and was hard enough to shear in a crash, but seemed to get the mainshaft anyway.
Good to see some ingenuity in fixes for the Blade.

[EKIM]

I'll have to give that one a try. it seems like if some one sneezes to hard near my blade cp I bend the main shaft and I have to dremel it out. Thanks for the tip!

[Crash Gordon]

So I take it that this is something I need to do sometime soon? I am just starting to get the nuggets to "fly" my CP instead of just trying to hover pack after pack, and although I managed to keep the spinning side up on my recent crash landings I don't expect to have that luck all the time and I'd really like to keep the repair costs down as much as possible.

Could you hook me up with a pic please?

Got any more tips??

[heliboy1023]

Here is one:
http://www.helifreak.com/album_mod/upload/a81e5a1a796b0502dae79f56467d68f3.jpg

And here is the other:

http://www.helifreak.com/album_mod/upload/f86369ee70ad722782065140b8da3d49.jpg

Sorry they aren't that clear, also if the links don't work, they will be in my gallery.

[Renfield]

Another cheap and easy sheer pin solution for the BCP: LHS carries .032 Brass rod in packages of five/12" pieces for $1.09 USD.

[Crash Gordon]

Right on, thanks a bunch!

[knockers]

If you bend the main shaft, just get a small piece of brass tubing that will fit snug over the shaft. Roll the shaft on a bench vise anvil and tap tap tap as you roll the shaft. Don't pound! just tap. Insert into the tubing and spin. If it still wobbles tap a little more. Just keep doing this until the shaft is straight. Works every time! I've got three that I rotate and haven't bought any new ones for months. The sheer pin thing works and keeps you from stripping gears also.

[Gary JP4]

I have chucked the shaft into a drill, turned and straightened by bending with finger pressure and re-chucking at different positions and from both ends until it was straight. That works pretty well.

I was going to hit something once and shut down, landed going pretty fast and slid about 20 feet on hard troweled concrete floor into a stationary object (tire). The blades stopped about the time it hit the end of a blade and bent the shaft. I thought it was going to stop, it almost did. No other damage. Pretty soft. I accidently bumped the throttle once while disconnecting the battery connector. The blade made one hit on the ground and bent the main shaft.

Edit: Pins are .040" dia. Saw some speced online at .0399". I tried .041 aircraft safety wire and it was too large (probably to strong also). I tried paper clips (the small ones were .035", and the large .045" I think. Haven't tried T-Pins or the plastic covered paper clips.

[Crash Gordon]

I actually just found out that my shaft is bent (don't ya hate it when you bend your shaft and don't know it! :oops: ) but back to the heli...

I am going to get a new one but then I am going to straighten the original and use it next time.

Is it pretty easy to get the shaft out? Am I going to have to re-set the pitch or anything? I wouldn't think so by looking at it, but I have NEVER taken anything apart on this, or any heli before.

-not trying to hijack your thread or anything, just figured I'd ask instead of starting a new one.

[Renfield]

It usually bends at the collar. This can be fixed without removal. Use your transmitter to spin it up slowly, observe the wobble and correct as needed with light finger pressure.

Since switching to the brass shear pin, I haven't noticed the bending problem as much.

Good luck!

[Crash Gordon]

geeze these shafts are that weak?? I'm hoping to get this shear pin upgrade asap

[Renfield]

If you think the main shaft is weak, wait 'til you try and straighten the feather shaft. Like cooked pasta! LOL.

I read about the shear pin fix a few months ago, but never thought much about it. Just happened to spy the .032 brass rod at my LHS and though for a buck, I'd try it. Now I'm kicking myself for not doing it sooner.

[zooland1]

"T" straight pins are the perfect diameter for the shear pin. A little stiffer, but will still shear to avoid head trama if necessary. Plus with the T head they're very easy to insert. Then just trim the T and point off after it's in.

[Crash Gordon]

There is only the one pin in the shaft right?

The pix are kinda blurry but I only see one one the shaft and it's above the swashplate and below the blade grips??

I tried to bend it back by hand without taking anything apart, but couldn't get it done and it felt like I was about to break something if I tried any harder. I'm going to take things apart and upgrade the pin at the same time, wish me luck!!!

Anyone know the correct pitch to reset to afterwards??

[heliboy1023]

Pitches for the cp I have mine set at -/+ 8. Anything higher or lower will bog the motor to much.