The flying monkeys got me...

Helis and fixed wing

AMA 957918
IRCHA 4345
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Pirate Kid Skeleton by RadDezigns.

Wednesday, September 11, 2019

Replacement Tail Wheel on on the 30cc MX-Bach

I could not find a collar with a tail wheel rod connection without buying an entire tailwheel set. This piece fails a lot, so I found it curious there's no replacement collars. But I don't like that design anyway, preferring something more robust. So I did this.


I bought this on eBay because it looks robust, is the right size and a fair price. The link may expire someday...



Compared to the original. You can see the rusted collar on the top of the old wheel. I used the same CF brace.



I came up with the idea of using a blue servo arm I have that allows the top to screw down tight against the servo spline. This fit nicely and tightened up sweet. A drop of CA for good purchase but it wasn't slipping at all.  I used a snug fitting rubber grommet as a bearing, allowing a little shock absorption and there is a little play in the ball link connector screw. I don't have a ball link big enough to fit the M3 screw. I trimmed about 5mm off the top of the tail wheel axle.



I used a 600 size helicopter control rod turnbuckle to act as an arm. I angled the blue servo arm a bit to allow things to fit, and to allow a clean full side to side range of motion.



You can see the plywood plate I put in on the end of the fuse as the tail wheel hardpoint, epoxied in place, and then 3 large wood screws attach the CF wheel brace to the hardpoint, with a touch of CA as well.



Seen nicely in this pick, I used an M4 bolt into the rudder, about 2cm deep secured with epoxy, with vertical play allowing it to move up and down as the wheel bounces, and it too has a tad amount of play between the bolt and the ball link connector. All of the play amounts to very little but needed movement.



Here is full range of motion! Solid stuff right there.

Now that is what a tail wheel assembly should look like!

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