Landing gear replacement
When I bought the SBach the aluminum landing gear had been twisted in a rough landing. The previous owner did a good job of bending it back, but the damage was done and the plane never tracked quite straight on the ground. Add a few hard landings of my own as I was getting used to this plane and it was time for a replacement.
I wanted carbon fibre and after looking around a bit I decided to try a set made for the Pilot RC 50cc SBach. When I ordered them from Aircraft Modelers Research (AMR) in Montreal (part no. 3191), I asked if the gear was pre-drilled - it was. A novice with carbon fibre, I asked how to fill the holes if they didn't match. The answer: JB Weld. To the shop!
Here's the new gear fresh out of the box.
A quick look confirmed it - the holes don't match.
The landing gear bolts are hard to get to and I didn't want them to fall out between gear changes. A small O-ring on each bolt made sure they wouldn't.
With the gear off I weighed the two. Stock gear...
92 g (3.25 oz). Weight loss is good!
Here's a closer look at the old gear. It's done.
I used masking tape and non-stick paper to make a backing before I filled the holes.
Holes filled with JB Weld.
I took the backing off the next day.
I used a small utility knife to scape off the extra JB Weld underneath and a light touch with the sander to smooth it on top.
Now to mark the holes for drilling. There was already a centre line on the new gear so I carefully marked one on the old. I aligned the new and old gear carefully by eye and clamped them together, then used a transfer punch to mark the holes. I circled them to make them easier to find while drilling.
To the drill press. I supported the new gear on a block of wood and used a 13/64" brad point drill bit for the holes.
New holes drilled.
I removed the O-rings holding the gear bolts in place and gingerly worked the new gear onto them, being careful not to push the bolts up into the fuselage. Here's the new gear, mounted.
Here are the new wheels mounted - the pair came in at about 40 g (1.5 oz) less than the old ones.
I used two O-rings on each axle, one on either side of the wheel. Pushing in the wheel collar while tightening it resulted in a mild braking effect on the wheels - not nearly enough to nose over the plane under power, but just enough to keep it from rolling at high idle and to help slow it a little bit after touchdown.
We'll see how the new gear works next time out.