i have just ordered a gms 61 engine that i am putting in a goldberg super chipmonk kit that i am also building just wondering what you guys thought will the plane handle the load from this engine and will the engine handle the abuse that the plane will administer

It will be a good combination.

Put the engine on its side and not upside down.

Be sure and not let the engine run hot.

other thanthe normal beefy bulkhead should i brace the firewall up any way special im a fan of overbuilding sometimes but usually aply some tri stock on the back side just for good measure will this be all right or should i maybe do something more exotic

The usual tri-stock and epoxy coating should be good enough

I've gotten in the habit of drilling a couple of holes through both sides of the fuselage an inch or so into the firewall and epoxying hardwood dowels into the holes to pin the firewall in place. It might be overkill, but it hardly adds any weight and it's stronger than balsa tri-stock. After you sand the dowels flush and cover the model you'd never know they were there.

On several of my planes used some button head screws sort of looks like a round head rivet with a socket head
to beef up the fire wall they look sort of neat too spacing about 1 1/2 inchs martin

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I use round toothpicks (cherry sticks) with epoxy and insert them into predrilled holes through the sides and into the firewall. It doesn't take much to add a lot of strength to the firewall. Triangle stock is good too.


Ed Cregger

thanks for the ideas i think ill try the pinning of the firewall with dowles as was suggested never seen it done before great idea

Ah, triangle stock. That usually comes after ther first time I break out the firewall. I have even used a piece of control rod, drill a hole in a penny, put a ninety degree bend in the end and slip the penny up to the bend and solder it. On the other side I thread the end, drill another penny and torque it down using the second penny as a sort fender washer. That holds the firewall in place and keeps the firewall from moving forward too.

That way I do not have worry about whether the epoxy will stick on the fuel soaked surface.

Cheers,

Chip

new model no fuel soaking but its a good idea for a conversion think ill stick with the dowles on this one though thanks