IMAC Double Build, Carden Pro 124" Extra 300 40%

[Notorious B.E.N.]

I am going now to look and see what it is. Seems that the throttle servo froze. It was a forced dead stick landing.

I've had that happen and it always seems to happen around full throttle. I don't know if I wear them out or they get too hot and it fries them.

 

[orthobird]

I removed the cowl, and inspected everything. The servo was working!!

I changed it out anyway. All i can think of is this:

these servos have magnets inside of them, and I know, that heat will affect a magnet.

"When heated above 176° Fahrenheit (80° Celsius), magnets will quickly lose their magnetic properties. The magnet will become permanently demagnetized if exposed to these temperatures for a certain length of time or heated at a significantly higher temperature (Curie temperature)."



I am going to open more holes in the bottom of the fuselage to help improve the air flow so that it is not as hot.

an alternative plan, would be to remove the servo from this location, and install it way back from motor, and use a long push rod.

I believe, too much heat?

 

[BalsaDust]

I think moving it to rule out the heat would be a good choice. As long as your keeping it in front of your CG it really shouldn't affect your CG all that much.

 

[Rusty 73]

It appears that some of the red silcon wrap on the header is melted on the ends .
So that high can effect the magnetics in the servo , wow wasn't aware of this !!!!

 

[orthobird]

Interestingly, my motor temps are great.
I have a sensor on each cylinder, and the peak temps are 240, 240, 260, and 290 F

and the sensor is on the bottom side, under the baffle plate. SO i believe, I need to improve my air exit strategy.

 

[JAG]

Yeah thats pretty close to the pipes, I'm sure its getting pretty hot. I'm with you, I would replace it if its already caused some issues. Can you mount it inside the motor box, away from the heat?

 

[thurmma]

I would definitely relocate the servo. Never have been a big fan of mounting them in that location due to the potential heat issues. Glad to hear that everything turned out good

 

[TonyHallo]

If you head temps are 280, those exhaust pipes are much higher. I'd move the servo location and send that back for a check up.

 

[orthobird]

Thank you all for the advice. I will probably do that.

But, now..

drumroll please!!


It is my distinct honor to announce, the LE and TE have been shaped, and its time to set the incidence!!

 

[orthobird]

Before setting the incidence, I will be doing a modification, and some prep work, to the stabs/tail of the fuselage.

I have obtained this 9/32 aluminum tube, this is the OD, and the ID is 1/4"

I then mark a point, 25 cm from the trailing edge of the fuselage forward and 1" down,, from the top surface of the fuselage...

I then use a small drill bit, like 1/16", and slowly, make this pilot hole bigger (not shown), until I eventually drill from one side to another using a 1/4" drill bill.

once this is done, then I opened the hole with a 9/32" bit, and then passed the aluminum tube all the way across..

I then realized, this hole is not thru and thru parallel to the stab tube, so i made the hole bigger, and then glued them in with donuts and also used a long 1/4" rod, thru the tube, to check that it was parallel in both planes.

this morning, I will sand the tubes flush with the fuselage sides, and then this afternoon, I can set the incidence.