Scale RCM 1/3 Scale Champ Build

[TonyHallo]

I converted my first fixture over with tubes. When I found the Honeywell fixtures at Sam's club they were cheaper than my conversion so I pitched all my fixtures, I don't think those tubes will work in the current fixtures. Thank you for the info.
The icing has already started this morning.

 

[TonyHallo]

Added details to the cowl. Air cleaner. Used element from a B&S mower filter. I looked at many photos on Airliners.net and couldn't decide how to make the filter, finally Googled the replacement part and came up with this photo.

 

[TonyHallo]

Spent the better part of the day messing with telemetry. I want to measure three temperatures, each cylinder and the ignition module, According to the instructions the ignition shuts down at 140F, wonder who came up with that scheme? Every device I came across does 2 temperatures. I found that it is possible to change the channel on FrSky devices with a channel changer, just happen to have one that I used for changing the channel assignment on their 1 to 4 SBUS to PWM expanders. I ordered two RPM sensors that monitor brushless motor RPM and two temperatures. Changed the channel on one device to 15 from 5 but it still didn't work, after about 3 hours I discovered the Ignore Instances box on the telemetry page, checked that and everything worked. I have the temperature devices mounted on the second fin down from the head on the back side of the cylinders. Each are set to read the current temperature above 290F every 10 seconds. The ignition has two sensors set to read the temperature above 125f every 10 seconds and alarm at 132f.
Tomorrow I hope to do a weight and balance check and might just make to the back yard for a test run.

 

[TonyHallo]

Before painting the fuselage the weight 36 pounds and the CG was 6 5/8"back from leading edge. Weighted the finished plane today and it came in at 39.8 pounds and the CG is now 6 3/4" behind the leading edge, this results in a static margin of 6%, I'm good with it. Based on the weight an wing area the loading is 32.76 oz/SQFT, the cubic loading is 7.43 oz/CUBICFT and the stall speed comes in at 25.6 MPH. Time to test run the engine.

 

[Snoopy1]

Tony take a good look at this picture do you think you have your temperature probes in the correct location. From what I read I think you have them to high up on the cylinders

 

[TonyHallo]

Check it out

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I don't know, wonder what a reasonable cylinder head temp might be? Easy to change if need be. I emailed Roto and got no response some time ago.

 

[pawnshopmike]

Check it out

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I don't know, wonder what a reasonable cylinder head temp might be? Easy to change if need be. I emailed Roto and got no response some time ago.

SOUNDS GREAT!!

 

[Snoopy1]

Yes I do like the sound of that. Nice work.

 

[-Rick-]

Check it out

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I don't know, wonder what a reasonable cylinder head temp might be? Easy to change if need be. I emailed Roto and got no response some time ago.

That sounds so nice!!

 

[TonyHallo]

I do like it, I'm thinking I might just finish off that Super Cub with one. The plane was built using a 3W 56 CS engine, never ran, just might sell it and buy another Roto 85. Need to check the cowl size, the 3W fit in just fine.

Back to work on the Champ, enough of this playing around with engines. I built a box out of scrap 3/8" plywood to support the form for the windshield plug. I treated the mold with Pam cooking spray for release then filled with Plaster of Paris, man does that stuff setup quick! From what I read on the web they suggested filling the mold 1/4 at a time so that's what I attempted, messy stuff for sure, I made a foam filler to minimize the amount of plaster needed, this was just short of a 25# sack.