Scale Wendell Hostetler 30% Piper Cherokee Glass Fuselage Build.

[TonyHallo]

Can't wait!

 

[TonyHallo]

I read over on another site that a fellow had broke a thermistor while making up plug temp sensors. I have made them in the past with success but could very easy see how one could break the thermistor while cripping to 10 mm lug terminal end. While making up the 3 watt position lights, heat sinks and thermal paste were purchased. The specifications for Arctic MX6 thermal paste indicates is good for continuous use to 150C or 302 F. Rather than cripping the thermistor bulb in sung, I made a loose fit and filled the cavity with the thermal paste then covered the area with heat shrink tube. I think this are going to work great. The mass is very low and should respond quick to temperature changes.

My prop arrived from Falcon, once drilled I hope to test run the engine.

 

[dhal22]

Great stuff here Tony.

 

[AKNick]

I read over on another site that a fellow had broke a thermistor while making up plug temp sensors. I have made them in the past with success but could very easy see how one could break the thermistor while cripping to 10 mm lug terminal end. While making up the 3 watt position lights, heat sinks and thermal paste were purchased. The specifications for Arctic MX6 thermal paste indicates is good for continuous use to 150C or 302 F. Rather than cripping the thermistor bulb in sung, I made a loose fit and filled the cavity with the thermal paste then covered the area with heat shrink tube. I think this are going to work great. The mass is very low and should respond quick to temperature changes.

My prop arrived from Falcon, once drilled I hope to test run the engine.

View attachment 124397

That guy was probably me. I've had two fail, and lightly crimped. I was going to try thermal paste but it doesn't harden which had my concerns with vibration. I have some Dowsil 340 lying around which is good for about 400F, Your MX-6 is good for 300F Continuous use it looks like. I might have to put some under a controlled heat source to see how it responds to 380F

 

[TonyHallo]

Do your plug temps reach 380f? I have my alarms set at 300F.

 

[TonyHallo]

It ends up the prop shaft is long enough to accept a full nut of an elastic stop nut without the prop washer. I bored the 10 mm hole in the prop washer to 1/2" and turned a step on the stop to fit the hole. There's no need to enlarge the prop bore as I had previously planned. I made a few spare nits for the field box. Still need to turn a 17 mm socket down to fit in between the prop bolts.

 

[TonyHallo]

Got a run on the engine today, wish I would have done so yesterday, it was 60f. Today it's 24f! The starter works great on 4S. Today I added an and switch to the logic to turn the starter off above 1200 rpm, on a warm restart it's running in a few revolutions.

 

[dhal22]

Running good?

 

[TonyHallo]

The idle isn't where I want it yet. I have it mounted on a flimsy board so it shakes quite a bit. It's running on 15 to 1 fuel right now, after another tank I will reduce the oil to the recommended 20 to 1. There's quite a bit of smoke coming out the exhaust. The right cylinder hisses on compression, I thought it might be the temp sensor causing it but that's not the case so a valve must be leaking, I didn't do anything to the valves when the engine was apart other than check freeness. There wasn't much carbon build up on the valves .

 

[TonyHallo]

I have built a test stand out of 10 gage steel plate that accepts this engine and the Roto 85. This will get mounted to a movable work stand for the next run. Sunday and Monday are forecast in lower 50's, so plan to get a run then.