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DA 200

Andrew Bird

Andrew Bird

30cc
Nope - but I happened to take a pic the other day. I was out with my older plane (same plane and set up as the one in the pic) to do the prop tests yesterday though - weather wasn't as nice in that pic, lol! When I was looking at replacing my old car, I also looked at an RS4 but the sport seats are a different shape so I couldn't fit the plane in. It only goes to show the levels of insanity we all go through to make big toy planes fit in with our lives!
 
O

orthobird

150cc
some interesting telemetry data on my DA 200ML. I went back and compared the peak rpm from 1st few flights and the rpm at the last flight (10 gallons thru her now), and this is interesting:

first flight:

1. high temp during flight (not after landing):
RIGHT REAR CYLINDER 240.6 F Temp max during flight, average temp 216 F
LEFT REAR CYLINDER 213 F temp max during flight, average temp 190 F
RIGHT FRONT CYLINDER 278.2 F temp max during flight, average temp 250 F
LEFT FRONT CYLINDER 276.4 F temp max during flight, average temp 250 F



2. temp range (see 1 above)
3. rpm range 1900 to 6660
4. rpm max during flight 6660
5. rpm max on the ground 6060
6. Rx voltage 8.0
7. Rx voltage minimum during flight 8.0


the last flight (#29, after 10 gallons thru it)
1. high temp during flight (not after landing):
RIGHT REAR CYLINDER 240.6 F Temp max during flight, average temp 216 F
LEFT REAR CYLINDER 227.3 F temp max during flight, average temp 205 F
RIGHT FRONT CYLINDER 303.2 F temp max during flight, average temp 290 F
LEFT FRONT CYLINDER 297.3 F temp max during flight, average temp 268 F



2. temp range (see 1 above)
3. rpm range 1070 to 7320
4. rpm max during flight 7320
5. rpm max on the ground 6450
6. Rx voltage 7.8
7. Rx voltage minimum during flight 7.6




the max rpm on the ground went from 6060 to now, that it is broken in = 6450
the peak rpm during flight, went from 6660 to now =7320
also, she is idling lower.
there has been no change to the needles or to the prop size, or anything else. the only difference was ambient temp, 20 degrees warmer on the last flight.

think it is now time to get a bigger prop.
 
O

orthobird

150cc
also very interesting, compared to my da 150 L, the 200 will turn the Delro 3 blade prop to 6450 on the ground, and the 150 L will turn the same prop, on the ground, to 5500, with a slow spool up. almost 900 more rpm.
 
3D-Joy

3D-Joy

50cc
Interesting data.
It looks like you went quite easy on the first flight (as anybody should do) with voltages not even moving and peak RPMs not going up that much compared to peak ground RPM. Temps look fine to me but someone may have better data than my feeling on this.

But between your 150L and 200, 900 rpm difference seems like alot. I'd look for solutions to bring back to life your 150L. A couple hundred rpm difference would be inline but 900 seems like too much.
 
O

orthobird

150cc
Talking with a fellow hobbyist, whom is a real life pilot, and also has flown in full scale aerobatics, and now is into IMAC, he and i have made some possible reason as to why the rear cylinders are cooler than the front two.
The Shroud from Piorun is made so that in the front it is bigger/wider, than the rear aspect.
as a result of this, the space between cylinders and the shroud is way bigger in the front and much tighter in the back 2.
this has an effect of the air, in the front being in a higher pressure, and thus, less flow. towards the rear, the air pressure is lower, due to tighter area, and from the effect of the higher pressure in the front, this increases air flow to the back.
he tells me, that in real air cooled pistons airplanes, there is a baffling system or as he describes. plenum, in which the distance from baffles to cylinders is same in the front as the back. this creates an equal air pressure throughput, and thus, and equal air-flow. Cooling, in theory, should be the same. My question is, how many 4 cylinder quads out there, in model airplanes, have all 4 cylinders with the same temp???
i am guessing, probably none. My statement being, fly the airplane and listen to the sound of the motor. if it is running well, leave it alone!!
 

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O

orthobird

150cc
I got two flights in today.
I thought it would warm up to 55 F,
but stayed basically too cold!!!

so now, i have the data with the new Falcon 3 blade prop:
29 x 13

here is some data:
Delro prop 3 blade 28 x 12.5 and da 200 ML

rpm range 1070 to 7320
rpm max during flight 7320
rpm max on the ground 6450


with the falcon 3 blade 29 x 13

rpm range 1080 to 6600
rpm max during flight 6600
rpm max on the ground 5990


in the air, the max rpm dropped by 700 (from 7320 to 6600).

which i believe is in the recommended range by DA.
 
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