CRRC Pro GF26I

[ken crane]

ok sky cleared enough today to do some numbers. the 50 with a 22x6 was 8000. way to flat of a pitch to make the plane fly well. might be a good 3d prop but not anything else. just the taxi out the tips sounded like the string on a weed whacker. flew slow and when you drop the hammer it just made a lot of noise. landings sucked as it was like someone threw out an anchor. ground clearance sucked as well. i am going to try a 20/10 and this should be in the ball park. 20/8 was a good flier but turned too many rpm.

[2robinhood]

OK, flew again tonight.
My CRRC Pro GF26I keeps getting better with every tank.
New rpm numbers, some level flight mph, and digital scale pulls.

SY 16 X 8
Top end @ 8900 rpm ( that up 150 rpm from last flying day )
Average MPH of left and right passes is 82 mph.
Pull in pounds on a digital fish scale is 13 lbs.4 oz.

APC 17 X 6
Top end @ 9450 rpm ( up 50 rpm from last flying day )
Average MPH of left and right passes is 83 mph.
Pull in pounds on a digital fish scale is 13 lbs. 13 oz.

Verticle is a tick better with the APC, but knife edge is better with the SY.

Just remember, these are two different size props.
I wish I had a APC 16 X 8 to test head to head against the SY.
Also as a comparison, I had the OS Max 1.60FX on this same plane with a Master Airscrew 18 X 6 and it was pulling 97mph in level passes.

I like the SY and am keeping it on my 26.

[ken crane]

	Quote: Originally Posted by 2robinhood
	OK, flew again tonight. My CRRC Pro GF26I keeps getting better with every tank. New rpm numbers, some level flight mph, and digital scale pulls. SY 16 X 8 Top end @ 8900 rpm ( that up 150 rpm from last flying day ) Average MPH of left and right passes is 82 mph. Pull in pounds on a digital fish scale is 13 lbs.4 oz. APC 17 X 6 Top end @ 9450 rpm ( up 50 rpm from last flying day ) Average MPH of left and right passes is 83 mph. Pull in pounds on a digital fish scale is 13 lbs. 13 oz. Verticle is a tick better with the APC, but knife edge is better with the SY. Just remember, these are two different size props. I wish I had a APC 16 X 8 to test head to head against the SY. Also as a comparison, I had the OS Max 1.60FX on this same plane with a Master Airscrew 18 X 6 and it was pulling 97mph in level passes. I like the SY and am keeping it on my 26.

i dont want to steal your thunder but i as well flew today after work. 1/2 gallon 6 flights and the 50 gets better and better. idles like a sewing machine. i aquired a new in box wagstaff and it requires a 50 cc. take one guess what motor i am putting in it? funny thing is i havent even wanted to maiden my laser as i am having too much fun with the extra...

[2robinhood]

You gotta run those other props to see how it compares to a DA / DL 50cc.

Actuall I just picked up a CRRC 50, I'll do some testing when it comes also.

[rcign]

REALLY good numbers...Gotta wonder how you're clocking the speed...We fly Giant Scale racers...Our very close speed@rpm numbers are rpm x pitch x .00095 = speed in mph...We usually deduct 2 or 3% for drag, depends on the airframe...
Our Giant Scale unlimited planes turn a 27 pitch prop at 9400 rpm...9400 x 27 x .00095 = 241 mph. Mulitple Radar guns show 234 mph, so the drag % is about 3%...
The Sundowners run a 17 x 12 prop about 8500 rpm...12 x 8500 x .00095 = 96 mph, pretty close to the radar speed.....
A 6 pitch prop at 10,000 would be 57 mph...An 8 pitch @ 10000 is 78.4....
The GT80 twins turn a n18 pitch prop at 11,500....18 x 11,500 x .00095 is 196 mph, radar about 190....
The ThrustHP chart shows 51 mph for a 6 pitch at 9000 rpm....
That chart pretty much agrees with the above numbers....
Looks like the OS 1.60 using my numbers was turning the 18-6 about 17,000.. A Secret weapon..My Chung Yang 29 strokers and Zenoah G26s turn a 16-8 Mejlik about 9800...I wonder how fast that would be ?????

[2robinhood]

Those mph numbers are taken with a Bushnell radar gun.
We checked the gun against a police radar gun and came up with the same mph, so the gun seems to be accurate.

The mph speeds shown with the 26cc were 6 up wind speeds of 79 mph and 6 down wind speeds of 91 mph.
Split the differance it is about 85 mph, I went conservitive and said 82 mph.

The best out of a dive, down wind run I got was 116 mph ( just for giggles )

By the way plane is a Seagull Laser 200 ( 11 lbs. 2 oz. ) since you were talking about drag issues.

[3Dguy]

Is this thing as powerful as a 50cc? Cause those numbers are really good.

[2robinhood]

	Quote: Originally Posted by 3Dguy
	Is this thing as powerful as a 50cc? Cause those numbers are really good.

Need to becareful, a few post by Ken Crane are of the new CRRC Pro GF50I ( 50cc ).
But most are of the 26cc.

[ken crane]

	Quote: Originally Posted by 2robinhood
	Need to becareful, a few post by Ken Crane are of the new CRRC Pro GF50I ( 50cc ). But most are of the 26cc.

i am sorry i didnt mean to hijack the thread should i start a 50 cc thread ? i didnt want to clutter the threads.

[2robinhood]

Here are some videos og the CRRC GF26I.
First videos is just a look.
Second video is numbers with an APC 17 X 6 prop..
Third video is an SY 16 X 8 prop.
In the third video, I could not believe how much putting the cowl on the plane affected the flight performance.
It was still OK, but with no cowling , it is an animal and has fast, unlimited verticle. With the cowl verticle was still good but it sure wasn't fast.
I had trouble downloading the videos without the cowl, so when I take more I will post them.
Needless to say, the cowl looks good, but I think I'll keep it off.
By the way, in the third video, some goof ball forgot to turn on the Opto kill switch on the TX.

[3Dguy]

Thanks for clearing that up.

2robin, that cowl is a parachute, but I guess it does a good job of cooling the engine!

This engine is really tempting. I wish I had heard of it before I got my BCMA-SPE 26. It's a light, good-running engine, but it lacks power. The CRRC will have to wait.

[krayzc]

kewl i have to check the vids out