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Old Feb 26, 2013, 05:06 PM
Dean
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USA, CO, Littleton
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Originally Posted by simonslim View Post
Had the tacho on the Fox today, 7250rpm at WOT and very smooth with it.
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Excellent there Mate...
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Old Feb 26, 2013, 05:48 PM
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geordie land,uk
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Originally Posted by A10FLYR View Post
Excellent there Mate...
Thanks, I'm very happy with the set-up and I am really looking forward to getting the plane in the air.
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Old Mar 07, 2013, 02:07 AM
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With the weather looking unfavorable for the next few days I thought I would knock up a nose weight that could be swapped out for the motor should the need/slope dictate. I had some 25mm chrome tube which I filled with lead and fitted a piece of 8mm shaft to the front of it which fits into the extended motor shaft bearing support in the nose of the fuselage. The weight is fitted with a mounting bracket at the back so it will fasten to the motor bulk head.
The motor and 10s battery pack weighs 1740g/61.5oz.
The removable nose weight weighs 500g/17.5oz.
With the motor out and the lead weight in, I have to relocate the 4000mah flight pack to balance the plane, this is no hardship as I am not exactly pushed for room with this plane.
As the 10s lipo sits on the CG, I can use it as ballast if I feel the need for it when the motor is not fitted.
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Old Mar 07, 2013, 02:53 AM
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North Yorkshire UK, on a big hill facing the prevailing wind. Coincidence?
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Looks like a fun bit of engineering there Simon, although I'm not sure why you'd need to remove the motor rather than just the prop for slope flying, unless it's a concern that an inch of 8mm steel rod poking out the front of a 7kg+ plane could make a nasty hole in somebody?

Could I ask what size prop gave you the 1720W? This motor might be just right for something I'm working on, and better quality than a cheapo HK option that spits its magnets out on the third run.

Rog
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Old Mar 07, 2013, 03:10 AM
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Hi Roger, don't know how far it's true but I had heard that there are some UK slopes where you are not allowed to fly with a motor installed even if it is disabled/prop removed. As for the drive shaft, I think the 7kg+ would still leave a canny bruise whether the rod was there or not, doesn't bare thinking about really.

The prop I had on for the 1720w reading was a Graupner CAM 18x10, this was at 46amps which is below the 60amp stated in the spec sheet for 1700w. I checked it out on a buddies meter and his read 1735w at 48amps, but that was on a freshly charged lipo so it is well within it's "comfort zone". The only thing is I bought a 100amp HV esc when perhaps a 60 or 80amp may have been better as I have read that esc's work more efficiently running at the upper end of their rated amperage.
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Old Mar 07, 2013, 03:43 AM
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Thanks for those figures - that's useful to know. I don't know whether having an ESC with such an excessive current rating is such a bad thing, but certainly it's known that running an ESC at low throttle (current) settings makes the ESC work harder, get hotter and shortens component life. It's maybe counter-intuitive, but ESC's like full throttle best.

Rog
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Old Mar 07, 2013, 04:41 AM
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I believe that is true Rog, and is why people are misguided when they think they can use a too small ESC and then just not run at full throttle to protect it. If a motor/prop combo would "see" 60 amps at full throttle it will still be getting 60 amps at a part throttle but not for the full duty cycle (and so the "average" current seen on a meter would be lower). Clearly whether or not the ESC would actually fail would depend on a number of factors, but it's not good practice

I wasn't aware that an ESC could be "too big" though...

Once again, the above is just my opinion based on things I have read by more technically competent than me

Simon
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Old Mar 07, 2013, 10:34 AM
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And for that same reason I use a switch to power the motor and not the throttle stick. After years flying electric gliders I noticed that the only function the throttle stick had is to get the glider up which is most of the time done at full throttle anyway. Now I use the throttle stick for crow or spoilers depending on the flight mode.
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Old May 04, 2013, 03:58 PM
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Wey hey, FINALLY, I got the Fox maidened today at long last.

Model weighed 7.4kg and had the motor and 10s lipo fitted as I wanted to try it out under power once it had been trimmed out in glider mode.

With a 20mph-ish wind just slightly off the slope with not a cloud in the sky, I had a good gut feeling about heavenly lift and found it as soon as my mate launched her. As soon as it left his hand it was going up in good lift and once I leveled it off it needed just 2 clicks of right aileron trim and that was it sorted. I did a few beats back and forth along the slope just to get the feel of it then I took her out to put her through some basic aero's, rolls were totally axial and I did one or two BIG loops which were very impressive indeed.

Next step was to try the motor out, this proved to be very powerful and pulled the Fox up at 55-60 degrees or so with just a slight tendency to go nose up under power. I did three climb-outs of about 300ft which took about 15 seconds and when I fitted the lipos to my checker I was pleasantly surprised to see the capacity had only dropped by 10%, I'll get a more accurate figure tomorrow when I charge them.

Landing was a fairly straight forward affair, I flew it a decent way back at good height then back into the wind, dropped the nose a bit and extended the spoilers and landed her in a heather free patch about 30m x 30m that I picked out earlier.
I have to admit I do prefer crow/butterfly to spoilers but felt totally comfortable and in full control with just spoilers and a touch of up aileron.

All in all a very nice plane to fly and I'm looking forward to trying it out with motor/lipo [1.2kg] removed. I have a wee vid that my mate took, just waiting for him to upload it, just a couple of minutes of back and forth but it doesn't half look good.
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Old Jun 06, 2013, 07:41 AM
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I gave my Fox it's first outing at the field this morning. A nice 4-6mph breeze straight down the strip, just a touch of cloud cover and best of all I was by myself.
For the take-off runs, I gave it full throttle and kept it on the dolly for about 30m before pulling up just to make sure it had more than enough airspeed when it rotated. Once airborne it just accelerates and climbs out at about 45-55 degrees and kept going until I closed the throttle at 300ft or so. On the first flight I did 5 climb-outs then landed, which was a fairly fast affair, taking about 50m to come to a halt. The next two flights were just a single powered climb to height, few circuits and landing.
According to my lipo checker I used 45% of the available 4000mah capacity, I'll get a more accurate reading from my charger once charged.
All in all, I'm more than happy with the set-up but I do prefer flying it off the slope

1507mahs put back in during charge.
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Old Jun 24, 2013, 03:53 PM
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Reichard Fox Long Nose Pinocchio 3.5m

For all of you Fox lovers and those interested on her, please check this:

http://www.rcgroups.com/forums/showt...t=reichard+fox

Best deal in town..!!

Alberto
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