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CARF REBEL 2m

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CARF REBEL 2m

Old 03-14-2024, 12:35 PM
  #851  
bluelevel
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Originally Posted by Dave Wilshere
The large tail is not balance critical, but if you balance it my method/ position with batteries, I think you will have a nice starting point.
That's the way I did it and was quite baffled that it didn't want to rotate. Your CG check is supposed to be done for turbine powered planes with just landing fuel on board, I did it with take-off weight.

Originally Posted by Dave Wilshere
The reason you can’t rotate is part EDF suck...
There's not a whole lot I can do to reduce the amount of air entering the nose gear opening but cut additional openings in the top hatch. As you can see in my earlier postings, I cut 8 "gills" in the top hatch but there's room for 2 or 3 more per side. I have already laminated some carbon to the inside of the hatch so opening it up even more is not a problem.

Originally Posted by Dave Wilshere
...but really just Electron nose oleo spring being too soft. I got fed up with modifying them for customers (Diablo too) so we are working with Electron for stronger springs.
TBH the Electron nose leg is a bit short for the Rebel, a 5mm spacer would make a huge difference, but what you need to do is fill the spring + 15-20mm extra of 3/32 Tygon. Sit the spring in the plunger, push a length of Tygon through till it hits the bottom of the plunger, with the spring uncompressed cut the Tygon flush with the top. Reassemble and go fly.
That's good advice. I can fabricate some wooden packers 5-6mm strong and put them between the nose retract and the mounting rails. Also stiffening the nose oleo spring sounds like a good idea as it was compressing way too much when I accelerated.

Last edited by bluelevel; 03-14-2024 at 12:37 PM.
Old 03-14-2024, 01:56 PM
  #852  
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Originally Posted by bluelevel
That's the way I did it and was quite baffled that it didn't want to rotate. Your CG check is supposed to be done for turbine powered planes with just landing fuel on board, I did it with take-off weight.



There's not a whole lot I can do to reduce the amount of air entering the nose gear opening but cut additional openings in the top hatch. As you can see in my earlier postings, I cut 8 "gills" in the top hatch but there's room for 2 or 3 more per side. I have already laminated some carbon to the inside of the hatch so opening it up even more is not a problem.



That's good advice. I can fabricate some wooden packers 5-6mm strong and put them between the nose retract and the mounting rails. Also stiffening the nose oleo spring sounds like a good idea as it was compressing way too much when I accelerated.

Leave the inlet set up. Do the nose leg and packer and it will be away
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DenisFerrari (03-24-2024)
Old 03-23-2024, 06:08 AM
  #853  
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RC Rich (03-27-2024)
Old 03-27-2024, 05:27 PM
  #854  
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Just wanted to post an update on my previously reported take off rotation problem. Also wanted to give huge a shout-out to Electron. Parallel to posting here I contacted Electron to report my issue and ask them for advice. My email was answered quickly and Adrian suggested to try a stiffer front spring and increase the front height by using a 70mm dia tire instead of the stock 60mm one. I received all promised parts in the mail free of charge, that's what I call awesome customer service!

I had already made 5mm packers to raise the front, the bigger front tire will be installed as well in case that I need a few more millimeters of height. The new spring feels fine as well.

No flying weather right now, I'll report back here as soon as I was able to test the changes.
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RC Rich (03-27-2024)
Old 04-07-2024, 01:20 PM
  #855  
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OK guys, seems as if I got my take off rotation problem sorted. As stated in an earlier post, I started with a stock version of the Electron ER-40 retracts and could not get the plane off the ground. The thick golf course like turf at our field doesn't help and coming from turbines I also learned that EDFs simply do not deliver the same thrust at take-off speed. In a first attempt I added 6mm packers under the nose retract to improve the angle of attack and put a thick 4mm spacer in the nose oleo to increase the pre-tension of the spring. That helped a bit, but I was only able to get the plane off the ground by jerking back the elevator stick completely. The take off roll looked as if I were a complete beginner and the plane was close to stalling.

Today I test flew the bigger front tire (70mm instead of 60mm) and I have also installed the firmer red spring I received from Electron. I started with the CG location as per Dave's recommendation but moved it way back. The small Rebel still needs a firm pull to get it off the ground but I can live with that. Flew 4 battery sets today to dial in the throws, expo & gyro gains and I moved back the CG 2 times (it is now about 3cm aft of the spar behind the wing tube).

Comparing the smaller 2m Rebel to my bigger Rebel Max there are still worlds between those 2 planes, but of course it's a bit unfair to expect that the Classic flies as nice as its bigger brother. All in all I am happy with the plane now. Still not a huge fan of EDFs but our field doesn't allow turbines on weekends, so what can you do...

Last edited by bluelevel; 04-07-2024 at 01:31 PM.
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grolleman (04-21-2024)
Old 04-21-2024, 12:48 AM
  #856  
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I haven't been able to fly yet, but I will adjust it as well, our field is not very long.
What size spring is it exactly?
Old 04-21-2024, 12:48 AM
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Old 04-21-2024, 03:37 AM
  #858  
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Originally Posted by grolleman
I haven't been able to fly yet, but I will adjust it as well, our field is not very long.
What size spring is it exactly?
As I said in my post, I am using the red (harder) spring instead of the stock (blue) one. Just ask Electron and they'll know exactly what you need.

But as I said in my previous post the spring swap wasn't the only thing I did. I also replaced the original 60mm tire with a 70mm dia and I added about 5mm of packers under the nose retract. This elevated the nose 10mm.

Last edited by bluelevel; 04-21-2024 at 02:52 PM.
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Old 05-04-2024, 01:07 PM
  #859  
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Can someone provide some input regarding if a King Tech 102 would have sufficient power to fly this plane from a grass runway?

Thanks
Old 05-04-2024, 02:22 PM
  #860  
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How long is the strip? If it is 400’ + it will fly, but really 120N+ is ideal
Old 05-04-2024, 03:00 PM
  #861  
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Thanks for the reply, strip is 1100 ft. but I think i may be better off with a 120 due to the grass is pretty thick and sometimes long
Old 05-06-2024, 01:28 AM
  #862  
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Hi Guys.
A question about the JP retract controller.
I connected the JP controller power line directly to a 2S Lipo and it will sucks it empty, if I connect it for some weeks together.
The hope was, that it only takes energy, if the RX is on. But it sucks energy every day....

Do you have a separate switch in the power line between the Lipo and the JP controller?

Thanks for your answer.

Holger
Old 05-06-2024, 02:25 AM
  #863  
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Originally Posted by Power_Edge
Hi Guys.
A question about the JP retract controller.
I connected the JP controller power line directly to a 2S Lipo and it will sucks it empty, if I connect it for some weeks together.
The hope was, that it only takes energy, if the RX is on. But it sucks energy every day....

Do you have a separate switch in the power line between the Lipo and the JP controller?

Thanks for your answer.

Holger
Pretty much all controller take a little power all the time, just unplug between flying session 🤷🏻‍♂️
Old 05-06-2024, 08:24 AM
  #864  
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Originally Posted by Dansy
Pretty much all controller take a little power all the time, just unplug between flying session 🤷🏻‍♂️
What he said. I have Electrons in multiple planes and as a matter of procedure I unplug the controller and the power safe receivers at the end of the day, or the weekend in the case of events.
Old 05-24-2024, 05:58 AM
  #865  
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My setup for the Rebel:
K142G4, 2 smoke tanks, powerbox sr2, 2 RX Futaba 7008 and 7108, 2 batteries Jeti lion 5200 for RX, Life 3S 3000 for engine, ER40 Electron rétracts landing gear and LGC15 controler. A lot off parts Asa and PC 3D printed.
11Kg with full uat . CG on the rear side of the wings tube. It flies perfectly














Last edited by looping-74; 05-25-2024 at 04:01 AM.
Old 05-24-2024, 10:34 AM
  #866  
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How heavy?
Old 05-24-2024, 10:49 AM
  #867  
looping-74
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Originally Posted by Dave Wilshere
How heavy?
Weight is 11 Kg




Last edited by looping-74; 05-24-2024 at 10:53 AM.
Old 05-24-2024, 12:50 PM
  #868  
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Makes sense, 600g heavier than our standard installation.

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