DerJet Cougar in the UK
02-03-2010, 01:13 PM
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RE: DerJet Cougar in the UK
Ali. . .
One, I am distressed I could not make the DR. . .Vertigo prevented me from jumping on Blue to Santiago. . .
Two. . .I probably have more experience with the DJM Cougar here in the US than other dealers around the globe. Mine now has over 20 flights, with minimal issues to sort out. Raul flew it while he was here visiting and pronounced it perfect. . .except the CG. He wanted it moved aft about 1/2 inch. Shui is playing with the CG and different control throws to get it just the way he likes it. . .
It does have very nice flight characteristics. One owner /pilot reports, the approach pitch sensitivity after burning off fuel is eliminated with body flaps down. Each pilot has their own idea's of what works or does not work for their flying style.
Measured weight out of the box is a tad over 23lbs while sitting on its wheels (sans fuel) it is just over 33lbs. Certainly not hateful. . .would you agree ?
Tell you what; I look forward to you flying my Cougar at FJ and to have the meeting we both looked forward to while in the DR. Deal ?
See you at FJ
Sincerely,
Eric
One, I am distressed I could not make the DR. . .Vertigo prevented me from jumping on Blue to Santiago. . .
Two. . .I probably have more experience with the DJM Cougar here in the US than other dealers around the globe. Mine now has over 20 flights, with minimal issues to sort out. Raul flew it while he was here visiting and pronounced it perfect. . .except the CG. He wanted it moved aft about 1/2 inch. Shui is playing with the CG and different control throws to get it just the way he likes it. . .
It does have very nice flight characteristics. One owner /pilot reports, the approach pitch sensitivity after burning off fuel is eliminated with body flaps down. Each pilot has their own idea's of what works or does not work for their flying style.
Measured weight out of the box is a tad over 23lbs while sitting on its wheels (sans fuel) it is just over 33lbs. Certainly not hateful. . .would you agree ?
Tell you what; I look forward to you flying my Cougar at FJ and to have the meeting we both looked forward to while in the DR. Deal ?
See you at FJ
Sincerely,
Eric
02-04-2010, 10:10 PM
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RE: DerJet Cougar in the UK
I would like to clarify some of the data.
My Cougar came it at just a tad under 34 pounds with redundant batteries, all scale accessories operable and the cockpit/pilot. A weight of 33 pounds is not out of the question with a smaller engine and a few other tweaks if the plane is built completely stock.
On the other hand, Eric's plane tipped the scales just short of 38 pounds, so it is possible to end up with a heavier aircraft. When we did the math on his plane using the scales, the CG computed at .6 ahead of the manual recommendation. I don't know if he ever moved it back, but if not, it would explain the comment that his plane might be 1/2 inch ahead of an ideal CG. I have talked to Shui, and it appeared he had moved the CG about 1/2 inch aft of mine, but the last time we talked, he was thinking about moving it forward a bit again. Not sure where he ended up, though. The CG in the manual is a conservative figure ... I would start there and move it back incrementally until you are happy with the presentation. If you are an experienced pilot, you might start out at 1/4 inch behind the aft edge of the wing spar.
It is not a glider, but it does slow down nicely and lands well with a little power. I would recommend expo on the elevator.
My Cougar came it at just a tad under 34 pounds with redundant batteries, all scale accessories operable and the cockpit/pilot. A weight of 33 pounds is not out of the question with a smaller engine and a few other tweaks if the plane is built completely stock.
On the other hand, Eric's plane tipped the scales just short of 38 pounds, so it is possible to end up with a heavier aircraft. When we did the math on his plane using the scales, the CG computed at .6 ahead of the manual recommendation. I don't know if he ever moved it back, but if not, it would explain the comment that his plane might be 1/2 inch ahead of an ideal CG. I have talked to Shui, and it appeared he had moved the CG about 1/2 inch aft of mine, but the last time we talked, he was thinking about moving it forward a bit again. Not sure where he ended up, though. The CG in the manual is a conservative figure ... I would start there and move it back incrementally until you are happy with the presentation. If you are an experienced pilot, you might start out at 1/4 inch behind the aft edge of the wing spar.
It is not a glider, but it does slow down nicely and lands well with a little power. I would recommend expo on the elevator.
02-05-2010, 02:03 AM
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RE: DerJet Cougar in the UK
Thank for the CG infos Keith, they will be very useful for my maiden.
By the way, did you try the stall behaviour? Is it predictable or not?
By the way, did you try the stall behaviour? Is it predictable or not?
02-05-2010, 03:40 AM
#34
Thread Starter
RE: DerJet Cougar in the UK
One I don't want to be accused of selling on RCU, you get your knuckles wrapped! and prices change with the exchange rate and people go back to the interweb and quote prices, the US Dollar has lost 4 cents in the £ in the last 3 days, who knows where it will be next week! I'm sure you can email me if you want a price...
02-05-2010, 03:38 PM
#37
Thread Starter
RE: DerJet Cougar in the UK
As anyone who has looked at the main Cougar thread will know this kit comes complete. Other than the airframe which is well finished, better than others I'm told by recent customers of these. The Undercarriage is complete, four airtanks, four valves (retracts, gear doors, sliding canopy and hook) plenty of tubing, nice air rams, ball raced ballinks on pushrods, glass board control horns, scale cockpit and in UK kits we will include pilots (cause they are all going to need one!) Anyone wanting a run down please feel free to contact me.
Dave Wilshere
Dave Wilshere
02-05-2010, 05:28 PM
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RE: DerJet Cougar in the UK
ORIGINAL: thunderceptor
Thank for the CG infos Keith, they will be very useful for my maiden.
By the way, did you try the stall behaviour? Is it predictable or not?
Thank for the CG infos Keith, they will be very useful for my maiden.
By the way, did you try the stall behaviour? Is it predictable or not?
We have flown the jet to very low speeds in a dirty configuration without incident. A light stall will produce a high sink rate, a deep stall will result in a roll. Nothing unusual so far, though I will admit the total hours of flight time are limited to this point.
02-06-2010, 04:23 PM
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RE: DerJet Cougar in the UK
Clarification of data - Re- Clarified !
Pilot28 (Kieth Sievers) wrote:
On the other hand, Eric's plane tipped the scales just short of 38 pounds, so it is possible to end up with a heavier aircraft. When we did the math on his plane using the scales, the CG computed at .6 ahead of the manual recommendation. I don't know if he ever moved it back, but if not, it would explain the comment that his plane might be 1/2 inch ahead of an ideal CG. I have talked to Shui, and it appeared he had moved the CG about 1/2 inch aft of mine, but the last time we talked, he was thinking about moving it forward a bit again. Not sure where he ended up, though. The CG in the manual is a conservative figure ... I would start there and move it back incrementally until you are happy with the presentation. If you are an experienced pilot, you might start out at 1/4 inch behind the aft edge of the wing spar.
02/06/10
OK, readers. . .let's get this back on the "accuracy table." Today, using a very expensive Digital scale made by AMPROBE (specifically model ADS-1) Eric's (my personal #386) weighed in as follows:
Left wing: 2.12.3 lbs
Right wing: 2.12.4 lbs JR 8711 on flaps and 8611A on ailerons using factory hdware
Nose cone: .7.7.0
Fuse*: 28.11.0 Jet Central Super Eagle with 2 Duralite 2s2p 7.4v LiIon batteries
Total : 33.05 lbs Exactly where we project the all up weight to be RTF w/o fuel
*UAT full of fuel (4oz) and estimated 1" fuel in the main tank
We also weighed two kits in inventory and respectively totalled: 23.14 and 23.12 ! Indeed, excellent quality control. This is parts content as removed from the box.
Balance on my #386 is right at the rear edge of the front carbon spar. . .has been there from day one. My #386 has been flown by Bevar, Raul Lozano our Jet Central Team pilot from Spain and myself. It has been suggested the CG be moved aft by 1/2 inch. Every pilot has his own preferences as to CG and handling. We will experiment with the CG further and post our findings here on RCU however, the CG as noted in the manual is a perfect starting point.
I hope the above information will be informative for prospective builders around the world. DerJet now has 4 great dealers to serve their respective market places. I look forward to meeting all those who attend Florida Jets 2010. Look for the DerJet display. . .and yes, we will have kits for sale !
I look forward to any and all questions readers might have.
Sincerely,
Eric Clapp
Der Jet USA
Jet Central Turbines
Pilot28 (Kieth Sievers) wrote:
On the other hand, Eric's plane tipped the scales just short of 38 pounds, so it is possible to end up with a heavier aircraft. When we did the math on his plane using the scales, the CG computed at .6 ahead of the manual recommendation. I don't know if he ever moved it back, but if not, it would explain the comment that his plane might be 1/2 inch ahead of an ideal CG. I have talked to Shui, and it appeared he had moved the CG about 1/2 inch aft of mine, but the last time we talked, he was thinking about moving it forward a bit again. Not sure where he ended up, though. The CG in the manual is a conservative figure ... I would start there and move it back incrementally until you are happy with the presentation. If you are an experienced pilot, you might start out at 1/4 inch behind the aft edge of the wing spar.
02/06/10
OK, readers. . .let's get this back on the "accuracy table." Today, using a very expensive Digital scale made by AMPROBE (specifically model ADS-1) Eric's (my personal #386) weighed in as follows:
Left wing: 2.12.3 lbs
Right wing: 2.12.4 lbs JR 8711 on flaps and 8611A on ailerons using factory hdware
Nose cone: .7.7.0
Fuse*: 28.11.0 Jet Central Super Eagle with 2 Duralite 2s2p 7.4v LiIon batteries
Total : 33.05 lbs Exactly where we project the all up weight to be RTF w/o fuel
*UAT full of fuel (4oz) and estimated 1" fuel in the main tank
We also weighed two kits in inventory and respectively totalled: 23.14 and 23.12 ! Indeed, excellent quality control. This is parts content as removed from the box.
Balance on my #386 is right at the rear edge of the front carbon spar. . .has been there from day one. My #386 has been flown by Bevar, Raul Lozano our Jet Central Team pilot from Spain and myself. It has been suggested the CG be moved aft by 1/2 inch. Every pilot has his own preferences as to CG and handling. We will experiment with the CG further and post our findings here on RCU however, the CG as noted in the manual is a perfect starting point.
I hope the above information will be informative for prospective builders around the world. DerJet now has 4 great dealers to serve their respective market places. I look forward to meeting all those who attend Florida Jets 2010. Look for the DerJet display. . .and yes, we will have kits for sale !
I look forward to any and all questions readers might have.
Sincerely,
Eric Clapp
Der Jet USA
Jet Central Turbines
02-06-2010, 04:57 PM
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RE: DerJet Cougar in the UK
Probably should have posted like this:
Left Wing: 2.12 lb
Right Wing: 2.12
Nose cone: .7
Fuse: 28.11
Total: 33.05
Hope this helps. . .thanks !
Eric
Left Wing: 2.12 lb
Right Wing: 2.12
Nose cone: .7
Fuse: 28.11
Total: 33.05
Hope this helps. . .thanks !
Eric
02-06-2010, 05:41 PM
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RE: DerJet Cougar in the UK
John:
Thanks for the compliment. . .I will have kits at FJ10. . .will you be there ? If not, pick your color and let me send it to your door. P-120 is perfect for you Purple guys !
Eric
[email protected] for email direct to Eric
Thanks for the compliment. . .I will have kits at FJ10. . .will you be there ? If not, pick your color and let me send it to your door. P-120 is perfect for you Purple guys !
Eric
[email protected] for email direct to Eric
02-06-2010, 07:38 PM
#44
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RE: DerJet Cougar in the UK
Excellent Eric,
I want the blue nose version #386. I will not be at FJ10 this year. Between baseball, getting the daughter ready to go to college, and paying the bills, I am staying at home. Enjoy the warm weather for me.
PM sent.
I want the blue nose version #386. I will not be at FJ10 this year. Between baseball, getting the daughter ready to go to college, and paying the bills, I am staying at home. Enjoy the warm weather for me.
PM sent.
02-06-2010, 11:02 PM
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RE: DerJet Cougar in the UK
ORIGINAL: BluFox
Clarification of data - Re- Clarified !
Pilot28 (Kieth Sievers) wrote:
On the other hand, Eric's plane tipped the scales just short of 38 pounds, so it is possible to end up with a heavier aircraft. When we did the math on his plane using the scales, the CG computed at .6 ahead of the manual recommendation. I don't know if he ever moved it back, but if not, it would explain the comment that his plane might be 1/2 inch ahead of an ideal CG. I have talked to Shui, and it appeared he had moved the CG about 1/2 inch aft of mine, but the last time we talked, he was thinking about moving it forward a bit again. Not sure where he ended up, though. The CG in the manual is a conservative figure ... I would start there and move it back incrementally until you are happy with the presentation. If you are an experienced pilot, you might start out at 1/4 inch behind the aft edge of the wing spar.
02/06/10
OK, readers. . .let's get this back on the ''accuracy table.'' Today, using a very expensive Digital scale made by AMPROBE (specifically model ADS-1) Eric's (my personal #386) weighed in as follows:
Left wing: 2.12.3 lbs
Right wing: 2.12.4 lbs JR 8711 on flaps and 8611A on ailerons using factory hdware
Nose cone: .7.7.0
Fuse*: 28.11.0 Jet Central Super Eagle with 2 Duralite 2s2p 7.4v LiIon batteries
Total : 33.05 lbs Exactly where we project the all up weight to be RTF w/o fuel
*UAT full of fuel (4oz) and estimated 1'' fuel in the main tank
We also weighed two kits in inventory and respectively totalled: 23.14 and 23.12 ! Indeed, excellent quality control. This is parts content as removed from the box.
Balance on my #386 is right at the rear edge of the front carbon spar. . .has been there from day one. My #386 has been flown by Bevar, Raul Lozano our Jet Central Team pilot from Spain and myself. It has been suggested the CG be moved aft by 1/2 inch. Every pilot has his own preferences as to CG and handling. We will experiment with the CG further and post our findings here on RCU however, the CG as noted in the manual is a perfect starting point.
I hope the above information will be informative for prospective builders around the world. DerJet now has 4 great dealers to serve their respective market places. I look forward to meeting all those who attend Florida Jets 2010. Look for the DerJet display. . .and yes, we will have kits for sale !
I look forward to any and all questions readers might have.
Sincerely,
Eric Clapp
Der Jet USA
Jet Central Turbines
Clarification of data - Re- Clarified !
Pilot28 (Kieth Sievers) wrote:
On the other hand, Eric's plane tipped the scales just short of 38 pounds, so it is possible to end up with a heavier aircraft. When we did the math on his plane using the scales, the CG computed at .6 ahead of the manual recommendation. I don't know if he ever moved it back, but if not, it would explain the comment that his plane might be 1/2 inch ahead of an ideal CG. I have talked to Shui, and it appeared he had moved the CG about 1/2 inch aft of mine, but the last time we talked, he was thinking about moving it forward a bit again. Not sure where he ended up, though. The CG in the manual is a conservative figure ... I would start there and move it back incrementally until you are happy with the presentation. If you are an experienced pilot, you might start out at 1/4 inch behind the aft edge of the wing spar.
02/06/10
OK, readers. . .let's get this back on the ''accuracy table.'' Today, using a very expensive Digital scale made by AMPROBE (specifically model ADS-1) Eric's (my personal #386) weighed in as follows:
Left wing: 2.12.3 lbs
Right wing: 2.12.4 lbs JR 8711 on flaps and 8611A on ailerons using factory hdware
Nose cone: .7.7.0
Fuse*: 28.11.0 Jet Central Super Eagle with 2 Duralite 2s2p 7.4v LiIon batteries
Total : 33.05 lbs Exactly where we project the all up weight to be RTF w/o fuel
*UAT full of fuel (4oz) and estimated 1'' fuel in the main tank
We also weighed two kits in inventory and respectively totalled: 23.14 and 23.12 ! Indeed, excellent quality control. This is parts content as removed from the box.
Balance on my #386 is right at the rear edge of the front carbon spar. . .has been there from day one. My #386 has been flown by Bevar, Raul Lozano our Jet Central Team pilot from Spain and myself. It has been suggested the CG be moved aft by 1/2 inch. Every pilot has his own preferences as to CG and handling. We will experiment with the CG further and post our findings here on RCU however, the CG as noted in the manual is a perfect starting point.
I hope the above information will be informative for prospective builders around the world. DerJet now has 4 great dealers to serve their respective market places. I look forward to meeting all those who attend Florida Jets 2010. Look for the DerJet display. . .and yes, we will have kits for sale !
I look forward to any and all questions readers might have.
Sincerely,
Eric Clapp
Der Jet USA
Jet Central Turbines
Ultimately, it doesn't really matter what your plane weighs ... the point of the post was to say that 33 pounds is possible if you are conscientious in not adding extra weight during the construction process. I think over time, as various people build and report out on weights, there will be a better sense of the typical number that folks are seeing. I am guessing now that it will be in the mid 30 range, which is not overly heavy for a scale plane of its size and with all the scale options available.
I did note tonight I am getting some separation of the live hinge from the horizontal stab at the outboard ends of the elevators, so those of you flying the Cougar now may want to keep an eye on this area and re-glue if you notice a problem.
Thanks, K.
02-07-2010, 12:56 PM
#48
Thread Starter
RE: DerJet Cougar in the UK
Ian
Sorry! Yep it has those too
It's a great scale aeroplane, one well respected pilot is thinking about one as a JWM qualifier aircraft. Until I fly one I can't comment with absolute knowledge, but I don't expect anything other than a nice flying scale aeroplane. You cannot say an aeroplane is heavy (and possibly hint at poor flight performance) until you have flown one...I tried to pick up Steve Elias's Ultra Bandit today, then I checked it was not nailed to the runway! It wasn't and it flies great. My tiny wing AW 1/7th L-39 is a brick at 27lb when I built it I still remember Trevor Skedge's face when he picked it up full of fuel...nicest flying aeroplane you could imagine.
Dave W
Sorry! Yep it has those too
It's a great scale aeroplane, one well respected pilot is thinking about one as a JWM qualifier aircraft. Until I fly one I can't comment with absolute knowledge, but I don't expect anything other than a nice flying scale aeroplane. You cannot say an aeroplane is heavy (and possibly hint at poor flight performance) until you have flown one...I tried to pick up Steve Elias's Ultra Bandit today, then I checked it was not nailed to the runway! It wasn't and it flies great. My tiny wing AW 1/7th L-39 is a brick at 27lb when I built it I still remember Trevor Skedge's face when he picked it up full of fuel...nicest flying aeroplane you could imagine.
Dave W
02-13-2010, 04:13 AM
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RE: DerJet Cougar in the UK
Today I weighted my model, the meter measured 13 kg (29 pounds), CG is in the correct point as Eric suggested.
Model is almost finished minus EV5U valve an other minor stuffs, and I think it'll reach 30 pounds complete, definitely not heavy, as it's almost the same as my AD F-100D.
Maybe my weight meter is not so accurate as Eric's one, but I think this value is correct for this model's size.
Bigger models like AW Cougar sure have lighter wing loading, as I noticed the bigger is the model, the lighter is the wing loading
.
Best Regards
Model is almost finished minus EV5U valve an other minor stuffs, and I think it'll reach 30 pounds complete, definitely not heavy, as it's almost the same as my AD F-100D.
Maybe my weight meter is not so accurate as Eric's one, but I think this value is correct for this model's size.
Bigger models like AW Cougar sure have lighter wing loading, as I noticed the bigger is the model, the lighter is the wing loading
.Best Regards