Rebel Hot by Comp Arf
12-14-2019, 03:18 AM
#251
Join Date: Oct 2002
Location: Leeds, UNITED KINGDOM
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I just ordered my Rebel hot a couple of weeks ago through Dave. I plan to use my X45 in it. One of our friends here in the North of England bought one of the original Pirroti models. He as a Kingtech 45 in it and it flies beautifully. Its quick enough IMO for a small model and the wing loading is light so it lands and handles superbly. I think it will be even lighter with the X45 in it.
John
John
12-14-2019, 08:13 AM
#252
Different strokes. My first turbine had about a .7:1 thrust ratio. Fun, sure. But not exciting. My second turbine has approximately 1:1 thrust ratio and does 180 straight n level. Exciting? Sure. But not exhilarating. My rebel will have at least 1.2:1 at take off and is a much cleaner airframe than anything else I own. I hope it's exhilarating!
12-14-2019, 08:17 AM
#253
The back of the tank is exactly on the CG point. Ive not seen too many jets with the tank over the CG. I usually CG jets with an amount of fuel in the tank that I expect to have still in it when I land. I usually land with around 1/3 of a tank in my other jets. This one, being so over-powered, I expect to land with a little under 1/4 tank, so I will CG it with a quarter tank.
I’m not ranting here, just asking the questions and “thinking out loud” so don’t take it the wrong way.
12-14-2019, 08:38 AM
#254
Use the instruction balance to get it into the air and then adjust to suit your thumbs and feel. Everyone is different. I have people with jets that fly for 10-12mins with fuel available and they fly 6 mins and land. A bit like the CARF Viper balance mission i'm on, people have been flying this model super nose heavy for 6 years and don't seem to realise!
12-14-2019, 09:57 AM
#255
I hate nose heavy models. I have been very conscience about the position.
i still have room to move the motor and pipe rearward if needed.
BTW the bellmouth on the supplied pipe is huge it would very difficult if not impossible to use with the X45 as the motor would be halfway into the bellmouth! :0
i still have room to move the motor and pipe rearward if needed.
BTW the bellmouth on the supplied pipe is huge it would very difficult if not impossible to use with the X45 as the motor would be halfway into the bellmouth! :0
12-14-2019, 07:09 PM
#256
I don’t get this but see it in the jet world all the time. You never hear about people CGing with fuel in the tank on a warbird or 3D plane but it’s really common on Jets for some reason. The manufacturer has to establish a baseline when they set the CG. Gear down, main tank empty, UAT full. They use that because everyone can put their plane in that configuration, the UAT should always be full so there will be no weight change from beginning to end of the flight. You can’t say “leave some fuel in the tank” because “some fuel” for this guy is different than “some fuel” for that guy. Once you do that your CG numbers although good for you maybe don’t correspond with anyone else or the original manufacturer suggested CG numbers. I realize we rarely end up using the manufacturer CG. Also if you go to re-CG it now you don’t have the exact same amount of fuel you had the first time. Wouldn’t it be better and more consistent to CG it with tanks empty and set the CG forward then you can adjust from there with a known configuration?
I’m not ranting here, just asking the questions and “thinking out loud” so don’t take it the wrong way.
I’m not ranting here, just asking the questions and “thinking out loud” so don’t take it the wrong way.
I'm also only talking about doing this because I have a sneaky suspicion that even with my batteries as reasonably far forward as possible(3,000mah 3s ECU battery all the way up front and two 2s 1300mah rx batteries on the nose gear mount, which is as far as they can go without soldering up extensions), I may end up slightly tailheavy, and I don't want to add lead. If I can hit the recommended CG with a little fuel in the tank, I'll be fine maidening it as such. And if I find(for probably the first time ever) that the Rebel's recommended CG is perfect, I guess I'll have to solder up some extensions ;-)
Last edited by bodywerks; 12-14-2019 at 08:22 PM.
12-14-2019, 10:09 PM
#259
Hmmm. fit fine earlier with them in when I tested it but I didn't look too close. I'll look at it. The capture hooks are over an inch forward of the forward-most screws and I believe the intake duct starts about where those forward screws are. I know for sure the receiver screws are well aft of that lip transition.
Worse case, ill drill relief holes in the canopy or do panhead screws.
Worse case, ill drill relief holes in the canopy or do panhead screws.
Last edited by bodywerks; 12-14-2019 at 11:03 PM.
12-15-2019, 07:17 AM
#261
Last edited by bodywerks; 12-15-2019 at 07:35 AM.
12-15-2019, 07:44 AM
#262
Just weighed it, less uat fuel. Just over 13lbs. Comp arf advertises a 6-7kg take off weight. Looks like I'll be about 7.3kg take off.
Not gonna be catching any thermals at that weight, but at 7.3kg take off with 8.5kg thrust, who cares!
I did all that weight conscious stuff back in my 3d days. A lot of effort for not a whole lot of improvement in flight performance.
it's honestly kind of funny to be on the opposite end of the spektrum now and watching people comment on how porky my plane is, lol.
Not gonna be catching any thermals at that weight, but at 7.3kg take off with 8.5kg thrust, who cares!
I did all that weight conscious stuff back in my 3d days. A lot of effort for not a whole lot of improvement in flight performance.
it's honestly kind of funny to be on the opposite end of the spektrum now and watching people comment on how porky my plane is, lol.
Last edited by bodywerks; 12-15-2019 at 07:50 AM.
12-15-2019, 07:47 AM
#263
Being fixed on the fact that another jet at 20lb was OK, does not mean this one will like being heavy!
Yes, thought it was strange Spekky dropped the 12ch normal Rx. I think you will miss the gyro in this particular model..its small
Yes, thought it was strange Spekky dropped the 12ch normal Rx. I think you will miss the gyro in this particular model..its small
12-15-2019, 07:54 AM
#264
I hardly consider a 0.5kg overweight plane heavy for this size, and as stated, thrust/ weight and speed with some aerobatic capability was my goal with this jet.
I have yet to fly a jet with a gyro, so there's nothing to miss.
Last edited by bodywerks; 12-15-2019 at 08:01 AM.
12-15-2019, 08:06 AM
#265
Wow.....you are certainly making a splash bodywerks.
I predict
- total destruction within the first few flights either through overstress or flutter
- the leaving behind of retract bits and pieces on landing attempts
- your blaming the manufacturers for "crappy " stuff
- not hearing from you again....
While I wish you luck in your irresponsible endeavour you are the one that give CDs nightmares
dw
I predict
- total destruction within the first few flights either through overstress or flutter
- the leaving behind of retract bits and pieces on landing attempts
- your blaming the manufacturers for "crappy " stuff
- not hearing from you again....
While I wish you luck in your irresponsible endeavour you are the one that give CDs nightmares
dw
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Mach1 (05-25-2022)
12-15-2019, 12:41 PM
#269
Bob. It’s not uncommon, I have six Jokers around me and they have all been faultless. Like all gear, it’s how you prepare. I have customers who have blown up and burnt out the Rolls Royce Electrons!
12-15-2019, 07:59 PM
#272
Good question. Compared to my HSD Viper, it is the same wingspan exactly, but the viper has a slightly thicker cord(maybe 1/8-3/16" thicker). Take off weight on it is nearly 20 lbs! But it flies surprisingly well, and I typically have a half-tank(roughly 25 ounces) left on landing and it literally FLOATS.
In the Pirotti thread there were a lot of 'over-built' and over-powered jets(one reporting a bone-dry weight of 5.72kg) in there and no complaints about flight or landing characteristics.
In the Pirotti thread there were a lot of 'over-built' and over-powered jets(one reporting a bone-dry weight of 5.72kg) in there and no complaints about flight or landing characteristics.
Last edited by bodywerks; 12-15-2019 at 08:01 PM.
12-16-2019, 02:16 AM
#273
Different strokes. My first turbine had about a .7:1 thrust ratio. Fun, sure. But not exciting. My second turbine has approximately 1:1 thrust ratio and does 180 straight n level. Exciting? Sure. But not exhilarating. My rebel will have at least 1.2:1 at take off and is a much cleaner airframe than anything else I own. I hope it's exhilarating!
Hope it holds together as a few have not, probably the Pirotti versions though.
Bob I am impressed at that weight, surprised me how light you got it.
12-16-2019, 04:03 AM
#275
That was back when I had patience and for-thought. Now I just want to fly!
I, too, am very impressed with your AUW.
I know Mine is not light, but I have messaged back and forth with a few people in the Pirotti version thread that have 70n or larger and all are around 5.7-6.1kg dry weight, so I'm not too worried.