Go Back  RCU Forums > RC Airplanes > RC Jets
Reload this Page >

Rebel Hot by Comp Arf

Notices
RC Jets Discuss RC jets in this forum plus rc turbines and ducted fan power systems

Rebel Hot by Comp Arf

Old 03-13-2023, 01:27 AM
  #1201  
authomassen
 
Join Date: Nov 2004
Location: Sandnes, NORWAY
Posts: 72
Received 2 Likes on 2 Posts
Default

Here is mine, finally RTF after a long and slow build. I started it before Christmas last year.

It's set up with my old and trusted VT-80 BL with about 28 hours on the clock, donated form my now retired Xcalibur. JP gear with Xicoy LGC-15 controller. All Kingmax CLS2875H servos that I belive is identical to the MacGregor MG2810HV. Jeti REX 10 Assist RX. 4OZ air trap from Zedjet. Original tank, but with a top mounted vent line. Original pipe.

I had to change out the included clevises to MP Jet, the included clevises had 1.4mm pins, and the holes in the control horns are drilled for 1.6mm pins. That's pretty much the only complaint I have with the kit.

I changed the front tyre form the included 50mm to a 55mm, it fits the original rim and strut, and gives me a bit more peace of mind flying off grass. I also used some 3mm packers made of ply under the front gear, lifting the nose a total 5.5mm giving it a slightly more nose up attitude on ground. I also turned the motors on the main retracts around, giving more clearance for the wire for the retract motors now clearing the former in the wing without removing any wood.

I've set the model up with a single battery, and it balances at the back of the wing tube with 1/3 fuel and UAT full, with a 3300mAh lipo and 20g lead taped to the battery. I'll probably get a 4000mAh battery to get rid of the lead, and to allow for one more flight per charge. From previous experience 3300mAh is comfortable for 3 flights, and 4000mAh allows 4 flights. This takes around half out of the battery.

I guess I'll maiden the model over the next month or so, work and weather permitting.









Old 03-13-2023, 02:18 AM
  #1202  
paulhat
 
Join Date: Dec 2006
Location: , AUSTRALIA
Posts: 401
Received 10 Likes on 9 Posts
Default

Thanks for sharing your build pics.
So I'm interested in the single battery idea.
I would like to use 2 rather than one but i guess its a similar philosophy. I would have one running retracts, turbine and 1 input to a regulator.
The other smaller battery would run the other side of the regulator.
Have you tried a single battery setup on this type of jet before? Any issues?

It would be interesting to put each piece of equipment (brakes, turbine ecu, powerbox, gyro and whatever else) on an oscilloscope and see which one has the noisiest line side power.
Then connect everything up and see if the THD has increased at all.
Noise would be my only concern running one or two batteries only.

Paul.
Old 03-13-2023, 02:53 AM
  #1203  
authomassen
 
Join Date: Nov 2004
Location: Sandnes, NORWAY
Posts: 72
Received 2 Likes on 2 Posts
Default

Hi, thanks for your interest. Yes, I've used single battery before, in only slightly smaller models. One being the sebart mini avanti, the other being a E-flite 90mm Viper converted to turbine. They were not perfectly equal to this one, on those I had to use a 3S LiFe for the king tech turbine, and a CC BEC Pro regulator for the RX and gear.

I've debated with myself using only one, or two batteries:
  • Using two separate batteries for RX/gear and turbine, the most likely scenario loosing any of the two batteries would be loosing the jet. I could be lucky and save it if the turbine battery died. It is less likely that a single battery fails, compared to how likely it is that one of two batteries fail.
  • Using two batteries through something like the AR multi switch could remedy the above. Then again, how likely is it that the multi switch fails? I don't know.
My conclusion was to keep it simple, and use one single battery, no switches, and connectors only. Fewer possible components that can fail.

I've not had any noticeable problem with noise running a single battery in my other models, but as mentioned, that was with a different turbine and a regulator for RX.
Old 03-13-2023, 03:01 AM
  #1204  
jstras
Junior Member
 
Join Date: Jul 2020
Location: Slovenia
Posts: 20
Likes: 0
Received 1 Like on 1 Post
Default

Hi fellow flyers,

Thanks for the pics.
I personally would _never_ fly a jet on single battery. Ever. In my opinion, double-up on everything you can, weight and space permitting.

One very simple solution is to use Jeti DSM10 which allows use of 2 batteries and provides basic failsafe. It also supports RCSW, so it can be turned on/off by Jeti Tx.
Old 03-13-2023, 03:19 AM
  #1205  
authomassen
 
Join Date: Nov 2004
Location: Sandnes, NORWAY
Posts: 72
Received 2 Likes on 2 Posts
Default

Originally Posted by jstras
Hi fellow flyers,

Thanks for the pics.
I personally would _never_ fly a jet on single battery. Ever. In my opinion, double-up on everything you can, weight and space permitting.

One very simple solution is to use Jeti DSM10 which allows use of 2 batteries and provides basic failsafe. It also supports RCSW, so it can be turned on/off by Jeti Tx.
I follow your line of thought. However, I would rather put my faith in a single battery, than a single small electronic device rated for 10A max continuous, and 20A peak like the DSM10. I would say either of the options are safe enough for the rebel hot. Only time will tell wether I'm right or not.
Old 03-13-2023, 09:15 AM
  #1206  
jvaliensi
My Feedback: (1)
 
Join Date: Apr 2006
Location: northridge, CA
Posts: 664
Received 89 Likes on 73 Posts
Default

My Rebel Hot has a single 2S 5000MAH battery. I know others that run one battery.
The battery is not the only single point of failure that can cause a lost airplane.
Old 03-13-2023, 09:56 AM
  #1207  
BarracudaHockey
My Feedback: (11)
 
BarracudaHockey's Avatar
 
Join Date: Jul 2003
Location: Jacksonville, FL
Posts: 26,454
Received 293 Likes on 235 Posts
Default

I run twin 1350mah lipos into a Powerbox Pioneer.
Old 03-13-2023, 10:27 AM
  #1208  
Dave Wilshere
 
Join Date: Jun 2002
Location: Watford, UNITED KINGDOM
Posts: 12,878
Received 652 Likes on 471 Posts
Default

Me too and I get 8 flights easily!
Old 03-13-2023, 10:33 AM
  #1209  
Dave Wilshere
 
Join Date: Jun 2002
Location: Watford, UNITED KINGDOM
Posts: 12,878
Received 652 Likes on 471 Posts
Default

If you are going to use the Jeti built in gyro do lots of ground testing the Rebels I have seen with that twitched and jittered because of the turbine emf.

I have 2700 2s li-po in the nose, the two 1350. 2s Li-Po Rx packs next to the tank and a 800mAh 2s Retract pack in the turbine opening.
Old 03-13-2023, 10:34 AM
  #1210  
authomassen
 
Join Date: Nov 2004
Location: Sandnes, NORWAY
Posts: 72
Received 2 Likes on 2 Posts
Default

Is that all the battery you have in the model, or is that radio only with an additional battery for turbine and gear?

With a 3S 2200mAh LiFe in my other models with a single battery, I put approximately 1200mAh back after 3 starts on the K45G3 and 3 flights.

Edit; I saw Dave’s post now. Yes, lots of testing, had that on my e-flite viper.

Last edited by authomassen; 03-13-2023 at 10:36 AM.
Old 03-14-2023, 01:15 AM
  #1211  
paulhat
 
Join Date: Dec 2006
Location: , AUSTRALIA
Posts: 401
Received 10 Likes on 9 Posts
Default

Hi Barracuda,

Do you run the retracts and turbine off those 2 batteries as well?

Paul.
Old 03-14-2023, 03:38 AM
  #1212  
BarracudaHockey
My Feedback: (11)
 
BarracudaHockey's Avatar
 
Join Date: Jul 2003
Location: Jacksonville, FL
Posts: 26,454
Received 293 Likes on 235 Posts
Default

No, its got a small 3S drone battery since the SW requires Lipo and an 800mah retract/brake battery
Old 03-14-2023, 03:53 AM
  #1213  
authomassen
 
Join Date: Nov 2004
Location: Sandnes, NORWAY
Posts: 72
Received 2 Likes on 2 Posts
Default

Originally Posted by jvaliensi
My Rebel Hot has a single 2S 5000MAH battery. I know others that run one battery.
The battery is not the only single point of failure that can cause a lost airplane.
My thought as well, there are several other single points of failure, and the batteries today are generally not failing very often.

How many flights can you get on the single 5000mAh?
Old 03-14-2023, 08:00 AM
  #1214  
jvaliensi
My Feedback: (1)
 
Join Date: Apr 2006
Location: northridge, CA
Posts: 664
Received 89 Likes on 73 Posts
Default

Originally Posted by authomassen
My thought as well, there are several other single points of failure, and the batteries today are generally not failing very often.

How many flights can you get on the single 5000mAh?
Hi,
More than I fly in day. The airplane uses approximately 600MAH per run.
The following users liked this post:
authomassen (03-14-2023)
Old 03-14-2023, 02:47 PM
  #1215  
Dave Wilshere
 
Join Date: Jun 2002
Location: Watford, UNITED KINGDOM
Posts: 12,878
Received 652 Likes on 471 Posts
Default

It’s not the battery that fails, like you say it’s rare without warning. But if say one items fries, it will take down the radio…it will fly without a turbine and with the gear up…but free flight jets are rubbish. I think it’s a stupid risk. I only charge my Turbine battery between most sessions, Rx and gear lasts several sessions…
It’s like people who are always on FB saying they don’t have time in their lives to do something…
Old 03-20-2023, 06:00 AM
  #1216  
JP-1
 
Join Date: Nov 2009
Location: Newark-On-Trent, UNITED KINGDOM
Posts: 1,928
Received 421 Likes on 355 Posts
Default

This Rebel Hot with a distinctive scheme at the JMA meeting at Buckminster Lodge over the weekend

Alistair Powers

Old 03-23-2023, 09:35 AM
  #1217  
Dave Wilshere
 
Join Date: Jun 2002
Location: Watford, UNITED KINGDOM
Posts: 12,878
Received 652 Likes on 471 Posts
Default

Video from last weekend of one of my flights, plus the take off and landing of another. Grass was very wet and boggy!

The following 2 users liked this post by Dave Wilshere:
grolleman (03-23-2023), Viper1GJ (03-23-2023)
Old 03-24-2023, 01:59 AM
  #1218  
Bob_B
Thread Starter
My Feedback: (11)
 
Bob_B's Avatar
 
Join Date: Nov 2003
Location: Bluegrass State of Mind
Posts: 4,657
Received 76 Likes on 67 Posts
Default

Is that your club field? Lots of jet activity.
Old 03-24-2023, 05:07 AM
  #1219  
Dave Wilshere
 
Join Date: Jun 2002
Location: Watford, UNITED KINGDOM
Posts: 12,878
Received 652 Likes on 471 Posts
Default

No, its our National Flying Centre (Muncie type) but we have a few acres and a grass 900 sloped take off strip. Problem was very wet ground, longish grass and 30 degree cross wind that day.

That was last weekend JMA event, we have 3 per year there


Old 03-29-2023, 12:09 AM
  #1220  
LewisE1
 
Join Date: Aug 2010
Location: Berkshire, UNITED KINGDOM
Posts: 102
Likes: 0
Received 6 Likes on 6 Posts
Default

Currently putting together a ARF plus version, and noticed that carf have mounted the thrust tube with a small amount of down thrust, which means I will need to pack my turbine to centre it, its a xicoy 85 so the mount is on the centre line, I had one before which I mounted the thrust tube and turbine all on the centre line and it flew great, I have looked through the posts here and I can't see any packed turbines, anyone else have a arf and noticed this ??? Dave W says they should have a small amount of down thrust so pack it, but just curious what you guys have noticed ?
Old 03-29-2023, 02:43 AM
  #1221  
Dave Wilshere
 
Join Date: Jun 2002
Location: Watford, UNITED KINGDOM
Posts: 12,878
Received 652 Likes on 471 Posts
Default

Measure from the fuselage floor to centre of the pipe as it is…?
Old 03-29-2023, 05:27 AM
  #1222  
jvaliensi
My Feedback: (1)
 
Join Date: Apr 2006
Location: northridge, CA
Posts: 664
Received 89 Likes on 73 Posts
Default

Originally Posted by LewisE1
Currently putting together a ARF plus version, and noticed that carf have mounted the thrust tube with a small amount of down thrust, which means I will need to pack my turbine to centre it, its a xicoy 85 so the mount is on the centre line, I had one before which I mounted the thrust tube and turbine all on the centre line and it flew great, I have looked through the posts here and I can't see any packed turbines, anyone else have a arf and noticed this ??? Dave W says they should have a small amount of down thrust so pack it, but just curious what you guys have noticed ?
Hi.
I have the same setup, X90 & CARF pipe in my Rebel Hot. The turbine is bolted flat to the wood framing. The pipe sits on the back supports without modifications. I screwed the pipe bell to the former (bulkhead) so it was centered on the turbine exhaust nozzle. It appears that the thrust line is parallel with the fuselage center axis.
It flies perfectly.
It is hard to say if you will have the same experience, since there seems to be minor variations in construction from the CARF factory.

Best regards-
Old 03-29-2023, 05:35 AM
  #1223  
LewisE1
 
Join Date: Aug 2010
Location: Berkshire, UNITED KINGDOM
Posts: 102
Likes: 0
Received 6 Likes on 6 Posts
Default

Thanks for the info, that is how I would have set it up, but Dave has my measurements so lets see what the verdict is, it might not even make much difference, but I like things right,
Old 04-23-2023, 01:31 PM
  #1224  
natxo
Member
 
Join Date: Jan 2022
Posts: 51
Received 0 Likes on 0 Posts
Default

Final steps to maiden, are those deflections posted at beginning of this thread, measured at surface root or end?

Deflections /
Elevator: "nose up" / "rudder": 12 mm
Elevator: "nose down" / "deep groove": 9 mm
(Elevator has a slight "nose up" / "height" in neutral, maybe 1 mm)

Aileron (differential): Up 9 mm / down 6 mm
Rudder: max deflection

Flaps, take off: 23 mm
Flaps, landing: 68 mm
- --- Crow @ landing flaps: 8 mm
---- Elevator @ landing flaps ("nose down" / "dykror") 4 mm

CG at 187 mm (from front leading edge) gear down, 25% fuel
Old 04-23-2023, 01:43 PM
  #1225  
Dave Wilshere
 
Join Date: Jun 2002
Location: Watford, UNITED KINGDOM
Posts: 12,878
Received 652 Likes on 471 Posts
Default

Look terrible. Differential wrong way for a start. Don’t recommend CROW on a Hot, it’s heavily loaded to start with.
I’m sure there are other figures in this thread…

Thread Tools
Search this Thread

Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service - Do Not Sell or Share My Personal Information -

Copyright © 2023 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.