Freewing A-10 1.7M Turbine Conversion 2 x P20-SX
07-27-2017, 01:58 PM
#1
Freewing A-10 1.7M Turbine Conversion 2 x P20-SX
i am Currently Retrofitting 2 x Jetcat P-20SX in a Freewing A-10 1.7M span
this is the best Foamy i have ever seen from Freewing , this thing is scale and since there arent many -10 for turbines exept the expesnive skymasters and Mibo,s.
i wanted something smaller.
i calculated that the fans incl the electronics weighted 330 grams each.
the 2 Jetcats weight about the same thing .
things i bought extra
2 conversion kits for the mini avanti.
equipment :
Jeti REX12
Jeti Dual BEC
Telemetric
Digitech TTU x 2 Dual engine setup
Batterys (instead of lead) 1 x 3S Life 4000 for both turbines
2 x Life 3X 2000Maf for receiver.
total weight should be around 5.5KG 6.5KG
first things :
remove old fans cables and electronics
this is the best Foamy i have ever seen from Freewing , this thing is scale and since there arent many -10 for turbines exept the expesnive skymasters and Mibo,s.
i wanted something smaller.
i calculated that the fans incl the electronics weighted 330 grams each.
the 2 Jetcats weight about the same thing .
things i bought extra
2 conversion kits for the mini avanti.
equipment :
Jeti REX12
Jeti Dual BEC
Telemetric
Digitech TTU x 2 Dual engine setup
Batterys (instead of lead) 1 x 3S Life 4000 for both turbines
2 x Life 3X 2000Maf for receiver.
total weight should be around 5.5KG 6.5KG
first things :
remove old fans cables and electronics
Last edited by digitech; 07-27-2017 at 02:14 PM.
07-27-2017, 02:10 PM
#3
i calculated i need about 1200ml of fuel wich is about a kilo or so.
there was 2 batterys 5000ah 6S needed for the fan setup.
after mounting all on the airframe i need about 900 grams in the nose to reach CG.
but then still need to add Receiver 2 fuelpumps 2 x ecu , 4 valves , so all in all i will be a bit more then the recomended weight.
but will come in with less weight.
anyone has experiance with this A-10? the real flight weight VS the sticker on box weight?
there was 2 batterys 5000ah 6S needed for the fan setup.
after mounting all on the airframe i need about 900 grams in the nose to reach CG.
but then still need to add Receiver 2 fuelpumps 2 x ecu , 4 valves , so all in all i will be a bit more then the recomended weight.
but will come in with less weight.
anyone has experiance with this A-10? the real flight weight VS the sticker on box weight?
07-28-2017, 12:20 AM
#5
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i calculated i need about 1200ml of fuel wich is about a kilo or so.
there was 2 batterys 5000ah 6S needed for the fan setup.
after mounting all on the airframe i need about 900 grams in the nose to reach CG.
but then still need to add Receiver 2 fuelpumps 2 x ecu , 4 valves , so all in all i will be a bit more then the recomended weight.
but will come in with less weight.
anyone has experiance with this A-10? the real flight weight VS the sticker on box weight?
there was 2 batterys 5000ah 6S needed for the fan setup.
after mounting all on the airframe i need about 900 grams in the nose to reach CG.
but then still need to add Receiver 2 fuelpumps 2 x ecu , 4 valves , so all in all i will be a bit more then the recomended weight.
but will come in with less weight.
anyone has experiance with this A-10? the real flight weight VS the sticker on box weight?
Lots of footage of it:
General scale flight:
It does handle very well at 6.5kg. Doesn't really feel heavy at all.
I would strongly doubt getting much below 8 kg on the turbine conversion. As you have already figured out, turbine A-10s need a good deal of weight compensation in the nose.
One thing to note though: Manual CG is quite a bit nose heavy and can be pushed back a bit. I fly at 86 mm, others have flown as far back as 90 mm without problems. CGing in the high 80ies will obviously help a little with the weight as well.
Are you planning on running one common tank for both engines? (I would). I would also strongly consider running some kind of UAT between the tank and the turbines.
Another thing to keep in mind is thrust lines. The thrust needs to be angled up somewhat, to compensate for the fact that the engines sit well above the center line. If available, curved thrust tubes might be a good idea. I know hab.se (henke torphammar here on rcuniverse) did that for the yak 130. The A-10 needs a lot less than that, but a slight up angle is necessary, otherwise it will be have a significant negative throttle to attitude mix.
I'm sitting at 112 flights on this model currently, so feel free to ask anything lol
If interested, this is the setup I currently use: https://www.rcgroups.com/forums/show...&postcount=339
Last edited by janmb; 07-28-2017 at 12:28 AM.
07-28-2017, 12:47 AM
#6
Thanks! That is a lot of info i can use.
actualy the turbines are a bit lighter then the edf system.
as soon i have time again i will start putting it on our cg wizard and play with the cg as you recomend.
the up thrust is allready done a little otherwise i will add a small tip on the end and bend it upwards like a vector
actualy the turbines are a bit lighter then the edf system.
as soon i have time again i will start putting it on our cg wizard and play with the cg as you recomend.
the up thrust is allready done a little otherwise i will add a small tip on the end and bend it upwards like a vector
07-28-2017, 01:31 AM
#7
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Yeah, turbines themselves are not a weight issue at all. The challenge is geometry and CG, forcing extra weight in the nose.
I'm sure this model will handle 7-8 kg just fine. The only thing to be aware of, especially with those turbines, is that you probably will need a fair distance for takeoff. Especially if operating from anything more draggy than tarmac.
Landings I wouldn't be worried about at all.
Another thing I would definitely consider: 2x P20 will have quite a bit of idle thrust. You need all the drag you can get on landing, so be sure to use as much flaps as humanly possible, and probably also consider som aileron crow mix.
I'm sure this model will handle 7-8 kg just fine. The only thing to be aware of, especially with those turbines, is that you probably will need a fair distance for takeoff. Especially if operating from anything more draggy than tarmac.
Landings I wouldn't be worried about at all.
Another thing I would definitely consider: 2x P20 will have quite a bit of idle thrust. You need all the drag you can get on landing, so be sure to use as much flaps as humanly possible, and probably also consider som aileron crow mix.
Last edited by janmb; 07-28-2017 at 01:45 AM.
07-29-2017, 02:35 AM
#9
Yeah, turbines themselves are not a weight issue at all. The challenge is geometry and CG, forcing extra weight in the nose.
I'm sure this model will handle 7-8 kg just fine. The only thing to be aware of, especially with those turbines, is that you probably will need a fair distance for takeoff. Especially if operating from anything more draggy than tarmac.
Landings I wouldn't be worried about at all.
Another thing I would definitely consider: 2x P20 will have quite a bit of idle thrust. You need all the drag you can get on landing, so be sure to use as much flaps as humanly possible, and probably also consider som aileron crow mix.
I'm sure this model will handle 7-8 kg just fine. The only thing to be aware of, especially with those turbines, is that you probably will need a fair distance for takeoff. Especially if operating from anything more draggy than tarmac.
Landings I wouldn't be worried about at all.
Another thing I would definitely consider: 2x P20 will have quite a bit of idle thrust. You need all the drag you can get on landing, so be sure to use as much flaps as humanly possible, and probably also consider som aileron crow mix.
its now 5.5kg incl weight in nose ,turbines and empty tank
cg at 85mm
i will use 1.4 liter fuel wich is 1.2 kilo so i am at 6.9 kilo at take off and about 5.9 at landing.
so i think it will be ok
07-29-2017, 04:59 AM
#12
so i did some more work today.
and checked the CG and Fuel position and cg change when tank is full.
finished the egine pods , and now my Friend is drawing a Tank mould , will print it and make my own fuel tank.
1.1 liter just in front of the tube
CG is now at 90MM empty tank and 75mm at full tank.
pictures shows our CG wizard and total weight empty tank.
900 grams of extra in the nose to compensate the weight distribution.
all equipment is in.
here is a picture of material to be cut out of the fuselage to reach the front tube.
i will hysol the tank inside to get more strenght on that section.
so all in all 5.5 kilos total weight empty tank is not bad. (no missiles attached yet)
fuel weight 900 gram,s so i am at 6.4 kilo take off weight..
and checked the CG and Fuel position and cg change when tank is full.
finished the egine pods , and now my Friend is drawing a Tank mould , will print it and make my own fuel tank.
1.1 liter just in front of the tube
CG is now at 90MM empty tank and 75mm at full tank.
pictures shows our CG wizard and total weight empty tank.
900 grams of extra in the nose to compensate the weight distribution.
all equipment is in.
here is a picture of material to be cut out of the fuselage to reach the front tube.
i will hysol the tank inside to get more strenght on that section.
so all in all 5.5 kilos total weight empty tank is not bad. (no missiles attached yet)
fuel weight 900 gram,s so i am at 6.4 kilo take off weight..
Last edited by digitech; 07-29-2017 at 05:03 AM.
07-29-2017, 07:28 AM
#13
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CG shift from 75 to 90 sounds perfect to me.
Be conservative with flight time the first few flights though. 1.1 liter doesn't sound very much for 2x P20.
Last edited by janmb; 07-29-2017 at 07:33 AM.
07-29-2017, 08:55 AM
#14
so using a topoff tank when starting up , i thnk we can get 5 minutes easy with fuel left.
dont think i need to fly it full throttle the whole time.
nd i got telemetric with fuel consumption.. ;-)
07-29-2017, 07:54 PM
#16
Hi
i bought one of these and it flys great as EDF. But I was thinking about conversion as I did that with a Stinger and it has been fun and great for goofing around. The only concern I had was the location of the fuel tank which I thought would effect the CG when if goes full or empty. It would be great if we could get so,eons to make proper pipes for it. I will be watching your progress.
Behzad
i bought one of these and it flys great as EDF. But I was thinking about conversion as I did that with a Stinger and it has been fun and great for goofing around. The only concern I had was the location of the fuel tank which I thought would effect the CG when if goes full or empty. It would be great if we could get so,eons to make proper pipes for it. I will be watching your progress.
Behzad
08-02-2017, 10:15 PM
#17
some small progress...
build a Tank 1.1 liter , 3d printed the fueltank halfs.
used some cloth and voila a small tank 120mmx80mmx115mm..
position is just before the CG , cant move it further backwards...
Presetup of the Pumps , bec and batterys..
build a Tank 1.1 liter , 3d printed the fueltank halfs.
used some cloth and voila a small tank 120mmx80mmx115mm..
position is just before the CG , cant move it further backwards...
Presetup of the Pumps , bec and batterys..
08-03-2017, 04:59 AM
#19
Saying this Carlos from Spain is making a New tank for me from kevlar..
speccialy for this A-10 if you also thinking about this retrofit here is carlos his post : http://www.rcuniverse.com/forum/rc-j...ets-tanks.html
speccialy for this A-10 if you also thinking about this retrofit here is carlos his post : http://www.rcuniverse.com/forum/rc-j...ets-tanks.html
08-04-2017, 10:48 PM
#20
Well its Allive!
first few testruns done , all the engine covers stay cold as expected , exept when in cool down the heat quickly goes into the Bellmouth of the exhaust.
but nothing to worry about. uses Heatshield and alloy tape
it really makes the A-10 allive with twin turbines , the sound is great.
total weight came out.
so as i needed weight in the nose i have now the following battery power to my disposal ;-)
2 x 2900 lion for the RX
and a 3S lipo 4000 for the turbines...
CG at 89MM LE total weight 5724 Grams tank at 25% fuel
total fuel 1050ML should give me about 4 minutes i think
see video here :
first few testruns done , all the engine covers stay cold as expected , exept when in cool down the heat quickly goes into the Bellmouth of the exhaust.
but nothing to worry about. uses Heatshield and alloy tape
it really makes the A-10 allive with twin turbines , the sound is great.
total weight came out.
so as i needed weight in the nose i have now the following battery power to my disposal ;-)
2 x 2900 lion for the RX
and a 3S lipo 4000 for the turbines...
CG at 89MM LE total weight 5724 Grams tank at 25% fuel
total fuel 1050ML should give me about 4 minutes i think
see video here :
08-06-2017, 02:12 AM
#23
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Henke Torphammar has produced tons of conversion kits for hab.se for various freewing EDFs. I'm sure he would love to get onto this model as well.
89mm CG is getting close to being a bit aggressive, but probably should work just fine. I assume you don't plan to drain it below 25% tank anyway.
What is that weird sound on the video? I hope that is something from the camera/audio recording and not an actual sound from the turbine lol
As for heat while cooling, definitely be sure to park nose into the wind before stopping. Other than that I'm sure it should be just fine. If necessary, you could obviously also arrange to have an extra fan for it after parking. The clue is to have airflow through the nacelles so heat isn't allowed to build up and stay in one place.
89mm CG is getting close to being a bit aggressive, but probably should work just fine. I assume you don't plan to drain it below 25% tank anyway.
What is that weird sound on the video? I hope that is something from the camera/audio recording and not an actual sound from the turbine lol
As for heat while cooling, definitely be sure to park nose into the wind before stopping. Other than that I'm sure it should be just fine. If necessary, you could obviously also arrange to have an extra fan for it after parking. The clue is to have airflow through the nacelles so heat isn't allowed to build up and stay in one place.