C-ARF Ultra Flash build Thread + Video
#5727
#5730
My Feedback: (19)
I got the first flight on my UF. REALLY PLEASED! Left the gear down but could still see that this thing will be fast once I open her up.
I am running the wing tank and fuse tank for fuel. I have heard that the fuse tank has some unuseable fuel. About how low is safe? 1" from the bottom? 1/2"? I flew it pretty mildly and didn't use much of the fuse tank after 5 minutes.
Thanks!
Dan
I am running the wing tank and fuse tank for fuel. I have heard that the fuse tank has some unuseable fuel. About how low is safe? 1" from the bottom? 1/2"? I flew it pretty mildly and didn't use much of the fuse tank after 5 minutes.
Thanks!
Dan
#5732
My Feedback: (114)
I got the first flight on my UF. REALLY PLEASED! Left the gear down but could still see that this thing will be fast once I open her up.
I am running the wing tank and fuse tank for fuel. I have heard that the fuse tank has some unuseable fuel. About how low is safe? 1" from the bottom? 1/2"? I flew it pretty mildly and didn't use much of the fuse tank after 5 minutes.
Thanks!
Dan
I am running the wing tank and fuse tank for fuel. I have heard that the fuse tank has some unuseable fuel. About how low is safe? 1" from the bottom? 1/2"? I flew it pretty mildly and didn't use much of the fuse tank after 5 minutes.
Thanks!
Dan
#5733
Join Date: Feb 2013
Location: Dubai, UNITED ARAB EMIRATES
Posts: 64
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When i tested the main tank i replaced the fitting with my wing tank fitting to establish if it was the fitting or the tank. Im glad to report it was the fitting. So i connected up the entire system and started fueling her up. On de fueling I noticed once saddle tank was empty and the other not...obviously the fuel is following the path of least resistance BUT what was starnge is that my pipe lenghts were identical.
So im not keen on having a model that creates doubt regarding fuel and flame outs..so i changed my setup to be 1 main tank and 1 wing tank. I also plugged the spare breather. Must say i feel a lot more comfortable.
#5736
Join Date: Feb 2013
Location: Dubai, UNITED ARAB EMIRATES
Posts: 64
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Couple of build pics from my Ultra Flash.
Running Wing tank to main tank, I will install the saddle tanks after the maiden for smoke.
I have been searching the tread regarding flap setups and every one has different settings. So going to start off with the following:
Take off flap 27mm (-1mm down elevator mix)
Landing flap 75mm )-5mm down elevator mix)
Crow on full flap +6mm
CG 232mm from LE cut line (tanks empty, CAT full, Gear down)
Aileron +9mm /-10mm (up/down) 40% expo
Rudder 45mm each way 40 % expo
Elevator +10mm/-11mm (40% expo)
Got these settings on here from a previous post from Phil (Thanks) Hopefully they are good.
Any comments please shoot!
Running Wing tank to main tank, I will install the saddle tanks after the maiden for smoke.
I have been searching the tread regarding flap setups and every one has different settings. So going to start off with the following:
Take off flap 27mm (-1mm down elevator mix)
Landing flap 75mm )-5mm down elevator mix)
Crow on full flap +6mm
CG 232mm from LE cut line (tanks empty, CAT full, Gear down)
Aileron +9mm /-10mm (up/down) 40% expo
Rudder 45mm each way 40 % expo
Elevator +10mm/-11mm (40% expo)
Got these settings on here from a previous post from Phil (Thanks) Hopefully they are good.
Any comments please shoot!
#5737
Thread Starter
Like always it depends how you like the model to feel, Phil needed a soft set up, for me its not enough Flap, turbines vary with idle thrust and with a clean model like the UF a small increase in flap angle makes a big difference to slowing it down. I'd say 85mm minimum, I still use the full 100mm.
Also the joining nipple you have used on the overflow-what size hole did that have? If you restrict the line pump figures will be high and an air leak is more likely as you have gone from one joint to three!
Dave
Also the joining nipple you have used on the overflow-what size hole did that have? If you restrict the line pump figures will be high and an air leak is more likely as you have gone from one joint to three!
Dave
#5738
Join Date: Feb 2013
Location: Dubai, UNITED ARAB EMIRATES
Posts: 64
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Like always it depends how you like the model to feel, Phil needed a soft set up, for me its not enough Flap, turbines vary with idle thrust and with a clean model like the UF a small increase in flap angle makes a big difference to slowing it down. I'd say 85mm minimum, I still use the full 100mm.
Also the joining nipple you have used on the overflow-what size hole did that have? If you restrict the line pump figures will be high and an air leak is more likely as you have gone from one joint to three!
Dave
Also the joining nipple you have used on the overflow-what size hole did that have? If you restrict the line pump figures will be high and an air leak is more likely as you have gone from one joint to three!
Dave
Thanks for the input, noted regarding flap and will proceed with 90mm for the initial flight. I do recall the UF at the field struggled to slow down with 75mm flap, however no crow was utilized. Since then he unfortunately crashed it due to a flame out.
Regarding my fuel line setup, with this being my first jet build there were a couple of learning curves. Firstly the fuel tanks I ordered came with a 8mm diameter fitting while I planned a 6mm setup.
I contacted Gary at jet tech whereby i purchased a few reducers from 8mm down to 6mm.
So, my wing tank over flow is 8mm dia tubing, the wing tank feed to main tank is reduced from 8mm to 6mm whereby i connected the jet flow fitting (http://www.dreamworksrc.com/catalog/...Kero-Fuel-Only) This feed to the main tank needs to be changed from 6mm to 8mm dia in order to fit on my main tank over flow (colorless tubing). The other main tank over flow is just stopped using a festo stopper.
The main tank feeds the CAT via a 8mm dia tubing (yellow tygon), CAT feeds pump via 6mm tubing.
I hope that makes sense what im trying to explain above. Yes there are a number of step downs but the main feed to the CAT is a straight 8mm dia, I dont forsee a problem unless you advise otherwise.
Looking forward to your thoughts
#5739
Thread Starter
OK, size should be OK if the joints are mechanically sound. I would lock wire the clear and other side of tygon to be sure in this case
Dave
Dave
#5741
My Feedback: (28)
Dave I have a question. I limited my max flap deflection to 75MM solely because any more flap than that and the curved plastic upper fairing on the flap falls below the wing TE. I was afraid if this was exposed it would grab the wind and rip it off. Does what I am describing make sense and do you see this as an issue? I can easily dial up the travel to as much as I would like if what I described is not a problem. Hoping to complete my build some time this century. Still plugging away at my Cockpit LOL.
Thanks
Thanks
#5747
My Feedback: (2)
quick question, I'm putting a jet munts 140 in mine, the destructions say 15 - 18mm from chrome piece on a jet cat. The Jet munts has a really short cone on the turbine is that measurement still relevant? Normally wouldn't you just measure from the end of the tailcone? also is there a better method of lining up the turbine in the thrust tube then eying it down the tube?
#5748
Thread Starter
No it's not. Turbines like the JM did not exist when we did the manual. 30mm from the tail cone to pipe is about right, you can make discs, but eye ball is perfectly good for the job in this case.
Dave
Dave
#5750
My Feedback: (81)
Well, RCU isnt cooperating on the website, so I will do the best I can to read your responses. Forum looks crazy for me right now.
Ok, anyone have any Kingtech 140G2 install pics to share? I am ready to put mine in and Im curious how you lined her up and made sure she was right down the middle of the pipe. The old 140's seem to lay in there just fine. The G2 seems to be a bit smaller and needs adapter plates.
Pics would be helpful!
Thanks!
Ok, anyone have any Kingtech 140G2 install pics to share? I am ready to put mine in and Im curious how you lined her up and made sure she was right down the middle of the pipe. The old 140's seem to lay in there just fine. The G2 seems to be a bit smaller and needs adapter plates.
Pics would be helpful!
Thanks!