C-ARF Ultra Flash build Thread + Video
03-15-2014, 04:15 AM
#4001
Thread Starter
Ok, I'm stumped. Never really messed with mixes before and I can only get 3/4 of what I want. I have the behotec brake valve on a 3 pos switch. Pos0=gear up, pos1=gear down, pos2= brake on. This works fine.
On my XG11-What I want to add is a mix that, when the gear is down, applies the brake when the elev stick is pushed forward. I have enabled the stick position switch and it works. Using offset and pos1, I can get the elev stick to activate the brakes. But, the undesired effect is that when the 3pos switch is in brake mode, applying elev overdrives the servo. This is the piece I am baffled about. How do I make this mix active only when the 3 pos switch is in pos1(center pos) and elev is pushed forward? I don't want the mix to apply any other time. Plus I want to retain the ability to activate the brakes on the 3pos switch without overdriving the servo.
Your help is appreciated,
Jeremy
On my XG11-What I want to add is a mix that, when the gear is down, applies the brake when the elev stick is pushed forward. I have enabled the stick position switch and it works. Using offset and pos1, I can get the elev stick to activate the brakes. But, the undesired effect is that when the 3pos switch is in brake mode, applying elev overdrives the servo. This is the piece I am baffled about. How do I make this mix active only when the 3 pos switch is in pos1(center pos) and elev is pushed forward? I don't want the mix to apply any other time. Plus I want to retain the ability to activate the brakes on the 3pos switch without overdriving the servo.
Your help is appreciated,
Jeremy
OK, I guess you have just set the three position switch values to what is needed, say 40% 0 40%, this gives you the servo movement needed for gear up, gear down (middle switch position) and brakes.
In mix 1 select normal, then mix Elev to the three pos switch channel you are using. Go into SW SEL and on the three position switch channel used for gear change the middle 0 to 1, so (0 1 0) This way the mix will only work in the gear down position.
Think that's what you want!
Dave
You might need negative figure on the mix to get to correct direction.
03-16-2014, 10:04 AM
#4003
My Feedback: (57)
The K-180G pretty much fits with no problem (it's 114mm, & the bypass is designed for 116mm or less). It's not much longer than my old-school P120. I moved the turbine as far forward as I could in the mount, then positioned the mount tight to the forward eng-rail former, & that equated to 3/4" between the end of the nozzle & the beginning of the stainless pipe. It's a little close to the bypass at the front of the turbine, so I plan to drill a few bypass cheater holes to make sure plenty of bypass air flows freely around the turbine can. I plan to use the full bypass system since it all fit in relatively easily (even with the saddle tanks). I'm also going to try to attach a schematic of my fuel setup. It's rudimentary, but gets the point across.
If anyone has any suggestions, or has had a bad experience with this setup, please post.
Thank you,
Jay
If anyone has any suggestions, or has had a bad experience with this setup, please post.
Thank you,
Jay
03-16-2014, 11:00 AM
#4006
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What's the residual thrust for the K180? Not sure if it was in this thread but I remember Ali talking about how he could fly the Flash with power off for much longer with the full bypass than without it as there's much less air disturbance in the fuse. Anyone else flown UF's in both configurations? Dave?
03-16-2014, 11:53 AM
#4007
Thread Starter
Flown the classic with both, little less drag with byepass, Every single UF I have flown (lots ;-) has had the full byepass fitted, but if you fitted the lower (installing lower) top sitting on wheels only, with the wing centre shape you don't lose much at all.
03-16-2014, 12:42 PM
#4008
My Feedback: (57)
Thanks guys! The residual on the K180 seems to be about 1/2lb (If starting & stabilizing at idle) to 3/4 pound (If reducing thrust from some point above idle), but my scale doesn't appear to be that accurate on the very low end. I am concerned about residual, but I think with full flaps (with proper servo arms) & crow, I will be able to slow her down. I have enough fuel on board to T/O, trim, & do A LOT of approaches to misses before being forced to do a full stop landing, so if I can't figure it out I'll kill the turbine on my final approach & come up with a new plan, but I don't see that being the case.
I may look into installing a FOD screen into the fiberglass oval-to-round transition piece since there is not enough room in the byepass, has anyone ever tried this? Seems easy enough
I may look into installing a FOD screen into the fiberglass oval-to-round transition piece since there is not enough room in the byepass, has anyone ever tried this? Seems easy enough
03-16-2014, 11:39 PM
#4010
Thread Starter
I just blow it up with my mouth, main tank you can easily pop the baffle, so till it creaks! Wing tank till the top and bottom expand. Insert whole tank in water and if its not leaking its fine. I usually expand/release a few times before dunking as the tank will do this is operation and you need to exercise the material to know its sound. Just built another wing tank and again, its solid. You can tell later tanks, they have a "gloss" bead around the seams.
03-17-2014, 05:51 AM
#4013
Dave I think your tanks are being hand picked by the factory 
But honestly 2 pinholes in one out of 6 tanks doesn't bother me. I do however think it should be mentioned to check them in the manual as some here have been less lucky.
The fuel diagram for 4 tanks looks good to me, But I am no expert. Most I know of leave the main tank to drain last, probably for the reason you stated.
I have the JR11X. It has two 2 position switches, top left rear (standard gear switch position) and the top right (throttle hold position). But I like using the right lever for brakes. In the UF the lever will drive the gear servo further to actuate the brakes (like on my Electra). In my Hawk it is a separate channel (not a mix) and operates the EV5 proportional brake system. Either way it is easy to use as a parking brake and convenient to actuate while operating the elevator stick independently. But it doesn't get knocked around like a switch might. Example is if I get on the brakes hard I will give down elevator to help runway tracking where with a casual stop it doesn't seem necessary.
But honestly 2 pinholes in one out of 6 tanks doesn't bother me. I do however think it should be mentioned to check them in the manual as some here have been less lucky.The fuel diagram for 4 tanks looks good to me, But I am no expert. Most I know of leave the main tank to drain last, probably for the reason you stated.
I have the JR11X. It has two 2 position switches, top left rear (standard gear switch position) and the top right (throttle hold position). But I like using the right lever for brakes. In the UF the lever will drive the gear servo further to actuate the brakes (like on my Electra). In my Hawk it is a separate channel (not a mix) and operates the EV5 proportional brake system. Either way it is easy to use as a parking brake and convenient to actuate while operating the elevator stick independently. But it doesn't get knocked around like a switch might. Example is if I get on the brakes hard I will give down elevator to help runway tracking where with a casual stop it doesn't seem necessary.
03-17-2014, 06:13 AM
#4014
Thread Starter
No, tanks have come from many customers kits and its just luck!
Brakes are something where there is no right or wrong, if it works for you then great. Simple is usually best
Dave
Brakes are something where there is no right or wrong, if it works for you then great. Simple is usually best
Dave
03-21-2014, 11:50 AM
#4016
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All done and ready for test flights tomorrow. Thanks again to Dave who devoted his time yesterday helping me out with the set up and running the turbine. A top bloke who really knows his stuff. 
03-21-2014, 12:19 PM
#4017
Thread Starter
Bit hassled yesterday...so remind me to set the elevator compensation...cause I forgot! :-)
Looking forward to you buying breakfast tomorrow ;-)
Looking forward to you buying breakfast tomorrow ;-)
03-22-2014, 01:33 PM
#4022
Thread Starter
Test flight went great, then Matt had a few flights himself, I think there were seven UF's at our meeting today. P-100RX is enough power for many, I flew this and a P-90Rxi version today and both performed just fine.
03-23-2014, 01:33 PM
#4023
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Thanks very much, Dave test flew it yesterday in pretty rubbish conditions but the model didn't appear to be bothered one bit. I had a blast and then followed up with a flight. Amazing model, just what I wanted it to be. Direct, precise and very clean in the air. Flew superbly on the 100RX.
03-23-2014, 04:49 PM
#4024
I just blow it up with my mouth, main tank you can easily pop the baffle, so till it creaks! Wing tank till the top and bottom expand. Insert whole tank in water and if its not leaking its fine. I usually expand/release a few times before dunking as the tank will do this is operation and you need to exercise the material to know its sound. Just built another wing tank and again, its solid. You can tell later tanks, they have a "gloss" bead around the seams.
Well, I have been chasing this problem with a tank. After assembly I put air pressure into tank and submerged the tank totally in water. Held for some length of time and did not find a single hint of any leaks. So before installing, I decided to fill with fuel and let it sit for a few days. To my dismay, I find a small puddle of fuel under tank. I redo a pressure test under water and no bubbles. Refill with fuel and I angin find puddle of fuel under tank. I totally clean and wipe down exterior of tank to make sure there is no leakage from fittings. I never find and wetness from any of the fittings or tubing, but have the puddle under tank.
I did try to redo the sealing the seam with another wrap of glass cloth with epoxy around seam and still no fix.
How or what can I use to either help find this problem of fix this problem to eliminate this leak ?
Thanks for any help.
03-23-2014, 11:17 PM
#4025
Thread Starter
Joe
That's an interesting one! Can you see any "dry" areas in the cloth. Only thing I can think of is a layered path through that air pressure seals enough, but liquid capillaries through. How much fuel in the tank?
You could rub the tank down with 200grit paper, clean and seal with a coat of finishing resin epoxy.
Dave
That's an interesting one! Can you see any "dry" areas in the cloth. Only thing I can think of is a layered path through that air pressure seals enough, but liquid capillaries through. How much fuel in the tank?
You could rub the tank down with 200grit paper, clean and seal with a coat of finishing resin epoxy.
Dave