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C-ARF Ultra Flash build Thread + Video

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C-ARF Ultra Flash build Thread + Video

Old 04-18-2014, 12:55 AM
  #4076  
Midas D.
 
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Congrats John!!

Jep she's big fun
Old 04-18-2014, 03:57 AM
  #4077  
phantom_najd
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Originally Posted by afterburner
Husa, It's always the little things that seem to take the longest time to correct and when they come back to back it just makes it harder to get motivated to finish it. At least that's the way it ends up for me. I remember the days of staying up on a Saturday night trying to finish up a .40 size ARF for a maiden the next day. Now unless it's for an upcoming jet rally I just say it can wait.

Here's the take off roll of the Flash. The landing looked pretty much the same but went further down the taxiway to the right due to no air left for brakes. Could have probably aborted the take off but we all know how those split second decisions go.

https://www.youtube.com/watch?v=as3CPYmfXKg
This short clip shows exactly what my flash was doing for the past couple of weeks. I had the problem fixed and I tested it today and it was tracking great. The problem I had was the mains were not toed-in. What I did to fix it was to drill and tap the M4 holes on the gear to M5 and fixed the flats on the pins so that when I screw the set-screws the tires are toed-in about 3-4 degrees. I don't know if it was necessary to use the M5 set screws but the M4 seemed too small to my liking.

Azzam
Old 04-18-2014, 07:03 AM
  #4078  
afterburner
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I found another problem with my steering when I looked into it a few days ago. Upon closer inspection, the strut was very hard to manually turn by hand. Some dirt or crud must have gotten in there. I blew it out and lubricated at the top and its smooth now. The cables probably stretched as well as they needed tightening. I'm using a high torque digital for steering only because it's what I had on hand from a previous project. In the state the strut was in, a standard servo would have burnt out in short order. I know when I assembled the nose gear it wasn't like that. Will have to keep an eye on it.
Old 04-18-2014, 06:08 PM
  #4079  
husafreak
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I think the gear down convention is just to make it easier to check. Kinda hard to handle the plane with the gear up...

I found a little problem with the brake line on one side it kinked with the gear up and now it always kinks. Probably a high wear point so can't have that but it is a pain to change out. I have to figure out some way to keep this from happening...
Old 04-19-2014, 12:07 AM
  #4080  
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Gear down is your landing configuration, if you have a trickle undercarriage, the front leg may swing forward or back changing the C of G especially if using a heavy wheel (Intairco come to mind) some main legs also rake forward/backward on retracting and would also move the C of G when extended, best to check C of G with the gear extended and retracted, unless you are confident the C of G will not move or extended makes it nose heavy.

Mike
Old 04-19-2014, 08:09 AM
  #4081  
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An other 6 successful flights today

What an brilliant toy!!
Old 04-20-2014, 12:47 AM
  #4082  
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I got a silly question as to how to mount the engine. To avoid any confusion as to which direction, if the model is right side up, is the turbine installed upside down or right side up?

Reason I ask is because the engine is installed from the bottom of the plane and its got me wondering. Please let me know as my k170 will be installed tomororw

Thank you!
Old 04-20-2014, 01:20 AM
  #4083  
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writing sky side up. Turbine doesn't know its upside down however.
Old 04-20-2014, 02:36 AM
  #4084  
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Originally Posted by andretorres89
I got a silly question as to how to mount the engine. To avoid any confusion as to which direction, if the model is right side up, is the turbine installed upside down or right side up?

Reason I ask is because the engine is installed from the bottom of the plane and its got me wondering. Please let me know as my k170 will be installed tomororw

Thank you!
Direction is important for the kero start. Indeed type writing needs to be facing the top of the fuse.

Mich
Old 04-20-2014, 05:02 AM
  #4085  
afterburner
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Originally Posted by Dave Wilshere
Have you put a straight edge on the side of your wheels? I can honestly say there is not an UF flying in England with a nose/rudder gyro. The three i flew on Friday were all raw and track straight down the strip. The trailing nose leg has to run straight (especially if the steering wires are slightly loose as I prefer).

Dave Bugz had his new UF at our grass strip BBQ today and made two great flights, landing well within our small grass strip without even breaking into a sweat....one or two P-140RX passes got some attention from the assembled audience :-) Great flying.

Dw
Sorry Dave, must have missed your post last week. I did check that and its good. My other problem with the nose gear that I found later in this thread will probably get rid of 99.9% of the steering issues I experienced.
Old 04-20-2014, 05:53 AM
  #4086  
Dave Wilshere
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Marty

Long as you are sorted!

Dave
Old 04-20-2014, 08:01 AM
  #4087  
husafreak
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One more try, any clever ideas how to keep the brake lines from kinking on the stock gear? I realize now that the side which kinks is the one where the gear had to be installed well toward the wingtip on the bearers due to the bearer being improperly positioned at the factory (on the other side...). So it kinks against the ply mounting rail and rib on that side. So I am probably the only guy to have this problem.
It is interesting how little problems will show their effects down line, this is a good example of that.
Another was with the nose gear door. Due to lengthening the mains I used packing to extend the nose gear a bit as well, so then the door wouldn't close. So I removed the packing and used a 6mm spacer to lengthen the leg, which put the steering arms fouling in the door opening, which required cutting them shorter, which meant having to redo the steering cables! I guess that the gear plate being out of position in the wing will cost me 8-10 hours of additional shop time and troubleshooting with its effects throughout the plane.
Reminds me of my time in the architecture profession. One small problem could propagate throughout a building.
While I am rambling, I just ordered a Powerbox smoke pump and some 4 servo ganged connectors from Altecare in Canada, nice shop.

Last edited by husafreak; 04-20-2014 at 08:16 AM.
Old 04-20-2014, 01:23 PM
  #4088  
Dave Wilshere
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Can you post a picture of your exit position? Maybe gear up and down...

Dw
Old 04-20-2014, 01:38 PM
  #4089  
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In regards to the turbine it has to be right side up for kero start?
Old 04-20-2014, 01:48 PM
  #4090  
BlueBus320
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Originally Posted by andretorres89
In regards to the turbine it has to be right side up for kero start?
With Kingtech, it needs to be oriented with the writing on the turbine facing the sky on startup, once stabilized and running orientation does not matter.
Jay
Old 04-20-2014, 02:09 PM
  #4091  
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Originally Posted by BlueBus320
With Kingtech, it needs to be oriented with the writing on the turbine facing the sky on startup, once stabilized and running orientation does not matter.
Jay
Right side it will be installed. Thanks Jay
Old 04-20-2014, 04:14 PM
  #4092  
husafreak
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I know Jet Central also specifies that you mount the engine lettering topside.

DW thanks for the offer of assistance. I will just explain it quick. Normally when the gear is mounted against the rib you only have that 3mm rib beyond the metal gear mounting plate. The brake line runs up the gear leg and easily passes in front of the rib and bends inside that cavernous wing when the gear retracts. On the side I am having trouble with the ply plate and rib extend out 9mm from the edge of the metal gear mounting plate. So the brake line runs up the gear leg and when it retracts it is kinking against that ply "shelf". There is only a few mm between where the air line is taped to the gear leg and that plywood structure. The tubing doesn't slide past the rib and bend, it jams against the plywood shelf, it kinks because the radius is too sharp. I thought of some ideas today, cutting away some wood to make a little channel, a rubber band to pull the line into the well as the gear retracts, putting a stiff brass or aluminum tube with a preset bend over the line, rerouting the line around the entire gear assembly. I will get it sorted. Then post a pic
Old 04-20-2014, 06:11 PM
  #4093  
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Hi Guys, I just re read the Jet Cat Manual having seen the post re enginee orientation...and it says any direction in a 360 rotation. ie Writing up or down etc....maybe Jet Cat Kero start is different... Its my first JetCat so maybe Im reading it wrong...Ihave writing down and would prefer to leave it that way...less fuel line bends that way for me......is there any reason this is not good...manual says okay......so Im just double checking. P140RX
Old 04-21-2014, 12:20 AM
  #4094  
Dave Wilshere
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The kero unit is installed from the front on Rx turbines, not the side wall like on the earlier conversions. Its not as fussy, I have installed a dozen Rx turbines and always do it based on easy tube route and wire access. They all start.

Dave
Old 04-21-2014, 12:46 AM
  #4095  
Dave Wilshere
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This is how I do the Flash. Its Robart brake line 169B, its super flexible. There is hardly any movement in the wing, the tube loops around the back of the unit and down the LE side out the wing

Dave
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Old 04-21-2014, 06:41 AM
  #4096  
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Thanks Dave, I will reroute my brake line around the back of the unit then.
Old 04-21-2014, 05:06 PM
  #4097  
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Just got the weekly deal email from CARF. All 3 checker color schemes are on sale for $1990. that is a smokin deal if you are on the fence about getting an ultra flash.
Old 04-21-2014, 06:17 PM
  #4098  
Jack28
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Hello Guys, Does anyone have one of the Airtec main gear legs (new or used) that comes with the Ultra flash landing gear package. I had a slight bend in one and tried to straighten it and I snapped it off. See picture below. Thanks , Jack.
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Old 04-21-2014, 11:28 PM
  #4099  
Dave Wilshere
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Jack

That's the early design, you are better off upgrading to the later version for both

Dave
Old 04-23-2014, 03:19 AM
  #4100  
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Hi

I'm about to do the final setup on my new Ultra Flash, and was wondering what the Flap setting should be, can't find it in the manual? How many mm should it be. my guess is somewhere about 90-100 mm?

//Jan

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