RE: C-ARF Ultra Flash build Thread + Video
 

Does anybody have additional info on the new saddle tanks I saw on CARFs site (capacity, dims, placement, etc.)?

[link]http://www.carf-models.com/public_carf/pages/shop/accessoryDetail.html?root=accessory&proId=2772[/link]

RE: C-ARF Ultra Flash build Thread + Video
 

Where do these tanks go?

RE: C-ARF Ultra Flash build Thread + Video
 

on either side of the intake ducting / bypass ... looks like at least 24 oz per tank .. would be great for smoke :)


~V~

RE: C-ARF Ultra Flash build Thread + Video
 

That is what I figured, but wasn't sure if it would fit if the full intake and bypass were used. I'll buy these if I can use them with the bypass/intake.

RE: C-ARF Ultra Flash build Thread + Video
 

I would imagine that the bypass could still be used. Looks like the full intake would not fit. Don't think this would be an issue?

I have just ordered a flash and think these saddle tanks may be a better alternative to the wing tank. Not having to disconnect the wing tank would have to be an advantage.

What do you guys think?


Paul.

RE: C-ARF Ultra Flash build Thread + Video
 

actually, on either side of the intake / bypass , there is almost enough room for two 20oz dubro tanks ... so if these are thinner but longer like they look, it could easily be 24+ oz of fuel per side . and keeping the full bypass / intake ducts ... At least that's what i'm hoping for :)

~V~

RE: C-ARF Ultra Flash build Thread + Video
 

I have 2x24oz du-bro tanks now and of course I can't use the bypass, so hopefully these will work with the bypass.

RE: C-ARF Ultra Flash build Thread + Video
 

Hi Guys,

I have just fitted 2x 20oz dubro tanks for smoke in mine. I don't think the tanks pictured in the link would be a better option for fuel than the wing tank as they are not of a good geometry. The wing tank is of a better geometry for fuel use. Those long thin longitudinally orientated tanks tend to be a bit of a problem if you pull a lot of vertical manoeuvres as the clunk will not find its way to the front of the tank in a dive. For smoke that would not matter so much. The other point to consider is that the moulded ones in the link would put the centre of the tank further aft in relation to the c of g than the dubro ones I have fitted.

Hi Paul,

I have a heap of flights on my standard flash now and I love it! I am sure you will like the ultra. I should be able to test fly mine some time in the next week or so once this crap weather disappears. Let me know when you are down in Perth next and we will go for a fly.

Those tanks look like they are moulded to fit with the inlet joiner duct in place. Now I have fitted the dubro ones I will probably stick with them.

Craig.

RE: C-ARF Ultra Flash build Thread + Video
 

Hey guys.

Just wanted to report on the first run of my Kingtech 140 (destined for the Ultra Flash).

I know the real test of an engine is in the air, but this thing runs sweet on a test bench.
This is my first kero start engine. Previous to the 140 I have had a P-70, PST 600 and SuperSport. All these engines ran great.

No vibration and really happy with the spool up time from idle to full.

Externally it doesn't look as nicely finished as some of the more expensive engines that I have seen. Its growing on me though :)

Hi Craig.

Look forward to hearing how your maiden goes. Would be great to catch up with you again some time. Has been ages !


Paul.

RE: C-ARF Ultra Flash build Thread + Video
 

Could someone please do me big favour and measure the length of the Airtech legs which come with the UF gear?
I still have my old Flash Behotec gear and would need to get new legs for the UF which I am planning for at the moment.

Thanks a lot in advance!
N

RE: C-ARF Ultra Flash build Thread + Video
 

Good stuff Paul... A guy at our club was flying a Kingtech 140 this weekend and he said he has been delighted with it in all respects.

Have decided to add smoke to mine too, using the same arrangement as Craig - 2 x 20oz Dubro tanks and a Tamjet smoke pump (I think Craig's using the Jetcat smoke unit).

Have done the back half of my UF so far, and starting on the wing. My JetCentral Cheetah should arrive any day now.

Cheers,
Colin<br type="_moz"/>

RE: C-ARF Ultra Flash build Thread + Video
 

Nils 153mm

Dave

RE: C-ARF Ultra Flash build Thread + Video
 

Hey guys, thanks for the comments so far about those new tanks from CARF. As I upgrade my flash with the new wing and stabilizer, I'm planning to add more fuel capacity. Right now I use the wing tank as my smoke tank. I also have a 1/2 liter tank under the canopy section that feeds the UAT. I think I'll convert the wing tank to become a fuel tank and put some Dubro tanks I have for smoke near the ducting above the wing like everyone else is doing.

Question, would 4mm OD tubing from the wing tank to the main tank be large enough not to cause to much hardship on the fuel pump? I'm using the DreamWorks wing tank with 4mm OD tubing attached. I don't think the barb on the tank will accommodate anything bigger. I need to take a closer look at this weekend though. I may have some tygon tubing slightly larger that might work.

RE: C-ARF Ultra Flash build Thread + Video
 

You should be able to get a 6mm tube over the 4mm, something like this, before adding the lockwires of course. ;)

http://frettavefur.net/Forum/uploadp...1273374508.jpg

RE: C-ARF Ultra Flash build Thread + Video
 

I would recommend using 6mm tubing between any tanks in series and I have always plumbed mine with the main tank feeding the wing tank which then feeds the header tank. I don't like using felt clunks in the pick up lines as I have seen them clog and cause cavitation in the fuel systems and that setup works really well for me.

I think Dave plumbs his as per the instructions with the wing tank feeding the main tank, but I think he uses felt clunks and that probably overcomes some of the potential issues caused by the flat geometry of the main tank. Each to his own. I suspect that in a cooler climate like the UK you may be less prone to fungal growth which is typically what causes clogging of the felt pickups, but in a warm climate like we have here it can cause some alarming problems (fuel cavitation) which can shut down your engine.....have seen it first hand here many times.

Hope that helps.

Kind regards,

Craig.

RE: C-ARF Ultra Flash build Thread + Video
 

Craig is correct, I use the stock set up and again would not use 2.5mm bore tube between the wing and main tank.
I don't think its just the temp, we see it here with Jet 1A users. I use a tripple refined parafin and never get clogging

I'm pushing to get the P-80SE UF ready for Sunday, finally kept a P-80SE in stock long enough to get it out of the box and start the install last night. At least all the building stuff is done other than mounting the nose door (which I have had to re make as the kit one is missing here somewhere[:@])

Dw

RE: C-ARF Ultra Flash build Thread + Video
 

14 hours straight in the work shop and I'm 97% done. Need to do the turbine cover and sort the Rx batterys position and we can finally fire it up!

Dw

RE: C-ARF Ultra Flash build Thread + Video
 

Hi Guys,

Test flew my ultra today and she went well, although she did appear to be nose heavy. I thought I had her balanced at around 220-225. I was having to carry a fair bit of up elevator trim so I will have to sort that out after confirming the current balance point. I only have two 2200mah lipos up front at the rear of the battery pockets for the receiver and the stock jetcat lipo next to the header tank for the ecu. I have alot less flap than the 100mm ( I had around 45 degrees of landing flap) that Dave uses and I was happy with the way she landed and we had only a little wind so landing speed was not an issue with the reduced flap.

She is very slippery and very quiet in the air. The other guys who were there thought she looked quicker than my classic flash. The ultra turned very tightly too. After Mark (flying his euro) and I pulled a couple of tight turns chasing each others tails, I popped landing flap, gassed her up and pulled harder and I reckon I out turned his euro! No hint of tip stall.

Only had a couple of flights so when I get her dialled in she will be even better. The Jetcat GPS clocked her at 365 kph but that should improve when I get rid of the up trim that I was carrying. One thing of note.....the trailing edge on this wing is much thinner (around 1.5mm) compared to the classic flash (around 4-5mm). That has gotta help the top end speed.

Now just gotta sort out how to get some weight further back.

Craig.

Edit: Thanks for the advice Dave. It appears that I have screwed up. I re-checked the c of g with a different method and found that my ultra was balanced at 215, not as I described above, and that is why I was carrying the elevator trim so 225 is probably going to be spot on. Thought I best report back on that so as not to lead anyone up the garden path. I will shift ecu and smoke batteries back to just in front of the engine mounting former and give her a run again this Friday, weather and wifey permitting! :D

RE: C-ARF Ultra Flash build Thread + Video
 

Craig
You can go back on the 220-225, this is a safe position that many people like, as always personal set up is required.
I also test flew the P-80SE Ultra Flash today in the colour swap blue to red (with boss induced red cheque bottom) I used my P120SX model set up, so the model was dialed in from flight one and surprised those that knew it had only 100N, it still gets a move on, take-off is about 60-70m with a breeze we had today, after one circuit full of fuel it will go vertical for about 1100-1200' before running out of puff. Full speed is over 200, I guess 220ish which is pretty good!
I flew 9 minutes and show the fuel left on a mixed flight fast/slow. All other flight was like the P-120 version. It holds knife edge as long as you like, big loops, eights etc. Couple of people said looked like a perfect sports model set-up.
We intended videoing the first flight, but mixed weather and dark clouds coming meant it didn't happen, then cameraman Trev had to leave for a jelly session :)

We will do a video next time out then its available to a new owner. QED

Dw

RE: C-ARF Ultra Flash build Thread + Video
 

Hey Craig and Dave.

Congrats on your successful maidens.
Any chance of some install pics Craig ? You always do a nice job and I am looking for ideas :)

I need some opinions on using spring airs on the UF. I have a set of Jet-1A's from my Elan that I was thinking of using.
Do you think these would be fine ? Not sure exactly why I am worried.

Made a quick video of my new K-140 if anyone is interested - [link=http://www.youtube.com/watch?v=ITwPJkW-dfk]K-140[/link]

Paul.

RE: C-ARF Ultra Flash build Thread + Video
 

Paul

Yep, I have some guys using the Jet 1A set up, it drops straight in

regards

Dave

RE: C-ARF Ultra Flash build Thread + Video
 

Thanks for that Dave.

Will give the Jet-1As a go.

paul.

RE: C-ARF Ultra Flash build Thread + Video
 

Paul... the K140 looks good. It has quite a whistle to it - do they all do that? I saw you also have an Elan. I have one too - a fantastic first jet. So easy to fly. When's your UF due to be delivered?

Cheers,
Colin<br type="_moz"/>

RE: C-ARF Ultra Flash build Thread + Video
 

Hey Colin,

I noticed that on the video it has a whistle.
I think its some band pass thing in the camera.
Sounds much more like a A380 when you are there :)
Seriously though, The camera makes it sound way different.

The Elan is a great jet. So much fun to fly. If Alan made a full composite one I would buy another (hint) :)

The UF should be here soon. Ordered it 2 weeks ago and I figure it would probably take about 3 weeks to get here.
Feeling alot better about it now i know others are using the spring airs.

Paul.

RE: C-ARF Ultra Flash build Thread + Video
 

Hi Paul,

I would go with the Jet1A's mate, every time. I will get some pics for you but there is nothing inspirational about my install....pretty much ran with a mirror image of the stock setup (modified a little) but I have a powerbox Evo in mine over the nose wheel steering servo. Have installed smoke gear up the back...pretty squeezy when you go installing smoke, and I am in the process of shifting the ecu and smoke batteries up the back....will get some pics when I have done that.

Let me know when you get yours Paul. There are a few other guys around here looking at getting one at the moment....man I should have been a comp arf rep! :D The more I fly mine the more orders Pete gets! They are a great jet.....very stable, very predictable, great for aeros and you can fly it like it is stolen and get away with it!...very forgiving airframe. I have been going into landings straight out of a full throttle vertical manoeuvre and nailing the landing....the point is you can pull of good landings even with really undisciplined approaches, the airframe is that forgiving. It has been a bit of a running joke at Whiteman......going vertical at around 300kmh and calling "in circuit for landing"...haha....no-one would take the call seriously in the beginning!

I have never really been a fan of sport jets but have loved the scale stuff. Since I got my flash it always comes to the field, even if I take one of the scaleys. It is just so much fun to hot dog around the sky with it.

One the topic of the c of g, I am putting 2x 2200mah lipos just in front of the engine bulkheads.....when I am not using smoke I will y-lead them together and use both to run the ecu. When using smoke I will disconnect one of the batteries and put that straight into the smoke pump, so I don't have to install an additional battery to use the smoke system, that way I won't have to mess around with the c of g, when using smoke.

Craig.