RE: Comp ARF Flash update
 

the new style wear rather quickly on concrete though

RE: Comp ARF Flash update
 

Yes, Ron, I did have a jet column in RC/Report Magazine years ago...As a matter of fact I used pictures and text in at least one of my columns of at least one of your models that you or one of your pals sent over to me from "across the pond"!!!...I have every issue and it would bring back wonderful memories to read them again...If my memory serves me correctly, you covered your models with brown paper and I inquired about the process...

I'm considering a CARF Flash and if I do give it the nod I will install a P-120 in her...That 3.5 litre tank would do nicely for the amount of duration I would need for that thirsty turbine...Please post pics if you can and tell me...How much would you charge for the tank if you were so inclined to mould an "extra"!!!!:D.....

Kevin

RE: Comp ARF Flash update
 

Hi Kevin, I hadn't realised that you didn't already have a Flash. My fuel tank (with a collector sump) is fitted at the expense of the by-pass system. I acquired my flash second hand with a missing coupling duct from the intake to the by-pass pod. I only intended to fit a Wren ss so i wanted to keep the model as light as possible. I dispensed with the by-pass pod and rear dual wall ducting to save weight. I fitted the Wren single wall augmentor thrust tube with some ceramic insulation wrap which works fine. The tank was constructed from an initial blue foam mould which is destroyed when extracted from the outer glass mould so no, I wouldn't want to attempt a second one. At my time of life my time is the most valuable asset I have left. I will post some stage by stage pictures to illustrate how easy the moulding process is. Buy the model you won't regret it. There is some valuable comments and suggestions in this thread that helped me through the test flights. Ron.

RE: Comp ARF Flash update
 

Kevin here are the sequential pictures of my fuel cell made from a blue foam mould, Ron.

http://i687.photobucket.com/albums/v...ust123/010.jpg

http://i687.photobucket.com/albums/v...ust123/015.jpg

http://i687.photobucket.com/albums/v...ust123/014.jpg

http://i687.photobucket.com/albums/v...ust123/022.jpg

http://i687.photobucket.com/albums/v...st123/0212.jpg

http://i687.photobucket.com/albums/v...ust123/020.jpg

http://i687.photobucket.com/albums/v...ust123/023.jpg

RE: Comp ARF Flash update
 

Anyone using the Pro-Link retracts from Dreamworks? Just ordered a set, will be ready to throw the old junk pinstyle units out the window.

RE: Comp ARF Flash update
 

I'm using them but only on the mains. It's good to be pinless. No more set screws and flat spots. Makes adjusting toe in very nice too.

RE: Comp ARF Flash update
 

Yea thats the reason Im making the switch, I had the prolink struts anyway, but the tolerances with those and the wheel wells are so tight that it the toe changes any the gear can bind and either not go up or come down all the way. The pins are just horrible for getting a set amount of toe, we made perfect grinds at the machine shop and still can not get them to hold over time.

RE: Comp ARF Flash update
 

Skymac:
My friend has the delux combo from Dreamworks and they are a pain to install. The retracts are a lot bigger than the stock restracts and you will need to do a lot of wood grinding and even cutting (You have to cut the main retracts and drill new holes). I recommend buying the straight legged struts that use the 6 mm pins. That way you can use the stock retracts and still have trailing links. This is what I did but I also replaced the stock 6mm with harder steel 6mm pins; or you can drill out the holes for 8mm as some have done.

RE: Comp ARF Flash update
 

i drilled and reamed my mains only out to 8mm, then loc-***'d the pins and grubs with no grinds on them, they've held with no slipping and no braking at all.

RE: Comp ARF Flash update
 

After taking an age to build Ifinally maidened my Flash last weekend. Everything went well and the model is quite 'solid' in the air. P-80 just about provides enough push and is relaxing but not particularly fast.

The model still needed a bit of nose weight even with the big Weatronic up front and only a P-80 on board. Iwill be swapping out the ECULipo for ahigh capacity Nimh battery for extra weight.

Unfortunately, whilst disassembling it after the maiden, the craft cuddler stand it was on blew over and the model dropped from about 3 feet. This caused a bit of damage to the fin which is a shamehttp://www.rcuniverse.com/forum/js/f.../sad_smile.gif

RE: Comp ARF Flash update
 

Hi friends !
My Flash with P120is ready for the first flight.
Can you say me, which settings you have on your Flash.
The manual settings are good or is there too much ????
Thanks
Regards
Nick

RE: Comp ARF Flash update
 

the aileron suggested in the manual are a little quick for some people it just depends on your flying style, everything else gives you a good smooth flier.

RE: Comp ARF Flash update
 

Ithink Ihave the aileron throws as per the manual with 30% expo. This is nice for me but aileron rolls are very quickhttp://www.rcuniverse.com/forum/js/f...eeth_smile.gif

RE: Comp ARF Flash update
 

Nick, read the earlier postings on control settings. I agree with the previous posts also I reduced the travel of the flaps both for take off and landing. I can't comment on the recomended settings but enough people have experienced pitch instability withe these settings that it will do no harm to reduce them and then increase after you get acustomed to the flight characteristics, Ron

RE: Comp ARF Flash update
 

Thanks Guys !
I hope that i can take the maiden this weekend.
Regards
Nick

RE: Comp ARF Flash update
 

<span style="font-size: medium;">Hi Guys,

Test flew my flash last sunday with the new wren 160 engine. CG was at 365 mm from the rear of the tip tanks. T/O flap was at 15 mm and landing flap was 50 mm. After rotation the plane took about 2-3 mm of up elevator to fly level and felt a bit nose heavy, after trimming, i had a great 5 min flight in clean configuration. After selecting gear down the plane again got her nose down which is normal. I selected flap 1 and the plane dived some more towards the ground, selected landing flap and the nice flight so far got pretty hairy with the PIOs. I was really struggling to fly the plane in landing config.
My question is if the plane is tail heavy, </span><span style="font-size: medium;">why did she take a fair bit of up trim to fly level.And if she is nose heavy, why did she go into the PIOs.</span><span style="font-size: medium;">
I am a bit confused now if i should add a little nose weight and get the CG to 370mm or remove some weight and get the CG to 360 mm, or leave the CG alone and just decrease the flap throws.
I was using flight modes on the 12x, and had trimmed the plane in clean config, so when i selected flaps i must have lost all the up trim i gave in clean config which must have added to the PIOs.

Thanks for any inputs
Chaitanya.
</span>

RE: Comp ARF Flash update
 

Had the same problem. Simple fix was to redcue the flaps and it was very easy to land than.

RE: Comp ARF Flash update
 

Had the same problem on my maiden. Reduce flaps to 40-45 mm and balance at mid-range of published c/g.

RE: Comp ARF Flash update
 

i found with mine, 362mm worked out to perfect neutral trim, where all surfaces are lined up flush and best of all, no trim change between slow and high speed flight with it cleaned up. it's so neutral that at modest speed you can slow roll for a mile with just aileron and not loose altitude.

RE: Comp ARF Flash update
 

Ditto for me, reduce the landing flap and the nose down pitch is small enough to control on elevator without needing a mix. I bet the flash causes afew headsto turnin India, where do you fly? Ron

RE: Comp ARF Flash update
 

Hi Ron,

What is the amount of landing flap you have on yours? I have 50mm on mine but even with T/O flap of 15 she had a tendency to nose dive.
I did not fly for long enough with T/O flap so cant say much., I will try flying her for longer with T/O flap next time and see how she goes.
Another problem i am having is the intakes are small on the flash and the engine is the wren 160 which sucks inn a lot of air and i had the engine stall as there was lack off air. We fly in Mumbai in temps of 35degrees c, this combined with low pressure gives us a high density alt.
Any of you guys flying the flash with 35 lbs turbine faced this problem. I may have to cut 2 additional naca ducts on the side of the fuse to solve the problem.
Ron, i fly in Mumbai and on our feild we have a few bvm jets, 2 Sg hawks, an Avonds rafale, F16, Aw L39 and a few more so the flash was just an other sport jet in the sky .

Regards
Chaitanya.

RE: Comp ARF Flash update
 

Hi Chaitanya, Your query prompted me to rig my model and double check the flap throws. Like you I have 15 mm deflection for take off and 35 mm for landing. I fly from a grass strip and have a Wren ss for power. I find I have to use a fair bit of elevator to get the model to unstick andyou have just reminded me to dial in a few clicks of 'up' elevator trim for take off. The landing flap deflection allows me to 'draw' the model in using a resonable amount of power. The speed bleeds off quickly when I close the throttle and the landing becomes very manageable. Flying from a grass stripwith a restricted length runway ensures that every landing is like a carrier landing.
Apologies for under-estimating your jet activity. I wish I had the same level of jet support in my club. Re. the intake area, as a former D/F flyer I am particularly interested in duct design and the Flash does seem to have sacrificed 'form over function' but I am no expert. This forum is testiment to the number of people who have experienced over heating for whatever reason. However the good guys seem to have it mastered and fly with turbines of similar size to yours although the factory addition of naca inlets at the rear bears testiment to the underlying problem. I fly without a by-pass and have experienced no problems with the rear end being only slightly warm. I use a Wren augmenting thrust tube with a 2mm ceramic blanket for insulation. Ron.

RE: Comp ARF Flash update
 

Chaitanya, are you running the full bypass??

it gets hotter than 35C here where I'm at, but we're only 300' ASL and with the Titan SE I've never had any issues, i do not run the lower bypass cover or the inlet ducting, this way the turbine can draw air from the fuselage (mainly the nose wheel hole)

RE: Comp ARF Flash update
 

Hi Kc36330,

I am running exactly the same setup as yours, no lower bypass cover and not used the inlet joiner. Infact i think i copied your setup which you posted some where here on rcu a while ago.
I think the wren and jc may have different compressor designs, and the wren manual says that this engine needs a fair amount of air to run.
The engine only stalls if i slam open thrust from idle to full. If i gradually open thrust from idle to full the engine performs flawlessly and runs very sweet even at full thrust.
Any idea what would be the best place on the fuse to cut the naca ducts, just incase i decide to take that route.

Regards
Chaitanya.

RE: Comp ARF Flash update
 

if i had to cut them, I'd do it just forward of the wing on the bottom between the two inlet ducts.