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Old Sep 10, 2010, 11:27 AM
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53859 Niederkassel, Germany
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Originally Posted by Ben D Wing View Post
IMHO, as the thin plastic tail cone is simply cyanoed to the thin section foam at the rear of the fuselage I believe the alloy mount is simply not required. It's simply a marketing ploy and purely a bit of 'bling'.
Well, I see it differently. Running an efficient motor (approx. 80% at 400W) creates only 80W in heat losses. The plastic mount stays cool.

Doubling the input power, while lowering motor efficiency (65% at 900W) requires getting rid of up to 315W in heat losses - thats approx. 4 times more.

The special Himax 2900kv outrunner has a fairly efficient integrated fan, but the alu mount acts as an additional heat sink for the stator. If it wasn't required, MPX would not have used it. The plastic mount getting soft and warping may be fatal for the model.

Jürgen
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Old Sep 10, 2010, 11:47 AM
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What set up will give me flat out 150mph or more constant speed for at least 5mins without any of this fustrating and annoying, bust, throttle management style of flying, which I can easily overcome with my high power nitro, tuned pipe sets ups.
I want 5 mins constant high speed concentration to get my adrenalin fix.

I flew the original funjet on a 2w-20 4s, but it was all noise and no real speed, it just looked faster because it was smaller, clocked at 124 mph.
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Old Sep 10, 2010, 12:02 PM
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Originally Posted by mk1spitfire View Post
What set up will give me flat out 150mph or more constant speed for at least 5mins without any of this fustrating and annoying, bust, throttle management style of flying, which I can easily overcome with my high power nitro, tuned pipe sets ups.
I want 5 mins constant high speed concentration to get my adrenalin fix.

I flew the original funjet on a 2w-20 4s, but it was all noise and no real speed, it just looked faster because it was smaller, clocked at 124 mph.

All out constant speed for five minutes? 150mph? I don't think there is such an animal that will go in a funjet. Jurgen, care to take this one......
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Old Sep 10, 2010, 12:27 PM
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53859 Niederkassel, Germany
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Originally Posted by mk1spitfire View Post
...
I want 5 mins constant high speed concentration to get my adrenalin fix.

I flew the original funjet on a 2w-20 4s, but it was all noise and no real speed, it just looked faster because it was smaller, clocked at 124 mph.
5 Minutes is a lo...ng time, depends what you are doing. Flying just fast from one side to the other side can be rather boring, as it is rather easy.

Flying 10 times around a pylon course may give you the adrenaline fix you are graving for - especially when a few other models are on the course with you - and when you are fast, it takes less than 60s.

If you really want something fast for 5 minutes, you need something like an F5B model. Instead of tuning it for climb rates of up to 70 meters per second, you set it up for speed. Instead of using 3000 to 5000W for two to three second climbs, you set the the model up for 1000W continuous. A 6S 5000mAh pack would give you that kind of power for 5 minutes and you'd still have approx. 17% capacity left in your pack for "emergencies".

But you also might use just a 6S 2500mAh pack, enjoy the better power to weight ratio and the agility of the lighter model, land after 2.5 minutes and swap packs. The variations are almost endless.

Jürgen
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Old Sep 10, 2010, 01:01 PM
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Thanks Jurgen for your input.

Whilst i appreciate that this thread is dedicated to the ultra funjet. I hope the relevance of overcoming 'BURST" flying can be overcome even at slightly lower speeds, including the funjet.

To me the this is the one obsticle that stands in the way of making the transition form nitro models to electric.
I can see the cooling is the issue, especially on the funjet where no new modlified design has been learnt from the previous funjet.

yes, flying high 'U' can be boring at high speed but time is of no relevance when you are concentrating on keeping clean momentum on the model. You can break that mold and a fly random to though.

10mins of pylon racing does sound exhausting.!! I looked already, and there are no event clubs near me.

I take it your suggestion of F5b was for the fact that you could actually fit a 6s pack in the fusalage? i hear you about lowering the watts for average speed!!

By the way I still have some multiplex primer left that I used to coat the underside of my previous funjet before applying acyrilic paint. I was told that this primer from my model shop was now banned in the EU. Any truth in that? I think it etches the wax coating found on the elapor foam to provide a key for painting.

I always remember gyphon's comment in another funjet post about a particular mega motor being an "AMP PIG".
That always makes me chuckle.!!

Heres a question.
What set up and modifications would give the most speed for a funjet ultra flying a constant 5 mins at full throttle?
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Old Sep 10, 2010, 01:21 PM
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Originally Posted by mk1spitfire View Post
Thanks Jurgen for your input.
...
I can see the cooling is the issue, especially on the funjet where no new modlified design has been learnt from the previous funjet.
...
10mins of pylon racing does sound exhausting.!! ...
You are welcome.

Cooling is actually not an issue in the FunJet providing you run a highly efficient drive system.

Fun Fly Racing lasts 3 minutes WOT around three pylons and ends with a precision landing. The motor of my 500W setup in my FunJet is barely warmer than ambient temperature, the ESC is cool and the 3s/2200mAh battery pack has warmed up by approx. 20°C. I could immediately put another battery pack in there and race again. After about 2 minutes of racing, you may start feeling a bit dizzy and you really have to concentrate.

It did not say 10 minutes, but 10 laps.

If you have a fast model, you can do 10 laps in under 60s !!!!

Jürgen
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Old Sep 10, 2010, 01:29 PM
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Originally Posted by Jurgen Heilig View Post
You are welcome.

Cooling is actually not an issue in the FunJet providing you run a highly efficient drive system.

Fun Fly Racing lasts 3 minutes WOT around three pylons and ends with a precision landing. The motor of my 500W setup in my FunJet is barely warmer than ambient temperature, the ESC is cool and the 3s/2200mAh battery pack has warmed up by approx. 20°C. I could immediately put another battery pack in there and race again. After about 2 minutes of racing, you may start feeling a bit dizzy and you really have to concentrate.

It did not say 10 minutes, but 10 laps.

If you have a fast model, you can do 10 laps in under 60s !!!!

Jürgen
I'll think I'll skip on the pylon as that often means standing in the middle and it goes back to control line days of feeling dizy sick from monotonous circuits!

I thought you fun fly racing pylon guys were true hard core and could hack 10mins!!
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Old Sep 10, 2010, 01:32 PM
You down with EPP?
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Originally Posted by mk1spitfire View Post
I'll think I'll skip on the pylon as that often means standing in the middle and it goes back to control line days of feeling dizy sick from monotonous circuits!

I thought you fun fly racing pylon guys were true hard core and could hack 10mins!!
You need an F5D to fly at those speeds for 5 min. It would be great to fly longer, but we are talking about batteries dude. I think there is a misunderstanding here.

I get about 3 minutes out of my speed 400 pylons. I get about 41/2 minutes out of a 4S Funjet, and that is with throttle management. If you want longet times, you will need a 5000mah pack. I don't think anyone is fitting batteries that big inside a Funjet fuse.
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Old Sep 10, 2010, 01:36 PM
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Originally Posted by mk1spitfire View Post
...
Heres a question.
What set up and modifications would give the most speed for a funjet ultra flying a constant 5 mins at full throttle?
If you want to fly for 5 minutes WOT, you don't necessarily need a FunJet Ultra, because you'd only carry additional weight around.

If you want the Ultra because of its stiffer structure, OK, so be it:

The recommended drive system is good for approx. 200kph (straight and level) and your battery will be down to 20% after approx. 138s at WOT. Using a 3S/4000mAh Topfuel Lipo (weighs only 30g more), you'd get approx. 172 minutes, or almost 3 minutes. I would not go for a heavier battery, because I like my model to handlauch easily.

If you want 5 minutes WOT, you either use a smaller prop and sacrifice speed for duration, or you land and swap batteries. Using a more efficient drive system will allow you, to gain some of the speed back, while keeping the duration at 5 minutes. Personally, I am happy with approx. 3 minutes at WOT and would use the extra efficiency to go faster.

Jürgen
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Old Sep 10, 2010, 01:40 PM
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Originally Posted by mk1spitfire View Post
I'll think I'll skip on the pylon as that often means standing in the middle and it goes back to control line days of feeling dizy sick from monotonous circuits!
...
Standing close to the baseline? Yes. Monotonous? No way. You are not flying circles, but straight lines interrupted by various turns, and when you are flying head to head at close distance, you get your adrenaline fix.

Jürgen
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Old Sep 10, 2010, 01:58 PM
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Originally Posted by Jurgen Heilig View Post
Standing close to the baseline? Yes. Monotonous? No way. You are not flying circles, but straight lines interrupted by various turns, and when you are flying head to head at close distance, you get your adrenaline fix.

Jürgen
You ever measure your pulse before and after?

Anyway do you believe removing the wing pods on the ultra adds much speed by reduced drag?
I miss them as they gave the old FJ some character, kind of like a Clingon space ship look.
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Old Sep 10, 2010, 03:26 PM
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Originally Posted by Jurgen Heilig View Post
.......If it wasn't required, MPX would not have used it. The plastic mount getting soft and warping may be fatal for the model.

Jürgen

If the plastic mount gets soft and distorts, that will will be the least of your problems as the motor will be so hot it'll probably be ready to give up the ghost and release some magic smoke!
Just a thought, why don't MPX supply the metal mount as standard if it's so critical? After all, people aren't bound to use the power set and will fit their own hot(sic) motors of choice simply using the plastic mount. My plastic mount is OK so far.
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Old Sep 10, 2010, 03:37 PM
You down with EPP?
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Originally Posted by Ben D Wing View Post
If the plastic mount gets soft and distorts, that will will be the least of your problems as the motor will be so hot it'll probably be ready to give up the ghost and release some magic smoke!
Just a thought, why don't MPX supply the metal mount as standard if it's so critical? After all, people aren't bound to use the power set and will fit their own hot(sic) motors of choice simply using the plastic mount. My plastic mount is OK so far.
I haven't seen the aluminum mount sold seperately through Tower yet.

The Ultra kit was supposed to be in stock by now, but of course no luck.
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Old Sep 11, 2010, 01:21 AM
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Originally Posted by mk1spitfire View Post
...
Anyway do you believe removing the wing pods on the ultra adds much speed by reduced drag?...
Some guys swear, the model was faster after cutting off the "tiptanks" on the normal FJ, some did not notice any difference.

As the Ultra is heavier, it comes in faster during landing. If you land in grass, the new rounded leading edges of the Ultra reduce the risk of damaging the wingtips.

Jürgen
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Old Sep 11, 2010, 01:33 AM
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53859 Niederkassel, Germany
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Originally Posted by Ben D Wing View Post
...
Just a thought, why don't MPX supply the metal mount as standard if it's so critical? After all, people aren't bound to use the power set and will fit their own hot(sic) motors of choice simply using the plastic mount. My plastic mount is OK so far.
It is not critical when you use the "normal" FJ drive set. For all others there is Warning in the instruction manual:

CAUTION:

The plastic motor bulkhead is only suitable for motors with an input power of up to 330 W, e.g. for the power set, # 332630.
If you intend to fit the ULTRA Tuning power set, # 33 2647, or a similar high-performance motor, it is a fundamental requirement that you install the aluminium motor bulkhead, # 33 2606, as supplied in the Tuning power set mentioned above.


MPX could have put the alu mount into the kit, but that would have most likely caused the kit to exceed €100.- list price. Adding the alu mount to the Ultra drive set, will also help selling the orginal drive sets.

Jürgen
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