Depron Eurofighter

[James Kane 1]

Hi Guys Anyone out there willing to guide me to a suitable selection of motor esc and prop for a 700mm span 750g Depron Eurofighter I'm literally frying my brain looking at all the selection and trying to make a choice. As you'll be probably be aware by now my experience of electric is very limited and I don't want to make the wrong choice. my current Eurofighter is currently fitted with a 2830 1100kv with a 8x4 and 3s lipo and the performance is a bit disappointing. I'm looking for it to have the performance of a fast jet. Any help on this would be greatly appreciated. Any recommendations out there? Thanks in advance Regards Jim Kane

[Nigel R]

Probably need at least 400W+ for speed on that sort of size/weight.

I have measured a 2836 2200kv motor on a 6x4 prop, at 350W on a 3S lipo. You'd want 30A ESC minimum for that.

Might want to go with a 40A ESC in case you need to fit a bigger prop for more power, 6x5 or 6x6.

I don't know what size lipo you use now. A 3S2200 might only give 5 minutes flight time, you may need a 3S3000 for more duration. Again if you go to a bigger prop, you might want the bigger lipo.

Obviously if that's a lot more lipo than you have fitted, then the weight starts going up and you may need to think about more than 400W.

Google Multiplex Funjet, lots out there - lots of people using different setups for varying amounts of quickness, in a similar size model.

[Simon Chaddock]

It might help if you can give some details of the construction of your Depron Eurofighter before you start to upgrade the performance.

Depron as a material has limited strength and stiffness so it could be that the original set up was chosen for a valid reason

If we assume your Eurofighter is correctly set up and it is a Hobby King Propdrive 2830 1100kv then it is rated at 26A max so maybe more power is as simple as going to a 4s LiPo battery. With thhe same prop it would give nearly 50% more power.

If you want to play around increasing performance you would be well advised to buy a Watt meter. This will give you a real time reading of exactly how many Amps and Watts it is taking. More to the point it also means you can stop a test before you "fry" something!

A new 40A ESC will be required unless the existing one is rated for 4s.

With the same mAh capacity a 4s LiPo will weigh 1/3 more but that is about as much added weight as I would recommend.

Note you don't get "something for nothing" so the full power endurance will also be reduced but hopefully you won't need to use full power all the time.

Edited By Simon Chaddock on 07/11/2018 12:58:57

[eflightray]

700mm span is quite small. The HK Glue-N=Go F35 is 960mm span, is a profile build, (not built up body, and the recommended motor is 2208 -2216 1600-2000kv and turning a 6" prop, the APCe 6x5.5 is a good one as you need pitch speed to go fast.

I'm using a 2208 -1800kv motor on 3s, I would probably go for a 2000 -2600kv in the 22.. range motor if you want really fast.

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[John Robertson 3]

James Kane 1 - it sounds like you've got the "Eurofighter Typhoon Kit" by GrahamGooch at

https://www.norwichmodelaeroclub.co.uk/eurofighter-typhoon-kit-new-improved-version

I have 2 - one flying, one yet to be built, once I have learned how best to both build it (light) and fly it properly.

The built one is a bit heavy at 834gms (my fault - I can never resist "improvements". I have a 3S 2700MAh pack in it, which is a bit heavy and doesn't help weight. The motor is a 2838 8-turn 1100KV outrunner, of supposedly 336 Watts output. I ran some power tests with the pack at 40% capacity and the results were:

8x4 12.9A 138W, 8x6 17.4A 184W, 9x6 18A 194w, 10x6 18.5A 198W, 11x4.7 3D flexy stunt prop 26A 272W.

Later, I checked the 11x4.7 prop at 100% pack capacity and got 30A 370W.

I practice, I'm running the 10x6 prop which, at take-off, should be outputting about 250Watts for a short time.

Once launched, the plane will go straight up. Rolling too, if you wish! I find that this truly vertical performance is, with a fully charged pack (and an overweight airframe/battery pack, remember), perfectly capable of being sustained to the absolute limits of my eyesight, to the point where I'm not too sure if it's still going the right way or not.

Is that enough information for you to work on?

 

Edited By John Robertson 3 on 13/11/2018 15:20:55

[Dave Hess]

Most likely, you don't need to change anything other than the battery. A 4s battery will give you a 33% increase in power (approx). You have to check that your ESC is rated for 4S as many are only rated for 3S. Sometimes, it's written on the ESC, otherwise you have to loo it up in the listing. An 8x4 prop sounds way too small to me for an 1100kv motor with 3S. Is there a reason you've gone so small. I'd have thought that around 10 x 6 would be better for that motor, and I'd be using a 9x5 at 4S.

If you're stuck with that size propeller, i think a 2000kV motor would be more like it with 3S and something like 1500kV with 4S.

I've started doing motor thrust tests with different propellers for all my motors. I made a thrust meter. it's not properly calibrated, but it's good for comparisons. I haven't tested my 2830 yet, but my 2815 910kV does about 1.25 kg with a 4S battery and a 9 x 4.7 propeller at only 19 amps. That compares with about 900g thrust at 3S drawing 18 amps with a 10 x 4.5. With a smaller propeller, the current and power will be a lot less.

Edited By Dave Hess on 13/11/2018 17:18:25

Edited By Dave Hess on 13/11/2018 17:21:00