70mm set - up
08-29-2011, 04:09 PM
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70mm set - up
Ok,,heres the skinney,,Im about to buy a 70mm EDF jet,,,now being new to the EDF family I'm lacking Equipment know how,,never being saticfied with stock equipment,,,I would like to get some input on a very hot 70mm set up,,( when fast ant fast enough) the models in mind are eather a Viper jet or a L-39,,,I'ed be very thankfull for any input in this quest for max knotage
08-30-2011, 07:13 PM
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RE: 70mm set - up
If you have a 70mm fan unit in mind...like the wemotec minifan pro...select a motor according to your battery. See if you can fit a 6 cell, of good capacity., i.e. a 6 cell 2200mah 40C or 2650mah 40C and then see if you can find a motor KV to suit the pack voltage, i.e. 6 cell is 25.2 (somewhat like 22-24 under load). The minifan pro max rpm is 48,000. (they can be pushed...the fan is factory balanced, don't damage it) So some math...50,000 equals 25 volts times 2000 rpm. Your motors should be something like 2000 to 2500 kv. (Cyclone CS480-2500-32EDF).
On the 25 volt 2500 kv motor like mine, the power level is over 1400 watts. I'm running a different fan unit though, a WM400.
To judge your top speed you consider, power to weight ratio, AND drag coefficient. So for your 'MAT IT AND WEAVE' max speed, keep the thrust up over the weight, and keep the gear up, good luck. Gear has to be up at top speed or it could be damaged.
Hope you have experience with HOT aircraft. EDF jets get from one end of the field to the other in a heartbeat, and you need expo throws to calm down the controls. When they are moving, you have to be small and smooth.
On the 25 volt 2500 kv motor like mine, the power level is over 1400 watts. I'm running a different fan unit though, a WM400.
To judge your top speed you consider, power to weight ratio, AND drag coefficient. So for your 'MAT IT AND WEAVE' max speed, keep the thrust up over the weight, and keep the gear up, good luck. Gear has to be up at top speed or it could be damaged.
Hope you have experience with HOT aircraft. EDF jets get from one end of the field to the other in a heartbeat, and you need expo throws to calm down the controls. When they are moving, you have to be small and smooth.
08-30-2011, 07:55 PM
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RE: 70mm set - up
Hay ace thanks for the tech tip,,,its still a little greek to me but I'll go slow and get schoolin on this new linggo,,,,I've decided to go with the sapac viper jet,,,I allways wanted to get into jets but thats big $$ no matter how ya put it,,,,then I saw some youtube footage and was really impressed on the performance,,,electric flight has come a long way,,,back in the day weak at best,,,I liked your comment on turning down the rates,,,,it also hides the new plane shakes,,I'm sure I'll be posting alot of questions,,,can get alittle pricey burning up equipment,,,thanks again
09-07-2011, 02:25 PM
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RE: 70mm set - up
The Viperjet is not a beginners model, and it flies like a pig if too heavy, its best kept light and bungee launched if you want to keep it more than a couple of flights. My advice to any EDF beginner is start with foam, and learn the characteristics of the genre, EDF models are different to prop models and starting with a heavy composite often leads to disaster and an empty pocket.
A good 70mm foamie like an F18 or Hawk is the way to go, you can get a decent 70mm power system to go in it and the performance will be very good, more than enough to satisfy you at the start. And if you buy the right gear first up you can transfer it to another model like the Viperjet down the track.
6 cells is not the way to start out in EDF, you want less complexity and light weight. The Wemotec Minifan PRO is the best 70mm out there, it consumes less amps to do the same work as the WM400, and sounds a LOT better too. If you add something like an HET 2W18 V2 Typhoon motor to the fan you will have a great 4 cell setup that can run on 2600-3200mah 4s packs, puts out around 1.5kg thrust and is very lightweight. ALso not expensive.
I would steer clear of epf alloy fans for now, they are heavy and not as efficient as the wemotec, you will be consuming the same amps but producing much less thrust and carrying more weight at the same time.
If you stick to the ideology of lightest weight &, best efficiency when choosing fan/motor combos, you will have a good basis for successful jets, and I dont mean just getting something to fly, I mean creating a model that flies superbly, is nimble in the air, has a resonable landing speed, and because of all this lasts a long time!
A good 70mm foamie like an F18 or Hawk is the way to go, you can get a decent 70mm power system to go in it and the performance will be very good, more than enough to satisfy you at the start. And if you buy the right gear first up you can transfer it to another model like the Viperjet down the track.
6 cells is not the way to start out in EDF, you want less complexity and light weight. The Wemotec Minifan PRO is the best 70mm out there, it consumes less amps to do the same work as the WM400, and sounds a LOT better too. If you add something like an HET 2W18 V2 Typhoon motor to the fan you will have a great 4 cell setup that can run on 2600-3200mah 4s packs, puts out around 1.5kg thrust and is very lightweight. ALso not expensive.
I would steer clear of epf alloy fans for now, they are heavy and not as efficient as the wemotec, you will be consuming the same amps but producing much less thrust and carrying more weight at the same time.
If you stick to the ideology of lightest weight &, best efficiency when choosing fan/motor combos, you will have a good basis for successful jets, and I dont mean just getting something to fly, I mean creating a model that flies superbly, is nimble in the air, has a resonable landing speed, and because of all this lasts a long time!
09-07-2011, 03:43 PM
#6
RE: 70mm set - up
anybody know about the MOTOTURBINE unit ?
Never heard of it, why don't you tell us? Photo would help also? Website, cost, where to get it?
Charles
10-02-2011, 08:19 PM
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RE: 70mm set - up
Get w wemotec minifan pro.. Motor of your choice based on the #of cells you want to run... The het motors work good.. ExtremeRc is pretty knowlegeable and I would take his advice.. and every aluminum EDF in that size range that I have seen so far is a POS compared to the wemotec... In weight, price, and performance...
10-03-2011, 08:25 AM
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RE: 70mm set - up
Scotch19,
A great firts EDF si the HET F-18 single fan 70mm. It's cheap, easy to build. and flies great. It's strictly a bungee or hand launch bird (I recommend bungee). Flies great on a Wemotec Mini Fan Pro. Some reasonably priced motor choices are the Mega 16/15/2 (3 cell), Mega 16/15/3 (4 cell) or the HET 2W (3 Cell) HET 3W (4 Cell), HET 2W-20 (4 cell).
It's available from Electric Jet Factory. The Blue Angel version is easier to see and maintain visual orientation with.
Rob
A great firts EDF si the HET F-18 single fan 70mm. It's cheap, easy to build. and flies great. It's strictly a bungee or hand launch bird (I recommend bungee). Flies great on a Wemotec Mini Fan Pro. Some reasonably priced motor choices are the Mega 16/15/2 (3 cell), Mega 16/15/3 (4 cell) or the HET 2W (3 Cell) HET 3W (4 Cell), HET 2W-20 (4 cell).
It's available from Electric Jet Factory. The Blue Angel version is easier to see and maintain visual orientation with.
Rob
