Max thrust from GWS 50mm fan w/ brushless?

[proptop]

I see a 12mm (Fiegao, sp?) brushless motor available for the GWS 50mm fan unit...

Anybody got any experiences with such a power package and what would be the max thrust you would say is possable?

Thanks...

[Dr Kiwi]

If it is the 4100 you can't, safely, push more than 5-6A through it, and there is no way you'll get 10oz.

Here is what I got on my Thrust Stand:
Feigao 4100 in EDF50 (2030x5 impeller)
10.6v, 4.15A, 43W, 32880rpm, 93.4mph, 104g, 3.66oz, 2.42g/W

If it is the 5300 it goes over its limit (5-6A) at only 10v on the PS, (I didn't dare try it on 3s equivalent - say, 10.6v) and it only gets you a little bit more:
Feigao 5300 in EDF50 (2030x5 impeller)
9.8v, 6.20A, 61W, 36720rpm, 104.3mph, 126g, 4.44oz, 2.07g/W

Cheers, Phil

[watt_the?!]

good post Dr. Phil....interesting too, i had no idea eh?...

thanks.

tim.

[proptop]

Thanks guys...
So we can figure on around 3.66 - 4.44 (approx.) oz. thrust and perhaps 90-105 m.p.h. pitch speed?

Reason I'm asking is not for an airplane, but for a top speed record attempt for slot cars (!:))

There's a site called www.oldweirdherald.com (http://www.oldweirdherald.com) and a bunch of us are bantering about with the idea of a loooong straightaway for setting max. speed r4ecords with 1/24 scale slot racers.

The motor/wheel driven record is somewhere around 200 m.p.h. but there is no category (yet) for thrust driven cars...

We're envisioning a car like Art Arfons "Green Monster" or the "Thrust II" types...

Things like converting 16V. @ the track braided pick-ups to work with the ESC and various other items are things we need to work out...


I can post a link if any of ya'll are interested in a different sort of challenge...;)

edit: Here it is...http://www.oldweirdherald.com/slotcartalk/showthread.php?s=&postid=129266#post129266

[proptop]

Phil...
Being a racer, or using that mentality, how hard do you think one could push such a power unit for say...oh maybe 10 seconds???

[Dr Kiwi]

good post Dr. Phil....interesting too, i had no idea eh?...

thanks.

tim.

Hey Tim - just a thought - how did you manage to completely remove your original post - I occasionally want to do that, but find I have to leave at least 3 characters in it??? Some special moderators trick?

Cheers, Phil

[Dr Kiwi]

Phil...
Being a racer, or using that mentality, how hard do you think one could push such a power unit for say...oh maybe 10 seconds???

Only one way to find out!

[Tim Wolff]

http://www.balsapr.com/catalog/motors/1208DFThrust.asp

[watt_the?!]

:D Tim, excellent reference...never seen it before.

[roccobro]

Here is a link to some numbers I got with a Medusa 12mm motor on 4s. You might also want to check out an EDF-40 with the Feigao 5800 motor on 3s. It lives happy with a heat sink. The 4s 4000kv setup is still being tested in some A-10's.

http://www.rcgroups.com/forums/showpost.php?p=3947456&postcount=22

Justin

[keven64]

- with a Feigao5800kv motor ! :D

I gave up worrying about the performance figures advertised at BalsaPR...

proptop,

I have flown my 28" Starjet ( pictured below ) for six months - with a 5800-powered EDF-50 on 3S-1500 packs... :)

A 5800 in an EDF-50 with a 5-blade rotor will draw around 7.5A.
A CC Phoenix is perfect, but it WILL cut the power if your battery capacity is too small...

Thrust is almost 6.5oz static for the first minute or so, dropping to around 6oz after that.
My Starjet weighed 8oz. :D and so performed quite well.

One problem... after about 4 minutes of flight, no matter how you treat the throttle, the little motor will get so hot that the shaft MELTS the hub of the ABS rotor - and it goes PZZINNGG - out the air intake - if you're lucky ! :eek:
( More often than not it cuts into the depron and lodges itself... )

This is with TWO heatsinks fitted to the back of the motor !

In fairness, Blasa PR do advise not to run the motors at more than 5 or 6A - but if where would we be if all followed advice like that...? :D

NOTES

Pitch speed - you're never going to get anything that the EDF-50 PUSHES along to reach those speeds ! ;)
THE motor for an EDF-50, is a 5300 Feigao - on 3S - with TWO heatsinks fitted

So - I can advise you that in a slot car, you'll get away with much more than 10 seconds on 3S ( 11.1v nominal ) providing your controller is man enough ( ie not a Tsunami ;) ) and your battery has a high enough C rating... :cool:

Keven. :)

[keven64]

proptop,

BalsaPR's figures state only 6.6A on 11.1v - with the 5-blade rotor...

That's bench testing ! :)

No model was flown at the 'local patch' to arrive at those figures...

Also, there is no mention of the length of the ducting that was used, or the size of the cone used as a tailpipe to increase static thrust... if any at all ?

Note that weight, and drag ( surface finish ) all play a part in the performance of a model anything...

Good luck with your record breaking slot car, by the way... ;)

Keven. :)

[Dr Kiwi]

proptop,

BalsaPR's figures state only 6.6A on 11.1v - with the 5-blade rotor...

That's bench testing ! :)

No model was flown at the 'local patch' to arrive at those figures...

Keven. :)

I have no idea where they get 'em from, but I've found that BalsaPR's amp draws are consistently lower than one can achieve in the real world, whether bench testing or flying! I don't trust 'em at all, 'cos one could easily fry a motor if one believed their numbers implicitly!

And their thrust figures are consistently higher than I can ever achieve at the same power input - go figure!

Cheers, Phil