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Dr Kiwi
09-05-2005, 04:35 PM
I posted this in RC Groups, but I thought I'd share the data with you guys.

JustGoFly MMM 400DF - DD speed demon!

Test stand data for the 400DF in direct drive mode.

I had previously tested this motor, for Vinnie at JustGoFly, in geared mode and found it to be very powerful on 3s - almost 40oz thrust at just over 18A with 12x8 GWS HD (3.89:1) and 11x7 GWS HD (3.5:1).

Vinnie suggested that it worked well in DD with 5" props, and that the motor's amp limit might be a lot higher than we had suspected. He had briefly run it at >30A!

Below is the gist of several e-mails to Vinnie - essentially verbatim with just a couple of expletives deleted!

I've just run a few tests on the 400DF with little props - I am going to demand Hazardous Pay and Protection Money - if any of these .... props let go at >20,000rpm, it could be dangerous to my health! With my new stand (obviously facing away) I am pretty safe, but since I am stuck with testing in my TV room I worry about bits bouncing off the walls or going through the (school's) windows!

My PS runs into trouble at ~15A @ 7v, so I can't try any bigger props than these to see how they would be for 2s useage. And it is limited to ~25A @ 11v so I can't push the little .... much harder than I have done - though, I must say, it seems willing enough to be pushed further.

I would think the Jet Boys would be happy with 93.8mph and 101.7mph wouldn't they?

I am very impressed with how smoothly it runs at these speeds, and how cool it remains under fire! These little props may be pushing quite a bit of air through the motor as well as past it. My gut feeling tells me that maybe 250W is getting close to its limit - but then again maybe not!

Both the Zagi and a 5x5 APC E on the 400DF should come in under 30A on 3s and, if so, would probably get you 120mph+ pitch speed - a brave man might try that! The Graupner CAM is a nice prop but at 11v the amps would be >30A - too much I would think.

With Vinnie's permission I have posted the numbers (see Table below) - I figured that speed freaks might like to see these 'em.

Cheers, Phil

Mike Parsons
09-06-2005, 06:14 PM
Great information! Thanks Phil!

JustGoFly.com
10-25-2005, 05:01 PM
Phil,

Thanks for posting the info. Have you done EDF tests ? Seems the 400DF is very good in a PowerFan, but some guys here are looking for results on the WeMoTec. I'm planning on running some tests, but independant tests from the industry icon would validate my results - or save me the time to run them ;)

Vinnie
JustGoFly.com

Dr Kiwi
10-25-2005, 11:00 PM
Phil,

Thanks for posting the info. Have you done EDF tests ? Seems the 400DF is very good in a PowerFan, but some guys here are looking for results on the WeMoTec. I'm planning on running some tests, but independant tests from the industry icon would validate my results - or save me the time to run them ;)

Vinnie
JustGoFly.com

I only have a Wemotech MicroFan (for 20mm motors) into which the 400DF will not fit. If you really need the numbers, send me a suitable Wemotech and I'll see what I can do.:D:D

Cheers, Phil

watt_the?!
10-26-2005, 09:13 PM
Phil,

whats the max static thrust you can get from this motor please?

or at least if you can do some tests on a 5.5x3 or 6x3 prop please (i.e. no cavitation)

edit: oops, shoulda read your thread a bit more thoroughly.

i guess im interested in a blend of thrust to speed for the jet pushers....so either geared prop up to 8 inch diam or DD at up to 5.5-6 inch.

any data?

Cheers.

JustGoFly.com
10-26-2005, 10:10 PM
I have run EDF tests on the Wattage MicroFan but not the WeMoTec. Here is the Wattage Powerfan :http://justgofly.com/images/edf/JGF-400DF-400-PowerFan-EDF-.jpg
It'll take a while before I can get to the WeMoTec fan since I'm working on prop data for some new 450 size motors. The larger version of the 400DF is the 450TH. We're doing some EDF tests with Kress EDF, so we'll see if the larger EDF's work well with one of our motors. Seems the larger EDF's like the slightly lower KV - so we now have a 1700 and 2250 KV 450 size motor. The 1700 is yet unreleased but turns a 7x5 prop with authority at 25 amps and extremely nice in my draggy jet.

Prop tests by JustGoFly and Dr. Kiwi can also be found on http://www.JustGoFly.com The good doctor is an industry icon that works circles around the rest of us.

Vinnie
JustGoFly

watt_the?!
10-26-2005, 10:55 PM
thanks vinnie.

good luck with the kress fans... the assembly has to be the worst of any fan and the prices are crazy.

many have tried to help kress, but you cannot help those who dont want to be helped.

Bob was great.

Tim.

Dr Kiwi
10-27-2005, 04:59 PM
Phil,

whats the max static thrust you can get from this motor please?

or at least if you can do some tests on a 5.5x3 or 6x3 prop please (i.e. no cavitation)

edit: oops, shoulda read your thread a bit more thoroughly.

i guess im interested in a blend of thrust to speed for the jet pushers....so either geared prop up to 8 inch diam or DD at up to 5.5-6 inch.

any data?

Cheers.

My problem is that I don't have a Power Supply which can give me 20-30A at 2s voltages, which is what I reckon you'd need for 5.5-6" props DD.

TaSaJaRa
10-29-2005, 05:56 AM
whats the max static thrust you can get from this motor please?
or at least if you can do some tests on a 5.5x3 or 6x3 prop please (i.e. no cavitation)
Cheers.
I run the 400DF on a 52" ZagNutz with a APC 5.5 x 2.5 pulls around 18amps Static
with about 22000 rpm @ 228watts. I am using a 2100 3s 15c from www.justgofly.com (http://www.justgofly.com)

This setup works good for me. My ZagNutz (http://justgofly.com/images/customers/JustGoFly400DF_CThompson_Finished%20electronics.jp g)

JustGoFly.com
10-29-2005, 04:23 PM
The 400DF will give 24.5 oz's of thrust on a 5.5x2.5 at 11.1 volts at 19.6 amps, 52 mph static.

5.7x3 give 25.8 oz's , 11.1 volts, 20.8 amps, 63.9 mph static.

I have 6x2 and 6x3 props as well - but are untested.

Check out the 450FT for thrust higher than 30 oz's, 77mph, 29 amps.

Vinnie

watt_the?!
11-01-2005, 09:18 AM
The 400DF will give 24.5 oz's of thrust on a 5.5x2.5 at 11.1 volts at 19.6 amps, 52 mph static.

5.7x3 give 25.8 oz's , 11.1 volts, 20.8 amps, 63.9 mph static.

I have 6x2 and 6x3 props as well - but are untested.

Check out the 450FT for thrust higher than 30 oz's, 77mph, 29 amps.

Vinnie

me thinks ive found a winner for my f14....

24.5oz static eh?

watt_the?!
11-01-2005, 09:21 AM
vinnie,can you supply the data for use in motocalc please?