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Old 01-20-2008, 12:47 AM   #16
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All I've got is a robotrinic and novak gtb. Do you know what esc they used?
I used a Robitronic with my GTB & 6.5 and it worked fine.
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Old 01-20-2008, 06:22 AM   #17
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Ok I got it working! Turns out it didn't like running from a mains 12v power supply.

Then receiver pack went flat, doh

Next problem is the software does not let me save graph so I have to do a screen print . The link to robitronics order page does not work.

People spend all that money on the hardware and they want even more for the software sheeesh

This is going to be great for comparing esc. I hear people saying one speed is faster than another and with this setup you can find out for sure.

Bring it on!
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Old 01-20-2008, 07:20 AM   #18
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In a sense most of the timing is controlled by the ESC and its profiles, so it is just as important to use the same ESC on the dyno as on the car.
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Old 01-20-2008, 07:53 AM   #19
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99.8% effeciency

That can't be right.
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Old 01-20-2008, 08:40 AM   #20
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That was a Novak 8.5 with 12.3mm sintered rotor. There was a 70 amp limit.

Here is my 10.5 with 12.3mm sintered. Now with 100 amp limit.

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Old 01-20-2008, 08:46 AM   #21
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Nice job,
Why the current limiting?
Thanks for posting these.
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Old 01-20-2008, 09:04 AM   #22
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Looks like Robitronic need to rewrite their software to graph efficiencies over 90%!

I'm also quite surprised at the near 100% efficieny of the first motor, perhaps there really is a sweet spot in the power band that is that efficient? Or perhaps is related to your setup with an external ESC driving the motor.
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Old 01-20-2008, 09:38 AM   #23
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Quote:
Originally Posted by gacjr0 View Post
Nice job,
Why the current limiting?
Thanks for posting these.
You're welcome, I wish I had other 10.5's to test and other esc's.

I had the amp limit low at first because I was wary of blowing something up. I forgot to try the 8.5 with a higher amp limit.

The 10.5 graph started below 100 amps so that was fine.

I do have an old supersport esc I could test.

Quote:
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Looks like Robitronic need to rewrite their software to graph efficiencies over 90%!

I'm also quite surprised at the near 100% efficieny of the first motor, perhaps there really is a sweet spot in the power band that is that efficient? Or perhaps is related to your setup with an external ESC driving the motor.
The fact the effeciency went off graph the scale did make me chuckle . I don't think there is anyway I can have it go to 100%.

Not too important because the peak efficiency is way higher than the peak power.

For 17.5,13.5 and 10.5 I don't suppose efficiency is going to be much of a worry, especially with lipo's.
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Old 01-20-2008, 10:23 AM   #24
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Here is the same motor but using an old Novak Supersport Esc. Please bare in mind this esc had been repaired by a friend as the fets had become unsoldered. I do not know if it has impacted the performance or not.


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Old 01-20-2008, 10:52 AM   #25
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could you post a 13.5 with the standard rotor and that same 13.5 with the big rotor? if you have the stuff.
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Old 01-20-2008, 12:09 PM   #26
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Sorry Russ I don't have a 13.5 motor or 13mm rotor.

If anyone wants to lend me one I would be happy to test it

Or alternatively someone could do the same test with a gtb and 13.5 if they have the gear.

I tell you what, how about a dyno thread as a sticky?
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Old 01-22-2008, 06:17 PM   #27
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Quote:
Originally Posted by JevUK View Post
This is going to be great for comparing esc. I hear people saying one speed is faster than another and with this setup you can find out for sure.

Bring it on!
Jev we await the test results..

Expect you'll come up with some interesting findings.. like showing up the ESC's lacking in the FET department, our top brushed MX has almost as many FETs as some top 'racing' BL speedo's (from what I've heard).. you can't beat a decent number of high-end MOSFETs, plus a well designed pcb with the lowest resistance tracks etc. Having said that it's what works best on the track, speed is good but it needs to be speed with good control, especially when it comes to racing.
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Old 01-23-2008, 02:46 AM   #28
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Hi Terry.

Well I'm suprised people have not used this method to compare brushed esc's in the past. .

You can already see how much better the GTB is than the Supersport with a 10.5. 178w versus 154w, that's a 14% drop in peak power!

As I've got a spektrum receiver in the loop, I could even compare a 2.4ghz version of the gtb to a regular one

I know there is more to a motor and esc than just what these dyno plots show. But it takes away the randomness of track testing.

Once the spec brushless classes are in full swing we can get more feed back on how these dyno plots translate to on track performance.
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Old 01-23-2008, 03:09 AM   #29
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Back in the old days there used to be 'intensive' speedo testing, pushing them to their limits to see how they performed, don't seem to see it these days though.

It's good to see someone with technical knowledge and experience carrying out independent unbiased testing, it's worth a lot more to serious racers than the 'bigging up' from marketing.
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Old 01-25-2008, 04:33 PM   #30
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Thanks terry, I started up a thread in the electronics section.

http://www.rctech.net/forum/showthre...22#post4117222

Just put the results of Tims Orion 10.5 and Andys Novak 10.5
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