R/C Tech Forums - View Single Post - Robi Dyno, How do you choose your best motor
Old 02-08-2006, 08:33 AM
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SA_Racer
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Originally Posted by erock1331
In stock we always used 18-26 amps on the robi to test, but if the math is correct then it appears our stockers are pulling more like an average of 27 amps.

on our banked track a runtime pack of 385 comes off with around 195 seconds. So we use about 190 seconds of the pack.

190 x 35 = 6650 / 240 sec-- 27.70 amps
Maybe we should bump up the ave amp calc too look at 23-33 range ?
What do you think?
So I have run a few packs and have calculated that I draw ave 26 amps from my packs during a 5 minute stock race. so This is what I figure.

2/3rds of 26 is 17.3 amps so I round it up to 18 amps 26-18=8 and 26+8=34

so I figure a good range is perhaps from 18 to 34 amps (I know very un-scientific) But I had to decide on an upper limit and 34 sounds like a fair value. The problem I have with this is that the range is probably to broad so I narrowed it by 1 on each end so I set my range to be 19 to 33 amps.

My favorite motors produce around 110 watts in this range and I have found that they are screamers on the track. I also found that going below 106 watts equates to having an average motor on the track.

Also based on this I think one should try tune a motor for max power round the 30A mark

Perhaps you guys can give me your views on what you think could be a good range for measurement, I Believe it is now important to get a broad range for good power delivery at both low speed acceleration as well as on the high speed sections.
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