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Old 27-05-2009
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Default Brushless CRT

hi guys, what motor would you reccomend i want to go with a Neu motor but don't know whether 5s or 6s lipos is best in the truggy

thanks richard
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Brushless CRT.5 - Mamba max - medusa 36-50-4800 motor - ftx 5K lipos
Brushless CRT - Mamba monster - Neu motor - RCPD conversion kit {for sale}
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Old 28-05-2009
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Either 5S or 6S is good in a truggy. I would go with 5S however, as you have more choice of ESC's, the batteries are slightly cheaper, and if you are running a MMM, you have a small amount of lee-way for the voltage.

Is it the X1 or the X2?

X1:
Differential Ratio: 3.3076923076923075
Transmission Ratio: 1
Additional Ratio: 1
Spur Tooth Count: 62
Pinion Tooth Count: 16
Battery Voltage: 18.5
Motor KV: 1663.4551
Tire Diameter (inches): 5.6
Top Speed (MPH): 40

(This is gearing for 40mph, using a 16T pinion, which is a nice size, as it gives a good mesh, but is still readily available)

X2

Differential Ratio: 4.3
Transmission Ratio: 1
Additional Ratio: 1
Spur Tooth Count: 48
Pinion Tooth Count: 16
Battery Voltage: 18.5
Motor KV: 1674.1871
Tire Diameter (inches): 5.6
Top Speed (MPH): 40

(Same as above)

So you need a motor at between 1600 and 1700 kV.


I would try:
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Old 28-05-2009
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cheers for that marvin i will probably go with 5s but what rpm ranges are good for a cool setup on the medusa/neus?
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cars:
vintage 1988 tamiya grasshopper
Brushless CRT.5 - Mamba max - medusa 36-50-4800 motor - ftx 5K lipos
Brushless CRT - Mamba monster - Neu motor - RCPD conversion kit {for sale}
Ebay items : http://shop.ebay.co.uk/merchant/terzo53
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Old 28-05-2009
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Approximately 30,000 - 35,000rpm. This doesn't tax them too much. It is generally accepted that below 40,000rpm is best for track use, and if you aren't going for speed runs.
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Old 28-05-2009
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Quote:
Originally Posted by Marvin View Post
Approximately 30,000 - 35,000rpm. This doesn't tax them too much. It is generally accepted that below 40,000rpm is best for track use, and if you aren't going for speed runs.
ok, so my medusa 35-60 2000 would be ok for 18.5v's
i am probably going to get the MMM 2200kv combo for the crt though and run it on 5s
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cars:
vintage 1988 tamiya grasshopper
Brushless CRT.5 - Mamba max - medusa 36-50-4800 motor - ftx 5K lipos
Brushless CRT - Mamba monster - Neu motor - RCPD conversion kit {for sale}
Ebay items : http://shop.ebay.co.uk/merchant/terzo53
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Old 29-05-2009
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Quote:
Originally Posted by electric View Post
ok, so my medusa 35-60 2000 would be ok for 18.5v's
i am probably going to get the MMM 2200kv combo for the crt though and run it on 5s
No, it won't. It is too small for the CRT, which is a heavy truck as it is.

And I probably wouldn't bother with the 2200kV motor, as even at 18.5V it will be revving over 40000 rpm. Considering that when the pack is fully charged, it will put out 21V and will rev at 46200 rpm. This is going to wear out your motor much faster than if you are running it on 14.8V.

I would get the MMM from RC-Monster (who are splitting combos, so you can get an MMM for ~£95), and a Tekin T8 1700kV motor to go with it (also on the same site). This kV is much better suited for the voltage in my opinion.

Or, just go with an RX8 combo. It's only £35 more than the MMM. It hasn't had any problems yet (apart from a couple of motors have lost their magnets, though this is isolated, and Tekin are replacing them for free anyway), and it is hybrid sensored, so you have sensored start up, then sensorless power at a higher rpm. It's also much smaller and neater looking than the MMM.
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Old 30-05-2009
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Quote:
Originally Posted by Marvin View Post
No, it won't. It is too small for the CRT, which is a heavy truck as it is.

And I probably wouldn't bother with the 2200kV motor, as even at 18.5V it will be revving over 40000 rpm. Considering that when the pack is fully charged, it will put out 21V and will rev at 46200 rpm. This is going to wear out your motor much faster than if you are running it on 14.8V.

I would get the MMM from RC-Monster (who are splitting combos, so you can get an MMM for ~£95), and a Tekin T8 1700kV motor to go with it (also on the same site). This kV is much better suited for the voltage in my opinion.

Or, just go with an RX8 combo. It's only £35 more than the MMM. It hasn't had any problems yet (apart from a couple of motors have lost their magnets, though this is isolated, and Tekin are replacing them for free anyway), and it is hybrid sensored, so you have sensored start up, then sensorless power at a higher rpm. It's also much smaller and neater looking than the MMM.
i got the MMM 2200kv off ebay today as i decided since all i will be doing is bashing and not racing why not
i got it cheap...very cheap compared to others that were selling
so now my 8B has the medusa 36-60-2000 and MMM on 5s/4s and the CRT has the MMM 2200 on 4s/5s when the CRT arrives i will get pictures
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cars:
vintage 1988 tamiya grasshopper
Brushless CRT.5 - Mamba max - medusa 36-50-4800 motor - ftx 5K lipos
Brushless CRT - Mamba monster - Neu motor - RCPD conversion kit {for sale}
Ebay items : http://shop.ebay.co.uk/merchant/terzo53
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