RCCrawler Forums

radishkid · 06-30-2006, 08:59 PM

JRH, Micro, or someone else...

I'm looking to run a big truck (as in X-Factor axles on a Rockraider) with an E-Maxx tranny. I'd like to run brushless and I'm trying to keep my CG very low. Hence I was thinking of Hacker or JRH's Revolver outrunners with parallel Mamba 25's.

I'm quite pleased with my Hacker on my 1.9" TLT, but it only has an 8" wheelbase and weighs less than 4lbs with the battery. The rockraider has an 18" WB. Can two of these motors sufficiently move a ~10lb truck?

JasonInAugusta · 06-30-2006, 09:05 PM

One of the Revolvers will be plenty.

Mnster · 06-30-2006, 09:15 PM

Why not just get one big motor?

JohnRobHolmes · 06-30-2006, 09:27 PM

I vote one big motor too. One Revolver would work, but if you want stupid excess power then a double stack (20mm long stator instead of 10mm long like my motors) would work well too. To my knowledge the MP JET 28/20-7 is the only motor with a 5mm shaft that will bolt up too. AXI makes a 2820, but I think the shaft is 6mm.

edit: just checked over hackers site, looks like the "big" stators are 20mm, which is pretty small if you are looking for big power. 28mm stator diameters are really the way to go for max power with a motor that will still fit where a 540 goes.

Mad Scientist · 06-30-2006, 09:37 PM

I have also heard that running dual brushless motors on the same spur isn't generally the best thing for them. Both motors would have to be in sync, and if not, one will cause the other to overheat. I'm not sure - I've never tried it - that's just what I have read.

JohnRobHolmes · 06-30-2006, 10:02 PM

If they were on different esc's it wouldnt matter. If you try and run both on one esc, they have to be in synch. Having two brushless motors tied together by a spur is the only time you can run two brushless motors on one esc (for ground setups at least) It really isnt worth the trouble or risk unless you are the kind of guy that likes to do hard stuff just to say you have.

JasonInAugusta · 06-30-2006, 10:14 PM

After seeing JRH's Beaver, I still think one Revolver would work.

JohnRobHolmes · 06-30-2006, 10:18 PM

The beav had a double stack hiding inside....

It sheared the diff last weekend too

JasonInAugusta · 06-30-2006, 10:48 PM

ahh, thought it was the same motor.

666 · 06-30-2006, 10:54 PM

Quote:

Originally Posted by johnrobholmes

The beav had a double stack hiding inside....

It sheared the diff last weekend too

Which gear did it shear? Pics?

Any more info on the 'double stack'?
I am intested in more power for my TXT!
Mamba 25 powered?

JohnRobHolmes · 06-30-2006, 11:35 PM

yeah, mamba 25 powered.

The motor is the mp jet 2820-7 I spoke of. 5mm shaft is the only downfall. It was the diff in the pede case, it took about 1/4 of the diff teeth off. I shouldnt have pushed it that hard, I had a tire wedged. Normally the truck will just pull out or do a backflip- but there was no give and she just snapped.

EeePee · 07-01-2006, 02:23 PM

I've only put two packs through my Revolver/Mamba 25 combo in the TXT 14'r but it's got the power. I went from a 9 tooth to a 13 tooth pinion and still plenty of power.

06-30-2006, 08:59 PM	#1
radishkid Quarry Creeper Join Date: Nov 2004 Location: In the saddle... Posts: 473	Dual Outrunners... JRH, Micro, or someone else... I'm looking to run a big truck (as in X-Factor axles on a Rockraider) with an E-Maxx tranny. I'd like to run brushless and I'm trying to keep my CG very low. Hence I was thinking of Hacker or JRH's Revolver outrunners with parallel Mamba 25's. I'm quite pleased with my Hacker on my 1.9" TLT, but it only has an 8" wheelbase and weighs less than 4lbs with the battery. The rockraider has an 18" WB. Can two of these motors sufficiently move a ~10lb truck?

06-30-2006, 09:27 PM	#4
JohnRobHolmes owner, Holmes Hobbies LLC Join Date: Nov 2004 Location: Volt up! Gear down! Posts: 20,290	I vote one big motor too. One Revolver would work, but if you want stupid excess power then a double stack (20mm long stator instead of 10mm long like my motors) would work well too. To my knowledge the MP JET 28/20-7 is the only motor with a 5mm shaft that will bolt up too. AXI makes a 2820, but I think the shaft is 6mm. edit: just checked over hackers site, looks like the "big" stators are 20mm, which is pretty small if you are looking for big power. 28mm stator diameters are really the way to go for max power with a motor that will still fit where a 540 goes. Last edited by JohnRobHolmes; 06-30-2006 at 09:32 PM.

06-30-2006, 09:37 PM	#5
Mad Scientist RCC Addict Join Date: Mar 2005 Location: Saginaw Posts: 1,721	I have also heard that running dual brushless motors on the same spur isn't generally the best thing for them. Both motors would have to be in sync, and if not, one will cause the other to overheat. I'm not sure - I've never tried it - that's just what I have read. Last edited by Mad Scientist; 06-30-2006 at 09:40 PM.

06-30-2006, 09:05 PM	#2
JasonInAugusta 06 Super National Champ Join Date: Jun 2004 Location: Stark Industries Bar and Grill Posts: 11,361	One of the Revolvers will be plenty.

06-30-2006, 09:15 PM	#3
Mnster MWRCA'er Join Date: Apr 2004 Location: Machesney Park IL Posts: 3,995	Why not just get one big motor?

06-30-2006, 10:02 PM	#6
JohnRobHolmes owner, Holmes Hobbies LLC Join Date: Nov 2004 Location: Volt up! Gear down! Posts: 20,290	If they were on different esc's it wouldnt matter. If you try and run both on one esc, they have to be in synch. Having two brushless motors tied together by a spur is the only time you can run two brushless motors on one esc (for ground setups at least) It really isnt worth the trouble or risk unless you are the kind of guy that likes to do hard stuff just to say you have.

06-30-2006, 10:14 PM	#7
JasonInAugusta 06 Super National Champ Join Date: Jun 2004 Location: Stark Industries Bar and Grill Posts: 11,361	After seeing JRH's Beaver, I still think one Revolver would work.

06-30-2006, 10:18 PM	#8
JohnRobHolmes owner, Holmes Hobbies LLC Join Date: Nov 2004 Location: Volt up! Gear down! Posts: 20,290	The beav had a double stack hiding inside.... It sheared the diff last weekend too

06-30-2006, 10:48 PM	#9
JasonInAugusta 06 Super National Champ Join Date: Jun 2004 Location: Stark Industries Bar and Grill Posts: 11,361	ahh, thought it was the same motor.

06-30-2006, 11:35 PM	#11
JohnRobHolmes owner, Holmes Hobbies LLC Join Date: Nov 2004 Location: Volt up! Gear down! Posts: 20,290	yeah, mamba 25 powered. The motor is the mp jet 2820-7 I spoke of. 5mm shaft is the only downfall. It was the diff in the pede case, it took about 1/4 of the diff teeth off. I shouldnt have pushed it that hard, I had a tire wedged. Normally the truck will just pull out or do a backflip- but there was no give and she just snapped.

07-01-2006, 02:23 PM	#12
EeePee MODERATOR™ Join Date: Jul 2004 Location: Ohio Posts: 18,928	I've only put two packs through my Revolver/Mamba 25 combo in the TXT 14'r but it's got the power. I went from a 9 tooth to a 13 tooth pinion and still plenty of power.

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