Print

Please login or register.
1 Hour 1 Day 1 Week 1 Month Forever
Login with username, password and session length.

[6705russell]

Hi all,

As anyone used these on 12 volts? What are there power output? I am thinking of changing two existing MFA 850,S to these but dont know if there will be a power difference?

Thanks

Russ

[stallspeed]

From supplier data only,maximum power output for a 700BB 12 on 12v is 127W
max power output for 850 is 186 watts on 12v

[HS93 (RIP)]

From supplier data only,maximum power output for a 700BB 12 on 12v is 127W
max power output for 850 is 186 watts on 12v

can I ask where you get the 127w figure for the 12v bb ?

Peter

[stallspeed]

The missing power and efficiency figures come from the 4 points on the two dc motor straight line graphs
http://www.mabuchi-motor.co.jp/en_US/technic/t_0201.html

The raw data care of Eddy..

47% efficiency is at 50% no-load rpm
270 Watt input and 127 watt output

[HS93 (RIP)]

having played with both  the bb is a lot higher output and the build quality is far higher than any standard Mabuchi.

Peter

[6705russell]

Are we saying the 700,s are a better motor? I cant find any spec on them showing what the power output (watts) is....

Russ

[HS93 (RIP)]

yes we found them a lot better they have a ballrace and thebuild is far better, they are also a different wind and number of polls.they are also able to take a higher voltage so you can up the power and revs with a few more cells and they don@t complain.
what boat is it going in , a friend is running the 9.6 v at 19.2 v geared 2 x 1 and it runs very fast and runs stone cold and is very efficient, we have tried the 12v and the 8.4 as well. also sound's good, he gets about 20 + min on 4300 nicads that are getting a bit tired. look at the vids on this link. i's stooped bouncing now also the older huntsman vids are a 8.4v graupner

Peter

http://www.youtube.com/watch?v=ZcHjDWUYJvU&feature=channel_page


http://www.youtube.com/user/onehs93

[6705russell]

Hi Peter

I currently have two 850,s in my 1/12 Trent lifeboat, i was going to go the brushless route but will do that with my Tamar, i have two 700,s doing nothing so i was going to try them..... i didnt want to go bigger than 12 volt though.

Russ

[HS93 (RIP)]

the first two vids are of a huntsman 42" wood build powerd by a brushless, we have just alterd the gearing and it is very very fast http://www.youtube.com/watch?v=yitqLxoSIJs&feature=channel_page.

Peter

[stallspeed]

Are we saying the 700,s are a better motor? I cant find any spec on them showing what the power output (watts) is....

Russ

I just gave you the maximum power available for each motor because that is what you asked for.That figure has got nowt to do with quality.How much power you get out a motor depends on how much load you put on it.

Page 1 of the mfa gearbox publication shows a table for the 850
 

[HS93 (RIP)]

the MFA is less efficient the ball race help it stay efficient. also the chart is for standard mabuchi motors they are not all the same specification , so how do you know it is the same as the MFA

Peter

[stallspeed]

the MFA is less efficient the ball race help it stay efficient. also the chart is for standard mabuchi motors they are not all the same specification , so how do you know it is the same as the MFA

Peter

I only did core and winding design and never dealt with motor bearings.I don't have any info on small bearing loss but it's not significant compared to the waste power of the iron and copper part.