9 replies to this topic

[Mark Onofri]

Refresh what's left of my memory if you would. What is the performance difference between the two? (Vertical/ horizontal) I remember putting the NEW for 89-90 style on a 12-C, but, I can't remember what was standard and what was NEW..

[Mark Onofri]

I believe that vertical is the standard?

 

[Mike Patterson]

Yes.

[blue&orange]

If I understand it correctly, the standard brush is not square, so the horizontal brush gives a wider, less arc contact point with the comm, whereas the vertical brush contact point is narrower but touches a larger arc on the comm.  Does it make a difference?  More precise timing, maybe?

[slotcarone]

If I understand it correctly, the standard brush is not square, so the horizontal brush gives a wider, less arc contact point with the comm, whereas the vertical brush contact point is narrower but touches a larger arc on the comm.  Does it make a difference?  More precise timing, maybe?

No it is the other way around Chris The illustration is backwards.

[Mark Onofri]

I know I have dyslexia but, what part did I get basakwards?

[Dave Crevie]

I lifted this illustration from another thread discussing brush orientation. They talk about how the brushes can short across the comm segments. The drawing is not easy to decipher, so I re-drew some of it to make it more understandable. What is important here is to know that the comm is a large enough diameter that the brush can't create a direct short by bridging the undercuts and creating an electrical path through the comm segment. In the view on the right, the power has to travel through the windings on the poles. It can't bypass them.

 

 

[Mark Onofri]

Thanks Dave, I'm still wondering what the advantages of horizontal brushes provided. Besides the obvious larger contact area. More breaks ?,less overlap? Both?

[MSwiss]

I know I have dyslexia but, what part did I get basakwards?

Taller ones, height wise, are horizontal and what would  be in old school Mura motors.

 

Vertical, also occasionally referred to as laydown, were first marketed by Koford in the early 80's. 

 

Not reading what Dave posted, with less wrap around, you have less of a chance of a high time motor needing a pushstart.

 

After much resistance from non-Koford racers, they eventually became the standard for G7 motors as the comm will run cooler with them.

[Mark Onofri]

Thanks Mike, I was hoping you chimed in on this. Was it the late 80's when they gained popularity? If I remember correctly,it was about the same time as the perimeter chassis.