8 replies to this topic

[NSwanberg]

Some are of the opinion that the Pro Slot FK motor may be better served with a 16D size motor brush. I have not hammered out a set of 16D size brush hoods to experiment with but I am wondering if any other speed crazed morons have tried them on a PS FK?

[havlicek]

Well, but the comms on those (and similar) motors have a very small diameter... maybe even smaller than the original Mabuchi 16D motors, yet the brushes are the same width as used in most other modern motors. Those large brushes wind up "overlapping" ("shorting between") two segments for a great deal of time as the arm turns, and that overlap only gets worse as the brushes fully seat and the entire face of the brush is fully in contact with the comm.

 

 A brush the size of these 16D brushes would be much more appropriate for the stock comm in this type motor, and people have done things to reduce the size of the brush face that contacts the com to sort of "band aid" the situation. With no hoods or hardware commonly available to modify the endbell... AND with somehow cobbling together the Mabuchi hardware to fit probably not being feasible or worthwhile, it's kind of a moot point. It might be possible to use some square/rectangular brass tubing as "reducers" with the original hoods to accomodate these brushes if the right size were "out there".

 

-john

[smichslot]

Vertical brushes!

 

A lot of high-performance motors are using vertical brushes, so there might already be hardware that fits the purpose.

 

Steen

[Gator Bob]

IMO - Easier to re-face the 36D size brushes than make new hoods for 16D brushes.

[Rick]

We have been running 36D brushes on Asian sized coms for decades with very little issues.Ye they do short more than 16D size brushes but the problem now is compounded because of neo strength magnets. It just becomes too much to break the short loose when the magnets hold so strong. It doesn't happen much, but is does happen. Trimming the brush face will reduce this. I figure, IMO, its worse if the hood is canted and giving the brush even more surface contact area...

[MSwiss]

Nelson,

 

Like everyone said, reducing the face is the economical/practical solution.

 

I did it to the 4002FK motor in my hardbody, and it holds the highest lap total record on our King.

 

I geared it slightly more aggressive.

 

It definitely cured any start up issues, that we continue to have regularly, especially on the low amp flat track.

 

Even if all the cars start up OK, you can tell if someone has one that is "working hard", because all the other cars will start up slow at the start of a heat or after a track call.

 

Any particular reason you brought it up?

[Ramcatlarry]

I like the idea of the vertical brush as well. Should help cure the issues. Would be nice to include that design change in the next order batch and organizational rules update.

 

In the old days the small 13/16D brush WAS smaller and would be a good use in these smaller motors. FYI the SCX motors still use them. The (OLD) 36D brush is the common brush of the modern era (16D/C-can). The PS 4000 series uses a shortened version of them and Pro Slot does sell them pre-shortened.

[Cheater]

Any particular reason you brought it up?

Mike,

Nelson didn't really "bring it up" in the way you're thinking.

He made a comment in Lone Wolf's for sale ad for the NOS 16D brushes and it started to evolve into a small discusion, so I split off his post and those following into a new thread here in Motors.

[NSwanberg]

What he said.