B4rcracer

what is the diamerter of the comm when u have to trash it

Speedmunkey

.270, unless it's a Reedy. Those are .300 I THINK.. Never worn out a big comm Reedy, so I dunno.

RCInfusion

There are 2 sizes of comms for 540 size motors, small ( 7.5mm/0.295" ), and medium ( 9mm/0.350" ). (These are the sizes when new). You can get away with 0.270" on the small comm but 0.275 is recommended as in some cases the copper could grenade. For the medium comms, 0.310" is the minimum, (with 0.306" being the 0.270" minimum equivalent).

B4rcracer

thax

guver

My Feedback: (325)

nice topic, how much end play when building a motor low to high please?

Speedmunkey

end play? what do you mean?

That0neGuy

My Feedback: (-1)

I think he means the arm play in the can.....There should be some but not too much.Put it this way.A washers wirth and thats it.

Speedmunkey

ahh, ok.. Yeap, about 1/64" to 1/32" on each end and yer golden..

XXT-CRer

yup, agreed. i even try to find magnetic center so that one end of the arm isnt pressing on its shims harder than the other end. i use those teeny tiny brass ones from trinity although im lately becoming anti-trinity due to every time i order something from them, it seems to be packaged incorrectly, like single shunts on dual shunt brushes. they even said dual shunt on the package. its a pretty funny story, i called trinity about it and told them that they were labeled dual shunt and that they were only single. the trinity rep said"are you sure". i started laughing a little bit and it seemed to ruffle his feathers. i responded by saying "im not an expert, but i can count to one.

ps. i also got some brush springs that were labeled wrong from them.

Speedmunkey

Yeap, their QC is lacking lately.. I got some EP1201's for my D6 recently and there was only 1 brush in the tube.

wetzelpretzel425

how many times can you cutt a comm before it is trash

-wetzelpretzel

zaphod42

My Feedback: (3)

That, of course, depends on how deep you have to cut it to get a clean surface. The ultimate determination is the diameter. The thinner a cut you can get away with the more times you can cut it. I've been told that an comm will actually last longer if you cut it regularly than if you wait until the performance drops off. Comms can get out of round if you wait too long between cuts then you have to take off quite a bit of material to get back to round

XXT-CRer

it depends entirely on how often you cut them. i cut my chameleons every 3-4 runs. if you do this, you only have to skim about .001-.002. so i get about 12-15 cuts, maybe more. if you wait till you notice the motor getting weaker, you have to cut much deeper, and you would be lucky to get 5. it also greatly increases the brushes life to cut often. in most cases, your motor will wear as much on the 5th run as it does on the 1-4th because the wear rate becomes progressive. as it wears, it does so much faster with each consecutive run.

XXT-CRer

you beat me to it zaphod, and yes, comms cut often do indeed outlive those cut every 15 runs or so.

guver

My Feedback: (325)

end play is the amount the shaft will travel when forced one way and then measured forced the other way. I usually center the comm in the field, but really never saw a spec on the minimum end play on the shaft. I was thinking more like .010" total ?

I supose any amount is good as long as it doesn't get to zero at some point. Maybe there's no standard?

B4rcracer

i run a peak dynisty so what should the diamiter of the last cut untill i can trash it????

Thank you
Tyler