Question on Brush selection on CrawlMaster Expert 13t

[merin_83]

Hi Guys, I have a Wraith PS, for which i bought the CrawlMaster Expert 13t very recently and its good. But when i checked the brush length after 2 trail runs, it 8mm, and HH website says we should change after 7mm. So i guess it almost time to replace, but when i look the website there are many options, but not much info and whats the difference. Please help me choose one. Am on a budget and i do mostly trails and some rock crawling. Also don't wan to change brushes too often ;)

these are the options in the website...
1. Holmes Checkpoint Copper 540 motor brush
2. Holmes Soft Copper Standup Brushes - Default
3. Holmes Soft Copper Laydown Brushes
4. Holmes Checkpoint Silver 540 motor brush


Also please let me know if this is normal to change a brush with 2 packs 2200mah lipo ?

thanks,
merin

[axial 4x4 crawler]

Hmm, from experience that is not normal. It could be a fault form the factory cause if you do just trail runs then that shouldn't affect the motor that fast. Most of the brushes are out of stock however, you could try the checkpoint silver brushes...from my understanding, silver passes the current faster than copper but like the page said it requires cleaning the commutator more often. Well I'd see what John would have to say about the brushes burning out first.

[merin_83]

Originally Posted by axial 4x4 crawler

Hmm, from experience that is not normal. It could be a fault form the factory cause if you do just trail runs then that shouldn't affect the motor that fast. Most of the brushes are out of stock however, you could try the checkpoint silver brushes...from my understanding, silver passes the current faster than copper but like the page said it requires cleaning the commutator more often. Well I'd see what John would have to say about the brushes burning out first.

thanks, if silver does that, then i will stay away from that, as of now i dont have budget for lathe. And my gearing is 56:14 32p and stock esc. 3S lipo. Timing i dint change its at 0.

[JohnRobHolmes]

You want the regular soft copper standups.

Your gearing should be 5:1 for a brushed motor. Your driving style may also be hard on it. YOu should also add 6 to 12 degrees of timing. All found here: 540 Brushed Motor Care, Installation, and Troubleshoot | The Search for Power

[Master Basher]

Ive measured brand new brushes that were barely longer than 7mm... so I dont know... how long are they usually when brand new?

[JohnRobHolmes]

14mm

[merin_83]

thanks, i saw this 56:14 in one of the stickies i guess, let me chk again...

[merin_83]

Originally Posted by JohnRobHolmes

You want the regular soft copper standups.

Your gearing should be 5:1 for a brushed motor. Your driving style may also be hard on it. YOu should also add 6 to 12 degrees of timing. All found here: 540 Brushed Motor Care, Installation, and Troubleshoot | The Search for Power

yup, you are correct, i revisited the stickies and it said 56/12 32p for brushed, i had looked on 56/14 32p for brushless... :( ..., i will change it, thanks for pointing it out !!

[Master Basher]

Originally Posted by JohnRobHolmes

14mm

so are my brand new ones that are much shorter due to being a cheapo brand motor? I'm sure my integy brushes weren't that long when new.

[merin_83]

Originally Posted by JohnRobHolmes

14mm

I ordered three pairs of the soft copper standard brushes.. it arrived today... still in package... the avg length is 9.9mm .. so am confused here .. why so?

thanks,
merin

[JohnRobHolmes]

I was wrong on the new length, sorry about that. Closer to 10mm on those.

[merin_83]

Originally Posted by JohnRobHolmes

I was wrong on the new length, sorry about that. Closer to 10mm on those.

So every 3mm use we need to change the brushes ?

[JohnRobHolmes]

I'll recheck the wear limits to be sure it can't go further, but brushes are a wear item that depends heavily on gearing and drive habits. What color is the motor label, red?

[merin_83]

Originally Posted by JohnRobHolmes

I'll recheck the wear limits to be sure it can't go further, but brushes are a wear item that depends heavily on gearing and drive habits. What color is the motor label, red?

Its red ...

[JohnRobHolmes]

Making sure you didn't get a TorqueMaster, those really eat brushes with the 13t.

Add timing and gear properly, they will wear a ton better.

[JohnRobHolmes]

3mm of wear is optimal for brush spring tension. You could push it to 4mm of wear or 6mm remaining brush length, but if the spring hits the hood you can ruin the comm very quickly.

[sic1to]

That's great info...learn something every day!!!

[merin_83]

Originally Posted by JohnRobHolmes

3mm of wear is optimal for brush spring tension. You could push it to 4mm of wear or 6mm remaining brush length, but if the spring hits the hood you can ruin the comm very quickly.

Thanks, I will measure the gap and see how much will be safe... btw the color of label decides it torque or crawl masrer ?

[JohnRobHolmes]

Different models have different colors, I was double checking what you got.

[merin_83]

Originally Posted by JohnRobHolmes

Different models have different colors, I was double checking what you got.

Also please please update the maintenance link u provided earlier... as it states that brushes should be changed when its half size ...