[DIYguy]

Here is some feedback on from Helwig, specifically on my original brushes and a few other things....

Hello Gary,

The brushes have current density of 34.1-90.9 Amps/sq-in at 160-170V. The peak load at acceleration is 227.3 Amps/sq-in on brushes. The original grade is 497 from our competition named Mersen (old name was Carbone). It is moly flake type grade and based on the properties of the grade it may struggle at higher voltages but could be a good grade up to 90v. Moly flakes helps for filming and lubrication. The film on comm was decent medium dark. How was the original grade performing? I am not sure about the new grade you are using now but it would be interesting to find the grade name or properties such as resistivity and hardness.

The brush face pictures were not available but if you see edge burning on the brush face then split design with red top will help. Please pull up the sleeve and see if you see any heat discoloration on the wire.

The top bevel will reduce the downward force of the spring a bit but might help position the brush against the rotation. The spring force should be 2.5 pounds to get 4.55 PSI at brush face. You need a force gage to measure this or send a brush card to us to measure the spring force. Spring force must be same on all brushes. One brush will always be slightly shorter than other due to polarity effect and in your case it is exaggerated due to the advance position (brushes out of neutral). Hope all this helps!!!

[DIYguy]

I pressed them a bit to find out what Netgain uses..... reply below....

NetGain uses multiple grades but H49 and H60 are more popular. In this application I would recommend H49.

H series Electrographite..... "Electrographites are the most common grades used on modern equipment
with good performance at high voltages, high current densities and high
speeds. There is a wide range of characteristics within this category.
Most electrographite grades are capable of handling overloads well."

[DIYguy]

Originally Posted by elektroboy

Yes, very interesting. Thanks.
The ones with copper in it are also for high currents. I'm curious what they will advise.

The copper graphite do handle high currents, but are meant for lower voltages.

[DIYguy]

So I pulled one pair of my replacement brushes (ones I have been driving on since rebuilding the motor) out and turns out that they have H100 stamped on them. This is apparently one of the better quality grades. It is comparable to Helwig's K254. They still recommend the H49 over it though.
Also, according to some pictures, they said my brushes showed signs of significant "electrical stress". (No wonder as I had my Soliton maxed out just before it blew up... and that was the last time I drove it...lol). He indicated that the split brush would help this situation significantly. The leading edge, about 1/3 of the face was quite shiny compared to the rest of the face. I'll load pics later....

[Yabert]

So now?
Will you buy Helwig Red Top Split Brushes?

Canadian supplier?
Price?

[DIYguy]

Originally Posted by Yabert

So now?
Will you buy Helwig Red Top Split Brushes?

Canadian supplier?
Price?

Here are a few pics of my brush gear and current H100 brushes as well as the original brushes.

What's next? Yes, I will get a set. They have a distributor in Brantford, Ontario... about 40 min from my house. You may need to talk direct to head office engineering though. They will give me a set for evaluation.

I will get a quote for 10 sets, and let you know price.

I need to measure my spring force next.

[ndplume]

Hey DIY Guy,
This thread went ... dead. Is there and update. I understand that the red top brushes make quite a difference.
I saw a group buy on the Helwig bruses for the 8" ADC. Did you start one for the 9" ADC?
NDP

[DIYguy]

Originally Posted by ndplume

Hey DIY Guy,
This thread went ... dead. Is there and update. I understand that the red top brushes make quite a difference.
I saw a group buy on the Helwig bruses for the 8" ADC. Did you start one for the 9" ADC?
NDP

Hey ND.
My motor is a GE not ADC. I think this thread was the introduction of the Helwigs to this forum. It took maybe a year after for it to catch on. I did get a set of the red tops. Unfortunately, they didn't radius them so, since I had other plans for a different motor, I didn't put them in. I will use split red tops in my 13" though.
Also, its not that difficult to radius them, just takes a bit of fiddling. Much easier with the motor on the bench. remove old brushes. Get some 100 grit sand paper, wrap comm with grit facing out, install one pair of new brushes. . Lower on paper, and spin comm back/forth till shaped. Then u still need to run them for several days to seat/film.

[ruckus]

Have folks checked out the EVTV testing which includes a Hellwig video showing exactly why the brushes are better? EVTV found much lower heat with higher rpm which amounted to greater efficiency. This has also been tested in an EV with the same results. I will be posting the temperature results as soon as the 8" bulk order is complete and they are installed.

http://www.evtv.me/
Testing vid 1: May 18th
Testing vid 2:May 25th

Cheers

[DIYguy]

Originally Posted by ruckus

Have folks checked out the EVTV testing which includes a Hellwig video showing exactly why the brushes are better? EVTV found much lower heat with higher rpm which amounted to greater efficiency. This has also been tested in an EV with the same results. I will be posting the temperature results as soon as the 8" bulk order is complete and they are installed.

http://www.evtv.me/
Testing vid 1: May 18th
Testing vid 2:May 25th

Cheers

Yes, I watched them when they were made. I watch pretty much all of them... although I do skip some of the lengthy verbiage... lol
The improvement in efficiency noted will be different under driving loads, I'm sure. Still, this IS the critical part of a brushed motor and I'm surprised it never got more focus prior to this. (for EV and racing applications that is)