[DIYguy]

I'm starting this thread to gather info and opinion on this product. These brushes are being used in the new Netgain motor design I believe. These brushes have a split design that is suppose to help with commutation. They also have a padded top (Red-Top) where the spring pressure is concentrated. I believe this is to help bounce and cushion for vibration/movement. I think they are recommended to be used with "increased" spring pressure (4 psi ??). It seems that these folks are conversant with advanced brush design in various applications.

www.wmea.net/Commercials/Helwig.pps

http://www.helwigcarbon.com/products...n-brushes.html

http://www.helwigcarbon.com/images/c...er%20promo.pdf



Claims are better brush life. Lower operating cost. Higher currents. Better commutation. I've also heard claims of higher voltage capability, but didn't read this on their website.

Comments?

Thanks,
Gary

[Yabert]

Interesting subject.....

Higher voltage with same motor... hum!
I waiting for more comments.

http://www.youtube.com/watch?v=YpR3hfL94fs

[Bowser330]

sounds excellent, how much are they?

[DIYguy]

Originally Posted by Bowser330

sounds excellent, how much are they?

Ya, I dunno. I sent a message to them. They don't sell direct, but have some reps/distribution. When I rebuilt my GE lift motor, I replaced the brushes and it was more than I expected at around $150. We'll see what these come in at.

[Bowser330]

Opps, skipped over how Netgain is using them on the warp motors, no wonder they can typically handle more current & voltage than the average, off the forklift, DC motor....

[DIYguy]

I have some interesting feedback that I will share. First I want to link to this document covering many aspects of bush design including various compositions and their respective benefits. Also, troubleshooting pictures and just a wealth of great information with a lot of graphics.

http://www.helwigcarbon.com/images/tc2008.pdf

[DIYguy]

I had several back and forth emails until I reached the right technical guy. Seems they were worried about us getting too much proprietary info. This was my last message to them.....

"Thank you for your reply. I (and other forum members) have no interest in learning your trade secrets and composition details.

I want to know if I can purchase brushes from your company (based on info given) that are better suited to my application. I want to know what model number to ask for and how much they cost. I would also like to know what benefits I can expect in technical terms.

I (and they) are interested to know if they can improve performance in general terms and if so, in what technical terms. Example, if you order model xyz split, red top brushes for applications utilizing "I" current levels and "E" voltage levels, u can expect improvements in "these" areas. (Like ability to handle 10% more voltage and current with better commutation.

You already list different composition brushes in your literature and what the characteristics are. I just don't know if I should use only this data to select my own "best guess". I'm looking for general feedback on selection information. Is this not something you do????"

I received a great reply.......

"
Hello Gary,

We will be glad to assist you and thank you for the understanding. As you have seen on our website we have hundreds of different electrical carbon grades. Net Gain has used some of these grades successfully. We select the grades based on application information given. The key information we are looking for is running current, number of brushes per motor, voltage, speed and if possible spring force. We do make certain industrial size springs as well. And certainly can recommend products or spring force.

We will also inform you about the benefits of a particular grade or product over other. The electro graphite grades such as H49 and H60 are popular on high voltage EV applications. H60 works best from 50-80 Amps/sq-in current density range whereas H49 takes higher loads up to 100 Amps/sq-in. H49 also commutates better as well if there is electrical stress situation. For lower current densities below 60 Amps/sq-in and low voltages ranging from 24-90v graphite grade K254 is very popular. It also films well in low humidity and dry atmospheres where other grades struggle to film. Following is some additional information for your reference if needed.

Advantages of a multiflex red-top brush over a solid brush-

1. A multiflex brush has more points of contact compared to solid brush.
2. As more wires are used compared to solid brush, the wires are more flexible.
3. We have used multiflex redtop brushes over decades to resolve problems.
4. A multiflex brush runs cooler and helps the commutation by preventing the circulating currents in high voltage and high current applications.
5. Two section Red-Top pad invented by Helwig is an Industry standard now. It acts as an insulator to prevent the current to the spring. And rubber section helps to dampen the vibrations.

Hope this information helps.
We thank you for starting the thread on our product. Please let us know if we can be of further service to you."


I will supply more details now about my application and see what is recommended. This is not a "one size fits all" selection process.


Regards,
Gary

[Yabert]

Many thanks!

Very good information.
Please continue to give us details.

[DIYguy]

Originally Posted by Yabert

Many thanks!

Very good information.
Please continue to give us details.

My pleasure. I sent them a lengthy email with pics this morning. No reply yet.

Will advise when I get something. Did you look at the document on brushes? Did you see the various chemistries and their corresponding current handling and voltage drop info? I'm sure the ones high in silver are good....but also very expensive. They go up to over 90% silver! Yikes.... .lol

[elektroboy]

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