# Brushed/brushless motors and "carbon dust" from forced air dryers...



## SoCalEngr (Apr 11, 2020)

One of the hazards of Google-foo is finding stuff you have zero idea about the validity of...and then not being able to find independent sources to compare notes with.

In my perusing, I came across the idea of using brushless motors in a forced air dryer. There are many advantages to brushless motors, but they're also more expensive. The most intriguing of the claims had to do with "carbon dust" from the brushes used in brushed motors. The argument made was that this is being blown onto the dog, as well as into the air. It seems fairly straightforward that carbon particles would not be good for a dog's coat, nor the groomer's/dog's lungs.

But...

Is this a "real concern" (however slight), or is this a pure marketing ploy to justify over-the-top prices? In checking most of the available forced air dryers (including the higher-end brands), most seem to use brushed motors. Even the manufacturer of the brushless unit sells units with brushed motors (lower price points). But, aside from my personal fascination with over-the-top engineering decisions, is there any discussions in the hobbyist community about the potential dangers of carbon dust?


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## Prism Goldens (May 27, 2011)

I've never heard of anyone being concerned w the carbon dust- I suspect if it is really a concern it stops being one immediately after turning the dryer on (but that probably shows my lack of dryer knowledge- I just want it to work and work well!)


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## Brave (Oct 26, 2012)

I'm in a couple groomer groups and I've seen a few posts about carbon dust (whether it be from a cage dryer or a stand up dryer or a HV dryer) and from what I understand, you just re-wash the dog, and have that motor serviced before using it again. No harm no foul. In my experience, in the like 7 years I've been using a HV dryer, I've never had that problem. I make sure the filter is on my machine and is clean.


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## SoCalEngr (Apr 11, 2020)

Brave said:


> I'm in a couple groomer groups and I've seen a few posts about carbon dust (whether it be from a cage dryer or a stand up dryer or a HV dryer) and from what I understand, you just re-wash the dog, and have that motor serviced before using it again. No harm no foul. In my experience, in the like 7 years I've been using a HV dryer, I've never had that problem. I make sure the filter is on my machine and is clean.


Grazi. So, while the potential for carbon dust from the brushes is real, the actual solution (and, maybe, a reason why it's not a major topic of discussion?) is "_simple maintenance_"?

I have to admit, irrespective of the carbon dust argument, the geek side of me thinks the whole brushless motor is uber cool (e.g., lighter, more efficient, quieter, etc.). I'm just very unsure that it's $300 "cool". 😁 And, while I fully get the "longer life" for the motors, I'm thinking that may not be a huge issue for us and our one (1) golden.


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## Robert0s (Apr 24, 2021)

That looks intriguing. I'm wondering if it could work for my heating duct as well. My doggy loves getting a hair dry, but it takes too long most of the time to do it, This is how we ended up burning our hair dryer a few times. I'm tired of buying new ones all the time, so I think I will ask the guy that will come to do a heating duct repair for my heating system in the house to look at them as well. He might be able to fix them. You never have to lose anything with a paid service, plus most of their employees are always very happy to help.


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## Atis (Jul 8, 2014)

I work as an industrial maintenance mechanic and have serviced both brushless (i.e. AC motor) and brushed (i.e. DC motor) motors. In an industrial motor the brushes may be roughly the size an old school desk pinky eraser (or larger) and a motor may have as many as 8 of these installed and yes with years of running that motor will have collected a very large amount of carbon dust within itself and will generate a cloud of dust when blown out with compressed air. A motor as in a dryer may have two brushes about the size of a daily vitamin in it. By design in order to cool the motor the air flow will carry away the dust while in use so it will never collect in quantity. I've had my blower over 5 years and not had to replace worn out brushes so the amount of dust generated over this period would be so negligible I would not worry about it at all. As far as reliability yes brushless motor are likely to not need any service during their use but they do require more complicated controllers to run and in this case the controller is more likely to fail than the motor itself. A failed controller would never be a do it yourself repair and probably not cost effective for a dryer. Replacing brushes is an easy job for a handy person and a very inexpensive replacement by a service person.


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