# DC Motor Brush Replacement



## GrowleyMonster (Apr 7, 2014)

I recently re powered my sailboat with a brushless DC motor, rather than a brushed motor, due to explosion potential when propane and gasoline vapors are present in a confined space. However, this boat is sort of a test bed, and I will likely be building a solar electric houseboat at some point in the future, and I am also considering converting a car as well. In either case, my primary reason for going with a BLDC motor on my current project won't be much of an issue with future projects, so I am considering brushed motors. What has me hanging back a bit from them now is brush replacement. Let's say a motor that hasn't been manufactured in 20 years needs new brushes. Are there generic brushes that can be made to work with little trouble? Can they be ground or machined to suit the motor by a reasonably competent DIYer without expensive equipment? I would hate to build something with a motor that might be in fine condition at some point in the future but obsolete due to lack of brushes. Or bearings or whatever.

And another question... is there much interest or activity in DIY building or modding of brushed motors?


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## major (Apr 4, 2008)

Most of the DIY EV propulsion motors are very, very similar to forklift truck motors. There is a huge legacy fleet of electric forklifts using these DC motors which will be serviced for decades to come. Brushes, bearings and the skills to service these motors should not be a worry


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## favguy (May 2, 2008)

Hi,
Motor bearings should always be available as they are standardised and any good bearing supplier will find you replacements in the right size and spec. if you take yours in to them. 

Even if brushes and springs do become unavailable for an obsolete motor, (As I have personally found out with my own motor, not made now for around 35 years!) Helwig Carbon will make you a custom set of brushes for your machine from compound suited to its use. Brush springs (uprated to suit custom brushes if desired) can also be made up by a good clock spring manufacturer if you supply them with an old spring and tell them what you want.

In fact, there are plenty of firms who can rebuild almost any motor if needed, usually for around 50% of the cost of a new machine.

I reckon with a little care and maintenance DC brushed motors can live longer than most humans actually


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## GrowleyMonster (Apr 7, 2014)

So how many hours does a set of brushes typically last, with the average forklift type motor? Assuming operation well within design load and power, of course. Should I try to accumulate several sets of spares, or is that overkill? 

I still like BLDC motors, but a brushed motor controller sure is a lot simpler. Also, in an emergency a brushed motor can be ran directly without a working controller, just a contactor, but a BLDC motor cant. Lots of factors to consider.


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## major (Apr 4, 2008)

GrowleyMonster said:


> So how many hours does a set of brushes typically last, with the average forklift type motor?


Maybe 5 to 10,000 hours on the hourmeter on the truck. There are many threads here about brushes and motor maintenance. Use the search function. Here's an example: http://www.diyelectriccar.com/forums/showpost.php?p=342196&postcount=20 










New vs used (45,000 miles).


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