# brush spring issue - D&D ES-31B



## brainzel (Jun 15, 2009)

I need two new brush springs that hold down the brush to the commutator of my D&D ES-31B Motor.

Unfortunately I can not even biy the single part from D&D so I have to look for a replacement part.

Can anyone help me to find two new springs?
They are about 40mm (1.57 inch) long and 8mm (0.315 inch) thick.


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## major (Apr 4, 2008)

brainzel said:


> I need two new brush springs that hold down the brush to the commutator of my D&D ES-31B Motor.
> 
> Unfortunately I can not even biy the single part from D&D so I have to look for a replacement part.
> 
> ...


Hi brain,

D&D should be able to inform you of where you can order those parts. And so should the place where you bought the motor. Also search for other vendors who sell D&D motors and contact them. 

However, from the photo, that motor may need more than just springs  Is that condition just a result of normal use in your bug? Appears like you may be overloading it or running too high voltage.

Regards,

major


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## brainzel (Jun 15, 2009)

D&D wants to sell much more than just what I need and not only the two springs.

The dark area on the commutator is more the missing light. I should have made more light to get a good picture, sorry 
It's a motor after 1 year and after 3000km carbon dust and environmental influences. That's all OK.

But the incorrect placed spring produced an arc, welded against the cover and melted some metal of the neighborhood spring.

And that's what I need: only two new springs ...


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## major (Apr 4, 2008)

brainzel said:


> But the incorrect placed spring produced an arc, welded against the cover and melted some metal of the neighborhood spring.


Something here ain't quite right. If what you say is true, you must have another ground point of opposite polarity to cause such arcing to the case (or coverband). A single point ground, like one spring touching the case, will not cause an arc. It will give you a ground potential, which is undesirable. You had best check for grounds, now and periodically. If you had done that before, you would have known the spring was touching the case and could have corrected it before damage.


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## brainzel (Jun 15, 2009)

I don't know exactly the reason of this malfunction, so I have to guess. The body of the motor has naturally a connection to chassis and thus to the auxiliary battery ground.
The attached picture shows the melted spring (it's not really sharp).

For whatever reason I need two new springs 
In the meantime I've found that the springs are produced in germany, so I will call them today and see if they could help me.


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## major (Apr 4, 2008)

brainzel said:


> The body of the motor has naturally a connection to chassis and thus to the auxiliary battery ground.


Yes, that's my point. The motor circuit (or high voltage battery) should not have a connection to chassis (ground). You obviously do (or did) to cause the arcing. This ground is an unsafe condition. The auxiliary battery must be isolated from the high voltage circuit so it does not take the high voltage circuit to chassis ground.


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## DIYguy (Sep 18, 2008)

brainzel said:


> I don't know exactly the reason of this malfunction, so I have to guess. The body of the motor has naturally a connection to chassis and thus to the auxiliary battery ground.
> The attached picture shows the melted spring (it's not really sharp).
> 
> For whatever reason I need two new springs
> In the meantime I've found that the springs are produced in germany, so I will call them today and see if they could help me.


Hi Brainzel, please give Major's comments a re-read. It is likely that you need more than "just two springs". You are seeing the visible problem. You may have another invisible one.


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## brainzel (Jun 15, 2009)

Perhaps it's a language/translation/understanding issue?! Sorry.
The auxiliary battery (12V) has a connection to "ground" / chassis. That's normal.

The batterypack (144V) has no connection to the chassis or the 12V System. I know that this would produce problems and in worst case a hazardous environment.

It's a personal presumption of me how that could happen.
Perhaps the departing spring caused something else inside the motor that causes this obvious result.

Michael

addendum:
eventually I found something: other post
I use a MES DEA RM4 ... I have to check this later.


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