Greetings,

Sorry if I posted this in the wrong forum.

I have a vitamix 7500, have had it for years. I replaced the brushes on it about five years ago (Vitamix 764 brush kit), cost me about 20 dollars and wasn't a big deal at all to replace. Brushes have worn out again and it looks like they are an obsolete part that is no longer being sold.

Is there a way to identify the kind of brush used it the vitamix? It is approximately 1/4 inch x 7/16 inch x 1 inch long and it appears to be heavy in graphite composition. I do a fair amount of electronics repair for a living, but I am ignorant of brushes and whether or not their composition is that important. I would rather not install a brush that is the wrong composition and destroy the commutator. It would not be a big deal for me to snip the wire off the end of the brush, solder a new one on, and reinstall.

Thanks

 

This is a more difficult repair than I first thought, because of the enclosure the brushes are held in. Ideally you don't replace just the brush, but the whole thing. And yeah, they don't seem to be easily available.



Can you remove the actual brush and spring from inside that plastic enclosure? I think there's a fair chance you can match the brush dimensions if you can. I'd start at the usual places like eBay or Amazon
https://www.amazon.com/Carbon-Brushes-Electric-Different-Replacement/dp/B0BYJZD29G
and then move to the supply houses like Grainger or
https://www.mcmaster.com/products/electric-motor-brushes/
...if I can't find it at the cheaper sites.

 

This is a more difficult repair than I first thought, because of the enclosure the brushes are held in. Ideally you don't replace just the brush, but the whole thing. And yeah, they don't seem to be easily available.

View attachment 326061

Can you remove the actual brush and spring from inside that plastic enclosure? I think there's a fair chance you can match the brush dimensions if you can. I'd start at the usual places like eBay or Amazon
https://www.amazon.com/Carbon-Brushes-Electric-Different-Replacement/dp/B0BYJZD29G
and then move to the supply houses like Grainger or
https://www.mcmaster.com/products/electric-motor-brushes/
...if I can't find it at the cheaper sites.

Yes, the brush pulls right out. I'm not terribly concerned about the plastic housing either, push comes to shove I will design a new one and 3d print it. It is only held in by a plastic tab and a single bolt on the motor itself.

I was hoping to find a brush with a similar composition and just do a snip and solder onto the old wire. I will check those websites out, thank you.

 

I do have some generic brushes lying around, and an Ametek vacuum cleaner brush thatI removed from the plastic housing. It's quite a bit lighter in color than the vitamix one (less carbon I would guess, but I know little about this), but the dimensions are very similar.

Pictured
Ametek vacuum cleaner brush, 1/4 x 7/16 x 1
Ametek vacuum cleaner brush removed from housing
Generic brush that is not quite as wide
Vitamix brush that is wearing out.

 

did it work?

 

One solution that may work for you is to file down brushes you have in hand do that they fit the plastic holder. It might be messy but it is a possible solution.

 

did it work?

I will report back Monday, left for vacation up north before I got the machine buttoned back up.

 

Where is "up north" for you? I'm in northern Illinois and up north around here means Door County, Wisconsin Dells, or the UP (upper peninsula of Michigan). Any of those sound really good right now. Smoked whitefish, cherries, fishing towns. Love it.

 

Where is "up north" for you? I'm in northern Illinois and up north around here means Door County, Wisconsin Dells, or the UP (upper peninsula of Michigan). Any of those sound really good right now. Smoked whitefish, cherries, fishing towns. Love it.

I'm in Iowa, up north is Minnesota with the relatives.

 

Yes, the brush pulls right out. I'm not terribly concerned about the plastic housing either, push comes to shove I will design a new one and 3d print it. It is only held in by a plastic tab and a single bolt on the motor itself.

I was hoping to find a brush with a similar composition and just do a snip and solder onto the old wire. I will check those websites out, thank you.

Are these the brushes that came out of the Vitamix? If so - they don't look worn to me.

 

Are these the brushes that came out of the Vitamix? If so - they don't look worn to me.

I hastily bought a broken Vitamix off Ebay for 40 bucks when our daily driver started to act up a few weeks ago, it only has a broken on/off switch which is a trivial fix. The brushes on that are in pretty good shape.

In case these non OEM brushes don't work long term, I will at least have that and avoid having to buy a new one for a few years. I should have cleared that up in the first post, there was maybe a 5mm sliver left on the brushes of the old machine.

Update - the ametek vacuum cleaner brushes worked. I had to saw the end off to get the brush out of the ametek housing, as the housing appears to be solid brass and it won't let go of the brush. Then I snipped the wires on both brushes and soldered the ametek brush into the vitamix wire/spring thing.

Time will tell if the brush hardness is too much and it wears the commutator too quickly.

 

Time will tell if the brush hardness is too much and it wears the commutator too quickly.

It shouldn't be the commutator that wears, it should be the brushes. Since the brushes are the softer material it should eventually conform to the curvature of the commutator and make really good contact. Just make sure the commutator is clean.

 

Bit of an overdue update, but the brushes that I soldered directly in to the copper wire of the brush assembly are getting the job done, 5ish months strong.

 

Bit of an overdue update, but the brushes that I soldered directly in to the copper wire of the brush assembly are getting the job done.

Glad to hear of the success. Certainly, 5 months is a decent break-in period. And that things are going well is a good sign.

Happy mixing. And happy holidays.