Hoover Convertible Brush Seating Stone

[hooveru4089]

This is a follow-up from an earlier thread. Has anyone had success using a brush seating stone on a Hoover Convertible motor?

 

[lesinutah]

Hmm

You mean using a commuter stone to help seat the carbon brushes.
I'll let you in on a secret on what I do. I completely remove the armature. I get a drill with an open chuck. I put armature in the drill. I tighten the armature so it rotates as if it was in the vacuum. I use the commuter stone I then make sure there is no excess dust from the stone. I then rotate it and make sure the armature blades are all straight.
I've done a Hoover 913 motor but not a convertible. I've done this on lamb motors from late 20's and newer.
No I haven't but you now know how I do it and a vacuum shop owner who owns a chain of 4 stores does it.
Les

 

[vacuumlad1650]

What Les described is how I've done mine for years

 

[bnsd60m9200]

are you looking to actually seat the carbons? or just polish the commutator as stated above?

 

[madman]

I use Les' method but with sandpaper, the grit depends on how torn up the commutator is. If it's in good shape, a scotch brite pad is plenty. If it's really torn up, I suppose a stone might be better, or a flat block wrapped in the sandpaper. The flat block will keep the surface of the commutator flat. If you have new brushes or brushes that are worn wrong, I would wrap the commutator in sandpaper (maybe 150 grit), with the sand facing out. Then use it to sand its curved shape into the brushes. Just hold the brushes at 90 degrees. They need not be perfect, they will wear in as the motor is used.

This is kind of the lazy man's method but it works.

 

[vacman1961]

When I had my vacuum store I took an old top bearing plate and drilled a large hole in it, you remove the motors bearing plate and cooling fan, install the drilled bearing plate, turn on the motor and chalk the motor, you need to do it this way to both clean the armature and it gets the proper curve in the carbon brushes. After you seat the brushes, remove drilled bearing plate, blow out any dust residue, reinstall the cooling fan and bearing plate, Make sure this is done with the belt off the motor pulley.

 

[hooveru4089]

So far, I have just polished the commutator itself, per Lesinutah's method, but with sand paper (400 grit emery). The motor has new carbon brushes. Currently it does not run well; lots of sparks, runs slow, and sounds raspy.

Another user suggested using a stone to seat the brushes, but that it is particularly difficult on a convertible. That is what I would like some help with.

 

[lesinutah]

Link

This will help you.
Les


https://www.vacuumland.org/cgi-bin/TD/TD-VIEWTHREAD.cgi?17552

 

[madman]

Try my advice to shape the brushes. Technically, you don't need to take the motor apart. Stick a slice of sandpaper (~150 grit) between the commutator and the brush, sand facing the brush. Get something to push the brush into the sandpaper (the springs are likely not strong enough), and slide the paper back and forth over the commutator, to shape the brush to its curvature. Also ensure that the spaces between the commutator's contacts are clean, assuming there is space between them - some are filled with epoxy or whatever.

 

[bnsd60m9200]

les, a convertible motor CANT be seated like that. the motors arent designed that way.

U4089, run the machine with the belt ON for 10-20 mins on the highest height setting NOT on carpet. that is what is recommended by people i know who repair these machines for a living. hoover didnt think through very well about seating carbons in thier uprights. there really is no way to seat them aside from a long duration static load test to get the carbons to seat on thier own

 

[hooveru4089]

@madman:
I did already try your method; it helped slightly, but the Hoover brushes come stock with ridges, far from that smooth, curved edge characteristic of well-seated brushes.

My machine definitely needs a new top bearing so I think I will try vacman1961's method.

@lesinutah:
In the thread you shared the link to, eurekastar warned of a hazard, saying "Be [careful] not to touch [the lead wires]. You might be in for the shock of your life!" I'm not sure I understand what he is referring to.

 

[vacman1961]

It definitely works, I have been in the vacuum business for over 40 years, we have saved many convertible motors.

 

[lesinutah]

Uh no

It a thread on how to seat carbon brushes.
The motor can be done where the fan goes put the armature on drill.
I only mention because when turned on RPMs are high and I don't like the zap a carbon brush inflicts. It hurts like a mother. Don't ask it hurts.
If you need a bearing replaced on bottom of the armature fix the bearing before doing anything. The bearing could cause armature to not rotate in perfect motion. The bearing could be the reason nothing is working.
Les

 

[hooveru4089]

Attached please find a link to the thread to which this is a follow-up. In it I describe the original problem I had with the unit that, upon recommendation of other members, prompted me to replace the brushes.

https://www.vacuumland.org/cgi-bin/TD/TD-VIEWTHREAD.cgi?31349_58

 

[hooveru4089]

Listen to the motor of this Convertible in the video. Notice the sort of raspy sound it has. My machine sounds somewhat like this, but worse.

 

[vacuumlad1650]

That's my 33. It was just rebuilt before the video was taken.
Add that to my using a very low quality microphone on a cheap cell phone and you get the raspy sound. The old girl purrs like a kitten in person.
A 40 year Hoover dealer taught me how to rebuild a convertible using that machine.

 

[vacuumlad1650]

The way EVERY old Hoover dealer taught me to seat the carbon brushes is to run the machine with new carbons in it for 15 minutes with no belt atached, then raise the front of the sweeper off the floor so the agitator will not contact the floor and run another 15 with the belt on.

 

[hooveru4089]

Success!!

Here is what I did:

1) Took motor apart, vacuumed it out and wiped it clean
2) Cleaned, dried, and re-lubricated top bearing w/ 3-in-1 blue
3) Put commutator in drill; used fine garnet sandpaper to refinish bearing shaft and armature
4) Took strip of same sandpaper, wrapped around commutator and seated brushes
5) Cleaned motor of all carbon deposits
6) Greased lower bearing

Thanks everyone for all your help; it now purrs!

Now all I need is a light bulb. I recall an earlier thread regarding LED replacement bulbs; I know some members don't care for the look of the light, but what wattage, etc., do I need for this machine (719)?

 

[madman]

Nice work! I believe it takes a normal small appliance / vacuum / sewing machine light bulb. 2 contact bayonet base bulb? Pretty sure any old thing will work. Look on ebay or amazon for either 'vacuum light bulb led' or 'sewing machine light bulb led.' Just ensure the base looks the same as yours, and that they say 120v not like 12v.