Replacing a small DC motor from a paper collator

[ryancparadiso]

Hi all





I am looking to source a specific mini DC motor for a paper collator tower. I have removed the motor, and attached pictures of it. The motor runs intermittently when in test mode, but sometimes sputters (turns a little, stops, tries to turn a little...), which trips the error system. When testing its wires for continuity, I consistently get a reading of 10-15, so it seems like there is some resistance. And, when I turn the spindle manually, it seems to get 'stuck' / find patches of physical resistance, though I'm not familiar with motors and so am not sure if this is normal or not.

All of the information I have about it, which is also on the picture, is:

DC Motor
Type SP
No. FM-36E
China | Fuji Micro
(and on the other side, a sort of serial(?) number: ID24 JSP)

measurements:
- body: 1.5 in diameter, 2 in. length
- spindle: 5/32 in. diameter, 1 in length

The company no longer supports this machine, and does not have any replacement motors. I have not been able to locate it online, and don't know enough about it to know what sort of new motor might work. Any help would be appreciated! Thank you so much~~

 

[waross]

Is it brushed?
The brushes may be shot.
What voltage?

 

[crshears]

ryancparadiso: when I turn the spindle manually, it seems to get 'stuck' / find patches of physical resistance

Depending on the type of motor, you may be sensing what's called "cogging", which may be completely normal . . .

 

[waross]

I am suspecting the brushes worn to the point that they are jamming between the brush holders and the commutator.
The DIY description may be more consistent with brushes jamming than with cogging, but who can tell with a DIY post.

 

[Compositepro]

It appears to be a pretty standard brushed DC motor with only two power leads. It is not sealed so a small metal shaving probably got into it and stuck to the magnets, or one of the ceramic magnets got chipped. It also appears to be very simple to take apart. That certainly is not done these days by professionals, but it is done by hobbiests who will become professionals. How much time will you spend looking to buy an exact replacement? Just look at this as a valuable educational opportunity.

 

[ryancparadiso]

Thank you all! I'm super down to open it up, seems like I need to un-solder one piece and can access it by removing a couple screws. I'll report back when I do so.

It seems that a commutator can be cleaned/polished with fine grit sandpaper, but I've not seen folks who suggest replacing brushes is possible. Does this seem accurate?

 

[waross]

Eventually, the brushes wear down to less than the clearance between the brush holders and the commutators and get jammed under the
the edge of the brush holder.
It may need new brushes.
If the brushes are gone, you may not find the exact replacements but you may file oversized brushes down to fit.
It's really dirty but it works.

 

[crshears]

And be sure not to leave any grit, especially conductive grit, between any of the commutator bars. Shaping the brush contact face to conform to the commutator circumference may be fun . . .