Do not use wrong polarity on the 880 dirt bin.

[LazyRoomba]

I did this, and killed the motor. Looking at the motor, their's no way to open the cover without permenantly damaging the mounting plate.

Now looking for a small, powerful motor.

upto 24mm diameter,
10mm tall,
23.5mm screw spacing using M2 screws,
2mm shaft.

Any ideas would be great! Thanks.

[vic7767]

See if this is close. No matching part numbers.

http://www.ebay.com/itm/1PCS-For-Nidec- ... SwxYxUu2RC

[LazyRoomba]

I've purchased. Won't be delivered until the end of next month.

Thanks

Edit:

I've roughly measured the are for the 880 motor, and their is room for after market motors. The absolute maximum I managed to measure was:

31mm diameter
27.4mm height

As technology improves, It won't be long before someone has an 880 motor mod (Like from an RC plane or something).

[a1robotrepair]

You may want to try and fix your motor. I hooked one up in reverse, only momentarily, read 0.9A and shut it down before any damage occurred. You are probably looking at a failed Hall effect transistor. I see they are labeled on the board. The motor is a stock, modified for iRobot, motor.
I think it's this one before factory modification. http://www.nidec.com/en-Global/product/ ... /P0000018/

[LazyRoomba]

Hmm.. Had a closer look, this is the best image I could get

I'm assuming the H# on the PCB is a hall affect sensor. Their was an audible "pop" before it died.

[a1robotrepair]

Have you checked the 3 windings continuity?

[LazyRoomba]

No continuity. Their's circuitry under the mounting plate, that I cannot access. Seems to be a chip or something there, can't make it out.

The PCB is sandwiched with the coil bushing.. it's press fit.

[LazyRoomba]

Update:
Got the mounting plate off, will have to redesign and 3D print a new mount.

Note the "hole" top right of IC1.. I think the IC blew.

[a1robotrepair]

What, if any marking are on the ic? If none how many pins are there and how are they situated around it.

[LazyRoomba]

IC1 is a BGA package, text on the chip is too small for me to read

[a1robotrepair]

That's a lot of complexity for such a small motor. Can you identify where the motor coils are connected?

[LazyRoomba]

I'll try and do a schematic today

[LazyRoomba]

Did try, my probes kept slipping off the smd components, so wasn't able to trace where H1, 2, 3 went.

#

Hole in IC1:

[LazyRoomba]

Just had a Frankenstein idea. The motor coil is ok, but the driver is fried, so what would it take to get the coil to run again? Would a pwm signal into a mosfet work? I know timing will be difficult without the hall sensors.

[a1robotrepair]

You need to figure out where the positive side of the coils are connected, where the pickup sensors are, and how the coils are switched. Give a brief description of the spinning part and fixed part. If the ic is fried, you're probably looking for a high speed DC brushed motor, 500mAh @ 12V and torque of vacuum assembly, as the brushless motor needs to know its position for switching the coils field.

[LazyRoomba]

Update:

Motor delivered today, and designed a plate to be 3D printed so the motor can be installed into the existing mountings.

Again, still working on my 3D printer, so will give another update within the next few days.

For those who want to use this motor,

http://www.nidec.com/en-IN/product/moto ... /P0000020/

[LazyRoomba]

Done!

The motor does lack the power, but at least the bin now has suction. Saved me $60 on a new bin.

Download the adapter:
http://www.thingiverse.com/thing:1787964