141:1 gear motor with quadrature ecoder 7.95 used

Alsowolfman

i found these and just bought a bunch, and i think this is a really good deal and wanted people to know.
they show up every once in a while, but last time i saw them i hesitated, and missed out, so if you want them get them.
these are made for 12 volts.

http://www.bgmicro.com/index.asp?PageAction=VIEWPROD&ProdID=12829

there is also a similar right angle version available elsewhere for 11.49, which are made for 6 volts.

http://www.goldmine-elec-products.com/prodinfo.asp?number=G16279

and someone wrote up a good description of the motor including the pin out of the encoder here:

http://www.robotroom.com/FaulhaberGearmotor.html

Whit

Alsowolfman,

Great find!

▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
Whit+


"We keep moving forward, opening new doors, and doing new things, because we're curious and curiosity keeps leading us down new paths." - Walt Disney

Alsowolfman

I got the motors from bg micro in a couple of weeks ago, and i thought i would post an update. They really small, just a little wider but shorter than a chap stick. I attached a picture of my original plan which was to build them into an Altoids can robot. they fit fine, but i couldn't get my lid on when i had all the electronics inside because i am using a socket-ed dip prop. one thing that was really surprising is that they do not have 1 pulse per motor revolution, they have 16, meaning that there are 64 positions per motor revolution, and 9024 positions per shaft revolution. they are also really efficient, free spinning they use less than 10 mA at 9 volts, and to drive my robot forward they use 15 mA. they stall somewhere above 300 mA. connecting to the shaft is the only thing that i had trouble with, they are 2mm, and have a slot, so i ended up having to solder together some brass tube to go around the shaft, with a little piece of brass sheet to fit into the slot, to get a connection i could do anything with. they are obviously used, and came with tape on them that had changed the color of the metal a little, but i got all the tape off with a little rubbing alcohol. I would recommend these to anyone that can think of a good connection to the shaft, they are really cheap accurate and efficient.

CounterRotatingProps

AlsoWolfman,

this looks good - thanks for the update. Thinking about grabbing a few for a little project.
What are you using to control the motor voltage (between the Prop and the motor that is)?

Noting the pulse-per-rev mistake in specs you discovered ...
Would you say that this (from their site) is *approximately* accurate?

" Motors operate from 3-12V volts. At 3V, RPM is approximately 23.6. At 6V 47.2 RPM and 12V, 94.5 RPM. "

At 141:1 it's probably unstoppable, eh?

cheers
- Howard

▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔

Alsowolfman

I got two of these motor controllers http://www.allelectronics.com/make-a-store/item/BA6886N/MOTOR-DRIVER-6.5-28VDC-/1.html they work well, but they are a bit of overkill as they have a max current rating of 1 amp each, and the motors have a stall current in the 300 mA range at 9 volts. the motors and the drivers draw a total current of about 28 mA when my robot if going straight, which is pretty good, but half of that consumption is from the drivers.


the rpm state are accurate. i got 23rpm at 3 volts, and 90 rpm at 12 volts. running with a nine volt and those drivers i get about 60 rpm.

they are really powerful, but the shaft is so small it is hard to get a good connection, i cannot stop the shaft with my fingers at 12 volts, and with a 2 inch wheel on it it still requires some effort.


also, the encoders in mine are working fine at a around 3.3 volts.

CounterRotatingProps

Sweet! looks perfect for what I need too. thanks for the info - H

▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔