Geared DC Motors....are they Reversible?

[kirs]

Hi all,
I know DC motors are reversible, but I need a high torque low rpm motor, and these are invariably gear driven.  Are these gearbox DC motors reversible? can i apply reverse polarity?

Also, which is a good source to buy from (this is driving me crazy, so hard to find motors to specs).?

I need 12V (prefer 5V) DC, to run at 30rpm (running, not No Load) and 20kg-cm torque (=2Nm) Not stall/start torque but this is application torque (i guess stall torque would spec at double or 40kg-cm.

thanks

[Resilient]

I can not vouch for all geared motor setups, but I have several RC cars which seem to do just fine in reverse and deliver said power through a series of gears.

It would be wise to consider what will happen when going from forwards to reverse and just ensure that the gearbox can handle the reversal without stripping gears.

[Soeren]

Hi,

I know DC motors are reversible, but I need a high torque low rpm motor, and these are invariably gear driven.  Are these gearbox DC motors reversible? can i apply reverse polarity?

I have only seen a few non-reversible types over the years and it is a thing that will be noted on the sales page.

Also, which is a good source to buy from (this is driving me crazy, so hard to find motors to specs).?

Always see if you can find something that fills your needs at surplus stores - cheaper and/or much better quality.
Check out a page like this:
http://www.surplustraders.net/a/0184.shtml
Googling "surplus gearhead dc-motor" will turn up lots of good parts and refining your searches by further specs should get rid of some of the noise.

I need 12V (prefer 5V) DC, to run at 30rpm (running, not No Load) and 20kg-cm torque (=2Nm) Not stall/start torque but this is application torque (i guess stall torque would spec at double or 40kg-cm.

Search all the robot part sites you can Google up.
You really need to make up your mind about the voltage - if you prefer 5V, don't ask for 12V motors

[kirs]

will do. because some mfr mention a direction of rotation (eg. CCW) which confuses me as to whether it's reversible.

many thanks for the surplus parts link. great stuff, within 5 minutes on the link I have already found my exact spec motor! they are good with specs, plus they are in our country (US). {I was losing my mind searching on Aliexpress: too much choice but not enough stuff spec'd like this surplus site!}