Choice between two motors.

[johnmoth]

I am currently at a tossup between getting  this

http://www.pololu.com/catalog/product/2285

and this

http://www.ebay.com/itm/FAULHABER-DC-9V-Motor-1524B009SR-Gear-19-1-Encoder-512CPR-USED-free-ship-/150968781120?pt=LH_DefaultDomain_0&hash=item232670c940

The only problem with the first one is that it might need a 90 degree gearbox because they are too long to place next to eachother. 

On another note, we wanted to reduce the gear ratio cheaply.  what would be a good way to do that?

[Astroplio]

Hi john, welcome to the forum

on the first link from Pololu you have the option to select a lower ratio gearbox  34:1 or even lower 9.7:1 to go with the motor
(see where it says "select options")

If you plan on modifying gear ratios anyway maybe you should check other options, like the Tamiya gearboxes I see on the Pololu site, since they also come in the angle configuration you talk about.
You can also find mods from other people on the internet that have added encoders on these gearboxes, if you absolutely need to have an encoder.

About reducing the gear ratio cheaply, I don't know any solution to that.
I assume you ask about that because you want a better control of the rotational speed, so you need to get a lower ratio gearbox than desired, and play with PWM to reduce further the rot.speed. Also operating DC voltage comes into play with these, if you run the motor on a higher voltage than the specs, then you will get a faster speed (the opposite if you reduce the operating voltage). But I don't recommend using a higher voltage, there is a risk of burning the windings (unknown tolerances... you can experiment if you like of course...)

George

[johnmoth]

Excellent.  Thanks!