Trimmer for Cheap Gearmotors

I have hacked up a couple of RC Servos via removing all the electronics and using them as inexpensive gearmotors. I now find that one is more efficient than the other. I am planning to use a
Hall effect / PWM closed loop control structure to avoid this problem in the future, however I want to give a demonstration of what I have so far and I need the damn thing to go straight : ) . I was thinking about throwing a trimmer into the cicuit for the short term to balance out the problem. Any ideas on what range the pot should have...ie 100k? Whats the best method to figuriung this out? They motors prob recieve about 6 volts.
Thanks,
Rick-
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Follow-up: I used a 5k trimmer and it works alright..however its not what it could be due to the non-linear turns off the trimmer. The closed loop system is really neccesary.
Rick-

and
a
the
have...ie
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Rick Cassidy wrote:

Why is that an issue? Don't you just adjust it to a single value so that it goes about straight and then leave it alone?
If not, it is possible to get linear taper pots as well as non-linear (e.g., log or audio).
Mitch Berkson
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Polytechforum.com is a website by engineers for engineers. It is not affiliated with any of manufacturers or vendors discussed here. All logos and trade names are the property of their respective owners.