Friday, April 23, 2010

Foot drive adjustments and shock dampening idea

This evening I did some work on the foot drives.

One issue I have had since I got R2 operational has been one side is faster than the other.  So, driving R2 with the remote is similar to driving your car with one of the front tires pulling to the right.  Its manageable but despite trimming on the remote and reducing power to the stronger motor, nothing has really changed.

With the legs off, I inspected the feet and noticed that one of the ball-casters was very worn compared to the other.  I had purchased a spare set last year, so that was an easy fix.

While a dragging omni-ball could slow one side down, I decided to check the belts.  The side that runs stronger had about 1/2 inch of slack.  The slower side was about half that.  So, I decided to loosen the mounting bolts, reduce the tension a smidge and made it even with the other.  Between these two changes, perhaps we'll solve this oddity.

Finally, I came across some rubber grommets at the hardware store recently.  My thought is that placing these on the shoulder bolts, between where the leg attaches to the shoulder, may help reduce some vibration.

With the legs back on, now its on the tuning the electronics and re-connect everything.  Here I am about to plug into the Roboteq AX3500 motor controller card.  The software will allow me to make changes to the card's settings.  In this case, I am going to change the power settings to the motors so they are both equal again.  And, I am going to adjust the acceleration a bit.  I had it tuned way down but need to bring it up a tad to a faster walking pace.