Eccentric Spacer Adjustment

• Eccentric spacers are used for making fine adjustments to the spacing between the v-wheels on either side of an aluminum extrusion.

• Adjusting this spacing is key to achieving smooth and wobble-free movement of the gantry across the tracks, the cross-slide across the gantry main beam, and the z-axis up and down the cross-slide.

• If the spacing between v-wheels is too little, then the extrusions will not fit between the v-wheels at all or be tough to move.

• If the spacing is too great, then the connection will be wobbly and loose.

• Let’s adjust the eccentric spacers throughout AgriBot to be just right.

Fit test

• First, see if the extrusion will easily slide in between the v-wheels.

• It will very likely either be too loose and wobble, or too tight and not fit at all.

• Take note of which v-wheels need adjustment.

Adjusting the eccentric spacers

1. Separate the extrusion and the wheel/plate assembly

2. Using an 8mm wrench, turn the eccentric spacer that needs adjusting about 1/32 of a turn.

   Depending on the direction you turn the spacer, and the current orientation of the spacer, the spacing will either increase or decrease.

   Your goal is to adjust the spacer in the direction you need.

   Make the spacing smaller if the connection was loose.

   Make the spacing larger if the extrusion did not fit between the v-wheels or if there was a lot of friction.

   The notch in the side of the eccentric spacer indicates the shortest distance, so moving the notch towards the other wheels will decrease the spacing.

3. Once you have adjusted the spacer 1/32 of a turn, do another fit test.

4. Continue the steps above for all eccentric spacers until your connections are smooth and wobble free.

Gantry wheel plates

• These eccentric spacers on the gantry wheel plates affect the fit of the gantry wheel plates on the tracks.

• To set the spacers to the loosest setting, position the 6mm engraving on the spacers facing away from the track extrusions (down).

Cross-slide

• These eccentric spacers on the cross-slide affect the fit of the cross-slide on the gantry main beam.

• To set the spacers to the loosest setting, position the 6mm engraving on the spacers facing away from the gantry main beam.

Z-axis

• These eccentric spacers on the cross-slide affect the fit of the z-axis in the cross-slide.

• To set the spacers to the loosest setting, position the 6mm engraving on the spacers facing away from the z-axis extrusion.