Mendel Troubleshooting

I cannot figure out why my Z axis is binding.

If you remove the belt you can tell if one of the Z drive screws is more restricted than the other by feel.

Measure that your Z drive screws are parallel to each other. The X bar measurements in the spec make them a little longer than may be ideal. You may have = to loosen the 2 x-bar-clam-m4 on the motor end and slide the assembly containing the x-vert-drive-nut-trap toward the center of the machine . The x-motor-bracket-spacer does not fill the gap between the bracket the motor is bolted to and the next assembly.

The x axis needs to be level once sitting on the Z screws. If your machine is on a (near) level surface, placing a spirit level on the extruder carriage will help you get the x axis close to correct.

The belt may not have sufficient clearance. If there are issues with the printed parts you may need an additional M4 washer or two with the idler bearings for the Z belt. The belt may be incorrectly routed.

Nuts may not be seated right in the x-vert-drive-nut traps.

Some 608 bearings may bind when the washers are placed either side. You might try using a nut directly on the bearing instead.

Some 8mm washers are too big (diameter). The 8mm washer then catches on the 4mm washers that hold the bearing in place as the Z screw turns. If necessary, you may remove the 8mm washers (as above), use different washers (15.8mm or smaller diameter seems to work), or mechanically adjust the 4mm washers (trim or file off a piece of the washer).

Check the Z screw for grit and/or paint (usually nearer the ends, but can happen elsewhere).

How do I move the extrude hole in reprap host software? The software thinks its on the right side and mine is on the left.

You need to add the settings for your build platform to the file - <Your Home Directory>/.reprap/reprap.properties

You need to add:

DumpX(mm)=5

DumpY(mm)=5

or replace the 5s with the correct coordinates for where you want the extruder to purge before prints for your machine.