Mendelmax 3.0 X-axis Tensioner

I found the standard X-axis tensioner plate on the Mendelmax 3 was a pain to adjust and it was too easy to compress the bearings so they wouldn't spin well.

This is a screw-adjustable X-axis tensioner for the Mendelmax 3. It separates the fixing to the X-bar and the belt idler bearings to different screws. It squeezes into the gap at the end of the X-axis bar between the Z carriage angle fixings and the cable chain holder. At the moment you have to remove the cable chain holder to access the adjustment screw - I may make a longer version to avoid this but at the moment it seems to work OK.

I added a smooth idler pulley for my X belt so this tensioner will accept that but the standard bearings would also suffice (with appropriate washers to guide the belt).

Required hardware:

M3x30 screw and M3 nut to connect the tension arm to the idler. A washer at the screw end may be good.

2x M5x8 screws and 2x M5 T-nuts to connect the idler assembly to the X-axis bar.

1x M5x16 screw (or however long you want the adjustment distance to be) and 1x M5 nut this is for the adjustment.

1x M5x25 screw and nut, 2x 605XX bearings (or idler pulley kit) for the belt idler.

EDIT 1 Nov 2016: In the pic it shows that I didn't have a M3x30 to use as the axle between the two parts. So I just used a M3x25 and it is captive held in by the x bar.

EDIT 4 Nov 2016: The problem with the original parts were that the cable chain holder needed to be removed to adjust the X belt tension. Pretty soon after I installed the parts I realized that if they were reversed/mirrored then they could be installed upside-down and the cable chain holder would not need to be removed to make adjustments. facepalm

I have now had some time to mirror the parts and install and test that - yes - it works better now. I have updated the parts and the pictures with the mirrored versions.

-