Top-plate for the X Axis Stepper on the TOM.
I noticed that with all the Adjustments on the X axis tension, my wood began to warp and crack a bit around the channels. Especially around the T-Slot for the left side.
This plate should reinforce the wood making things sturdier.
Also a tensioner is integrated for making belt tension adjustments without disassembly.

This design uses countersunk M3 bolts rather than the stock ones in order to allow a thicker ABS Plate. This will provide more strength with the same height.

I liked it so much I put one on the Y axis too.

I just noticed there is a similar design here on thingiverse:
http://www.thingiverse.com/thing:11502

I printed using 90% infill for added stability. Slide a M4 nut into the tensioner slot. Swap out the existing M3 bolts for countersunk ones and screw them into the stepper gently.If you use countersunk bolts, X axis mobility will not be compensated. If you try to use regular head bolts, the carriage will run into the bolt heads.

Drill a hole for the M4 Tensioner Bolt into the left side as shown in the photo. I recommend using a M4 washer to protect the wood, but you can see I used a scrap ABS plate for this purpose. Screw a M4 bolt through this hole into the tension nut on the plate. This will allow you to make minor adjustments to the belt tension without disassembling the carriage