Print-Rite Carriage with sensor mount

Replacement part for the Print-Rite DIY carriage.
I took the model from shawdreamer (take care to thanks him too).

I made some improvements to fit the original parts better.
It's also compatible with this cooler :

http://www.thingiverse.com/thing:1514276

I printed it upside down (some support will be needed), but I assume you can try to print it upright.

When your print is done, assemble the main, bloc_2 and bloc_3 with the belt (you can glue main an bloc_3 together).
Then adjust the tension with bloc_1 (I think it's simplier this way).

Don't pay attention to the photos, that was an earlier version.

You will need M2 or M3 screws (I used 2.5 there was nothing else at my local store) to secure bloc_1 and bloc_2.

I added a support for a sensor, I can give you the exact offset if you want.
I will provide a version without the support if you don't have a sensor but want to change the carriage.

I did not test this "final" version, any feedback would be appreciated