I've just made a little remix to fit 2 COB strips inside and added a diffuser.

The brackets remains the same as there are very nice designed, you have to print them from the original creator here

I originally print the led channel in PLA Though but it quickly deformed under the effect of the heat, so I printed it again in PETG and no more problems.

I put some electrician's tape on the inside of the brackets to add a tiny bit of thickness so that they're firmly held on the horizontal bar of the Z axis.