The original design of this was a little too tight using my printer. I simplified the connection to the extrusion & made it parametric as well as being able to use this with any of the V-Slot or C-Beam. I have only tested the 2060 version. Since the dimensions are similar for all the extrusions, the others should work.
There are a few variables in the openscad script you can change, but the two you will probably change are Len & Cut_Size. Set Len to either 20,40,60,80,100,120.
20 = 2020
40 = 2040
60 = 2060
80 = 2080
100 = C-Beam (To simplify the openscad script, I use 100 for this & 120 for 4040)
120 = 4040
Set Cut_Size to either 0,1 or 2
0 will give .2mm clearance on each side of the V-slot or .4mm wider than V-Slot
1 will give .25mm clearance
2 will give .3mm clearance. One of those should work for you.
I included a STL file of all the types in one file with the 3 different clearances. as well as a STL for each type with a clearance of .2mm. The clearance size is in the filename so it should be obvious which is which.
If you have 2020 extrusion, I would print a test print of that to start with. If you want to do a minimum test print for V-slot size you are using, set AccessHole_Ht = 6, Cover_Ht=6 & Cut_Size to what you want to test as described above.
Instead of using a tap, I used Rick's idea in this thread to just drill with 3/16"(4.76mm) bit & thread it with a screw which worked well for me. I used a stainless steel screw.