February 17, 2026
Description
It has come to my attention that if you have v-slot framing and not t-slot you might struggle getting anything smaller than MGN12 to sit nicely (mainly because the gap in the V-slot is over 9mm). Now I know many will say “Just buy T-slot profile instead”, which is a great suggestion however if you ALREADY have the V-slot that isn't very efficient cost wise, also some Countries you might find T-slot is harder to come by or simply a LOT more expensive (3x the price for some) so not really a viable option.
I also figure it could be convenient to help turn the v-slot into something more like a 20mm piece with a centre hole, so I had an idea…
Solutions:
Use MGN12, many do for this reason, even though the cheaper MGN9 or even MGN7 might actually be more than enough for your needs, it wouldn't be a solution for other use cases though.
Make something (we are 3D printers/modellers after all, why not right?) to solve this issue. THIS seemed the right idea.
These little printed pieces should fit pretty snuggly into the V-slot, (they are 10mm long) making it in line with the 2020 profile and thus help you get the MGN9 rails straight and centered along with my MGN9 & MGN12 Linear Rail 2020 Alignment Tools
https://www.printables.com/model/450861-mgn9-mgn12-linear-rail-2020-alignment-tools
They are also small enough not to interfere with your bolt spacing, thus saving you any headaches there.
As I don't know what size bolts you might be wanting to put through this (and it can be used for other things OTHER than fitting MGN rails), I have modelled the part with 3 options in mind.
M3 bolt hole
M4 bolt hole
M5 bolt hole
Hopefully that is more helpful than just the M3 I was going to go with.
Any issues re-sizing or any feedback is more than welcome. These were modelled from the OFFICAL 2020 spec, though quality of 2020 varies from brand to brand, as well as printer calibration. If you need to adjust the size to make it flush it is worth flipping the model (smaller flat side down) and then reduce the height of the model to desired size and reprint for a snug fit.
You should be ok printing these in any material, they are unlikely to get hot enough to have issues, even in an enclosure, though it is something to take into consideration if you are heating the printer chamber (if that is the case as most parts should be, print in a more heat tolerant material). Please be aware different filaments have different properties after printing so type could affect fitment (worth doing a test print).
Please like and leave a comment if you find this model useful
License:
Creative Commons — Attribution — Noncommercial
7