M5 T-slot nut substitute

by csweichel Aug 18, 2012
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Such a disappointment. Your post doesn't specify 2020 or 3030. I mistakenly thought it would fit my 2020 and it doesn't. It's about 2-3mm too wide. So I'm guessing it's for 3030 then. Luckily I cut the file down to only 10 pcs. so not that much wasted but I have to take away my "like" as the info here is incomplete as to what it's compatible with.

Okay I have never edited an scad file before, how do I make it for a m4 nut?

Is there a .stl file available for printing a single M5 T-slot nut substitute? Would be great for a testing. Thanks!

This shall suit my new project well! Thank you!

If you derived this from two GPL projects, how can you make the derivative NC?

In this case the derivation is more like inspiration rather than actual asset reuse. This thing is developed from scratch and the items I "derived" it from were more like the starting points that made me design it in the first place.
Thus I'm not bound by the GPL in this case and get to choose the licence.

Hey Blacki, 
I´m curious to know if your printer is holding up with your printed t-nuts.
Did you use it intensely enough to test the durability?


The nuts are holding just fine. I tightened them all again after about two weeks and they've been working fine ever since

cool, very good to know. Thanks for sharing!

Forget what these chaps bellow are saying (except wilot309) this is a very good design. The only force applied to the plastic part is rotational. It acts like a wrench holding the nut in place when tightening the screw, after that all it does is keeps the nut and washer centered in the channel so they cant move and pop out.

This is probably the ONLY printed t-nut that is as solid as the real thing.

The naysayers below have probably not printed or tried this solution - I have and it is ROCK SOLID. Not only is it fit-for-purpose (as described), it is also the cheapest solution.

Glad to ear it! Never needed them as i had plenty in stock but ill give them a try before reordering. Thanks for the review!

Very nice, I like how this is simplified from the ones it is derived from, I did not see the point in the extra plastic that was in the groove of the T-slot nad now you are able to add a washer.

I am confused by why people think this will not work, or would not be as strong, possible not quite as strong, but the essence of this part is to merely hold the nut and washer in place until they are tightened up, once tightened up, in theory the plastic servers no purpose?

that is correct, the plastic only holds the nut and washer in place. Once tightened, the plastic part is only needed then the nut is to be loosened again.

This thing just makes the nut/washer combination more convenient to use (or usable at all).

Won't be as strong as a real metal t-nut, but may do just fine for many uses. I've always just purchased carriage bolts and then ground off two opposite sides of the flange on the bolt. That makes a t-bolt instead of a t-nut, but most of the time you can use that instead. On the rare cases where a t-nut is really required, I've used a thick washer with the edges ground off in combination with a nut. They can be epoxied together to keep them from falling apart when you insert them. This design is great for light use.

I don't get it. Aren't these pretty much useless? Your design doesn't actually trap the nut, so once you tighten the nut, it just slips through the printed T-slot piece. You'd be better off not printing anything and just using the washer.

thantik, it goes the other way round. They are upside down in the picture. Imagine the bolt coming up through the table, thru the printed part and /ending/ at the metal nut.

If you look at the pieces you derived this from you'll notice that the nut trap does not go entirely through like yours does. That's for good reason. Your design is flawed and basically serves no purpose in its current form.

The nut is trapped by the aluminium extrusion itself and does not slide through. Besides, if printed on a well calibrated machine, the nut is pres-fit into the part. There is good reason not to trap the nut completely, as it allows for some tolerance in regards to nut thickness.

My design serves the purpose of holding the nut and washer in place and it does that very well.

Exactly. The nut isn't trapped by any 3d printed part. Looking at the design, the nut is free to basically sail right through the piece. Screw it in outside of T-slot exactly like you're saying, and then pull on the printed piece. It'll slip right off.

you would be incorrect.. after printing them the nut is press fit with the washer on top and a tight fit in the extrusion. once the screw/bolt is even slightly tight the plastic is no longer an issue and it tightness right up. wouldn't recommend a lot of disassambly/rebuild of them but for a set it and forget it. They work like a charm