Hi all, new here.

General CNC CNC Routers
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Hi all, new here.

I’m about to start a build of something similar to the Mantis 9.1 (but scaled to support a minimum of 8"x11").

One thing that is never clear in all the online docs I saw about DIY CNC is how to attach the threaded rod to the step motor. Anyone has docs or exemples on that and what parts to use ?

Thanks.

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The most common, and straight forward way is to use a flexible coupler. These typically have two different bore configurations: Where bore A would be something like 5mm (to fit a nema17 stepper motor shaft) and bore B would be 8mm (to fit an 8mm threaded rod). But they come in a variety of configurations.

I have seen DIY solutions where you use a piece of clear plastic tubing (from a hardware store) along with two hose clamps.

I prefer the flexible couplers. You can generally pick them up for between $5-$10 each.

If you’re looking for a suggestion of somewhere to buy them, let me know. In the true spirit of this group, I don’t want to seem like I’m spamming the list with links to my store :slight_smile:

-Edward

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Thanks Ed for the tips. Please feel free to send the links in private if you would prefer.

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I’m also wondering, as I’m more equipped for woodworking than metalworking what you would think (for a first build) about using wood dowels (large enough diameter to avoid flexing) for the guide rails?
I’m pretty sure the flex in a length of 10 to 16 inch should be fairly minimal is not null.
Only thing I could see is the linear movement friction…

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I think the amount of variance in a wooden dowel (swelling/shrinking) would pose a problem, also, the amount of wear that would occur in a very short amount of time would be significantly higher than if you were to use a traditional material such as drill rod, or hardened steel.

With that said: If you could somehow make guide rails from wood it would be super cool! Although, I can’t think of a way to make a long term solution out of it.

Good luck!

-Edward

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True about the wear. ‘standard’ wood dowels are usually pine which is quite soft, but using birch, maple or oak could be pretty good.
A 1/2" dimeter birch dowel is about 0.75$/ft :wink: