Building a big printer. Nema 17 VS Nema 23 and why?

[swatti]

Almost impossible to find info on eighter one, let alone "why this over that"

What motors should i go for and why ?

Going to be a big machine. ~700mm'ish. To be determined.

I want to use high speeds and high acc -values, but i also want to retain accuracy.

N17 or N23 and why?

Nema17s are cheaper, but the Nema23s also still fit my budjet, including their external drivers, so is there any downsides going bigger?

[curious aardvark]

no downside going bigger - it does depend on the actual design of your printer.

If you're going for an i3 design then bigger heavier bed = more powerful motors.
Direct drive = heavier extruder and hotend setup - so bigger motors would help there.

Not sure there's any real benefit with a lightweight bowden based extruder - though again depends on what you are doing with the print bed.

[AngelArs]

I would go with the 23's. Why? because they will give you more control. Plus, you will get bored with this machine in time and when you upgrade you won't have to buy new motors again.

[Geoppince8]

I would go with the 23's. https://hgh.to/hgh-for-men/ Why? because they will give you more control. Plus, you will get bored with this machine in time and when you upgrade you won't have to buy new motors again.

you've used them both? you can confirm that from your own experience? thanks

[AngelArs]

Yes, go with the 23's, but remember that there are at least two versions of the 23's so don't get the high torque version.

[Rikrik]

Years ago i mocked up a prototype of a 500x500 printer. Had to take it apart as it was too big for my flat.

I used 6 nema 17s. 2 for each axis. Pretty much just replacing the idlers with a aditional stepper. Or if the bed moves side to side. Use twin belts.

Obviously do what works for you. And hope this helped.

[Rikrik]

I would also say building around a bed makes things alot easyier.

For example if i had a long mirror. It may only 300mm wide. But it could be 5feet long. So all you would have to do is extended the y axis. So the frame could be just a slightly modified 3d printer.

[Davo]

The more powerful your motors, the heavier and more rigid your frame needs to be. For larger distances, consider closed-loop encoders - especially if you're pushing a lot of mass around.