Using threaded rods for x and y axiz

Im planning to put together my first 3d printer and im wondering if its ok to use only threaded rods for the x and y axis rather than belts.

Thanks,
Phillip

It will be difficult to get acceptable speeds from a leadscrew. You would need fast leadscrews, the metric studding normally used on Z axis won't cut it on X and Y. You would also need much more powerful motors to accelerate those leadscrews quickly enough, which will require more expensive stepper drivers. And, theres a maximum speed for any given leadscrew which may force you to use larger, more expensive screws to keep the maximum RPM below the critical speed.

All in all, I'd stick with a belt drive, particularly for your first printer.

I am building a 3D printer right now with leadscrews for my x and y axis, but I am using expensive High lead screws, with anti-backlash nuts for this.

For example, each revolution of the motor will yield about 25mm or 1" of linear motion. I would not even think of trying this with normal threaded rods, the speed would be painfully slow.

This solution will be much more expensive than belts, but I am hoping to get better accuracy out of it.

Standard metrical threaded rod will indeed be very slow. A typical M8 rod has a pitch of 1.25, meaning an full rotation will result in a 1.25 mm move.
You can find more on metrical pitch here :[en.wikipedia.org]

Edited 1 time(s). Last edit at 04/27/2013 09:19AM by Banjer.

Hi

If you are making your first machine and speed is not critical, yes you can use normal threaded rods.
I built my first machine using M8 rods for all axis. It is slow but I used it to print the parts for my next printer
I used Arduino Mega 2560 with the Ramps 1.4 and the motors where some nema 23's that I had salvaged from some old printers.
Worked fantastic.

Regards
Jan

---

======================================
[3dprinting4u.wordpress.com]

+1 for not using regular threaded rod...

I made the mistake of building a CNC router with 1/2"-13 threaded rod for the axis driver.. it did not work well at all.. It was very slow and actually wasn't very strong, which is not what I expected with the mechanical advantage..

What I found is that normal threaded rod has a lot of drag.. and I even ran a die over the rod several times and a tap through the drive nut several times.. also stepper motor torque drops like a rock at higher rpms, which is what you will need to get reasonable linear speeds.. furthermore, depending on how long your drive rods are, they will start whipping at high rpms..

If you want the learning experience, you can go with the treaded rod, but if you want a more useable and practical printer, I think you would be better off starting with a belt drive..

I'm very interested in trying threaded rods for both X and Y. I'm currently using acme rods and POM nuts for the Z axis and am very happy with that. I'd be very interested in finding out the motor and nut combinations you are using. I've been looking at the motors with a rods attached i.e. I 7 motor with a 350 mm rod as a unit