[Sion1138]

Greetings people,

I'm in the process of building a CNC router intended for Oxygen-Butane/Acetilene cutting. It's a hack build, real weird, made mostly out of structural steel using only basic tools and machinery.

The machine is fairly large, I'm going for a 1.5 x 1.5 m (about 4,9 x 4,9 feet) working area. The gantry will travel on Angle-Bearing assemblies propelled via lead screws.

I intend to use 2 stepper motors on the X-axis (3Nm or 425 Oz-in each).

Here follows my dilemma:

Now, keep in mind that I am a hack and an idiot, so I would appreciate if you went easy on me. Here goes, my main concerns are the following:

- First, the main gantry's weight, it's bloody heavy. I figure it's going to total at about 60 kg (132 lbs). I will do my best to eliminate friction but still...

- Second, my lead screws are... well, too big. 24mm major diameter, 5 mm per revolution.

Basically what I want to know is if my motors will be able to even move this thing. I don't have any special requirements as to acceleration. I will be doing some testing, perhaps on Monday but I thought I'd ask you guys before doing anything.

Any thoughts or experiences you can share?

[Walky]

I'm pretty sure you can move that weight with your steppers easily given that you use the proper drivers. The weight of the screws will limit things a little but since you're not aiming for high speed I don't see any problem.

[Sion1138]

I'm pretty sure you can move that weight with your steppers easily given that you use the proper drivers. The weight of the screws will limit things a little but since you're not aiming for high speed I don't see any problem.

Much appreciated. I will see about the drivers, I currently have one of those TB6560 based boards on hand, will see how that works.

I'll update once I get some testing done.

[Walky]

Much appreciated. I will see about the drivers, I currently have one of those TB6560 based boards on hand, will see how that works.

I'll update once I get some testing done.

Sorry to say this, but that's far from being a proper driver, just a bunch of components crappily put together (search TB6560 in the forums and look at the amount of problems people have with it and you'll see what I mean), and it also meant for smaller motors. If you can afford better drivers, going with something from Geckodrive with give you much better performance and reliability. A G540 is probably the best bang for the buck, but it depends a lot on your motors (what is their current and inductance?).

[Sion1138]

Sorry to say this, but that's far from being a proper driver, just a bunch of components crappily put together (search TB6560 in the forums and look at the amount of problems people have with it and you'll see what I mean), and it also meant for smaller motors. If you can afford better drivers, going with something from Geckodrive with give you much better performance and reliability. A G540 is probably the best bang for the buck, but it depends a lot on your motors (what is their current and inductance?).

I'm aware of these issues, but I got the thing cheap a while ago so I'll try and see what happens. It's a newer version of the board, the third I think with a redesigned architecture, so maybe it'll surprise me, who knows.

Current is 3 Amps, phase inductance 3.3x(1+20%) mH.

Also, Geckos are fairly expensive by my standards. More than half of a months work.