Strike CNC (My first CNC router)

[Gary]

Nema 23 motors are 56mm square.
the 60mm motors are an oddball so they called them nema 24.
We only sell the 3nm version of the 60mm motor, i tested the higher torque version and found that they performed worse than the 3nm version.
As john rightly says, you cant expect a company to make a bespoke enclosure for near nothing, £600 is not bad, we all need to make a living.

[Shinobiwan]

I suspect these are nema24 and I incorrectly called them nema28. Everything else seems to fit.

What does concern me is the points raised by some about the inertia and general mass of the screws being too much for the stepper motors. Obviously its hard to tell without testing and you can be sure I'll post some video's of the machine working to allow you to look for any issues that I might not be able to identify being a beginner.

Supposing I do find that the motors are inadequate, how big of a job would it be to upgrade them to something suitable?

[Shinobiwan]

As john rightly says, you cant expect a company to make a bespoke enclosure for near nothing, £600 is not bad, we all need to make a living.

Where there's clear panels, they've used Lexan too rather than just clear perspex. I've had a quick look at prices for a 4 x 8ft sheet and its not cheap. The machine is 1.8m D x 1.8m W so your looking at a couple of sheets of that if you arrange your cuts sensibly. Overall I was happy at £600.

I know what you guys are saying though. I DIY too (not CNC machine though) and don't consider my time spent as a commodity so £600 for a cover would seem expensive compared to something I could knock up. In this case though I wanted a neat package that ran straight out of the box.

[Jonathan]

i tested the higher torque version and found that they performed worse than the 3nm version.

Interesting, that's precisely the information I was after here:

http://www.mycncuk.com/forums/showth...ers-or-drivers

Please could you elaborate on what tests you performed?

[Gary]

I ran the SY60STH88 and the SY60STH100 on the same drivers at the same voltage and the larger motor could only get to about 60% of the speed as the 88mm long motor.
I ran them on the Leadshine M542 at 40V and the Leadshine M880 at 70V.
While the longer motor would give more torque at the lower speeds, this soon changed after hitting a few hundred RPM.
Also the specification in the link you posted looks all wrong.
Look at the inductance and the current and compare it to the 88mm long motor.
The Inductance is lower than the 88mm long motor but also the current is lower.
You would expect the inductance to be higher if the current is lower.
I suspect the inductance is actually a lot higher than is shown in the datasheet, and if this is true you need a much higher voltage driver to get a good performance from the motor.
even at 70V, the 88mm long motor performed better.


There is only so much power you can get from a motor with such a small frame, and if you want more power you have no choice but to go to a larger frame motor like a nema 34, but at the same time also use much higher voltage.

Interesting, that's precisely the information I was after here:

http://www.mycncuk.com/forums/showth...ers-or-drivers

Please could you elaborate on what tests you performed?