Z axis Slider - Stepper Motor Capacity


(Jeff French) #1

Question for anyone who has done an upgrade to your Z Axis:

I’ve decided to upgrade my Z Axis with a ball screw slider kit to gain a bit more capacity and reliability. One of the options available is increasing the capacity of the stepper motor for more torque. I asked the support line at carbide what is the capacity of the standard controller board for supply to the steppers. Unfortunately they didn’t give me a technical answer as to the capacity stating the Nema 23 2.0 A supplied steppers is all they tested.

The options I have are a couple of Nema 23 Steppers that provide 50% increase & a 100% increase in output torque, but both of these draw 2.8 A

My questions to anyone who has upgraded to a Slider:

  1. Did you need upgrade the stepper motor as well as the mechanics of the Z axis or was current stepper strong enough ?

  2. Has anyone tested a larger draw stepper motor with the standard Carbide Controller ? I don’t really want to experiment and blow up my board by drawing to much current.

Thanks in advance for any advice.

Jeff


(Neil Ferreri) #2

The ballscrew itself adds plenty of torque…you won’t need more.

The driver will only supply 2A…that motor will never reach it’s full capabilities, but your board would be fine. That said, see my answer to question one.

What ballscrew axis are you getting?


(Jeff French) #3

Fantastic, my plan was to try the ballscrew with the original stepper, was just thinking of the next step if the stepper didn’t drive the screw system. I’m going with the CNC4NEWBIE latest version. On the latest revision he totally replaces the carriage which. brings the center of gravity closer to the X axis bar which has got to be better for stability.
If this works out I’ll try and raise the Y Axis rails to get a bit more capacity in height. Most of my business is in the 1.5 to 2.5 thick, but been asked to carve details on 4x4 posts.


(Neil Ferreri) #4

Got a link?

Does it use a ball screw or a lead screw? The lead screw won’t handle the load a ball screw can, and it won’t be as fast or efficient. Maybe that’s why he recommends the stepper upgrade?


(Jeff French) #5

It uses a fast travel lead screw. https://cnc4newbie.com/store/en/shapeoko-3-slider/shapeoko-3-slider-p90c67/


(mikep) #6

This is not a ball screw, it’s a lead screw. I have one of the slightly older ones, and honestly, it’s not worth the money for me, I wish I had done the HDZ.


(mikep) #7

There are alternatives…
You shouldn’t see more than ~ 70% of the rated current. 2.8 * .7 = 1.98A
If you increase the psu voltage, you can get a lot more torque that way as well. The stock is ~24v, replacing it with a 35v supply can get you about 1/3 more torque.


(mikep) #8

Be sure to understand the difference between a ballscrew and a leadscrew. A leadscrew with an anti-backlash nut can have very low backlash, BUT (and it’s a big but) that’s only up to the strength of the spring in the nut - beyond that they have LOTS of backlash. Manageable, but you really should keep an eye on the forces you are producing. Can contribute to chatter in some materials. A ballscrew is driven in such a way that it will continue to have low backlash even at high forces. A ballscrew is also easier to drive (it has a rolling element on a ramp, rather than just a ramp element of a screw), the leadscrew can have much higher friction.


(Jeff French) #9

Thanks for the information, I’ll have to see how the unit performs. Looking at the Canada Bearing web site a Ball screw to fit the unit would be about $100 ~ $150. So if performance is no good for what I’m doing it would be looking at upgrading the Stepper for more torque as per one of the ideas here, or just ordering a replacement mechanism to lower required torque.


(Griff ) #10

Why reinvent the wheel (unless it’s something you get enjoyment from accomplishing)?

Mr Beavers design is tried and proven.

https://www.beavercnc.co.uk/product-page/bever-cnc-heavy-duty-shapeoko-3-z-x-upgrade


(Jeff French) #11

Yes, Seen that unit, he did a very nice job of engineering everything in. Unfortunately with the exchange rates to Cnd $ becomes very expensive for me.


(Luke) #12

I can certainly appreciate that. I do offer free plans so you can build an early version yourself?


(system) closed #13

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