Nema23 on Z-Axis

discussion of design changes / improvements / suggestions
RobCee
Posts: 587
Joined: Wed Jan 08, 2014 11:33 am
Location: Birmingham, UK

Re: Nema23 on Z-Axis

Post by RobCee » Wed Mar 12, 2014 11:45 am

I'm thinking about that myself, I have a TR10x2 leadscrew on it's way. The challenge is in expanding the diameter of the lead screw, you have to move everything else out with it. That moves the axis of the motor out further and pushes out the spindle more, increasing the load on the X-Axis rails.
I believe that the best way to cope with all of this is to move to a pulley driven Z-Axis, which would allow me to hang the Z-Axis motor off the back. This helps with the weight distribution and also reduces the amount of clearance you need in front of the spindle mounting plate. In my case reducing it from over 20mm to about 6mm. With a heavy spindle (2kg/4.5lbs), I think that every mm of overhang counts!
Here are the drawings of my current setup and proposed idea for inverted Z Motor:

Existing setup - note the extension and bolting in the X-Axis - I had left over 20x20 which I used to bulk it up a bit, then had to bolt the pieces together.
This is shown with existing M8 lead screw and 13mm lead screw nut.
22 Z-Axis Current.jpg
Existing Setup
22 Z-Axis Current.jpg (91.78 KiB) Viewed 3545 times
Proposed inversion of the Z Motor shown with TR10 lead screw and 16mm lead screw nut.
23 Z-Axis Pulleys.jpg
Pulley Idea
23 Z-Axis Pulleys.jpg (110.9 KiB) Viewed 3545 times
The only challenge now is finding a UK (or European) supplier of GT2 belts in small loops as it will need something like a 150-200mm loop if I use 20 tooth pulleys.
ShapeOko2 #3400 - Chinese 800W AC Spindle - Stiffened X-Axis - TR10 Z-Axis - Inverted Z Motor - Hall Effect Limits - Drag Chains & Custom Brackets

cchristianson
Posts: 54
Joined: Mon Feb 18, 2013 1:56 am

Re: Nema23 on Z-Axis

Post by cchristianson » Sun Mar 16, 2014 6:29 pm

I recently made this upgrade as well... here is what I cam up with:
Attachments
IMG_20140312_192801_802.jpg
IMG_20140312_192801_802.jpg (317.09 KiB) Viewed 3492 times

Auzze
Posts: 38
Joined: Thu Sep 05, 2013 8:30 pm
Location: Ballarat, AU

Re: Nema23 on Z-Axis

Post by Auzze » Mon Mar 17, 2014 6:35 am

Hey...

this is what i did to convert to neam23 on the Z axis.

Image
The part is on thingyverce.
http://www.thingiverse.com/thing:269745


cool stuff,
Auzze
Shapeoko #1996F w/ double MakerSlide (500mm) X-Axis, (750mm) Y upgrades, Acme Screw Z-axis, ¼″ drive shaft, Outside belts, cable drag chain.

http://oz3dprint.info/

Threefer
Posts: 24
Joined: Mon Dec 23, 2013 6:02 pm

Re: Nema23 on Z-Axis

Post by Threefer » Mon Mar 17, 2014 2:42 pm

The only challenge now is finding a UK (or European) supplier of GT2 belts in small loops as it will need something like a 150-200mm loop if I use 20 tooth pulleys.
This seems to be what you are looking for: https://sdp-si.com/eStore/Catalog/PartN ... R51M079060
There are many different sizes also and it looks like it should be a simple online ordering process with no minimum purchase. Not sure about shipping though.
---------------------------------------------------
Shapeoko# 3456, Makita RT0701c. Stock size for now but have 13"x13" travel by trimming down belt clamps and lip on smooth idler. Dovetailed wooden track clamping setup. Dust shoe in works.

RobCee
Posts: 587
Joined: Wed Jan 08, 2014 11:33 am
Location: Birmingham, UK

Re: Nema23 on Z-Axis

Post by RobCee » Mon Mar 17, 2014 2:49 pm

Thanks Threefer, it's the shipping that kills it for us International folks.
I did manage to find some suitable belts, but couldn't get GT2 in the end.
ShapeOko2 #3400 - Chinese 800W AC Spindle - Stiffened X-Axis - TR10 Z-Axis - Inverted Z Motor - Hall Effect Limits - Drag Chains & Custom Brackets

cvoinescu
Posts: 4442
Joined: Thu Jul 19, 2012 6:50 pm
Location: Camberley, UK
Contact:

Re: Nema23 on Z-Axis

Post by cvoinescu » Mon Mar 17, 2014 4:13 pm

In my experience, SDP/SI won't ship to the UK. Davall Stock Gears are the UK distributor of SDP/SI. Their prices are ridiculous, but at least shipping is a flat £12 + VAT (not that that's great, either). They have their own catalog, but they can order anything from the much larger selection at SDP/SI. Their service is amazing, though: when they weren't able to get the right pulley from SDP/SI because their factory in New Jersey had been flooded by Hurricane Sandy, they took a similar one they had in stock and contracted a machinist to re-bore it for me, at no extra charge.
Proud owner of ShapeOko #709, eShapeOko #0, and of store.amberspyglass.co.uk

danilomariotti
Posts: 1
Joined: Mon Jul 14, 2014 1:05 pm

Re: Nema23 on Z-Axis

Post by danilomariotti » Mon Jul 14, 2014 2:21 pm

Hi RobCee,
great work!! Can you post sources?
Many thanks.

RobCee
Posts: 587
Joined: Wed Jan 08, 2014 11:33 am
Location: Birmingham, UK

Re: Nema23 on Z-Axis

Post by RobCee » Tue Nov 04, 2014 5:46 pm

It's taken me a loooong time to get around to making it, but I finally assembled my updated Z-Axis today.
47 Z-Axis Upgrade.jpg
Z-Axis belt drive
47 Z-Axis Upgrade.jpg (195.1 KiB) Viewed 2943 times
It took a bit of tinkering to adjust the height of the TR10 bar (TR10 is the metric equivalent (ish) of ANSI 3/8" bar) so that it didn't bind too easily.
I was previously limited to rapid Z-moves of around 500 mm/min (and an acceleration of 25mm/s^2). Now I can get up to 1000mm/min at the same acceleration which is much better. I should be able to push my engraving code through a lot faster now that I am not quite so Z-limited.

Here is s shot of the plates straight after cutting them:
48 Z-Axis Plates.jpg
Aluminium plates
48 Z-Axis Plates.jpg (194.81 KiB) Viewed 2943 times
Some things I have learned in making this:
  • 1. Getting the correct bit for cutting aluminium is very important - a 1/4" shank cutter is way more rigid than a 1/8" cutter
    2. Don't trust a drill bit for a finished size - my 6.1mm drill gave me a 6.5mm hole so my pulley is a bit wobbly on the motor
    3. You will get really used to disassembling the assembly while working out how much length you need to shave off the threaded rod
    4. Thickness gauges are your friend when trying to resolve item 3 - I only thought about them on my 4th dis-assembly (Doh!)
    5. Making things like this with a ShapeOko is awesome fun!
ShapeOko2 #3400 - Chinese 800W AC Spindle - Stiffened X-Axis - TR10 Z-Axis - Inverted Z Motor - Hall Effect Limits - Drag Chains & Custom Brackets

LouisV
Posts: 316
Joined: Fri Dec 13, 2013 3:41 am

Re: Nema23 on Z-Axis

Post by LouisV » Tue Nov 04, 2014 9:38 pm

Looks great! :) I really like this z-axis solution for the Shapeoko 2. I agree that getting the right endmill for cutting aluminum is important, I've tested quite a few of them (and broken some). After a while I eventually settled for a 1/8th" 3 flute variable helix endmill with ZRN coating. I've had no problems with lack of rigidity or strength and is the endmill I use to cut plates out for my HDX machine. I try to stay away from 1/4" endmills if I'm just cutting parts out, though for pocketing and rough cuts they're great. :)

RobCee
Posts: 587
Joined: Wed Jan 08, 2014 11:33 am
Location: Birmingham, UK

Re: Nema23 on Z-Axis

Post by RobCee » Tue Nov 11, 2014 8:55 am

Thanks Louis!

When I referred to a 1/4" bit, I meant 1/4" shank, with a 1/8" short cutting end. It gives it so much more rigidity than a long 1/8" cutter. This is invaluable for cutting Aluminium, where the tool deflection can be a significant challenge.
ShapeOko2 #3400 - Chinese 800W AC Spindle - Stiffened X-Axis - TR10 Z-Axis - Inverted Z Motor - Hall Effect Limits - Drag Chains & Custom Brackets

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