Lets make a Z axis - design files and parts list

CNC Machines Shapeoko
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Following on from my Z axis linear guide upgrade I’ve been asked by a few people for drawings and spec, so here it is.

For reasons why and more detail on the results please take a look at my youtube.

IMG_8558
IMG_8558.JPG3024×3024 1.49 MB

The approx cost of this is £50 or $75 + time.

First off you will need a ball screw and nut - I had mine machined in china this is the one I bought. This company will be able to mill a custom size which is very important if you want to use the below design. If you do not adhere to this spec the below will not fit.

When purchased ensure you ask for 300mm – have one end milled at 8mm x 10mm the other at 10mm x 25mm. I repeat t’s important it’s milled to this spec of the base plate will not fit.

Other items to buy include:

• 20mm x 40mm aluminium bar
• 6mm aluminium sheet (around 60 x 13cm)
• A selection of bolts M5/M6
• 1 x 8mm x 22mm bearing
• 1 x 10mm x 26mm bearing
• 4 x M4 grub screws
• 12mm stainless rod (approx. 70cm)
• A 6.35mm / 10mm coupler – Don’t buy the spring sprung version
• A 23 motor bracket – 57BU
• 4 x 12mm sliders – LM12UU

Any other hardware can come off your existing Z.

You will also need a set of hand taps, machine vice masking tape and super glue. You will also need a 1/4and 1/8 mill bit. You will need some kind of probe - I used the Carbide motion probe with great results.

Now for some design files. My tool paths are no not useful for most, as I use metric buts but the files them selves are good.

Lets start with the plates, I milled these by using the super glue and tape method.

The router plate – 6MM aluminium plate – the 4 holes in the centre are for my mount – you might need to drill new holes for a stock mount.
http://a360.co/2BykM0C

The base plate – 6mm aluminium – this is the most complicated part of the guide. It also requires 2 sided milling.
http://a360.co/2BAuY8x

Now for the mounts – these are made from 20mm aluminium, I did them in a machine vice. I milled the main detail to a depth of 16mm. I then flipped them and took a further 4mm off each face. I then use peck drilling to do the holes on the sides - the side holes were done using the last of the files called ‘Holes’

The top mount
http://a360.co/2EfKsSt

The bottom mount
http://a360.co/2AyTFFJ

The carriage top – this will take a 24 or 22mm nut – I want to tidy up the design – The nut holder could be more accurate.
http://a360.co/2DHAuIo

The carriage bottom (if you want you can mill 2 of the top carriage – either will work fine)
http://a360.co/2DK4E21

Holes – these are for the side mounting holes.
http://a360.co/2DIVLFQ

Spacer – to mount the motor correctly
http://a360.co/2DIF11o

Know yourselves out!

At this stage I don’t have a step by step guide but I’m here to answer any questions.

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Okay a few questions as I start to look through this:

  • For the Base Plate, I’m not seeing the two sided milling in your design, although your Setups are kind of difficult to follow. I understand, you probably posted what files you have without any cleanup, which happens to me too. It seems like for the Base and Router plates that you can do all the machining on one side.

  • I noticed you didn’t do any facing operations on the large plates, but facing on some of the smaller parts. Do you feel that it would have been beneficial to face the large plates to ensure they are within tolerances across the whole face plane?

  • For the parts that mount the router, did you include any way to adjust the rotation of the router about the X or Y axis, so that you can easily tram the spindle in precise increments?

Edit: I did watch one of your earlier videos and I see that you can tram with your setup, very nice.

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There are only 2 counter bore holes on the rear of the main plate - I will need to check the files - I think it needs a tidy. What I might have done is flipped the part and created a setup on the main face - they were just to recess screws if the z was fitted to an upgraded x - essentially I made sure that the main plate has suitable holes to accommodate 2 more guides fitted vertically, this results in the whole setup moving 14mm down. I explain a bit more in the video.

I don’t see any real benefit to face the plates - if the were out by 0.1mm it should not effect the milling capability - happy to listen to reason though.

And yep you can adjust the rotation of the router - and you can do so without removing the whole setup - worth nothing that the adjustment holes align to my spindle mount - the might need to be adjusted for a stock mount.

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I was curious on the facing, but I don’t have enough machining experience one way or another to say if its necessary. If I was to buy the Al plate from my usual source, the thickness would be +/- .3 mm (+/- .012") so I thought that would be good enough tolerance wise, but was just curious. Precision ground plate is obviously much more expensive.

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Okay, now I love fusion also. I don’t have fusion but I just discovered that downloading a fusion file gives the option for downloading a sketchup version. First file came through fine and just waiting on the rest of the files. They send you a email to download the file. Thanks Luke, I’ll build a wooden one first just for practice…but that might screw up the screw. Jude

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I haven’t used sketch-up for years, before buying a CNC I was outsourcing to china and had terrible trouble exporting stuff from it… Probably an issue fixed by now mind.

A test in wood is a great way to do it. I made the first two prototypes of the back plate in 9mm MDF. Helped me iron out a couple of issues.

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By the way, have you had any backlash issues, or have you measured backlash on your screw? Just curious since I don’t think you are using an anti-backlash nut on the acme screw.

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Files are a little confusing, base plate file is the new mount … no worries, I’ll sort them out when this project raises on the priority list, new roof is on top right now. Just glad to have them saved away, I’ll be patient for your eventual write up. Thanks again Luke

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Not yet, ball screws are different to lead screws so don’t used anti backlash nuts as a separate part but are integrated into the ball screw its self.

I did have a small issue with the first type of coupler I used, but swapped out for the version above quickly - since then all is well.

@grumpa I’m not following? Do you mean the files are named incorrectly?

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no, ex: the base plate fusion file has the name “new mount” when it downloaded, so there is no “base plate” file downloaded but the “new mount” file appears to be it.

when you pull up the fusion file it is named “new mount”.
Just confusing, I know my file naming get confusing to me, I’m not worried as I won’t be onto this project for some time, apparrently you referred to it as the base plate but named it “new mount”, no worries. Thanks for the concern. Jude

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I got you. My naming conventions are all over the place :slight_smile: I did tidy them up this morning.

I might be making slight modifications to the files over the coming months so if it’s not a immediate project you might be downloading them again anyway…

If you were worried that I would charge for the files later on that won’t be the case. We’re a community, sharing is caring :smiley:

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Thanks Mate. Even from the other side of the pond. Legend states that my Mother’s family (very distant relatives) came over on the Mayflower… so maybe we’re closer than a community, but we’ll keep it like that because they’ve never given a discount to family just full charge without the service. Thanks for caring enough to share. Jude

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Thanks for this Luke

I appreciate you probably don’t want to play favourites with suppliers but it would be really helpful if you could supply links to the suppliers you used for your components to allow us to make sure we’re looking at the right things.

For example, you list “4 x 12mm sliders – LM12UU”. I can search for “LL12UU” but I’m not sure if that’s a standard, a specific part number or if your cat just wandered over your keyboard :slight_smile:

Once again, thanks for this. It really looks the business and the timing is great for me as I’ve just started needing to work more aluminium on my SO3 and my 0.4KW spindle just isn’t cutting it (pun intended)

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Hi there,

Other than the ball screw all the parts are stock or generic. Here is a link for some sliders;

Happy to point you in the right direction, my rod and bearings came from the UK

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Thanks Luke

I should have said, I’m UK based too.

Well, Northern Ireland so I often sit in the same shipping rate zone as Antartica for many England based suppliers :angry: When it comes to aluminium I think it would be cheaper to set up my own mining, smelting and rolling company in the back garden compared to some of the shipping quotes I get :slight_smile:

tg

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Do you happen to know the total weight?

Anyone know a good source in the U.S. for metric sized aluminum? :stuck_out_tongue:

Edit: It might be easier for me to use yours for reference and design my own - I would want to add some side stuff for a suckit mount setup and maybe see if I could add some extra v-wheels for an experiment.

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Luke

Another thing that would be a great help is if you have a Fusion 360 assembly with all the components. It would help visualise the whole thing.

I’m just being lazy, I’ve just imported all the parts into Fusion and am starting to work out how to put them all together but there do seem to be a few holes missing. They’re easy to add in but an assembly would give me more confidence that I haven’t gotten it wrong i.e. the holes aren’t missing, I’m just putting it together wrong :slight_smile:

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Ah so you will have all the sourcing issues I had then. I buy most stock from china or ebay.

@lxkhn don’t know the over all wight sorry I didn’t weight it.

I have only played with assembly once, in F360, I might struggle though as the bits are not components. Happy to send some detailed pics if you need them?

It’s only really 6 bits of aluminium - fairly straight forwards…

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I’m working on an assembly at the minute.

It all seems fairly straightforward as you say other than the base plate. It’s a bit confusing.

Some more detailed pics of the mount including from the back would definitely help, I daresay they’d answer most if not all questions.

You mentioned previously that you’d probably added the countersinks on the front of the plate for expediency so that’s part of it. Also, there seem to be a lot of redundant holes which are obviously for the future proofing you discussed above but they make working out what goes where a bit confusing.

For example, on the base plate where I believe the bottom mount goes there are two holes that will be covered by the bottom mount so I can’t work out what they’re for? Could they be for using a screw to push the mount out for adjustment? Not sure how permanent that would be so maybe not?

Will post a screenshot with the parts highlighted.

Base Plate v2
Base Plate v2.png1024×1024 75.8 KB

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Luke

This is my version of the assembly so far. Before I start adding the bearings and suchlike can you confirm if the orientation of the top mount and carriage plates are correct? I’m guessing the carriage plate should be flipped over i.e. the cutout is facing downwards?

Assembly_2018-Feb-06
Assembly_2018-Feb-06.png656×873 226 KB

Thanks

Tommy

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