Has anyone replaced their Z axis assembly for greater travel?

Hmm, I was thinking more about allowing additional space below the lowest Z height so I could carve thicker material with longer cutters, but I get the additional stresses and strains on the machinery and affect the rigidity.

I suppose it would be a lot more rigid to mount the machine on to a welded steel or bolted aluminium extrusion frame, and incorporate a removable/adjustable waste board, but that would need to be bolted down to ensure that remained rigid to the frame. A bit like your frame/table combination, @Aiph5u, but I don’t have shares in an aluminium extrusion company :rofl:!

It’s a curse, for sure!

Will that be big enough, in depth? I’m happy to be proven otherwise, but I thought (without checking) the minimum recommended table dimensions are 4’ by 5’?

Decisions, decisions… :thinking: :thinking:

Yes, it’s only the frame, I have not built the top yet which will be larger. At least 50x75 from what i believe others have done. But I am waiting until I have the Journeyman here and can take measurements directly. I want the table to be big enough to support an enclosure. I need that for two reasons.

Here is one of them.

His name is Ziggy, and like most cats he gets into everything. And in this corner of the basement where I will setup the CNC was one of his favorite things. Since I moved that out I suspect when the CNC gets zipping around to him it won’t be much different than those HO cars and he’ll be jumping up there wanting to play. Which would end in a bad way, mostly for him.

So I can’t have that.

The other reason is the laser. I want the enclosure to protect eyeballs, mostly Ziggy’s because he won’t know not to look at the light and he has told us he does not like to wear sunglasses. We tried; he wanted no part of them. :slight_smile:

It’s not possible to isolate this part of the basement from the rest of the house. And closed doors are against his rules. If there is a door closed somewhere he will sit that and scratch at that door until he digs a hole in it or you open it for him. I think he does it just to mess with me. :slight_smile:

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I thought @Ziggy was a real person, not a cat! :wink:

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Well there’s Ziggy Marley, Ziggy the comic strip character, Ziggy the Elephant (1917-1975) and no doubt a few more.

And then there’s our Ziggy, the cat. Not the most well known of the bunch but he’s a celebrity [more like a character if you ask me] around our house. :slight_smile:

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Not to forget Ziggy Stardust, role played by someone who left us way too early.

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Hey Peter,

Yes, in fact this should be the Riser Blocks Topic as it differs from thread’s creator topic

When Riser Blocks discussion once more raised up, some time ago @MikeH suggested in:

This may be a compromise that makes tabletop stiffier when rising. I would then add two more reinforcements, perpendicular to it, under the tabletop.

Seriously, in fact I try to avoid aluminium whenever I can, I prefer steel. In contrast to iron, the main steel component, aluminum cannot be found in elementary form in the Earth’s crust ( → note), but has to be extracted from Bauxite, a process which not only is highly energy-consuming, but which brings extreme environmental problems with it, even environmental catastrophies.

Also I have decades of experience constructing things using softwood and hardwood (not MDF, OSB Chipboard, or Plywood, I mean wood! :slight_smile: ) Many people forgot what mechanically strong things were built through the centuries using wood.

Tags: Aluminium, Bauxite, red mud

Sorry if my questions and comments contributed to taking this thread off topic.

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Hey Bob,

this terrible offense is always forgiven when you show a cat picture.

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This YouTube video does a good job of creating a torsion box for the Kreg table.

Kreg torsion box build

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A good beginner and sincere video series. Especially suitable for those either on the purchasing fence or waiting for delivery.

I spoke with RoverCNC concerning their 200mm upgrade for the axis and they provided information and specific details as to how to mount the upgrade to the X axis. The install would require a “transition plate” to mount to the X axis to which the RoverCNC would then be mounted. This would move the center of the 80mm spindle out front of the X axis an additional 13mm. I believe Journeyman can handle it. I don’t plan to hog out cuts.

I also enjoy humor as well.

I really like that assembly, and am still contemplating it as a future upgrade - lots to accomplish before that purchase though.
When I did the calculations, using my original Woodworker, I found that it would increase the centre to centre distance between the tool and the x axis tube a fair bit.
My math put these distances at ~110 mm vs ~185 mm for the 1F and Rover add-on respectively.
Note: I used a 10 mm estimate for the adapter plate. I also assumed I would buy the Rover 80 mm mount, and guessed its thickness (between spindle and slider plate) to be about 20 mm. If the Journeyman uses a thicker z axis block than the Woodworker, then this would push the spindle out even further.
I have no real life experience yet with this or any other CNC, so I do not know what impact the extra 75 mm projection would have. Perhaps none, given the rigidity of the Journeyman and Rover Z assembly.

I am revisiting the AvidCNC website, and looking again at their pro z axis assembly.

I like its design even better than that from Rover. It has a slightly shorter projection, slightly longer travel, covers for the rails, and comes with an Oldham style coupler and mounting hardware.
Given the cost of any of these upgrades it is not significantly (~$169) more than Rover given its features and what it includes.

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I stepped back from this upgrade to spend sometime contemplating what would be the “Keep It Simple” approach. I will install my Onefinity 80mm spindle mount. I plan to install the Z axis in the top install position. I will then have the full clearance under the X axis if any height changes are needed I simply slide the 80mm spindle up or down within the mount. This should do away with repeat Z axis position changes and avoid tiny screw damage.

What do you think about this approach?

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It is a simpler, flexible, and less expensive option that can still be changed in the future if it does not meet your needs. I would just keep an eye open for issues in cuts done when the spindle is at extreme positions in the mount - only real-life testing will let you know if increased leverage forces will have an impact or not.

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Stability could become an issue. The higher you go, the wider the y axis bearing spacing should be, or at least the loading will be higher. Flex will create spring effect, so when you stop the axis, the whole gantry could “return” from its loaded position to free rest state, resulting in a tiny snipe cut. Now, the very direction of the cutter can cause the whole head to kick. It may all be tiny, but, the physics is there, so it’s a matter to how high, what loads and what precision is at stake. Best wishes.

I designed my table with a deep center trough for carving beams up to 11.25" tall. For typical projects the waste board will span across between the two x rail assemblies, limiting the z height to the standard
5.25". I guess this is similar to adding risers, but should be solid enough.

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I like this approach. You could easily mount a fourth axis in there too.

Just need a controller that can handle it.

Take a look at this:
Onefinity Riser Block

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Yes, I’ve seen that. My opinion is that creates a stability issue. Keeping the machine height the same and lowering or depressing the table in an area only large enough to accommodate your rotary axis or an opening for a vertical clamping surface seems like a more stable approach to me.