The Lampesian ZX axis: The future or just a wet dream?

Yes, I'm bolt enough to name it after me

It's a Cartesian Z-axis with the following features:
Only one Z-stepper drives both X-ends
The X-stepper is stationary
No extra shafts required
The smooth rods build a horizontal plane, which could fit the Duet Delta Smart Effector or Orion Piezo Sensor.
X-ends run on 2020 extrusion with Compact Carrier Teflon gliders
All other bearings are Teflon, too
Z-axis is belt driven ( fishing line optionally )
X-Axis is ACME TR8x8 driven, which replaces the rear smooth rod.

Now back to the drawing board to make a sketch of this wet dream

I hope the pic is self-explaining.
The Z-belts are fixed at the Compact Carriers*, but on the backpath it also runs through the toothed idler at the front. The toothed idler rotates the smooth rod and translates the motion to the other side.
The X-belt simply runs through the extrusion and turns the rear TR8x8 screw. That requires a new kinematic model, because every time the Z-axis moves, the leadscrew would also turn, which has to be compensated in firmware.
I haven't drawn a hotend, but any carrier would run on the front smooth rod with two Teflon gliders and will be driven by a Delrin Nut on the rear screw.
Adaptation for Orion Piezo Sensor or Smart Effector is possible, IMHO

* Compact Carriers aren't mandatory, V-wheels or linear rails would also work.



What you say? Is it worth building such a ZX-frame?

Edited 2 time(s). Last edit at 04/15/2018 04:30AM by o_lampe.

I don't see why it wouldn't work. It does seem a bit counter intuitive (bucking the trend?) to use a screw driven X and belt driven Z.
What sort of advantages do you see as opposed to a standard i3 arrangement or something like Nicholas Seward's coreXZ or something like the sli3Dr XY mechanism but used for XZ?

I'm personally a bit averse to i3/mendel style motion systems. The moving bed bugs me on so many levels, and no just for how it affects printing.

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What sort of advantages do you see as opposed to a standard i3 arrangement or something like Nicholas Seward's coreXZ or something like the sli3Dr XY mechanism but used for XZ?

The moving bed bugs me on so many levels, and no just for how it affects printing.

I'm with you. That's why I asked if it's worth it. Building a fancy ZX axis, while the bed is shaking the whole printer apart....

Actually IDK the other printers you mentioned, except the i3. The advantages are as listed above: single Z-motor without extra shaft, stationary X-motor, the chance to use a reliable No_Offset Z-probe.
But most of all, because it's off the fence. I like the dual purpose of the smooth rod and TR8 screw.

The coreXZ is basically a coreXY motion system, just applied to the X and Z axis instead of X and Y. He added some neat pulley based gearing to increase the resolution of the Z axis. Sli3DR is a neat little printer by RichRap with stationary XY motors, so you could again flip the XY motion system on its side for XZ.

By the way, what do you mean by "an extra shaft" on the z motor? The stationary X motor probably isn't a big deal-breaker, since on an i3 it only moves in the Z axis, very slowly, I wouldn't really consider the motor "moving mass", similar to the z axis beds in some Cartesian printers. The use of a no offset Z probe seems like a function of the X carriage more than the motion system itself. I really like unique designs, but I've just got to question the practicality of some of them (like the poor old rhombot). By the way, since most leadscrews aren't totally straight, using one as a guide rod the way you are doing (I think one of the x axis horizontal rods is a lead screw?) would cause the x axis carriage to tilt as the leadscrew turns since the bend in the leadscrew would cause the point where the carriage is to move up and down while the leadscrew turns.

If you're into "off the wall" designs, have a dig through some of the early pages on the reprap wiki. Nicholas seward has quite a few unique designs, the rhombot is another cool one, the trituperon/deltuperon (I probably didn't spell those right, but they are awesome), quadrap and more. It's a bit of a shame to see how the focus on new and innovative systems has sort of stagnated.

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By the way, what do you mean by "an extra shaft" on the z motor?

I could make the Z-axis much simpler by connecting the top-idlers with a separate rod and be done. With propper bearings, the rod could act as horizontal strut between the towers, too. But I like the elegant way of using the smooth rod instead, like Ultimaker did.

I agree with the wobble-issue of leadscrews. The stationary X-motor adds many problems, like new firmware kinematics and indirect drivetrain with belt, idlers and leadscrew. It might be better to focus on the single Z-motor axis.

The firmware changes would be very simple. However, the use of both a belt and a leadscrew for X movement would I think have the disadvantages of both.

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Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].

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dc42
The firmware changes would be very simple. However, the use of both a belt and a leadscrew for X movement would I think have the disadvantages of both.

Yeah, I initially thought the stationary X-axis would be the icing on top of the Z-axis. But it's better to skip this idea.