Ok. Z AXIS design time. What is the acceptable leverage ratio of a sturdy Z?
My length of linear rail is 450mm. I was hoping for 300mm
Of cutting depth but it seems like there would be excessive difficulty keeping my Z cutting straight with a 150mm (1/3 ratio) binding area for the spindle on a 450mm run. What do you all suggest?
Also, would be wiser to mount the linesr bearings on the spindle plate or on the gantry plate?
Rails on the spindle plate. To make a variable lever. Bearing blocks spaced at 50% of z travel and as wide as possible.
I'll let the resident experts correct me if I am wrong. I'm still drawing up my design. However, this is my understanding.
Few more updates. a redesign of the Z axis and some major work to keep it all straight. moves very smoothly now. Z axis is 6mm steel. working on the ball screws next.
Here's a quick vid of the movement: https://youtu.be/DRLe3EPQ01M
Here's some photos.
The Following User Says Thank You to Slixxor For This Useful Post:
OK, so progress has been slow but i've finalized and purchased the electronics.
PSU's: 70v 5.7A Switchmode PSU.
Manufacturer Part Number 23HS45-4204S Step Angle 1.8° Holding Torque 3.0Nm(425oz.in) Rated Current/phase 4.2A Phase Resistance 0.9ohms Recommended Voltage 24-48V Inductance 3.8mH±20%(1KHz) Weight 1.8kg
Thanks to CliveS and the others on suggesting not buying a kit.
More to come shortly. there have been some more changes :)
4 Weeks Ago #16
Z Axis finally fitted and relatively smooth with motion (No racking), Some filler welds will be done in the coming days and the wiring should be done shortly. :) I'm finally starting to see it all come together. I wasn't really sure if my Z design would work, but it seems extremely rigid. Although I've lost 100mm of travel on the Y axis I've maintained a good center of gravity on the Z axis and increased the X axis work area.
Hopefully cutting in January!
3 Weeks Ago #17
Nice concept of Z axis, only problem is that doesn't allow for any adjustment other than shims. How smooth it travels up and down?
Asking as I machined similar stuff on chinese mill and wasn't parallel.
Same thing for entire machine - you are mounting rails directly to profiles - no machined base, no epoxy for leveling (parallel, squareness?)
I do not criticize you - just wander if you aim for accuracy in your machine.
3 Weeks Ago #18
I think the reason for the success in motion is the heating of various sections during the fabrication process.
I like working with steel because it warps and moves when heated.
When designing the Z most of the welding occured on Job with clamps. As the steel heats and warps it smoothly contours around its pressure points. I.e: the fasteners on the bearing blocks and the tension applied by the SBR25 rail.
Not to mention meticulous time spent hammering the fudge out of it at times :) the outer walls were hardest. They have a slight warp in the 6mm and needed lots of bashing and even driving the car over it.
Cutting a square for the ballscrew bracket was the best idea. As it allowed me to drill it then weld it back in with just the tension of the ballscrew to warp to.
There really was no other way though. Accessing the correct drill points would have been almost impossible to get right as it was completely blind.
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3 Weeks Ago #19
3 Weeks Ago #20
It's hard with long runs like that. Partly the reason bojan S uses C channel for his bed. Although I find welding much easier, drilling and bolting would have given a better result.
Whats the link for your thread?
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