[Tigglebitties]

I've got my regular 3axis CNC router working and I'm daydreaming here...

My sister makes cookies for a living and I've been watching her decorate cookies in 1-200 count batches and noticed something- she's doing a repetitive process with identical tool paths & patterns using a frosting with a consistent viscosity out of the same size nozzle...

I'm gonna give it a try. I think the best way is to put a peristaltic pump on a stepper motor and put a tube with a nozzle on a stick that I can Chuck into the spindle.

Where do I look to make a tool path that'll correspond an x y z tool path to spin that fourth axis? I can do the simple 2d trace and contour toolpaths in Fusion, but how would I add the toolpath for this pump axis?
Thanks!!

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[awerby]

I don't think you need a 4th axis to run the pump motor. It's not an axis, and it doesn't need a stepper, it just needs to go on and off at the right times. Use a regular motor and the spindle on-off function instead, and trigger it with M3/M5 commands through a relay.

[Tigglebitties]

I don't think you need a 4th axis to run the pump motor. It's not an axis, and it doesn't need a stepper, it just needs to go on and off at the right times. Use a regular motor and the spindle on-off function instead, and trigger it with M3/M5 commands through a relay.

I was thinking about that, but I don't think the on off control would be as controlled as I want. As in I could probably find a pump that would work but I'd have no control over speed and portion...

Now I feel dumb, I realized Im talking about an extruder. I'm making a 3d printer attachment... That should be simpler.

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[MARV]

This discussion reminds me of an old Mad magazine how to. How to make a knife from a screw driver. How to make a screw driver from a cold chisel. How to make a cold chisel from a knife. A classic case of missing the forrest for the trees. Forget the CNC business. Buy a fractional HP universal motor driven gear motor tied to a speed control on/off switch with a mounted face plate. And get busy frosting those cookies!

[Tigglebitties]

This discussion reminds me of an old Mad magazine how to. How to make a knife from a screw driver. How to make a screw driver from a cold chisel. How to make a cold chisel from a knife. A classic case of missing the forrest for the trees. Forget the CNC business. Buy a fractional HP universal motor driven gear motor tied to a speed control on/off switch with a mounted face plate. And get busy frosting those cookies!

Ok I can do that, but how would I control it via g code?

I realized my end goal here is to make an extruder, so I'd need a stepper but I can probably make the g code in fusion 360 I think. My issue is with Mach4 - I haven't seen anyone run a 3D printer using Mach 4 yet...

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[ivanjhon]

This discussion reminds me of an old Mad magazine how to. How to make a whetstones for sharpening Japanese knives (https://toolsofchef.com/best-whetsto...panese-knives/) from a screw driver. How to make a screw driver from a cold chisel. How to make a cold chisel from a knife. A classic case of missing the forest for the trees. Forget the CNC business. Buy a fractional HP universal motor driven gear motor tied to a speed control on/off switch with a mounted face plate. And get busy frosting those cookies!

haha exactly i was thinking the same

[Tigglebitties]

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[MARV]

Still not clear to me just what you're trying to accomplish with the extruder, but regarding Mach4 and 3D printers; I'll be interested in reading what you come up with.

[Dean448]

The design would be exactly where you want the frosting laid out. That’s a vector file with lines and curves. The machine would be normal X-Y with a modified Z.
The Z axis would need to go down to the cookie top and then the pump comes on. Then pump off and pop back up.
So the design would be a series of moves at the same depth with this clearance move between passes.
The on off of the pump is not easily done thru the CAM program so I would control it by the Z axis motion. The faster it starts and stops the better.


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[MARV]

This is beginning to sound like those devices that apply a bead of adhesive or calk such as in engine assembly. I presume there is software that would accomplish this? On/off, move along vectors on a 3D surface, etc. An interesting variation would be to change the amount/width of bead as the design dictates. With multiple extruders, you could also change colors!