Z Lift

[lasersafe1]

Parts almost ready for my stepper controlled Z motion lift modification of the inexpensive Chinese engraver. Ordered 5/16-32 stainless allthread, .2" pitch timing belt pullies, 1/4" oil impregnated brass slip bearings, a 55" timing belt. I cut out some squares of teflon and drilled and tapped for the allthread. These will mount to the table that lifts and retracts. It's pretty slippery and has no backlash. I only have 4 inches to work with for depth, and I guess I didn't realize how big those timing gears were. Oh well, I'll get about 3" depth in the final lift.

The four lifting posts will be at the farthest perimeter of the inner table so they will not interfere with the X Y rails.
Still waiting on the timing belt.

Anybody know where to buy the honeycomb aluminum table?

[lasersafe1]

Progress this weekend. Bottom section of Z lift is near completion.

Removed laser, rails, exhaust plenum, lids and inner divider wall to allow work on Z lift.

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insert 1/4" press fit brass slip bearings at the four extremes

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test fit the four lift screws with belt

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Notch out wall to accomodate belt to motor. Stepper for lift will sit in the electronics section near laser power supply.

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[lasersafe1]

Inserting the table with the four lift posts in place. I did a few tests with the unit and found that it was not wise to purchase the timing gears without capture plates on both ends. I ended up making my own upper end plate to keep the belt from slipping off. The aluminum is from an old electronics chassis and I cut it to shape on my radial arm saw. It was kind of a bear to get that belt on the gears the way I put it together. This M40III engraver only has the top opening to work through.

[hutchcj]

From your first post, the Aluminium honeycomb is used in composites (fibreglass and carbon fibre layups).

Anyway you should be able to buy it at a good quality composite supplier. In Australia, I get it from Lavender Composites (http://www.lavender-ce.com/)

[lasersafe1]

Here's an idea I had last night. Looking at the price of aluminum honeycomb I was a bit put off. I then started to think about an automobile radiator. Better yet, the condenser coil on a typical home air-conditioner is very flat and thin (1/2") with very thin kerf aluminum blades. I just picked one up today for free from an HVAC guy (used and leaking). The condensors look thick, but when you have one in your hand you will realize that it is really two units folded back on itself. Just unfold the unit and you have nice clean (unbent) fins for your new work surface. You should also purchase a fin comb to straighten them out in the future when some idiot drops something on the table.

Now I need to decide if this is something I want to try to cut with my radial arm saw. Thin aluminum, a little lead, and the internal copper tubes. Sounds a little dangerous. Maybe us a handheld radial saw instead.

One could even imagine running the cooling fluid through the "radiator" for cooling the laser tube since this surface will have the exhaust air flow across it. Then again, what happens if I put a job on the whole surface which would block the air flow. Better to keep a separate radiator in the main exhaust plenum. Looks like I will have plenty of leftover heat exchanger after cutting off the work table portion.

[LeonS]

Very cool idea!

[lasersafe1]

So here is the final running machine.

[willyinaus]

Good work love to see it cutting something LS.

Looking forward to seeing the DSP working as well.
Willy

[Maberib]

Looks shiny!

I know the thread is old, but here's to hoping the OP or someone else will see this:

Have any suggestions for controlling the z axis? Is that being done through Mach 3? I'm thinking I might have a separate little board for driving the z stepper with physical buttons.

What is allthread with smooth ends like that called? Where is it available?