Experience with laser-cutting plywood gears?

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jonasb
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Experience with laser-cutting plywood gears?

Post by jonasb »

Hi,

Does anyone has experience with laser-cutting small gears from plywood?

For a hobby project I plan to cut some gears (20mm to 75mm in diameter) from 4mm plywood. Unfortunately, I have absolutely no experience with this. And having no laser cutter at hand, I have to order the parts somewhere, so I cannot make many test cuts.
I use the Gears WB to generate involute spur gears.

My main questions are:
- How small can the module be? Is a module of 1.5 mm sensible, when using strong beech plywood with 7 layers per 4mm?
- What clearance do you suggest?
- Which backslash to add (rather substact) from the gears?

Any advice is appreciated, Thanks.
edwilliams16
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Re: Experience with laser-cutting plywood gears?

Post by edwilliams16 »

I've cut larger gears following Matthias Wandel https://woodgears.ca/gear/howto.html with my bandsaw. I think that would be too fiddly with small gears. Gears that will fit on my 3D printer bed I've made with success. Have you considered making them that way? I think you might get more precision. If you don't have a printer there's plenty of services that can make them for you.
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jonasb
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Re: Experience with laser-cutting plywood gears?

Post by jonasb »

Thanks for the suggestions, but the material choice is deliberate. My goal is a lifting system, inspired by the Falkirk Wheel, for a toy train system where everything is made from beech. And cutting so many teeth on my mechanical fret saw is not an option :lol: thus the idea to laser cut.

I know Matthias Wandel's work. Also very inspiring, but my projects are usually on a smaller scale.
Brio-Falkirk-Wheel-WIP-2 -small.png
Brio-Falkirk-Wheel-WIP-2 -small.png (190.77 KiB) Viewed 1032 times
edwilliams16
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Re: Experience with laser-cutting plywood gears?

Post by edwilliams16 »

Could you make router template? I'd 3D print one if I were trying this. Maybe two - one for rough cut with a larger bit and a finishing one with a smaller bit. The gears would have to be a simple extrusion of a 2D template.
chrisb
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Re: Experience with laser-cutting plywood gears?

Post by chrisb »

3D printing gears is probably not directly comparable to lasercutting. I have printed some gears, and they were too tight, while I guess that a lasercut would fit well or be too loose.
I had to experiment with the print parameters to get it right. If there is interest, I can look them up.

In your case I would guess that you could adjust things by changing the positions of the shafts. If you want to make this easier, you could redesign it and use only a single gear in the center, which would change the overall layout, but would provide the same fun in playing with it. Adjustment could then be made by slots instead of holes.
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M4x
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Re: Experience with laser-cutting plywood gears?

Post by M4x »

Is a CNC router somewhere in your area? Hackerspace...?
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