wood cnc machines?

[vivi-d]

Hi I'm curious about the cnc machines on this site: https://www.bobscnc.com/

They claim wood is a good material to make the machines out of. How could wood be better than metal? Are these overpriced?

[TimFox]

Note that their products are to fabricate and shape wood objects, using routers and other woodworking tools.

[ataradov]

It is not better. It is just good enough for their application. Plywood is dimensionally stable and easy to work with especially if you already have woodworking CNC. The machines are pretty light duty, so you don't need them to be really strong.

Unless you buy a pre-cut kit or have a CNC anlready, typical aluminum extrusion would be much easier to use.

[Roehrenonkel]

Hi,
 
wood will shrink and expand depending on humidity.
Metal will do the same with temperature.
Real "stone-solid" CNCs are made from granite:

CNC machine made out of granite - part1:

Another Granite-CNC:
https://www.flyingfoxcam.com/cnc
....if one can affort it. :-(

Ciao4now

[Coordonnée_chromatique]

Is anymone knows how this material is handling the mechanical stress and the gradients of temperature within time ?

[Jackster]

It is a router bed made with slotted plywood and screws holding it together with small rubber belts for movement.
It just limits you to how much stress you can put onto the machine (speed, feeds and depth of cut).

My 3D printer made from 20x20 aluminum extrusion would have more rigidity that any of those "CNC machines" to put it into perspective.


Wood is in no way better than metal for this type of application.

If you want a kit build CNC machine that looks pretty and can do light work for hobby use, then it is fine.
But if you actually want to cut some material or do anything more than some light hobby projects, you would be better off finding a used metal router.

[johansen]

Is anymone knows how this material is handling the mechanical stress and the gradients of temperature withing time ?

because the cutting forces needed to cut wood with a 20,000 rpm 1/4 hp router is just not much. a few pounds of force.

If the wood body of their cnc router was twice as thick, and a square closed box section instead of open I beam sections, you could put a 1hp router with nema 34 steppers.

the next thing to upgrade would be the rails and rollers, for just regular cheap 20mm linear rail. then the next thing to upgrade is ballscrews instead of a belt. but all that costs money.

1500$ for a complete system that can do intricate carvings (they just take a long time) can pay for itself in 1 day if you have a customer base.