[rgillard]

Hi All,

What is the best material to use for a machine gantry?

Aluminium or Steel? I have been speaking with my local machine shop and they said that aluminium expands a lot with heat. How hot would the gantry of a machine get when cutting thick material with oxy fuel for example. I am thinking that aluminium would be far lighter and keep the inertia down.. The machinist has 40 years experience and was slightly put off by the thoughts of using 80/20 type extrusion for the gantry..

Regards,
Ron

[Med-Pac]

How big is your machine? Size could be a factor.
We have a 4' x 8' plasma witha 3" x 3" alum. gantry, works great. I cut quite a bit of 1/4-1/2 plate, never had any issues with gantry.

Mike

[rgillard]

Im currently just in the design process (for the last 2 years)...The table will be 10 x 5....

[WSS]

Hi All,

What is the best material to use for a machine gantry?

Aluminium or Steel? I have been speaking with my local machine shop and they said that aluminium expands a lot with heat. How hot would the gantry of a machine get when cutting thick material with oxy fuel for example. I am thinking that aluminium would be far lighter and keep the inertia down.. The machinist has 40 years experience and was slightly put off by the thoughts of using 80/20 type extrusion for the gantry..

Regards,
Ron

Ron, Most of the heat would be zone/reflective. You can contain that heat with shields. Aluminum is pretty stable but steel is somewhat less expensive. I have a steel gantry but aluminum would have been OK.

Here is a link to a really nice aluminum gantry build. If I was to build my own I would consider this route:

http://www.cnczone.com/forums/showth...105#post759105

WSS

[millman52]

I have a steel box tube gantry. It absorbs quite a bit of heat when cutting 1" material in a chain cut program. (lots of small parts in a tight area of plate) It never gets hot enough to make Aluminum become unstable. It doesn't get to hot to touch but does get to hot to hold on to. I don't think it is so much direct heat from the torch flame as it's heat radiating off the 1" steel that's being cut.

I agree with WSS Aluminum should be fine for a gantry. If you are using small motors & drivers Al will almost be a necessity.