Quote Originally Posted by IanS1 View Post
The gantry sides are 800 x 300 x 25mm Ecocast. I'm hoping I might get away with some ally extrusion to try and keep the weight down but not if it's going to compromise the strength too much.
Can I ask why you went with ecocast?

I don't think ecocast is structurally any stronger than 6082, (Jazz can probably confirmor refute this) it is just precision ground which is useful for mounting rails on but not required for the gantry sides. With the dimensions you provided, 6082 from aluminium warehouse would cost £90 +vat each as opposed to £125 +vat each for ecocast.

Edit to add, don't worry too much about the weight of the gantry, there is a really good spreadsheet here that allows you to play with figures and a few extra kgs has very little effect.

http://www.mycncuk.com/forums/faqs-p...do-i-need.html