[Apples]

Hi all.

I am having some weight issues with my gantry. I wish to use stepper motors that are direct drive to a rack via pinion. The weight of the gantry is 45kg or 100lb at the moment. I then have to add on the stepper motors, a rack and bits and pieces. So basically it is HEAVY!


As you can see the in the photo I have used angle iron to support the round bars on which the truck slides along. The weight of one round bar support (ie 2 lenghts of angle ) is 12kg. So I have two of them which is 24 kg.

I am thinking that I can save weight buy using aluminium angle as supports.

Maybe I should just use some aluminium shs and bolt on some of those duel'vee guides and use the groved bearings. If I was to do that, then I would eliminate the heavy steel angle iron and also the heavy round bar as well.

The idea of me reducing the weight is so that I can use small/cheaper stepper motors.

What do you all think of this?

Also what size steppers would I need to drive this system. It is only for a plasma cutter so there will be no contact. It is going to be driven on one side only. I have been thinking of using stepper motors in the 400oz range. Could I go smaller or should I go bigger. What speeds could I expect to reach.

Cheer Peter