Plasma Cutter Gen 2 - Part 5: Gantry
I got a little more work done on the gantry. I decided against adding more members into the design for weigh reasons. With the gussets down the center, this thing is more than strong enough as it is. Also, after adding brackets to attach the V Rail to, it resists bending even more. I have added loose tolerances for adjustability to allow for warping or non-perfect parts and so far everything is going together very well.
These are the brackets I made up to mount the V rail to the gantry. I made the holes larger than the fasteners that I will use to attach the V rail so that I can adjust the rail, should it not be level. Somehow, between the spacing between my gussets within the rail, and the spacing of the holes on the V rail, exactly 6 brackets fit perfectly spaced down the length of the gantry. It’s as if I planned it that way!
These were then welded down the length of the gantry. These are the brackets I referred to that should add strength and resist sagging, not that it was really necessary anyway. I also made some end caps to finish off the ends of the gantry.
Then pictures of the gantry with the rail mounted. I spaced the rail off the brackets by the thickness of one nut, to allow for fastener clearance on the X axis carriage. I thought i may need to shim the backside to make it nice and flat, even though I adjusted it to flat when welding in the brackets, but it’s looking pretty darn good! The gantry reminds me of the booms that were used on old tow trucks and small cranes.
After installing the rail, I made up a mockup X axis carriage to figure out the ideal spacing for my holes. To adjust the slack in the V bearings, I purchased some eccentric bushings so that I can “cam” the bearing up against the V rail.
It rolls very nicely on the rails, and is already extremely more tight than my old machine.