random thought

[2muchstuff]

I know from reading other posts that it is recommended that your first machine be a small one so you can work out the problems that come up. What about using the over-head gantry from an old x-ray machine used in a hospital, roughly a 7'x10' working area. Remove the several hundred pound x-ray head, flip the rails over and mount them to the table and reattach the gantry. Remove the electric brakes on the guide wheels and attach an acme screw from an electric garage door opener with double nuts to drive each axis. Does this sound too insane? I have a lead on an old x-ray gantry that is going to be thrown out and the acme screws I already have. I figure if an x-ray tech can move the gantry with head attached then with no head and stripped down it should move pretty easy. Any other thoughts or ideas on this?

[Torsten]

Sounds like you found yourself a pretty good project.
Seams like hospital stuff is usually off very good quality.
I am sure there will be plenty of headaches along the way.
Go for it and post us some pictures when you get it home.
Good Luck

[foamcutter]

Sounds like a interesting and good project to me! Keep us posted. Ron

[lerman]

Originally Posted by 2muchstuff I know from reading other posts that it is recommended that your first machine be a small one so you can work out the problems that come up. What about using the over-head gantry from an old x-ray machine used in a hospital, roughly a 7'x10' working area. Remove the several hundred pound x-ray head, flip the rails over and mount them to the table and reattach the gantry. Remove the electric brakes on the guide wheels and attach an acme screw from an electric garage door opener with double nuts to drive each axis. Does this sound too insane? I have a lead on an old x-ray gantry that is going to be thrown out and the acme screws I already have. I figure if an x-ray tech can move the gantry with head attached then with no head and stripped down it should move pretty easy. Any other thoughts or ideas on this?

My guess is that you will have a problem with stiffness. That isn't a problem when you just move the head to a position, pause, then take a picture. I suggest that you put a dial indicator on the base and indicate the head. Push on the structure with one finger and I bet you'll have it move 20 or more thousandths.

Ken

[2muchstuff]

UPDATE- The x-ray gantry that I was trying to get didn't pan out. The hospital decided to donate the entire unit (gantry, head and power supply) to some other small hospital in central america, ie: tax write off. Well back to the drawing board...... By the way, anybody got a lead on a used ballscrew out of Xerox 9000 series document feeder?