My initial drawing for a steel gantry machiene.

[nikodell]

I was going to build a Joes hybrid but it seems I can do a steel table foe less than 25% the cost with surplus steel. This is the initial table top drawing, I will continue to lay out gantry drivers ect. tonight when I get home. Any input on the initial design would be great. I am thinking it might be nice to get the motors out of the way under the table but that would require timing belt, any thoughts on this? Thought is 1 short belt on either stepper + belt connecting the 2,"this is with dual screw drives.

Basic idea:
Initially use of hobby level steppers and router + ability to upgrade to industrial level duty at later date.

LoL cant edit tittle.

[nikodell]

Busting the rust off of Autocad and got a start on a rough 3D model to plan the mechanics on. I need to get the drive system drafted and than I will place base supports. Got to study for finals next week also, but should have plenty of time for the plans.

[rowbare]

Looks like a good base for a MechMate. Check it out at http://www.mechmate.com

[nikodell]

Hmm yah similar but its a basic table so far. I like the Mechmate rack and pinion but it looks like they are using 10/1 gear reduction steppers, the ones I found on the forum are like 250 a piece, maybe I jumped to quick on electronics?? Oooo well this will do fine.
I got the geko 540 keling package with the 387oz motors. I guess it can be an update later if needed. I like the gantry too but think I may do something more like joes hybird for now and keep the mass lower for the 23's I am happy to see the 10/1's will work with my 540 if I decide to change it out in the future.
http://catalog.orientalmotor.com/ite...=prod&filter=0
I will have a sturdy table to base off of.

[nikodell]

Any idea on what the rack and pinion gears would cost? 7' on each side

[nikodell]

Not a lot done on the drawing today "homework and cleaning the shop", it was more of an Autocad refresher, did play with my thought on the gantry to help visualize how I want place the drive screws. I am thinking of pushing the lower 2 wheels closer togather to give them room from the base legs.

[nikodell]

My electronics show up tomorrow, it will be hard to study when I can have fun figuring out this stuff.

[oldhack]

Originally Posted by nikodell Any idea on what the rack and pinion gears would cost? 7' on each side

get them from mcmaster carr. about 200.00 U.S. dollars for a 4x8 table

[nikodell]

Well got my Gecko 540, limit switches, and E-Stop but no steppers or power supply, they are not shipping till the 5th or so? Anyhow I started putting my computer together.
Gigabyte GA-7VRXP
Atholon XP 2000+
1 GB memory
Ubuntu + EMC2
17 flat screen Dell crt
and some old slow hd, could this be a problem?

[FandZ]

Originally Posted by nikodell and some old slow hd, could this be a problem?

I Don't think so. The system requirements to run a cnc machine are pretty low. There are people running cnc's with sub ghz cpu's and 256mb of ram.

[jsheerin]

If you move your legs in a bit from the corners, you should get less sag in your horizontal beam. I forget what's ideal - might be 1/4 of the length in from the ends, but if you look up truss or beam design, you might be able to find something that talks about this.

[nikodell]

Originally Posted by jsheerin If you move your legs in a bit from the corners, you should get less sag in your horizontal beam. I forget what's ideal - might be 1/4 of the length in from the ends, but if you look up truss or beam design, you might be able to find something that talks about this.

I actually plan on putting some bracing in the base going to that center 2x2 horizontal, I am just on hold on the plan for a bit. but that is a good thing to consider. I also may go look and see what other steel sections I can find, I am hoping that I can get some 2x6 sections which should resist flexing more.

Ok I was looking at wiring the motors now 4/22 should be good I hope. This is what I am looking at.

http://www.jameco.com/webapp/wcs/sto...ductId=732452&