[nokillzone]

my parts stl.rar

Please take a look at my deign and Lend me your opinion ..

Thinking of using 2505 or 2005 ballscrew

Length is 48" or 56" long

i have few things made .. helps to have industrial CNC machine to make parts .. for home machine

[ger21]

What material is it?
Your gantry sides will probably have a lot of flex. They need to be much more substantial.

[nokillzone]

1" Aluminum ground Plate.... almost everything.. the z-axis is Built .. but now have to work my way down the machine..



Sorry i forgot to add the sides .. and the 3 beams for the table would be "8020 T Slot Aluminum Extrusion 10 S 2040 x 56"

table top maybe 1/2 to 3/4 alum plate? was thinking 1/2 steel plate but would be heavy !?

[aarggh]

If it's a moving gantry, the table can never be too heavy! If your looking 48-56" long, then the width i'm assuming is around 48"? If so, I'd highly recommend going to dual ballscrew on the Y axis, so you can then remove the koiner under the table for the X axis, and drive it from the sides. This will allow you to beef up the table as nothing will be under it. Two ballscrews will also help greatly given the size machine you want, for coping with load while still giving good performance. If your using a G540 which I would also recommend, you can simply "slave" the two ballscrews for the Yaxis so they move in lock step. Twice the torque. As Gerry said though, your X axis need a lot more rigidity, it will give a massive amount of flex while moving and espeically under load. Brace as much as possible with material at right angles to stop flexing. Also, if your Z axis height ratio is as drawn, the X axis rails are far too close together given the high suspension of the Z axis, under load the Z axis will rock in all directions you'll find. Lower the Z, or spread apart the X axis would be my recommendation.

cheers, Ian

[awerby]

Another suggestion would be to raise the height of the walls that the X-axis gantry runs on. The less height you've got on the gantry itself, the more rigid the whole thing will be. And not having to push that extra weight around makes the axis more nimble. See the Mechmate as an example: http://www.mechmate.com/

Andrew Werby
www.computersculpture.com

[victorofga]

before you buy rails take a look on automation4less

http://www.automation4less.com/store/hiwinlegacy.asp

the sideplates need to be as long as 1/4th of the width of table... means for 24 inch wide need 6 inch long for acceptable result..

on gantry rails should be on a distance as much you leave under gantry
so if under gantry you have 6 inch then rails on gantry also should be on 6 inch distance each other..

if you plan a higher gantry then side plate at rails need to be longer with an example table 24 wide, but you plan 8 inch under gantry then side plate is not 6inch but 8 inches long ..

if you using hiwin rails on the X i think the 3 inches 8020 aluextrusin will work..


if you were using 10 or 20 lead screw then possible need nema34 motor .. if width of machine over 24 wide, the 34 is suggested.. but again this is only an opinion..

this is a very rough thumbrule..

[nokillzone]

I all ready have all the rails i am working with what material i acquired past few years
I do have a 7'+ long Linear rails (for x)... but no place to build and keep that long machine as of yet ...

I built the z Axis ... i have rails for the Y... and y direction to me is where Z is mounted to !!!!!


i just need to figure out the frame and location for holes ...
My work was getting something water-jeted and the profile of the y Columns are result from it ..

I dont know if you guys seen the STL file... or whats best to use to show you guys ..

[tahustvedt]

I would make the gantry taller than 8". As tall as practical to spread the load and increase stiffness. It's a waste to have all that empty space behind the bottom half of the Z assembly, and it doesn't give you any more work height. If 8" is the max width material then move the gantry down as low as it can go.