CNC Gantry Design - Help Needed!

I'm putting together a gantry that I want to be able to use as a light duty CNC router for aluminium.

The frame will be welded 2"x1" steel tubing. (The "floating" X/Y Gantry will likely be aluminum.)

I have 4 IKO 24mm linear rails with two bearings each.

My big question right now is if the use of two rails on the X/Y is necessary versus just one. (The draft photo shows it with two.)
I've seen linear rail CNC kits that use smaller 18mm rails; so I'd like to use just one of my IKO rails for the X/Y for a total of 3 rails.

Please see the attached photos for reference.

Draft Gantry: [imgur.com]

IKO Rails: [imgur.com]


Thanks in advance for the help!

- .Jata



Edit: Just an FYI for anyone else working on a similar project; I found a stiffness calculator on the forum submitted by: davew_tx [forums.reprap.org]

Edited 1 time(s). Last edit at 09/14/2017 03:43PM by .Jata.

No such thing as light duty CNC for milling aluminum!

see
[forums.reprap.org]

2 rails per axis, minimum. Steel is not flat so you will to need to epoxy resin to level where the rails go. Aluminium T slot extrusion is also not flat but it's flat enough for your style router (Or mine for that matter).

Read this
[www.mycncuk.com]

for gantry design ideas, what you drew wasn't a gantry lol but I assume you just wanted to illustrate the point.

If you only have 4 rails (I assume you were thinking you could use 1 on the gantry and one on the Z axis?) I would get another 2 rails (Stronger ones, Hiwin 15mm or eqiv would be good) and use them for the Y axis (Bottom one) and use you 4 on the gantry (X) and Z axis.

Not sure if I'd the rail correctly I think this is the shallow IKO rail not the chunkier rail.

Edited 1 time(s). Last edit at 09/17/2017 05:31AM by Desertboy.

cozmicray is right to the extent that a lightly built CNC mill can't do any heavy milling on aluminium but as long as the milling is restricted to very light cut it can do very well. This is a 3D printer being used to cut a 1.5mm wide by 1.5mm deep pattern in an aluminium plate - [www.youtube.com]
Onre thing to make sure of is that swarf is picked up cleanly by something like the vacuum in the above video.

Mike

What spindle you using, nice vid of that suction plate.