[Blaisun]

Hi All, I have been lurking around the forums for quite a while now reading various build threads and trying to decide what I would like in a CNC machine. I have came up with a rudimentary design for the table. I am going to share it with you and hope to get some constructive feed back on where it might be improved.

I dont want to get rid of the drawers or the wood storage in behind the drawers, that is why there is a lot of bracing on the interior in hope to compensate for the lack of bracing on the exterior.

It will be 6 months plus before i can start building it.

Goals for the CNC.

This is just going to be my hobby machine, i have no expectation to earn with it.

Mostly woodworking(furniture, boxes, signage), maybe some aluminum but not a design requirement.

be self contained and mobile(small shop), drawers to hold tooling and electronics, small section in the back to hold materials. act as an assemble table for the items that i create with it.

Specs:

Work area ~30" x 50" 6" Z travel.

The frame is a combination of 2x4 and 2x2 1/8th " steel tube welded.

Spoil board is a MDF Torsion box.

Welding method is going to be distributed tacking to minimize distortion.

the Bearings are CNCRP bearing trucks on CRS

X axis will be dual drive.

Undecided/not yet designed.
motion is most likely going to be R&P for X&Y and a Chinese ball screw(1605 or 2005) for z

Gantry - after reading all the fine analysis from DMalicky, the Gantry beam is is probably going to be 6X6 1/8th wall steel beam

Spindle - going to start out with a wood working router i have currently and then update to a Chinese spindle at a later date.

Motors/electronics. I was waiting until had had flushed out the design for the Gantry before i made up my mind, but i am leaning towards a G540 and some Nema 23 320oz low inductance steppers w 48V regulated supply.

So....... Where can i improve?

[ger21]

I think you have more steel than you need under the table. What's under the frame doesn't have much to do with the machine rigidity, and only needs to be braced enough to keep the frame stable. Your wood panels will do a lot of bracing if you bolt them to the legs.

I'd go with a 1610 ballscrew for the Z axis, for more speed.

[Blaisun]

Hi, Thanks, i thought i was going a little over board... here is the frame with the diagonal braces removed, if there is some that i should have left please let me know, i agree that the boards for the drawers and wood storage area will provide that stability if properly bolted. I had added some small pieces in to replace the lost mounting surfaces for the wood.

I moved the x axis rails and bearings to the top of the table to allow for simpler Gantry uprights, taking inspiration from the CNCRP uprights building on a proven design.....
I have started on the basics of my Gantry. The beam is a 1/8" in wall 6x6 steel tube. The uprights consist of 1/4" plate and 2x6 1/8" wall tube....

Is the 6x6 tube too much for this span? The tube is 44" long end to end, 37" in between the uprights. or would 4x4 be ok?

[melbrandle]

I think your material storage looks fantastic. The drawers will definitely help to organize the items, even the tiniest one yet like a fastener. Furthermore, they can be pulled out so it will be so easy for you to retrieve your things inside. I can also see the bottom drawers are of a different size as compared to the upper and middle ones. That means you can store your bigger or bulkier items down there, making your material storage flexible.

[TSJ]

Looking at your material storage I would put one or two cross braces. Murphy's law will be proven when you want a piece from the storage area and it is on the bottom!