[afonsurbano]

Hy everyone,

My company wants to build a 4X2 (meters) CNC machine.
It is supposed to cut ALUMINUM, MDF and ACRYLIC.

I have some ideas for the motion control (electronics, motors, etc...) but am totally lost when it comes to guiding (rails, screws...)

Our budget would have to be below or at 10.000€, since if it goes above that the company will probablly go with something like https://www.radecalmachinesales.com/...o-cnc-routers/. Btw, if anyone has any input on this machine, please share, or any similarly priced routers. This one, the 4020, goes for 25.000£ (30.000€).

Anyway, the biggest concern I have with these areas is the torcion on the largest axe. I think I pretty much have to let go of the aluminum T-slot solutions, they bend to much (right?)

Thank you for the inputs!

[wizard]

Hy everyone,

My company wants to build a 4X2 (meters) CNC machine.
It is supposed to cut ALUMINUM, MDF and ACRYLIC.

That is a big machine! It is important to understand what you mean by cut Aluminum as that will be your most demanding material.

I have some ideas for the motion control (electronics, motors, etc...) but am totally lost when it comes to guiding (rails, screws...)

This is a big machine and I have to wonder what you have access to as far as machine shop equipment goes?

Our budget would have to be below or at 10.000€, since if it goes above that the company will probablly go with something like https://www.radecalmachinesales.com/...o-cnc-routers/. Btw, if anyone has any input on this machine, please share, or any similarly priced routers. This one, the 4020, goes for 25.000£ (30.000€).

The cost of a build is highly variable. The more robust the machine the more it will cost. A company also needs to consider cost of labor which isn't trivial on a large machine like this.

Anyway, the biggest concern I have with these areas is the torcion on the largest axe.

Generally the weakest points in DIY designs is in the gantry and supports for that gantry. The link you have above leads to a machine with apparently some thought put into dealing with flex in the uprights. Your span (assuming the 2000mm length above) is almost seven feet, depending upon what you expect to do with aluminum that beam and supports will need to be substantial. To get a better feel for design considerations I strongly suggest reading the Stickies for this forum.

I think I pretty much have to let go of the aluminum T-slot solutions, they bend to much (right?)

There are lots of reasons to skip T-slots but maybe the biggest one is finding something suitable for the span you need to cover. Generally I don't like Aluminum T-Slot extrusions due the expense of the material and all the special components your need for the "System". The second problem with T-slots and this varies a lot with supplier, is that they are not the most robust structural components and have a less that idea surface for mounting rails.

Now given that I have seen Aluminum extrusions of considerable robustness specifically designed for linear motion systems. I have no idea where you would buy such extrusions though. The manufacture of one of the machines I have in mind (parts extractor) changed over to steel some years ago. In this case they welded two steel tubes together which is an additional expense but I must have been cheaper than Aluminum. I guess what Im trying to say I haven't seen any extrusions suitable for such a span in the retail markets.

Thank you for the inputs!

No problem!!

By the way this machine will be heavy aluminum extrusions or not.

[ger21]

You might want to look into building a Mechmate.
Otherwise, My suggestion would be a machine made with welded steel tubing, and Hiwin linear rails.

[skrubol]

When does it need to be complete by? That's a lot of machine for that kind of money. If you don't have at least a year to put into design, obtaining used and NOS parts and fabrication, I don't think you would be able to stay anywhere near that budget and end up with a workable machine.
Note that the Pirhana router would probably only be good for fairly light cuts in aluminum. If that 1300kg figure is for the 2x4m model, it's definitely a lightweight machine. I'd think you'd want a machine at least 5x that heavy for much aluminum work.

[CutMasterCNC]

I built this machine using square tubing and flat steel for the rails. It runs on v-bearings. I used 3/6"x 2"x2" x6' long square tubing but you could go up tp 1/4" or 1/2" for longer axis. I used 3/16" flat steel for the motor and back plates. again for larger machine you could go up to 1/4" or 1/2". i do not think you would need to. I use it with a plasma cutter, Router and a 4 hp spindle. It cuts anything. It is very acurate. I am in the process of adding a 4th axis for turning and lathe. If you would like to see more pictures let me know. I have the gcode files to plasma cut the motor and back plates, I have it set up with Planet-cnc, Mach3 and mach4 for the controller using a gecko g540 motor driver. I will soon be adding UCCNC.
https://www.youtube.com/watch?v=SJKuMcHycms&t=20s
Your machine could be build for close to $2500 us dollars.