CNC router 4x4'

[Crawler374]

I have started another build. My other one was "okay", but it just was not big enough for what i want to do.

Browsing this forum everyday, I have gathered a lot of ideas and tips on build one. I was checking out www.buildyourcnc.com and I like his simplicity of design. So my build will be based off his, but larger. So far I got the table to be 4' x 4'. Seems to be plenty large for my application.

So far the build is just MDF. I am trying to use as much glue as possible because bolting together causes the MDF to split easy, as its a brittle material.

sorry about the blurry pics, my camera is covered in dust and i have low light conditions

[MadeInTheShed]

Looking good. I will watch this build.
A couple of suggestions tho, from experience - Ive built one but not quite as wide!;
You will need to stiffen up your gantry sides. Mine are about 300mm top to bottom and are made of 18mm MDF, and I have noticed it flexing. Im going to add a torsion box to each side to stiffen it.
Same with your Y axis. It wont flex up and down, but it will flex front to back and it will also twist if you dont use reinforcing.
I also found that tapping MDF was unsucsessful. I ended up using cross dowels and I can get these very tight.

I like the way you used the aluminium box for your bearing plates. I used angle and am finding they are digging into the hardwood guides. Ive been redesigning mine with a flat aluminium plate to prevent this, but I like your idea. Lots of surface area.

[Crawler374]

hey, thanks for the comment


I found out very quickly that support is a real big issue with cnc's. My last machine flexed a lot, and i couldn't stand it. This one is only using the MDF as a gantry guide. I have angle aluminum going on the tops of the gantry, same design as the Y axis. I also plan on getting aluminum or steel plate to go accross the gantry. possible angled steel or aluminum. only time will tell.

[Crawler374]

not much of an update, but i figured i'd post some more pics.

Here is the way i will support the Y-axis. Simple - large, thick, steel angle

[Crawler374]

Here is the Y bearing carriages.





supports for the X





added some supports here