My MDF CNC DIY machine--bone stock till the next one :)

[menace]

I'm really hoping my vacuum table does as good of a job as I'm hoping--figuring out how to hold down the parts while cutting gives me the willies--I just picture one mistake and my bit rams into a steel pin/screw--ugh..

[menace]

Slim vacuforming table top under construction.  the base is 1/4" 4x8 MDF sheet with 5/8"x5/8" plywood battons:



Capped with a 1/4" sheet of perf board that will be smoothed over when I get enough confidence to set the router free...



very rigid little board...

Set on table:

[CaptainMarvel]

Totally looking forward to the point where you fire this bad boy up and see the fruits of your labor.

Do you already have experience with CNC programming?

[menace]

Absolutely none    Reading the mach3 manual now....

[Yvan256]

Is this CNC project dead?   

[menace]

Nope just sidelined--I had ordered some acme thread for the x-axis and while waiting for it to arrive I got distracted by other shiny things :-)  I actually took some ribbing over the weekend so its coming back out to get finished.  I do need a proper spindle and have to wrap my head around holding pieces down while cutting.

Input on that would be appreciated!

[Yvan256]

Nope just sidelined--I had ordered some acme thread for the x-axis and while waiting for it to arrive I got distracted by other shiny things :-)  I actually took some ribbing over the weekend so its coming back out to get finished.  I do need a proper spindle and have to wrap my head around holding pieces down while cutting.

Input on that would be appreciated!

I don't think you don't need a spindle for the time being unless you plan on cutting dozens of parts every day, what you got is still better than the Black & Decker RTX on my CNC64.

As for holding pieces down, I make my own MDF slotted bed with a special router bit, then hold the pieces with the special nuts on that page. I simply use a large washer and scrap leftover of the same material thickness as what I need to cut. Sorry I can't find a proper photo right now, but searching for "CNC T-Slot Clamping" will give you a general idea.

[Slippyblade]

Question for all you CNC guys.  Doesn't the bed get diced up over time?  I mean, how do you cut completely through the material without leaving cuts in the table top?

[menace]

Slippyblade--I think most guys use a "spoil board".  Its a board that sits on the bed of the cnc machine that takes all the gouges then is tossed away after it becomes unusable.

I get how those hold down pegs work but what happens when you have the piece 95% cut out of the stock (piece being held down)?  I have visions of the piece being cut, shifting and getting fouled in the router bit.  I guess my question is what keeps the cut pieces from going anywhere?

[Yvan256]

I get how those hold down pegs work but what happens when you have the piece 95% cut out of the stock (piece being held down)?  I have visions of the piece being cut, shifting and getting fouled in the router bit.  I guess my question is what keeps the cut pieces from going anywhere?

CAD/CNC programs can usually add tabs to your piece. So the CNC can cut your parts all the way through, you cut the tabs manually and then remove them completely with a flush trim bit.