When I built my Burly, most builds I saw on the net had two cuts in the spoil board so that the feet were on separate boards than the middle. This allows the middle section to be slid out and replaced. Note the middle section does not have to match the working area, just be bigger than the working area.
When I upgraded my MPCNC to a Primo, I took a different approach. I built my machine on a base board (3/4" MDF), and then cut a spoil board just the size of my working area, and I mounted it on top of the base board. This means the spoil board stands 3/4" above the feet, so I needed to add 3/4" to the numbers output by the calculator to preserve my working Z height…or the feet could be put on blocks.
Mounting the spoil board on top allows me to work with oversized stock or to cut features in material that is bigger than my working area. At some point you will want to “surface” your spoil board. Using a wide bit, you will have the router skim off the top of your spoil board to assure that the plane of the router and the spoil board are parallel. In the original design (two cut lines), surfacing results in a pit in the spoil board, so, due to the pit, it is hard to mount oversized stock and keep level/parallel.
Give the built-it-yourself nature of the MPCNC, no matter what choice you make here, you can easily redo it with just a couple of hours and some new MDF. In my case, I made a lot of mistakes early on and went through my first spoil board pretty quickly.
Edit, here is an image where the middle slides out. The lighter colored MDF section is significantly bigger than the working area. And, here is a build with the spoil board sits on top of a base board.
Thank you , in advance, for your patience.
My first hitch already.
I am assembling the legs and the directions call for M5X30 screws
None were included.
All my hardware from V1 is imperial.
What Imperial screws do I need?
I have 57 pcs. of 6-32X3/4 and nylon nuts.
This is the only thing that will fit in the holes
Or should I just run to the hardware store?
If it is asking for M5 screws that is the Primo instructions. You said you have the Burly hardware, are you trying to assemble the Primo or Burly printed parts?
Thanks for the prompt response, Ryan.
I am trying to assemble the Burly.
I got all the cut info for the Burly but am not seeing the info specific to the Burly build
It may be a miracle if I complete this and it works.
So far, I’ve broken a foot and a top collar piece.
Superglued them back together,
On the broken top collar piece, have to leave one screw out because a tiny piece got lost
I have measured diagonals at the feet and at the top of the corners.
They are different.
IIRC, they are within 1/8"
I cut my conduit with a grinding wheel on a miter saw and that wasn’t as accurate as I’d hoped.
If anyone can tell me if this build will fail from what I’ve posted, I’d appreciate it.
Go far far looser. The clamping force is not what does all the work.
The parts are open ended so accurate cuts are not required. It makes it easier with the feet/legs but shimming is super easy there.
If you are fine with your cuts being within 1/8" diagonally you will be fine. If you have dual end stops you can tune that out, or you can loosen up your feet and get it a bit closer. It all really comes down to what you want to use it for. You only time you would notice a really crooked build is making parts that fit together with tolerances less than your build is off (boxes with finger joints). You would never notice on something like a V carved sign.
If you take it easy on the fasteners you will be fine. Start loose and you can snug anything up later if it needs it.
Ryan, thanks for the info and reassurance.
I have had my 31 yo son help because my old eyes don’t see as well.
He doesn’t always believe in instructions.