# Conduit Length Questions

So, I’m building a CNC dedicated to just milling and need it to be able to mill aluminum. Preferably up to 1" thick aluminum. I’m sorry in advance if I’m just being an idiot, but the calculator doesn’t make much sense to me as far as the conduit lengths are concerned. So, the default in the imperial version is 12x12x4. Does that mean I have a 12x12 working area with a 4 inch movable z height? I bought the bundle so I know I have the 300mm leadscrew and 13ft of belt. My true question is this, with the bundled materials can I follow the default 12x12x4 in the calculator and get what I want as far as having the materials and being able to mill aluminum? As far as the calculator is concerned for the belt it says 28 would be needed but 48 divided by 4 is 12. Sorry again if I’m just being an idiot, but I would really appreciate it if someone could just spell it out like cut these specific lengths and put it together. Thanks in advance.

When the calculator asks size and you put in 12x12x4 it means the final project will be able to cut 12x12x4. The actual machine size will be larger. If you’re planning on cutting aluminum up to an inch thick, I’d build it for 2 inches of Z. That gives you plenty of clearance and lots of rigidity. (Though IIRC the smallest height, with feet touching the corner pieces, ends up being slightly larger than 2".)

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Milling 1" thick aluminum is going to be pretty advanced. Pretty sure you will need to do a flip to make it all thew way through as most bit are 3/4" Max.

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So, for the calculator I should put in 12x12x2 and follow the lengths written there? Also, for the z rods I should drill the holes according to the spec sheet found in conduits, rails, etc. What hole size should those be 5 or 8mm? Also, should they be all the way through? Finally, with the dimensions I put into the calculator I will have enough materials as far as belts go? Thanks again in advance.

I built my mpcnc with short legs. Zero legs showing just corner pieces against the feet (leg conduit length < 2.25"). At my cutting plane I have a full 1 5/8" clearance under the tip of the bit (dewalt, 1/8" carving bit).

It doesn’t matter, that is why it is specified like that 5-8mm. Anywhere between and including 5 and 8mm.