Portable MPCNC

Had anyone built a mpcnc that can be brought to the work kind of like an origin shaper?

I was thinking about doing some v carves in existing furniture think epoxy inlaid desktops and tables. All small stuff 6-12"

I have my burly not doing anything at the moment. My thought is to trim the legs way down, cut a hole in the spoil board as large as my cutting area and adjust the z bracket to give me as much negative z as I can. Basically top of z would be where the spoil board is now and I’d sit the machine on the workpiece.

Anyway probably one of those projects that won’t happen but just thinking out loud.

People have built portable mpcncs not sure about the negative z space. But here is one portable build from my recent memory:

Portable Primo Build

Mr Potter’s portable MPCNC has a lot of great concepts for portability, so for a smaller build, it shouldn’t be a complicated issue.
I’ve also seen a couple builds that use a negative milling space below their spoil board level, so it’s 100% possible. You just need to get the numbers correct when setting up for a run.
Just keep in mind that the longer the Z axis is, the more prone you will be to core instability. However if you are only milling into furniture, I don’t foresee you needing to go very deep.

It sounds like a great concept that you need to get started on :sunglasses:

I was thinking about the same idea this evening. I was reading about how Full Spectrum Muse lasers all had the ability to drop the bottom out of the machine to laser on the surface the machine was resting on, and it occurred to me that something similar could be done with the the MPCNC…but then I had second thoughts.

I envision that engraving would be one of the main tasks for this portable MPCNC. In my experience, engraving is very sensitive to both the squareness of the machine with respect to the cutting surface, and the flatness of the stock. By cutting out the bottom and using the results on arbitrary surfaces you will reduce the rigidity of the setup, you won’t have a “spoilboard” to surface to compensate for “manufacturing defects,” and you likely will not be dressing the “stock” to assure its flatness. I’d hate to see an engraving failure on an expensive desk or table.

On the other hand, if you were using it to pocket out designs that then were filled with epoxy, the setup you describe would likely work well. The only catch I see is the need to somehow hold the machine down to the stock so that the machine won’t walk around.

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@robertbu a lot of good points… I was thinking about going down the bed mapping rabbit hole but you are on target about the cost of oopsies which are still frequent with everything I touch.

As for hold down I was just envisioning router pads and me holding the machine down to the piece.

Anyway this is just me thinking out loud. I sit on the front porch at the end of the day when it finally gets quiet and think up creations like this… I blame the whiskey.

In the morning when I’m on the 23rd daddy could? Daddy would? Dad? … Daaaaad! Before the first cup of coffee… the inspiration fades a bit.

In addition to my portable MPCNC, I have a lot of experience doing CNC with the Handibot, which can be sat on or screwed down onto any surface (even walls!) to carve them. I used that with tiling in VcarvePro to make some big signs, but as Robert says, any engraving or Vcarving is quite sensitive to variations in height or non-levelness. The Handibot has very good rigidity by using an
aluminum plate in its base, and having a box construction. I added some adjustable feet to my Handibot to help with the leveling.