[yellow73bb]

I'm not a mechanical engineer, just a dumb electrical one. I want to build a simple CNC machine (for plasma) that can easily be stored, so I came up with this design. It is designed to be mounted to a solid wall with the gantry sticking out from the wall, but the gantry can fold away so that it only takes up a few inches when folded. That means my Z movement is moving lots of mass, and my Y movement isn't. See attached drawing. The drawing is not complete, does not show motors, chains, belts, counter weights or springs for Z, etc. but does show the general design. Note, the lower left drawing doesn't show all of the Y components, it started getting too complex.

Does this design look like it could work? One advantage is that I can put things at different height under it. So, I can use a table if I want, or I can run the hood of my car under it if I want to.

I'm building this in Shanghai China, so aluminum is a lot cheaper, as are Thompson type linear bearings, so I'm using both. I'm using steel for the stationary part for strength.

Any comments GREATLY appreciated as I don't want to start shelling out money for aluminum if it ain't going to work well.

[Torchhead]

If this is going to be used in a small shop/garage shared with other tools, vehicles and humans you need to understand how incredibaly nasty and dirty plasma cutting is. You are vaporizing steel and other metal and it turns into smoke and a fine abrasive (and conductive) dust that gets EVERYWHERE!

Better consider aggressive dust extraction on any design. About the only thing that is fool proof is having the table in it's own sealed room!

I didn't look at the design but you might want to consider an "A" frame approach (somewhat like a panel saw) where the material is put on the table at about 15 to 30 deg from vertical. There are a lot of forces involved in slinging the head around and you can get some interesting vibrations and flexing in framework.

[yellow73bb]

I don't do all that much cutting. Building this is mostly a hobby right now. Once I get it built, I may decide to use it more, and once I get into a home with a shop I will have the option of building a room for it.

I considered placing the item to be cut at a vertical or near vertical orientation ("A" fram), but I decided it would be too restrictive. With the design shown, I can do that if I choose, but can still run it in a traditional XYZ format too.

If this is going to be used in a small shop/garage shared with other tools, vehicles and humans you need to understand how incredibaly nasty and dirty plasma cutting is. You are vaporizing steel and other metal and it turns into smoke and a fine abrasive (and conductive) dust that gets EVERYWHERE!

Better consider aggressive dust extraction on any design. About the only thing that is fool proof is having the table in it's own sealed room!

I didn't look at the design but you might want to consider an "A" frame approach (somewhat like a panel saw) where the material is put on the table at about 15 to 30 deg from vertical. There are a lot of forces involved in slinging the head around and you can get some interesting vibrations and flexing in framework.