Prop making with CNC

[Rebelscum]

The usable space of my table (2x4') is actually 1152 square inches... so you're looking at 1/36th the size of my actual workspace... reducing the size of the machine to 1/36th won't be possible - the motors, rails, etc used for movement still require physical space. That said, if you're looking to reduce the size of the machine, it can be done - Patrick (my co-author) has a tabletop version in beta that has what looks to be about a 12"x12" workspace... maybe a little bigger.

If you don't care about the size of the machine, you can limit this machine to a 4"x8" work area by simply defining that as the workspace in your CAD software. Software such as VCarve will let you define the length/width of your workspace and the CNC machine won't drift out of that area.

Jim

Sorry Jim, I didn't mean to imply "32 square inches", I meant 32" x 32" (32" square, ie, 32" on all 4 sides).

 

[jktechwriter]

Sorry Jim, I didn't mean to imply "32 square inches", I meant 32" x 32" (32" square, ie, 32" on all 4 sides).

I was trying to figure out how small you wanted!!! A 4"x8" CNC machine would be nice but extremely limited

Altering this to a 32" square work surface? Okay, that's roughly 3' x 3' versus 2' x 4' - here's what I see:

1. You're shortening the length of the table - that's not a big deal - you just cut the lead screw for the x-axis shorter...

2. Widening the Y-axis from 2' to 3' wil require some work - here's why: The y-axis support that runs from one side to the other is 2' in my machine - there's a matching 2' wide piece that moves under the tabletop and makes the y-axis parts form a rectangle for stability. Lengthening the y-axis an extra foot is totally possible but I'd be a little concerned about the stability of the support piece on top - this is the piece that the z-axis frame rolls on (left to right) - sagging probably wouldn't be a problem since the MDF piece is turned on its side (versus the surface of the MDF being parallel to the floor). Where I think the problem would occur is in the weight - the support piece is actually two pieces of MDF bolted together for a more rigid piece and to ensure that the z-axis frame moves in a straight line left to right and there's no warp in the support. Lengthening it would require more hardware for bolting it together (more weight) as well as possibly putting more tension on the motor for the y-axis as when the y-axis moves front-to-back along the table top, the enitre y-axis frame might have a tendency to twist a bit... the longer it is, the more likely the twist.

This is just me brainstorming... none of these issues may truly exist if you go 3'x3' but I can't speak from experience since we've never done these dimensions before.

Jim

 

[Rebelscum]

Thanks Jim...

In the build your own cnc world, any reason people don't use MDO plywood, other than maybe it's not something you can get at a home center? This is what I use to build with if strength is very important and you could do it with MDF. It's lighter and stronger and has the same nice surface to work with.

 

[jktechwriter]

Thanks Jim...

In the build your own cnc world, any reason people don't use MDO plywood, other than maybe it's not something you can get at a home center? This is what I use to build with if strength is very important and you could do it with MDF. It's lighter and stronger and has the same nice surface to work with.

MDO plywood would work, but I think it's a bit more expensive, isn't it? Ignoring the risks of water on MDF, I like it for its strength and flatness... MDO plywood is flat and strong, but it still has a fiber surface like MDF... the dust is probably less risky to your lungs than MDF, but if you can find it (it wasn't available at my HD even if I wanted it) I don't see why it couldn't be substituted.

Jim

 

[Rebelscum]

Yeah, I love MDF. My friends wonder why I don't ever make things from my hardwood collection instead of painting MDF all the time. They just don't understand how nice it is to work with.

 

[jktechwriter]

Yeah, I love MDF. My friends wonder why I don't ever make things from my hardwood collection instead of painting MDF all the time. They just don't understand how nice it is to work with.

I'm a big fan of Sandiply from Home Depot - plywood that's been sanded down very well for a very smooth surface. I used it for my arcade cabinet that I'm building (over at the byoac.com forums) and it made all the difference when it came to painting.

Jim

 

[Node Nine]

Well as long as we are discussing alternate materials :lol

This stuff is awesome

 

[Rebelscum]

Well as long as we are discussing alternate materials :lol

This stuff is awesome

Nice, I use baltic birch plywood pretty frequently as well. Nice with all the plys and no voids, but it will warp pretty easy, even if just leaning against a wall unfortunately.

 

[WhiteCommando]

I am going to try doing an output of this file on a Dimension 1200.

http://www.salegraphics.com/KelvinTextured/

Thoughts?

 

[jktechwriter]

I am going to try doing an output of this file on a Dimension 1200.

http://www.salegraphics.com/KelvinTextured/

Thoughts?

Very cool - you own one or just have access to one? I'm seriously considering purchasing a makerbot, but it could be a bit before I get the funds budgeted by the wife sub-committee.

My CNC machine can easily do this in relief if given the right file...

 

[Rebelscum]

Well, after ordering the book and reading it, I have started a build of this CNC. I have found the book to be very helpful, in fact the very thing that makes it possible to own a CNC of reasonable dimension without spending a fortune. I wouldn't say you could do this without some woodworking experience, but you don't need a complete shop and years of building to make it either.

I have just finished the fundamental build of all the components and next up is a table for it to sit on and wiring up of the electronics.

I have been very impressed by how well the mechanics of it work. I would never have believed you could buy aluminum angle from Home Depot and use skate wheel bearings to make something like this work.

 

[noble]

Nice looking build!

I have some garage space now.....

 

[fuelish]

The latest MAKE magazine, #21, has an article on jktechwriters cnc table as well as some other 3-D tools including a printer and scanner.

If I had the space I would have to build one.

 

[Darth Gius]

A friend of my dad's was able to build his own CNC and I've talked with my dad about doing this very thing (he's the machinist and I'm the IT guy). I'll have to look into your book and see how to pull this off.

 

[Fetts.Sobriquet]

I took the plunge and bought the book today. I'll start on this next week. This project seems monumental; I'm a little intimidated by it.

 

[Rebelscum]

I took the plunge and bought the book today. I'll start on this next week. This project seems monumental; I'm a little intimidated by it.

I have built the cnc from the book and will say you can't be using tools for the first time and do it well, but if you have any experience at measuring, marking, drilling and cutting, you will find it easier than it looks now.

Complexity comes when you get ready to mix up the electronics and software and actually do some cutting. Though the book does a great job of getting you through hooking it up and making it move.

 

[Fetts.Sobriquet]

I have built the cnc from the book and will say you can't be using tools for the first time and do it well, but if you have any experience at measuring, marking, drilling and cutting, you will find it easier than it looks now.

Complexity comes when you get ready to mix up the electronics and software and actually do some cutting. Though the book does a great job of getting you through hooking it up and making it move.

I'm pretty handy around the woodworking shop, the electronics/software are what I'm mostly concerned with. I'm relieved to hear the book does a good job in that area.

What were your costs? Close to $800? If you don't mind me asking.

 

[Rebelscum]

I'm pretty handy around the woodworking shop, the electronics/software are what I'm mostly concerned with. I'm relieved to hear the book does a good job in that area.

What were your costs? Close to $800? If you don't mind me asking.

I'd say real close. I made changes that drove up the cost, but by and large, that's a good number. It doesn't include the necessary computer or any software, so that's something to keep in mind.

 

[proptronix]

Just got my book, and can't wait to get to building. One question though: Would it be possible to modify this design to use different cutting tools such as a plasma torch or CO2 laser? I realize the x axis screw would have to be relocated to avoid being cut in half, but are there any other adjustments that would need to be made?

 

[Rebelscum]

Just got my book, and can't wait to get to building. One question though: Would it be possible to modify this design to use different cutting tools such as a plasma torch or CO2 laser? I realize the x axis screw would have to be relocated to avoid being cut in half, but are there any other adjustments that would need to be made?

Other than just making sure you don't catch it on fire, I'd think not. You would have to contain the laser from its tube to the final lens, and sort out how to keep that focused, which would be the most difficult challenge I'd think.