Seeking help building a machine

[43220]

I am here because I need to build my own cnc foam cutter on a modest budget (no $5000 or up machines). Requirements are about a 3 to 4 foot long hot wire with horizontal traverse of about 4 feet and vertical movement of about 0 to 4 inches.

I have been cutting with hot wire for years but doing so manually, so I have experience using the wire. I just know very little about motion control and software so need much help in those areas. Am an experienced cabinetmaker/builder with a shop.

What would be nice would be a source for complete plans, components, and support for a machine that I can put together. Looking for suggestions.

Thanks for your help.


P.S. What is meant by a 4 axis machine?

[43220]

I see many advertisements from many different suppliers on this site. Would be interested in any recommendations as to which are best to deal with which offer good products so I can build an easy to use (especially for a computer illiterate) machine, easy to maintain, and relatively trouble free.

[43220]

Still waiting...

I thought people here wanted to help those looking for it?





Financial remuneration is certainly offered!

[vulcom1]

The question I have is are you going to build it yourself and as a cabinet maker there should be no problems. Also you can either buy the electronics or roll your own. Hobbycnc is one source for a package. There is a lot of variables needed to know before you get a reply.
If you diy for the electronic's you can check the Yahoo forum under cncfoamcutters. There is a schematic(mm2001) for making your own board. I am also gathering up parts for making my own and a little searching will get lots of ideas that you can incorporate in your design.
I have not checked out where to purchase a setup as being a hobbiest with RC aircraft I like building my own. You need 4 axis and 2 motions are on each side. Requires 4 stepper motors and if you are cutting your own you know that a lot of wings the tip and root are different sizes. I believe the axis we use are x and z for cutting.
John

[43220]

Thanks for the response! Yes, I plan on building it myself, however, I know nothing about the electronics and programming so a package is probably in order.

I will be cutting into a slab of foam about 1-1/2" x 2' x 3' so it will weigh little - hoping I can use a simple sliding board (say 1/4" masonite*) for the foam. Since material is relatively thin, I will only need a few inches of vertical travel for the wire. Table will have to move/slide up to 3-4'.

Guess I need recommendation for construction details/tips and package components to suit these requirements. I do have experience with heat control and tensioning of wire.

Asked the guy at hobbycnc for some help, but he didn't seem anxious to provide much.

Maybe somebody here has some extra components suitable for my purposes they'd be willing to part with??

*Edit - actually since 1/4" masonite has considerable weight, perhaps a sliding table of a lighter material such as 1/4 to 3/4" foam core board would be better.

[onthemarc]

Hi
I'm not sure where your going with the 1/4 maisonette idea.
with a four axis foam cutter normally the foam stays still and the wire moves.
the four axis are called X.Y. and U.V . so you will need software that will generate four axis g-code. Each end of the wire moves in two independent axis.
This lets you cut foam with a different size or shape at each end of the wire.
What are you cutting the foam for? Hobbycnc has 4 axis kits if you want to solder one yourself or xylotex.com or stepper3.com has 4 axis controllers already made up .
I also am a cabinet maker. I have been researching and planing my foam cutter for a year now. my plan is a lot bigger. I want to cut and rout foam blocks 4'X4'X10'

if you want to talk
marcadvancedwood@msn.com

[43220]

I do not need the ends of the wire to move independently of each other - only in tandem and only a few inches in the vertical axis. Since my material is so lightweight, with a light weight carry board to move it with there would be no need to also move the ends of the wire in two directions (up/down & back/forth).

In other words, there is no need to add the weight of the mechanisms to move the wire ends to the carriage board for the foam.

Visualize a large table the machine is mounted on with the wire ends and mechanisms attached on either side of the table. Each end of the wire is driven in the vertical axis in tandem a few inches.* The lightweight board the lightweight foam sits on is beneath the wire and has dual motors to move it linearly beneath the wire in the second axis. This is all I need.

I hope this is clear.

* In theory, perhaps only one motor would be needed for each axis - one to move the board/foam and one to move the wire attached and tensioned on a rigid frame? But I have no problem if dual motors are needed for each (four in total).

As to suppliers, I'll be glad to buy from one that responds to my requests for help/advice(!). To quote Bill Paxton's character in Aliens, "So far, Zippo!"

[NinerSevenTango]

It sounds like all you need is a machine to slice the foam. In that case, all you need is two motors, and you don't need computer control at all. You could use a DC motor to jog your wire up or down to the height you want, and use another DC motor to drive your table. Everything could be driven off skinny timing belts. And the table part would be simpler if you used driven rollers to run your board through, that way you could avoid having to auto reverse it. Would something like that work for you?

[43220]

My thinking is: the less weight the motors have to move around, the better off you are (low torgue motors are less expensive?). Therefore, in my design, the motors would remain stationary in relation to the main table; only the foam would move in one axis and the wire in the other.

Also the less resistance the motors (lower torgue) encounter moving the wire is relevant also. Of course, with foam cutters, there inherently is little of this.

I believe I'm correct in this?

[NinerSevenTango]

I believe that is correct.

Could you just load the foam on one side of the wire and then drive it through and unload it from the other side? If so, you could just use driven rollers. No NC control necessary at all, if I read you correctly.

[43220]

Originally Posted by NinerSevenTango It sounds like all you need is a machine to slice the foam. In that case, all you need is two motors, and you don't need computer control at all. You could use a DC motor to jog your wire up or down to the height you want, and use another DC motor to drive your table. Everything could be driven off skinny timing belts. And the table part would be simpler if you used driven rollers to run your board through, that way you could avoid having to auto reverse it. Would something like that work for you?

No, I'm not just slicing the foam. The wire must move in the vertical axis while the foam moves linearly at the same time to cut programmable patterns in the foam.

[43220]

Here's simple sketch: