Linear guides and slides

[danhofer@comcast.net]

Hello all,

I've debated making my own CNC machine verses buying one. Untimately, I think I'll buy a shopbot. My reasoning is simple: I want to be in the business of making architectural mill work not making machines.

I've looked at the shopbots as best I can online; however, the machine detail presented leaves a little to be desired. I can't determine the bearing used by Shopbot for linear movement. It almost looks as if roller bearings are mounted to a piece of angle stock and then riding on another piece of angle stock. Is this true? If not what sort of lineat bearings are used? This issue of linear movement is one of my last hurdles in my purchasing decision.

Additionally, I have to determine what software I'll be using. I'm inclined to use Autocad for design work due to it wide acceptance. I can get classes for it via continuing education at Purdue. Beyond Autocad I'm not sure what I'll need. I'm an information systems manager so I'm technically literate on the systems side. That being said, I also know theres a lot I don't know. Any input of types of software required to go from concept to cutting?

Any input would be apprecaited.

Best Regards,

Dan Hofer
danhofer@comcast.net
Fort Wayne, IN

[gerald_d]

Dan, the angle stock has been ground so that the V-rollers run smoothly/correctly on top of them. For architectural mill work, nothing more need be desired, especially at the price.

[larryl@mypicayune.com]

Dan, the bearings were patented by Bishop-Wisecarver Corp. (interesting name, huh?). I have several shop-made machines using them and they are excellent. They also have track which can be fastened however you like to whatever you like. Their product name is Dualvee. All of my info is pre-internet. I will email you with what I have .

[densull@core.com]

The Dualvee system is a good one. I use it on two different models of the large digitizers that I build.

There are different ways to apply the tracks, and we use two different techniques. On our new Model 702, we contain the tracks in the slot of an 80/20 extrusion by a proprietary design. Our first approach was to "sandwich clamp" a track between a 3/8" x 1" aluminum bar and a 1/4" x 1" bar and lock the assembly together at both ends with small screws. The track clamping is accomplished by 1/4" button head screws along the length of the assembly. We use this design on both models of our digitizers.

Richard Still also uses Dualvee on his big "FastTrack" digitizers. You can see his machine on our "other guys" page or on his Outline Technologies site.

I have seen CNC routers that use Dualvee, too. The early Digital Tool machines used a "sandwich" construction for guideways. Later models, like our DT903 used a German radiused roller system which is very similar to the Dualvee, but better adapted to running horizontally.

There are some assembly detail photos on our website:
http://skalarcnc.netfirms.com

[graphicmetals]

Dan,

We got our ShopBot in December of 2002. We are about 1 hour from you in Bryan, Ohio. I would be happy to discuss the tool with you, and/or give you a demo.

Regards,

Kevin Fitz-Gerald
Project Manager

Graphic Metals, Inc.
P.O. Box 31
Bryan, OH 43506
Voice 419-636-5757
Fax 419-636-6404

kfitzgerald@graphicmetalsinc.com