HP 200LX Palmtop Runs Computer-Controlled Workshop Router

Typically, the entry-level cost for a "Computer Numerically Controlled" router is over $20,000. But this palmtop user has developed an HP 200LX-controlled woodworking router that's available for much less.

By Ted Hall

I have been an HP 200LX nut for several years now - it's just the perfect little computer for me. Since I've had my palmtop doing just about everything in my life, it only seemed natural to want it to be able to run the inexpensive CNC router that our new company has developed. Our CNC router (CNC stands for Computer Numerically Controlled) is a computer-controlled woodworking tool. It is capable of moving a router (sort of a generic cutting and machining tool) in 3-Dimensions over a 4' by 8' by 6" work area with reasonable power, speed, and precision. It can thus cut, machine, or carve just about anything. You control/guide/direct/program the tool with a PC. We call the tool a 'ShopBot', short for workshop robot. (See the sidebar at the end of this article for pricing and contact information.)

I run ShopBots on all sorts of PCs, but my favorite is the palmtop. At the time we were creating the software for ShopBot our goal was to have it run on as low a level PC as possible. But I confess that in the back of my mind was always the idea of being able to run it with my palmtop. For this reason, the software that controls the tool and cuts 'Parts' files (files with cutting instructions for complex shapes or parts) is DOS software that uses text mode and CGA graphics only, and is efficient enough that it will move the tool at a good clip using an 8086 (XT) and up. It also requires only about 400K of memory to run. This all means that the software runs fine on the palmtop.

ShopBot is attached to computers through a serial port, so it hooks right up to the 200LX using the cable and adapter from the Connectivity Pack. I also have to confess - as you might have guessed from my palmtop enthusiasm - that my 200LX has the speed and memory upgrade (from Times2 Tech). The speed upgrade is useful for ShopBot because it allows it to run at near full speed. The memory is not needed - though I love it.

Those are the basics of running our tool with the palmtop. Now let me give you a feel for why I get such a kick out of this capability. I frequently demo the ShopBot that is in my workshop to potential customers. As we walk out to my shop, the question frequently comes up regarding how big a computer is required to run ShopBot. I say "not very" with a twinkle in my eye. When we get into the shop and start having a look at the tool, rather than hooking the ShopBot into a desktop computer or the Pentium notebook that I usually have around, I pull my palmtop out of my pocket and plug ShopBot's cable into it and start running the thing around. This invariably captures attention. I usually start off moving the tool through a couple of ellipses and 'jogging' (fast move mode) it around, then we turn the router on and actually do some cutting - with all the action being controlled by punching commands into the palmtop.

I like the impact of demonstrating our tool with the palmtop. But there are a number of reasons that make the palmtop an excellent choice as a workshop computer for an application such as this. First, it's small and convenient in the shop, and you can move it around with you as you work on the project. Some of the high-end CNC tools actually offer the option of a 'training pendant,' which is a small keyboard you can take over to the tool on a cable to allow you to control the tool from up close. This is a capability that is automatic and natural with the palmtop.

Second, because the palmtop does not have a vulnerable disk drive and is pretty well sealed, it is a lot less susceptible to problems from sawdust and other debris in the shop - not to mention that you can just close it up and put it away if things get really messy.

Finally, the way many of our users work, they create a drawing of a part or project using a CAD system on their office or home computer and then transfer this drawing to a 'Parts' file that they bring out to the shop on a disk. With the palmtop, I just download the 'Parts' file into the palmtop and I'm ready to go (and in this regard, I do appreciate The HP Palmtop Paper's information on how to get CPACK working in Win95). [Editor's note: see "Using the HP Connectivity Pack with a desktop PC running Windows 95" in the November/December 1995 issue of The HP Palmtop Paper.]

That's my story of our application for palmtops (though I might also mention that we use palmtops for our customer support database and service management at ShopBot as well). We're looking forward to setting more and more woodworkers up with ShopBots that are controlled by palmtops as a way to bring the creative possibilities of computer-controlled tools to small shops and home workshops.

Commercial products mentioned in this article