It is hard to believe that it was almost ten years ago I witnessed a CNC router in action for the very first time. I was fascinated and simply had to have one! Although I had been in the creative end of the three dimensional sign business for most of my life I didn't really know what I would do with one of these machines - but I just knew it could do fantastic stuff.

Along with the CNC router I discovered the wonderful material called Precision Board and the glues, primers and other companion products they offer. Since then we have gone through many tons of the material using it in most signs and projects we tackle. This journal will chronicle our many adventures both past, present and future. I'll talk from the perspective of someone who pushes these products to the creative limit on a daily basis. I'll be adding to the stories two or three times each week. -dan

Tuesday, June 28, 2011

Coming up for air

Six years ago when I was first looking at CNC routers and considering just what to purchase I quickly found the choices overwhelming and confusing to say the least. It quickly became apparent that a MultiCam was at the top of the pile in terms of quality. As I talked to many people I learned what all the terms meant...  gantry, linear rails, planetary gears, spindle, servo, stepper and a hundred other terms, - all confusing at first... but now at last familiar. My local dealer helped me through the process, as eager as me to select the right machine for my needs and budget. Looking back, we made the right choices.

Now as we look forward to a new four axis machine it is equipped very much the same way as the old one. But there is one thing we chose to do differently, primarily because of the type of routing we do in our shop. While most routers are used as very fancy jigsaws, in our shop we use ours primarily for creating textures. This means the router runs continuously for long periods of time and not for short spurts as most machines would be used. 

We found that while adequate for most applications our compressor was woefully inadequate for our way of doing things. My big five horsepower upright compressor burned out in a hurry. It was time for something more powerful. Further complicating things was a single phase power source - no options there. This meant we were limited to about seven and a half horsepower. A screw compressor with a built in air dryer was the perfect solution. And it worked well. But after two years things began to go awry. Then it quit altogether. I called in the experts. As it was explained to me the compressor quickly gets up to maximum pressure and keeps up to the copious air supply needed to both cool the spindle and provide high air pressure needed for tool changes. Then it shuts down, waiting for the air to draw down. On demand it fires up again and so it cycles.

But the way this particular compressor works the high pressure air bleeds off slowly in the compression chamber, so the motor can start up without load. The trouble is the cycle completes before the air is totally bled off meaning the compressor starts under load. After countless cycles it burned our the brushes and windings. Thankfully the compressor company covered the damage under warrantee. Lucky me. But a permanent solution was needed.

The solution was an easy one, recommended by my dealer. The spindle on the new machine would be water cooled. This meant far less demand on our air supply. Research showed we could retrofit a water cooler on our old machine, not necessary for the short time we will continue to own the old router.

Even after almost six years of owning a CNC router I continue to learn lots of new things every day, both in the files I create and in the operation of the machine. It is exciting and challenging to say the least. I have no doubt this will continue for as long as I live.