I'm another rookie seeking for answers

[watergeorg]

To begin with, I want to mention that I have enough mechanical skills, but I lack deeper skills in electronics and programming.

I have some specific questions about using a A3-plotter as a CNC, with a Drammel instead of pen. One of the problems is that a plotter moves much faster then the Drammel is able to cut. So:

1- I cannot understand why most people on the web, when building a CNC, they start from scratch, recommending step motors, building beds with more or less complicated solutions, and so on. Then they need interfaces and drivers. As far as I understand, all those items exist already when I connect the plotter to a pc. Or am I wrong?

2- Is there any possibility of changing/programming a new driver that slows down the XY-speed of the pen?

3- Or is there any software that does this?

4- Am I wrong in my assumption that the easiest way to start with CNC is to rebuild a plotter?

Finally: At this stage I am not very much interested in extreme precision, I just want to build my first working CNC. From earlier experiences in other fields, I know that the first one is only a prototype that has to be re-evaluated before one can build a machine that one can live with.

Much obliged for all inputs,
Georg Ulvehøj
Norway

[markdem]

Hi watergeorg. That is a good idea, but I dont think it will work. The problem is that a plotter only has to carry a pen, and there is not much stopping the pen from moving. You will also notice that the frame on a plotter is quite small, as the pen is not very heavy. If you put even a small dremil on it, it will bow and start to move. Also, i dont think the motors will have the power to move the waight of the dremil.

in answer to slowing doen the rate of movment of the pen, you can do it with software, the rates are programmed intot he conntrol hardware of the plotter. The computer only tells the plotter where to go, not how fast to get there.

Mark

[apache405]

If you have a flex-shaft thing for your dremel, you could try using that in place of the pen. That solves some of the weight problem. You may be able to slow your plotter's feed rate down by using something like a "fine" quality setting. If you are cutting something like balsa wood or similarly soft material, you could put a hobby/utility knife in place of the pen. It would be interesting to see if any those ideas work.