Amateur CNC?

Everything that I study on my own, I try not only to implement it, but also to make it work longer than one day, to bring long-term benefits.

Once we needed to organize management for a homemade punching line. The line is self-made, and therefore the control, we will make an improvised one. We did not use industry standards for data transmission. It was decided to make everything from scrap materials and unnecessary old computer. The main conditions: simple, cheap, fast. Reliability - as it will. I'll tell you how we did it.

Punching line
')
The punching line consists of four blocks with hydraulic cylinders (main movement) and two blocks with pneumatic cylinders (blank feed). I will not describe the constructive. I note only that the cylinders are controlled using 24 volt distributors.


Control

The task is to make the cylinders work according to a given algorithm. Working stroke, pause, and so on. We need to get five control signals (4 hydro and 1 pneumatic). We decided to use the Atmega8 microcontroller as a connecting element between the computer and all the hardware.

The scheme turned out this:


All cylinders are labeled from A to E. Therefore, it was decided, without further ado, to send letters to the controller. He listens to the software, and if the letter A arrives, he gives a signal to cylinder A and so on for all cylinders. Also added the ability to control the temperature of the oil in the tank hydrostation. In the summer in the shop is hot, the oil sometimes overheats, so we decided to add such functionality. They took the usual DS1820 and thermopaste attached to a metal tank. The difference between the temperature of the oil and the tank was at the program level. The measurement error is about 2 C. For us - the most it.

Snapped up a simple software. The most difficult thing about it is data transfer through the com port. The control program, if you can call it that, is stored in the usual txt.
This is what the software interface looks like.



The process of drawing up a program to disgrace is simple. The operator directly in the program presses the buttons attached to specific cylinders. Between moves, pauses in ms. Pauses are necessary so that the cylinder has time to return to its original state after the working stroke. Yes, there is no feedback. Need not.

The control program itself looks like this:
A 1000 E 1250 E 1250 ...
Cylinder stroke A | 1000 ms pause | Cylinder stroke E | ...

After the operator has pressed the start, the cycle starts. The cycle is infinite, or tied to any counter cylinder moves, or simply set the time after which it should complete. The program parses the text file and sends the letters to the microcontroller.

I am sure that most readers can / imagine how to pull the mega and the like with their feet. I will not describe the controller firmware.


Conclusion

Homemade works 2 years. There are no failures. One time, the board with a microcontroller from the USB-Com adapter fell off the vibration. Eliminated according to the old Russian tradition - with scotch tape and tape.

Working for more than 10 years in private (small) production, as well as watching similar neighboring organizations, I come to the conclusion that we have a very poor connection with homemade products, for example, which are very numerous on Habré, with actual production. We are terribly lacking automation and innovation in small enterprises. Everyone is addicted to silicone startups, trying to make complex robots and train machines to think. It seems to me that you will bring much more value to your own shops and factories that are waiting for you and your inventions, and for which it is harder and harder to compete with fraternal China.