Passap Electra 4600 rebuilt
In the video on Youtube you can see the knitting machine and the motor Electra 4600 in action. More detailed information will follow over the next few weeks.
What is new?
The electronics of the Passap Electra 4600 motor have been replaced by a frequency converter, an interface and a controller. More project details will follow over the next few weeks. The latest version of the software will be published on Github. I hope this information will help you to realize your own project.
Electra 4600 connected to the frequency converter
I actually wanted to integrate the Electra 4600 engine in my project. Unfortunately the Electra 4600 engine had malfunctions. The control circuit board was damaged. We couldn't find out if more was broken. For example, the linear voltage regulator (REG 1) got very hot.
Since the board is very expensive, My husband came up with the idea to control the motor via a frequency converter. As tests showed the motor works wonderfully with the frequency converter.
Now the motor is connected to a frequency converter. A newly built controller drives the frequency converter via an interface. The controller essentially consists of an Arduino Uno, LEDs and switches. The controller is connected to the interface via an RJ45. The RJ 11 sockets for the yarn break detection and autocolor (detects if more than one eyelet is up) are on the interface and produce an emergency stop if an error occurs.
The reset button is on the controller. The new controller will be monted on the original location (the upper part of the box is not yet printed). I can regulate the speed manually using the potentiometer and automatically via the Raspberry Pi software. In this way it is possible to keep the speed constant when changing colors, regardless of how slow or fast the motor otherwise runs.
I have uploaded the "Service Instruction for motor drives of electra 4" and the scheme of the interface.
The Software is uploaded on Github, click link below:
In summer 2017, I also rebuilt my knitting machine. This worked well except for a few minor things.
I also wanted to replace the console. However, Hackerspace Bamberg's solution
does not work for me. It is unstable. I am a knitter. Therefore, the machine
must always work perfectly.
I chose a slightly different way. The knitting machine has been running error-free so far. In the VIDEO you see the knitting machine in action.
In my opinion there are several ways to control the knitting machine. I would like to point out only three central points, which should be considered regardless of the chosen path.
A first important point
The lock has two light sensors with a distance of 14 mm. The light sensors are moved over the guide rail, which has 2 mm wide holes at a distance of 3 mm. The 5mm correspond to a needle. When the lock is moved over the needle bed, the two light sensors produce a distinctive pattern due to the distances between the light sensors and the spacing of the holes on the guide rail. The position and direction of the lock can be determined by this pattern. Depending on the pattern, the electromagnets are switched on or off. As a result, the magnetic field of the metal plate next to the electromagnets is reversed. Depending on the polarity, the pushers are positioned. The position of the pushers determines which needles are selected and which are not.
Unlike Hackerspace Bamberg, I programmed two interrupt routines for each lock. Why? Depending on the speed, there are more or less false selections if only one interrupt routine has been programmed. In order to work stably, two interrupt routines are required for each lock (one routine per sensor). I...Read more »