I'm building a diy press brake for bending sheet metal. Key of getting this to work is having a reliable way of measuring the bend angle.
My question is whether Arduino in the opinion of the forum is a good platform for designing a control unit for the brake press?
The physical design of the press is quite straight forward. Think an oversized shop press powered by three 20 ton pneumatic to hydraulic bottle jacks. The bottle jacks presses the top die onto the sheet metal plate, which in turn is pushed down into the bottom die forming an angle. Please see attached illustration for the basic principle.
The idea for the controls would be to position one accelerometer on each side of the dies on the sheet metal. The actual bend angle is the combination of the two read outs which should be presented on a LCD. Preferably the accelerometers should be wireless.
Since I'm new to Arduino and don't want to be overwhelmed The plan is to split the project into two phases.
This would basically be a protractor function. Have the Arduino calculate the total bend angle based on the two accelerometers and present this on the LCD. While basic this functionality would get me up and running.
This phase would introduce a level of automation. Instead of operating the brake press manually like in phase 1, the Arduino would operate the pneumatic bottle jacks. This would entail having the user entering a desired angle and starting the program. Arduino would then open up a pneumatic valve and close it when the target angle is achieved.
Yes you could use accelerometers if the press speed is very slow. Otherwise they will feel the acceleration of being dragged around in a circle.
I would use 6-DOF sensors which include gyros as well as accelerometers. Something like the LSM9DS1. Two of them can be given two I2C addresses. Start with wired sensors, wireless will come much later.
Wouldn't it be easier to measure the extension of the hydraulic press, and calculate an angle from there? For a particular die and thickness of sheet metal, a given ram extension will always be the same resultant bend.
You might find that dual accelerometers will be too complicated, not only for the coding, but also for attaching them to the sheetmetal for each piece (how will this be automated?).
Interesting point John. What kind of setup would you recommend as far as sensors and so on go. The complicating matter here would be to calibrate everything for each top and lower die.
As far as attaching goes I was thinking clamps. Pity magnets will wreak havoc with the sensors Anyway, this aspect doesn't need to be automated.
Found THIS on youtube depicting something similar as to what I want to do. Pity he hasn't shared the code
Need to get myself a starter kit and commence experimenting!
DannyD666:
Interesting point John. What kind of setup would you recommend as far as sensors and so on go. The complicating matter here would be to calibrate everything for each top and lower die.
As far as attaching goes I was thinking clamps. Pity magnets will wreak havoc with the sensors Anyway, this aspect doesn't need to be automated.
Found THIS on youtube depicting something similar as to what I want to do. Pity he hasn't shared the code
The video you posted would be a very simple code, and his brake is different than what you want to do. He just has the accelerometer attached to the machine, and as he bends the metal he has a direct readout of the angle of the machine. Your project would be somewhat different - attaching the accelerometers to the piece you want bent, and the code would have to calculate both angles. Implementing your ideas are not difficult, but different and more chances for error, eg in the attaching of the accelerometers (what if one falls off?), or if the code does not take into account the orientation of the accelerometer.
DannyD666:
Need to get myself a starter kit and commence experimenting!
That's a good start. Get a starter kit and a couple accerometers. That's the only way to see if your idea will work! Something like this would be a good start for experimenting. Get a couple magnets and glue them onto the accelerometer and see if it works as you want it to.
One of my projects I tried using an accelerometer and magnetometer to determine the camera angle on a motorized pan/tilt head. It failed, because the camera interfered with the magnetometer and I could not get stable readings, but it was a learning experience.
35 or so years ago our bend guys tested the plunge with scrap pieces. Our press used stops, ran on 150psi air and delivered 15 tons. If we wanted more we had a 100 ton Cincinnati press capable of running progressive dies.
35 or so years ago our bend guys tested the plunge with scrap pieces. Our press used stops, ran on 150psi air and delivered 15 tons. If we wanted more we had a 100 ton Cincinnati press capable of running progressive dies.
Yup, only way to deal with it is to test each gauge and die combination as far as I know.
Anyway, this aspect doesn't need to be automated.