Hello all,
First of all i am new to the forum and hope i am putting this in the correct section. So im working on a control panel for a motorcycle lift table that utalizes a vfd to control a hydraulic pump motor for up direction and a 24vac solenoid that controls the valve for lowering the table. I have succesfully got all of that to work together and can make the table work but i want to put everything in a single box with up and down buttons and a panel/remote switch that way the table can be controlled from the main panel or a remote pendant. I will be using one three way switch to control panel or remote function, there will be 2 momentary switches mounted on the panel along with and estop, on the remote there will be momentary up and down buttons and an estop as well. i am also wanting to incorporate limit switches to protect the hydraulic cylinder from over extension and under extension. my questions are what would be the best way to incorporate an arduino mega into this project to do all the thinking and to take all the inputs and control relays to activate the functions. I have a little bit of understanding of how the arduino works but i am unsure of how to have the arduino monitor the limit switches and stop movment when it reaches the set level. and im also unsure of which pins i should use for all the inputs and outputs and also which pins for limits.
thanks in advance
so your trying to extend and retract a hydraulic cylinder with an arduino?
does your solenoid valve control both extension and retraction, and how many wires does it have coming out of it?
Interesting project. I think about safety. Lifting a 1000 lbs Harley You don't want it to come falling down.
Every safety conserned I/O must be designed in a way that neither a broken cable, shortened cable etc. produces an unwanted movement, thinking about both lifting and lowering. I was the chief designer for the same kind of logic in heavy fork lift trucks earlier in life.
MrEmeralds95:
so your trying to extend and retract a hydraulic cylinder with an arduino?does your solenoid valve control both extension and retraction, and how many wires does it have coming out of it?
Kind of in all reality I just need the arduino to signal relays when the buttons are pushed for up or down, be able to decide which buttons to use (panel or pendant control) by the position of the three way switch, and also monitor limit switches so it doesnt go to high or 2 low. Extension is controlled by the vfd all it needs is a signal to tell it when to start the motor and once that signal is lost the vfd will shut off the motor and stop the extension. Retraction is controlled on the pump via a pilot operated pump and once the solenoid is active it allows the pressure to escape from the cylinder.
Railroader:
Interesting project. I think about safety. Lifting a 1000 lbs Harley You don't want it to come falling down.
Every safety conserned I/O must be designed in a way that neither a broken cable, shortened cable etc. produces an unwanted movement, thinking about both lifting and lowering. I was the chief designer for the same kind of logic in heavy fork lift trucks earlier in life.
Safety was also a concern of mine but as far as the hydraulic system goes there are multiple safety's including a relief valve to not over pressure the cylinder if a fault were to happen and also not allow the table to be over loaded, there is also a restriction valve in the line that doesnt allow the table to extend or retract at fast speeds so if it does lose pressure or the down solenoid is activated accidentally the lift can only move gradually, there are also locks on the table that when its lowered it takes the pressure out of the system for a mechanical catch. Cables exit the table in metal conduit and are away and securely mounted from any moving parts. Also with incorporating the e stops it should stop signals. I have yet to figure out a good estop yet since there will actually be 120v mains 24vdc 24vac and 9 volts all in the same panel for the controls due to different voltage requirements of signals.
You have good safety built in in the hardware. Think in the same way about the controll system that no fault ever will make the logic act as if You pressed a button. You mentioned using a remote..... You on the floor, the bike up in the air....
Broken cables are the most common issues. Crossconnection the second. Make sure such failures in the Arduino project don't catch You like a rat in the trap.
Railroader:
You have good safety built in in the hardware. Think in the same way about the controll system that no fault ever will make the logic act as if You pressed a button. You mentioned using a remote..... You on the floor, the bike up in the air....
Broken cables are the most common issues. Crossconnection the second. Make sure such failures in the Arduino project don't catch You like a rat in the trap.
Thankyou and I'm on the floor and the table just lifts the bike to a workable height and the panel will be mounted on the wall roughly 20 feet away from lift and remote is there just so it can be operated while standing by the table
I would not use an Arduino for this. The project is very simple electrically so there's not much thinking to be done. The basic concept is: LIFT switch goes through normally closed top limit switch to pump contactor/VFD. When table reaches extent of travel the top limit switch cuts out the pushbutton signal and pump shuts off. This gives you a hardwired stop at the top of travel. Same for lower, LOWER switch goes through normally closed bottom switch to solenoid for hardwired cutout of the lower solenoid.
The 24vac will travel much better through the pendant cable than will a 5VDC logic signal.
YMMV
dougp:
I would not use an Arduino for this. The project is very simple electrically so there's not much thinking to be done. The basic concept is: LIFT switch goes through normally closed top limit switch to pump contactor/VFD. When table reaches extent of travel the top limit switch cuts out the pushbutton signal and pump shuts off. This gives you a hardwired stop at the top of travel. Same for lower, LOWER switch goes through normally closed bottom switch to solenoid for hardwired cutout of the lower solenoid.The 24vac will travel much better through the pendant cable than will a 5VDC logic signal.
YMMV
I do understand where you are coming from and that was how I had it originally for the most part. but I got into messing with the arduino platform and thought it would be a good opportunity to try to learn more about arduino itself and learn how to properly develop and create code (I dont learn well from books and just typing code from a book is not helping to explain it or helping me be able to learn the steps and thinking process to develop it) I also just thought it would be a neat project to incorporate it into and if it doesnt work as planned then I will redo the whole thing I already have all the components anyway.
