eaglewood
Supporting Member
Hello people,
I've got what seems to me to be a pretty straightforward automation project I'd like to run past you, since it's my first motion control project.
It’s been my experience that there are very often surprises even in relatively simple projects such as this one. Sometimes those surprises can bite. I prefer to not get bit.
That said, here goes.
Automation of a Coating Process
Existing manual state of process:
Several chemical bath containers are aligned in a row on the ground floor. An operator picks up a basket of work pieces, lowers the basket into the first container, lets the pieces bathe. After a specified time, the operator lifts the basket and moves it to the next container. After this same basic operation happens several times with various durations of bathing, the coating process is complete.
This is a low-volume operation. Quality is more important than throughput speed. In fact, speed is not an issue at all. It could take all day to complete the coating process and the owner would be pleased. I say this because when I heard of the project, I immediately started thinking of various ways to maximize throughput. Not necessary. Not now, probably not ever. What matters is quality.
My plan is to have a monorail running above the bathing stations. An electric hoist with motorized trolly will replace the operator (who will be reassigned, not fired). The hoist will pick up a basket place it in the first bath, wait, raise the basket, move to the next station, bathe the work pieces, etc.
The work pieces, which are fragile, cannot be jarred. All stops, starts, lifting, and lowering must be executed smoothly. Also, the baskets must not swing and hit the sides of the containers, passersby noggins.
I’ve completed process control projects before---heaters, pumps, valves, etc.--- but I’ve never dealt with motion control. This seems like a very feasible starter project.
I am about ready to order a gantry crane with electric hoist and motorized trolley. It will come with a pendant for control, but I don’t want to use it. It seems feasible to me to chop off the pendant and run the wires to a control panel. I will program the motion of the hoist and trolley using mostly a PLC, but I figure I also should use a VFD to attain the required smooth operation.
Here are what seem to me the needed components other than the monorail crane, trolley, and hoist:
-Limit switches mounted somewhere on the I-beam to let the PLC know when the trolley has arrived at the drop target
-VFD to control motor speeds
-PLC, relays, push buttons, and other basic components I’ve worked with plenty
My tendency is to just get rolling on this. But I wanted to run it past any of you who may give a pointer or two.
Anyway, please let me know if you see anything that stands out as a possible issue. I’m working alone, and as I said, this will be my first motion control project.
Thanks in advance.
I've got what seems to me to be a pretty straightforward automation project I'd like to run past you, since it's my first motion control project.
It’s been my experience that there are very often surprises even in relatively simple projects such as this one. Sometimes those surprises can bite. I prefer to not get bit.
That said, here goes.
Automation of a Coating Process
Existing manual state of process:
Several chemical bath containers are aligned in a row on the ground floor. An operator picks up a basket of work pieces, lowers the basket into the first container, lets the pieces bathe. After a specified time, the operator lifts the basket and moves it to the next container. After this same basic operation happens several times with various durations of bathing, the coating process is complete.
This is a low-volume operation. Quality is more important than throughput speed. In fact, speed is not an issue at all. It could take all day to complete the coating process and the owner would be pleased. I say this because when I heard of the project, I immediately started thinking of various ways to maximize throughput. Not necessary. Not now, probably not ever. What matters is quality.
My plan is to have a monorail running above the bathing stations. An electric hoist with motorized trolly will replace the operator (who will be reassigned, not fired). The hoist will pick up a basket place it in the first bath, wait, raise the basket, move to the next station, bathe the work pieces, etc.
The work pieces, which are fragile, cannot be jarred. All stops, starts, lifting, and lowering must be executed smoothly. Also, the baskets must not swing and hit the sides of the containers, passersby noggins.
I’ve completed process control projects before---heaters, pumps, valves, etc.--- but I’ve never dealt with motion control. This seems like a very feasible starter project.
I am about ready to order a gantry crane with electric hoist and motorized trolley. It will come with a pendant for control, but I don’t want to use it. It seems feasible to me to chop off the pendant and run the wires to a control panel. I will program the motion of the hoist and trolley using mostly a PLC, but I figure I also should use a VFD to attain the required smooth operation.
Here are what seem to me the needed components other than the monorail crane, trolley, and hoist:
-Limit switches mounted somewhere on the I-beam to let the PLC know when the trolley has arrived at the drop target
-VFD to control motor speeds
-PLC, relays, push buttons, and other basic components I’ve worked with plenty
My tendency is to just get rolling on this. But I wanted to run it past any of you who may give a pointer or two.
Anyway, please let me know if you see anything that stands out as a possible issue. I’m working alone, and as I said, this will be my first motion control project.
Thanks in advance.