thinksabunch
Member
Hi,
I am an inventor looking for a way to automate a block-making press I made out of a log splitter. It makes blocks for building homes from recycled paper. I am leaning toward Allen Bradley products because of their huge installed base and because used PLCs and parts appear to be readily available on Ebay. My press video is located on YouTube at http://www.youtube.com/watch?v=yIqTBQA8_Yo
I've learned some things by asking a similar question on this forum before, but am still a bit stymied because some of the answers seemed to indicate that I should have to buy expensive add-ons to the PLC to accomplish what I want to do. It seems to me that what I want to do should be fairly straightforward PLC work. Maybe I'm missing something.
What I want to do is:
1.) move the fully retracted ram at normal speed forward for several seconds,
2.) slow it down well before it approaches its stop (block thickness) point,
3.) stop it at that point within +- 1/32 inch
4.) retract it a tiny bit (an inch or less) to take pressure off door,
5.) (door opens)
6.) move ram forward again normal speed a set distance to push block out of press,
7.) ram then stops and retracts all the way, stops and waits for press to fill
What I need is an idea of the type of AB analog instructions that would be used to talk to a solenoid-operated proportional hydraulic control valve. I would hope that I could use simple reed switches and timers for start, slow down, stop, reverse, stop, forward, stop, retract, stop. What I’m hung up on is the AB analog instructions to the proportional valve to change speed, reverse direction, etc. The valve will most likely be +-10V variety.
Anything to get me going in the right direction to find the PLC analog instructions needed to control the valve would be appreciated.
Do I really need expensive add-on speed controls, etc.?
Thanks.
Barry
I am an inventor looking for a way to automate a block-making press I made out of a log splitter. It makes blocks for building homes from recycled paper. I am leaning toward Allen Bradley products because of their huge installed base and because used PLCs and parts appear to be readily available on Ebay. My press video is located on YouTube at http://www.youtube.com/watch?v=yIqTBQA8_Yo
I've learned some things by asking a similar question on this forum before, but am still a bit stymied because some of the answers seemed to indicate that I should have to buy expensive add-ons to the PLC to accomplish what I want to do. It seems to me that what I want to do should be fairly straightforward PLC work. Maybe I'm missing something.
What I want to do is:
1.) move the fully retracted ram at normal speed forward for several seconds,
2.) slow it down well before it approaches its stop (block thickness) point,
3.) stop it at that point within +- 1/32 inch
4.) retract it a tiny bit (an inch or less) to take pressure off door,
5.) (door opens)
6.) move ram forward again normal speed a set distance to push block out of press,
7.) ram then stops and retracts all the way, stops and waits for press to fill
What I need is an idea of the type of AB analog instructions that would be used to talk to a solenoid-operated proportional hydraulic control valve. I would hope that I could use simple reed switches and timers for start, slow down, stop, reverse, stop, forward, stop, retract, stop. What I’m hung up on is the AB analog instructions to the proportional valve to change speed, reverse direction, etc. The valve will most likely be +-10V variety.
Anything to get me going in the right direction to find the PLC analog instructions needed to control the valve would be appreciated.
Do I really need expensive add-on speed controls, etc.?
Thanks.
Barry