Very nice, but you have to build the machine first.
This talk of PICs brings up the subject of automation.
Currently, the machine is all manual. If you adjust the web speed, you have to adjust the emulsion volume as well. On paper, linking the two to allow the user to dial in an emulsion thickness and a coating speed is a simple. In reality, the system needs to be designed with that goal in mind.
I dabble in automation systems as part of my job and I have the basic hardware needed to do the job. In this case, a Unitronics M90 or twowith the option of upgrading to a Unitronics Vision 120. The benefit of these units is that they are a type of PLC (Process Logic Controller) that have key input and a display screen. Unlike the more chunky and complex Rockwell and Allen Bradley hardware you may pick up for a carton of beer, the software to program them is downloadable from the net, and is free rather than costing an arm and a leg.
However, while the 'brain' of the system is easy to get and to program, you need drive controllers that can talk modbus or similar, (Not gunna happen on this version of the hardware unfortunately) and preferrably some type of feedback system - emulsion rate just requires some fancy (read: expensive) meters unless you happen to use positive displacement pumps such as the Zenith, in which case RPM feedback (in the form of a mag sensor on the pump drive shaft will do. Same method for web feed speed.
Apart from that, automation should be easy. With only a few engineering tweeks you should be able to thread the machine, connect the emulsion hopper, punch in the web speed and emulsion thickness required, and stand back.
The system will turn off the lights, prime the emulsion pump up to the coating head, start the chillers and when the correct temperatures have been reached, it then starts the drive and when the correct speed has been reached and the splice comes past, wind the coating head into the base for a complete revolution then back it off and shut the system down.
The system can then optionally prime another emulsion and do a second (or third) layer.
The user then has to just cut and discharge the finished product before turning the lights back on.
This field is, unfortunately, an area the builder is not familiar with and as he is quite comfortable having total manual control over everything, I am not sure it is an area he has any desire to explore.
Last edited by Dark Orange; 12-28-2007 at 10:13 PM. Click to view previous post history.
Reason: Punctuation and stuff.