Step 8: The Feed System
At this point in the modification you've got most of the straight printer work done, but if you look at what's in front of you you'll notice that there's still no good way to feed material into the printer and you also still have a sensor sitting off to the side of your work. Since you'll ultimately be using a heat gun on your printed work it's a good idea to create a system that can feed your carrier and copper clad material into the printer pretty much hands free. As such I built a rail system that supports the carrier and allows the printer to function without me having to hand feed it.
Again you can devise your own system, but here's what I've done with my printer. My first consideration was where I wanted to attach the feed sensor. This sensor is absolutely necessary or the printer will not function. What it does is it senses when material passes through its gap and relays that message to the printer so it knows exactly where the printing material is. The seond important thing to know about this sensor is that it expects a delay between the time that the rollers of the printer start feeding paper in and when the sensor is triggered. I'll go into detail about that more later though when I talk about the carrier piece. Since the sensor needed to be mounted in a place where the carrier would pass through it and I was already planning on making a plywood deck area to level the back of the printer body I decided it would be best to hot glue the sensor right into that decking near the edge of where the carrier piece would travel.
As you can see in the images I basically used a few layers of scrap plywood to create a level area in the rear of the printer. This decking area covers the large felt waste ink reservoir you'll see and also the metal power supply area. Basically all I did for this area was to measure out those two enclosed areas and cut layers of plywood until they were level. As you can see in the images again that took two additional layer in the waste ink reservoir and then I was able to lay one larger piece over the entire surface. Once I created this decking I cut a corner off of the top layer and lined up the feed sensor with where the carrier material would travel. This ensures that the material can travel through the sensor and set it off as the printer expects it to.
The main point of the decking area however was to create something to which I could attach support rails to. Using these rails I can simply lay the carrier and copper clad in the tray and let the printer take over. What I did for that was to take some aluminum that was bent into a 90 degree corner and cut it to the length of my expected carrier piece. From there I epoxied the rails to the decking and a third piece across the back for extra support.
With the feed system taken care of I wanted to test and make sure everything was functioning properly. To do that I finally cut my carrier material. I had a sheet of anodized aluminum lying around so I decided it would make a good carrier. To start I measured the width of the print gap which in my case was around 9 inches. With this in mind I decided to aim for something similar to paper size and drew out a 9 inch by 11.5 inch rectangle. Luckily however I read more information about the feed sensor before I cut that sheet because as it turns out that carrier would not have worked very well. From what I've learned the carrier piece needs to have a notch cut out of it that is about 3.5 inches long to allow for the proper delay between the feed rollers activating and the sensor triggering. So with this new information I modified my carrier outline to be a 9 inch by 14.5 inch rectangle with a 3.5 inch section cut out of one corner.
After cutting this carrier I installed the printer drivers on my computer and taped a piece of paper onto the carrier before running a print cycle to check for complete functionality. Everything came out and the printer functioned normally so I began to look forward towards the printing of PCBs.