By far the biggest change in the machine was moving the syringe up on top. I did this for several reasons.

The first is that it is just more convenient. It's really easy this way to get a run started. Load up your syringe, drop it in the hole in the top of the machine, and go. Can't get much simpler.

With the syringe on the side we need to use tubing to deliver material to the emitter (needle). You have to take care to match the type of tubing to the solvent you are using, which means keeping a supply of different kinds of tubing on hand. Then you have make darn sure you grab the right one or you're likely to bust the tubing in the middle of a run.

It's also not all that convenient to run the tubing down into the machine, either.

Putting it up on top makes all of that go away. But it does have a few downsides. For one, it means I can no longer choose to run the emitter up and down and leave the plate at the bottom, as opposed to moving the plate and leaving the emitter at the top. That could, and I'm sure it will, effect future design decisions as far as accessories go. I'm willing to live with that.

One other down side is I really needed to make sure the wiring going to the top was shielded. It was fun running the shielded cable up inside the tubes, but it's worth it in the end.

As far as loading the syringe when it's up on top goes, I saw two ways to do it. One is to simply make the track the syringe rides on tall enough that running it all the way up leaves us room to drop the syringe in under it. That's not the way I decided to go. Instead I went with making the syringe mount swivel out of the way for loading/unloading. Taking advantage of the square shape of the extrusion I made it lift up and swing to the side, and when it's down it fits into the square hole and can't turn. That, naturally, would leave it able to get pushed up during a run and the screw pushes down on the syringe. That's solved by making a sliding plate on the bottom side that holds both the syringe itself in place and stops the syringe mount from lifting up. Works like a charm.

I love it this way. It takes the hassle out of starting a run. The hardest part of making a run now is mixing up the polymer and solvent in the right ratio, and anyone can do that.

That's the biggest change in the machine. It's not, however, the only change. I'll be getting to those shortly, so stay tuned in. :)