Weekend Project: Stamp

One of my favourite go-to materials is Sugru and I've been wanting to try out making a stamp from it for a while now. But first I needed a handle. I wipped up a quick one in Fusion 360.

Printing didn't take long, even at .1mm layer height. Infill was 30%. On the next print I will increase the top layers to 7, instead of 5, since the printer wasn't able to create a completely smooth top surface. It would probably work just fine it the infill was higher - like 50%.

Since I'm printing on a glass surface the bottom was pretty smooth. I made good use of a knife to make more grooves to be sure that the Sugru had plenty to adher to.

Printed the "Thumbs up" on a secondary printer. The depth of the relief could probably be half as deep in retrospect. In this one it was 2mm deep. That would make it easier to keep fine details when separating the mold from the stamp.

Note to self: don't mirror the print. Since we are making a positiva - the stamp will be automatically inverted for you.

Before adding the Sugru I swabbed the pattern lightly with canola oil so it wouldn't stick. A Q-tip was perfect for this. I think it came out pretty well considering the finished quality of the printed surface.

Make sure the Sugru get plenty of time to cure. I left it a couple of days since we didn't have the ink-pad yet.

Not perfect, but enough to show that the principle works. The ink doesn't adhere extremely well to the stamp, but that might hopefully change over time as the surface get roughened up. Maybe using some fine sandpaper would help as well.

The stamp handle and "thumbs-up" model can be downloaded here:
http://www.thingiverse.com/thing:1052496

Finally printing again

After several months of not printing I finally have a working 3D printer again - Yay! I can only blame myself for this; since I in my eagerness to improve the printer tore it apart before printing the new parts I needed. Even though my J-Head arrived swiftly I had nothing to mount it on...

J-Head Mk V-BV. Excellent build quality!

The aluminum plate mounted on top of the slide-bearings did not have enough stability using zip ties alone. I tried replacing the zip ties with brass wire (the sort used to hang paintings with), but that turned out even worse since you can't get the wire tight enough.

My best friend Sugru at work again.

Enter Sugru. I had a batch in the fridge that was nearing it's use-by date so why not try that. I made sure to protect the bearings with scotch tape so the sugru wouldn't stick - only support. Apply healthy amount of sugru and wait 24 hours. Worked like a charm!

Next I needed a new mechanism to feed the plastic. The easiest would have been to print something, but without a working printer that proved ... difficult.

Initial setup with the spring mechanism.

After a lot of thought and a fair number of iterations I came up with a design that let me have a spring as tension mechanism on the filament feeder.

Need more springs Scotty!

When calibrating the feed rate I quickly discovered that the original spring didn't have nearly enough force to keep the flow of plastic consistent - especially when the filament spool needed to be unreeled by the printer as well. Adding three more springs fixed that issue neatly - although it doesn't look as pretty any more.

First print: new tension lever.

First thing I printed was the Minimalistic Mk7 replacement by +Whosa whatsis. This is so I have a replacement part ready for if when my cobbled together setup fails.

As for now the feeder seems to hold up pretty good as well as consistent results. I think I'll keep it for a while. The J-Head I'm really impressed with; great build quality and excellent print result!