New 3D printing journey

Technique fascinates me :-) I was unsure if I should make a new blog about this project but then decided to keep this one because the end-product will be miniatures.

During the last years I have made a few 3D-printers. Some better than others but I learned a lot.

The last 3d-printer was made during november 2014. It was an Ultimaker classic and actually that printer was better than all the other designs I previously had built. It is reliable. It make nice prints. Why didn't I make the Ultimaker from the beginning? Well, because my cnc was too small for cutting the panels. After having made a few modifications to the cnc it was possible to cut the ultimaker panels..

Ultimaker

When I need a print I just power up the printer and start printing. I have not used the printer for making miniatures, but for making parts for other projects.

Printed parts

Well, I tried once printing a 1:24 Queen Anne chair but as the photo show the finish is not good enough for miniatures (as expected). Looking forward to print the same chair in scale 1:144.

So, What next? Answer is SLA (Stereo Lithography Apparatus)

During the recent years the materials for SLA has been better and cheaper and easier to get.
One of the SLA techniques is based on a liquid resin that cures (hardens) when illuminated by ultraviolet (UV) light. The UV-light can be from a special lowpower laser or from a standard homebio projector.

The SLA printer then works as follows.

The 3d-drawing is sliced in very thin layers (f.ex. 0.01mm) Every single layer is then projected on a thin layer of resin. When the resin is cured the printer moves 0.01mm up and the next layer is illuminated and cured. and so on...

I found a cheap used projector with few hours on the lamp.

Projektor

Next was to decide how to build the printer. A few hours browsing the net I decided to build something like the B9Creator.

B9Creator

My design is mostly based on materials I have in my junkbox except for the 6mm birch-plywood.

I was happy with the Ultimaker way of assembling sheets of plywood so based on the open source drawings and plans for the B9Creator I made drawings to be cut on my CNC-machine.

Cad drawings. Layers is a good thing.

Some of the panels are split in two because the cnc is too small :-)

Dry assembly of the panels. 

An essential part of the printer is called the VAT (I don't know what it stands for but it's not Value Added Tax) The VAT contains the uncured resin.
The plate that holds the object(s) to be printed is lowered into the resin leaving a small cavity between the VAT-bottom and the buildplate (0.01mm high). When the resin is cured the VAT slides away to release the object from the VAT-bottom. The VAT-bottom is covered with a silicone layer that prevents the cured resin to stick to the bottom, The sliding action is a way to overcome the adhesion between the build and the bottom.

Sliding VAT with guides. 

Next is to assemble the panels and make bottom half where projector will be mounted. Again I wan't a bigger cnc...

Have fun
Niels