New DLP build started! / Pico-projector part 3

I keep saying this, but it's been too long a time since I updated my project blog. It's not for the lack of progress mind you. Things have been very busy for me lately. I'm not sure if I mentioned it before, but I started a new forum dedicated to all things DLP/SLA www.buildyourownsla.com . I have to say, never expected the explosion of interest! It's only been up for less than 2 months, but there are hundreds of active users (and about 1000 spammers).

Creation Workshop http://www.envisionlabs.net/ continues to advance rapidly, largely due to the herculean efforts of the co-programmer Shai (Thanks man!) . I've had a lot of interest with DLP/SLA printer manufacturers wanting to distribute Creation Workshop along with their printers, and I've been signing them on rapidly. I've devised a plug-in system that allows me to create vendor plug-ins to completely customize the GUI and code for each machine. It also allows me to distribute custom machine and slicing profiles tailored to each machines unique capabilities.

I've been talking with a bunch of groups/ start-ups/ companies about their machines for months, and I'm in a pretty unique position to see exactly what's going to be coming out on the market this upcoming year. I'm under NDA with a few of them, so let's just say that 2014 will be the rise of the SLA machine in the 3d printing world.

That all being said, I've been giving some thought as to how to create the 'Best' machine possible. 'Best' is an arbitrarily chosen words really. 'Balanced' would be a better descriptor. As I noted elsewhere http://www.buildyourownsla.com/forum/viewtopic.php?f=17&t=149 , there will always be tradeoffs between build size, resolution, and print speed. I think I've come upon a good balance between the 3.

What I came up with is a pico-projector mounted on an x/y linear assembly. The projector can expose smaller image tiles on a much larger vat bottom. This allows the pico-projector to maintain a 25micron (or greater) x/y resolution. The vat can be arbitrarily large. This is a good trade-off between size and print speed.

I'm still in the early stages of the build, but it's all coming along nicely.

New parts for the build

Shown above are a few parts I'm using for the build. Here's an incomplete BOM of items so far:

• 12v 6A power supply
• 5x Nema 17 steppers (I'll probably use 4)
• 12x LMU88 linear bearings
• 6 meters of GTK belt and 4 pulleys
• 10W UV LED 405nm on an alum heatsink
• Modified AAXA P2JR DLP projector
• 3' of 1/8 hose for the resin pump
• 3 prong outlet
• Mains switch
• Printed 3 way corner brackets for the 80/20 construction
• 4 printed feet

A bunch of 350mm and 300mm 25mm 80/20 aluminum.

The constructed bottom portion of the machine. Measures 350x350mm.

I'm still waiting on a few more parts in mail:

• Arduino 2560 with RAMPs board
• 8mm hardened steel rails
• 8mm threaded rod
• UV transmissive plexiglass for the vat
• UV blocking plexiglass for the outer casing/window
• Other things I forgot

I'm probably going to do a bit more construction today. Look for the next part of this build soon.
-Steve

Creation Workshop Version 13 - Last BETA release

This is probably the quickest turn-around I've had between releases. Version 13 doesn't have anything earth-shattering in it, but it does have the following:

• Fixed all reported issues in version 12
• Improved Camera Controls (Thanks Shai!)
• Huge reduction in memory usage
• Instant Slicing
• Volume & Cost Estimator
• Revised future-proof config files
• Additional support generation tools
• Fixed the intersection issues in support generation & object selection
• Simplified GUI (G-Code controls)
• New Plug-In System
• Other things I forgot...

Now that I look at the list, this release actually does have quite a bit to offer. You can download version Beta 13 from the usual spot here: https://github.com/Pacmanfan/UVDLPSlicerController/tree/master/UVDLP/Published

DefCon 2013 Re-cap

As a few of you know, I attended DefCon https://www.defcon.org/ this year in Vegas. I've been bugging my work to send me for the past few years, but thanks to my co-worker Jeff who pulled some strings, we both were able to attend this year. This post is going to be kinds picture heavy, so please bare with me.

Hacker Jeopardy!

Walking Bar

General shot of one of the convention hallways

I loved her dress!

Booth Babes!

SDR Radios!

A very tall Type A machine.

Add caption

Me and Eric from Hackaday.com

Here's a general shot of the vendor room.

There were a few 3d Printers there

At the Hardware hacking village

A hardware vending machine

There were a ton of interesting talks related to security. Some of the best parts were meeting random people in the hallways to talk tech. All in all, going to Defcon was a great experience, and I look forward to heading back next year. 

An update

So, I haven't made a blog posting for a while, but it's not because of lack of progress. Progress continues on my Slicing and building software https://github.com/Pacmanfan/UVDLPSlicerController .The main issue that I'm facing right now with my UV DLP Printer is the resin sticking to the bottom of the vat. The UV light cures the resin, and it adheres fairly well to the glass bottom of the build tray as well as the build arm platform. 

 The problem happens when the arm (and platform) try to lift the slice up. The printed resin slice is too firmly attached to the glass bottom of the vat, and the resin releases from the build arm platform instead of the vat platform. I've tried roughing up the bottom of the build arm platform for better adhesion, as well as greasing up the glass vat with silicone lubricant. No luck so far.

   Other designs I've seen use a mechanism for sliding and/or tilting the build vat. This allows the interface between the resin and the bottom of the vat to release suction before/during the lift sequence. 

One problem that I'm facing now is that my vat is fairly large, and I don't have room on the surface of my printer to add in a tilt/slide mechanism easily. The reason my vat is so large is because I didn't modify my projector optics for a shorter throw distance. I suppose the "ideal" throw distance would project the 1024x768 resolution of the projector onto a 102 x 77mm area on the bottom of the vat for a 10 pixels per mm resolution. My projector's minimum throw distance is a little longer, giving me a size of approximately 155 x 120 mm. This is fine by me, however; if I want to add in a tilt mechanism, I may have do one or more of several things:

 1) Adjust the projector throw distance to be shorter, so I can have a smaller vat, and more room for a slide/tilt mechanism on my existing machine.

2) Rebuild my machine with a larger top surface for additional space for the tilt/slide

3) Completely rebuild my machine - Now to be fair, I was thinking about doing this anyways. I want to have a smaller design that uses a horizontally mounted projector and a mirror to project the image to the surface of the bottom of the vat.

Well, I should just choose an option and stop stalling so I can get up and printing. 

On some good news, several people have reported to me that they've used my software along with their printers to successfully print!

I'm still in the process of adding more functionality to my application. Look for some good new features real soon.

-Steve

Resin tray rebuild and UV Resin testing.

Last week, I purchased some UV resin specifically designed for 3d printing from 3DInk http://buy3dink.com/p/59/uv-resin . It arrived yesterday and I immediately started conducting a few print tests. One of the first things I noticed is that the resin was much less viscous than the SolarEZ resin I tried before. The 3DInk resin flowed almost like water. Again, I put a few drops in a sandwich bag and placed it on my resin tray.

I fired up my software and picked a nice slice from the 'Goldberg Sphere'. The resin cured within seconds! Good progress so far. The next step was to test the adhesion (or hopefully lack of adhesion) to my polycarbonate resin build tray. I used a silicone spray and paper towel to grease up my build tray, and I place a small amount (few drops) of resin on the tray to be exposed.

The remains of my first build tray.

Unfortunately, The resin firmly adhered to the build tray. No amount of coaxing could remove it. I decided polycarbonate might not be the best choice, or I might have to use a thin film of Teflon coating on the polycarbonate. Either way, this build tray was toast. 

Shown here is the resin stuck to the tray.

I found a nice small pane of soda glass I had been saving, and re-tried with a few more drops on an un-coated pane. Even un-coated, the resin did not adhere very well to the glass. I was able to slide a few test prints off the pane.

Some test object slices of the 'Goldberg Sphere'

New build tray

I used some aluminum channel stock I had lying around along with the glass pane to construct a new build tray of the proper size. I used silicone sealant on all bottom edges and the corners to ensure a proper watertight seal.

I think this new build tray will do the trick. The last thing I need to do is finish the arm that connects to the ZAxis and dips into the resin. I've already added a leveling system to the bottom of the build tray on the printer. I may have to add a small leveling system (some screws) to the build arm.

Exposure Tests

I ran some exposure tests last night. I placed a small amount of UV resin into a plastic sandwich bag and laid it flat on the Resin tray. I went to a middle layer slice of a model slice and I let the resin expose for approximately 30 seconds.

Exposing the Resin to the projected image

As you can see, the resin set into the slice of the projected image. Exposure time took longer than I thought it would, and the resultant piece was still very soft and rubbery. I think I'm using a non-optimal UV resin for this printer. (I bought a quart over 2 years ago from www.solarez.com that was meant for surfboards). I need to bite the bullet and invest in a small quantity of of resin that is specifically designed for 3d printing.

The resultant created object.

If anyone knows of a site where I can purchase a small (quart or liter size) amount of UV resin specifically designed for 3D printing, please let me know.

Rigid Heddle Loom

What do you mean "Rigid Heddle Loom"? I thought this was a technology projects blog?! Well, a few days ago, after dropping off my girlfirend, I came home to find my daughter Chloe building something out of Popsicle sticks and tape. After my initial puzzlement, she told me that she wants to start weaving. She was trying to make a weaving loom.

She and I talked about weaving for a few, then started to browse eBay for a simple beginners loom. After going through many pages, I determined several things: 1) Any weaving loom in the price range that i was thinking (~50$) was only going to buy a toy - not suitable for anything other than learning and 2) a decent loom for her age and skill ability that was able to actually weave something nice was going to be 150-300$.

After putting the kiddos to bed, I started doing research on looms. The history of weaving, companies that made decent looms such as Ashford, Beka, Harrisville, Kromski, and several others. I took the time to analyze several popular designs, took note, and watched a few dozen videos on loom weaving  and loom use on YouTube. 

After sleeping on it, I started designing a 24x18 Rigid Heddle Loom that took the best properties from several designs. I made a few patterns, and started cutting wood for it today. I downloaded and started printed the heddle portion from http://www.thingiverse.com/thing:11374 on my 3d printer. 

Printing some heddles

2 heddles are 7 1/2 inches

The 2 sides of the loom

I'm making good progress on this and expect to be done with it in the next few days. My 3d UV DLP printer is on hold for now. 

Some Progress this weekend

I didn't get as much done on my project this weekend as I had hoped. I did manage to print and attach some handles to the cabinet I built. I also put together the polycarbonate build tray with some plastic glue. Hopefully this will be a suitable tray for build. I still have a pane of glass that can be used if the UV resin sticks to the polycarbonate plastic too much. I also started the assembly of z-axis that I printed from my Thingiverse "Generic 23 printed axis" object http://www.thingiverse.com/thing:37123 .

The Z axis being assembled

The completed polycarbonate build tray

Completed Inkshield kit.

The goal here is to see if UV resin can be sprayed through an inkjet nozzle.  This may allow construction of an Objet-like printer.

Inkshield kit

I finally have all the pieces for my ink shield kit. My intent is to see if I can use to and shield kit for a UV printer. I'm going to have to experiment with the UV resin to see if I can use the ink cartridge to emit it.