Infill Hash

by tolomea on September 2, 2012

Infill Hash
GXR A12, 50mm (35equiv), ISO 200, 1/125s, f/2.5, 2012-09-02

This is worth mentioning. The picture here is a partial print of the extruder body. The original extruder body I got wasn’t the greatest print and it’s a high wear part so I decided to print a new one. This is a failed attempt, I forget why I aborted this particular print but it shows the infill hash well. To reduce print time and save plastic the printer can be set to only partially fill the inside of “solid” objects, this is a 50% fill. You can also see the solid border around the infill.

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Rocket Fuel

by tolomea on September 2, 2012

Rocket Fuel
GXR A12, 50mm (35equiv), ISO 200, 1/133s, f/2.8, 2012-09-02

It’s a rocket shaped shot glass, for drinking the really good stuff.

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Printrbot Back

by tolomea on September 2, 2012

Printrbot Back
GXR A12, 50mm (35equiv), ISO 400, 1/14s, f/2.5, 2012-09-02

Here’s a shot of the back.
The motor center right and the belt to the left of it drive the extruder carriage.
You can also see the filament going into the top of the extruder. Currently I the roll of filament is lying on the floor next to my desk, fixing that is high on my todo list.
At the bottom there is a big bundle of cables, one of todays tasks was fitting the control board into the substructure and tying up all the loose cables. Previously it had been sitting on the table next to the printer. It doesn’t seem like a big deal, but having all that tidied away has greatly improved the feel of it.

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Printrbot Front

by tolomea on September 2, 2012

Printrbot Front
GXR A12, 50mm (35equiv), ISO 200, 1/111s, f/2.5, 2012-09-02

This is as good a shot as any for doing a brief overview.
The heart of the system is the extruder, this pulls in ABS filament, melts it and squirts it out the hot end (kinda like an automated hot glue gun). In the picture the gears in the top left are for pulling the filament in, the bright red bit is the hot end and the black bit is a fan. The fan is something I added, it helps the molten filament set faster so another layer can be added on top.
The extruder is positioned and moved so that the extruded plastic builds up into the desired object. This requires moving it along 3 axis.
X, left to right. The extruder is on a carriage that slides along the two horizontal rods, it’s driven by a motor and belt on the other side, you can see them better in the next photo.
Y, forward and backward. Instead of moving the extruder we move the object being printed by moving the bed it is resting on. This is driven by a motor and belt underneath, the white bit center front holds one end of the belt, you can see the motor just to the right of it.
Z, up and down. The entire extruder and X axis assembly is raised and lowered along rods at the sides. Looking at the right, the inner rod is the guide while the outer rod is threaded and transmits the motive force from the motor bottom right. The left side is the same.
Additionally the bed on which the object is constructed is heated, this is necessary because ABS, our material of choice, expands as it heats. Since it is extruded hot we need to keep it hot during the printing to prevent it from warping.
The heaters and motors are controller by a small computer, this is mounted below the bed, you can see some of the connectors and plugs, bottom center.
The only other component of note is a standard PC power supply that isn’t visible in this shot.

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Printrbot

by tolomea on September 2, 2012

Printrbot
GXR A12, 50mm (35equiv), ISO 200, 1/79s, f/2.5, 2012-09-02

And now a 3d printer post, if only so people will stop bugging me about it :P
This is going to be long…

Edit: A Printrbot is a type of 3d printer, a device that makes 3d objects, a 3d model file goes in and a plastic object comes out.

I’ve been interested in 3d printing for some time, it’s an interesting technology that is a great enabler for a whole bunch of other things. My initial interest grew out of my photography hobby. I wanted a custom tripod bracket and looking around online turned up 3d printing as the most cost effective way of doing that. Over time and I designed several different brackets and had them printed by a couple of different firms. Of particular note are Shapeways who provide a good service and have an active and positive involvement in the community.

During that time I was keeping an eye on the growing RepRap community, I knew I wanted my own printer and I knew I didn’t want to pay 10′s of thousands for a commercial one. For a couple of years I was just hanging out waiting for the open source ones to reach a useable standard. Eventually they got there and I started to seriously consider my options. I could write a whole post just about the current state of the market but for now I’ll skim. I knew I wanted a printer that was popular so there would be lots of help available online. And a printer that had itself been printed so that I could mod it and upgrade it as the community advanced. That effectively narrowed the field down to the Prusa Mendel. However I was concerned about the build complexity, there are many blogs around where people of my general experience level document their attempts to build one and a concerning portion of them end in failure. So I was unsure how to proceed.

Then Kickstarter happened. One of the big early success stories on Kickstarter was the Printrbot project which made headlines as it skyrocketed past it’s funding goal. I could tell from my years of lurking that Brook the project leader had a reasonable working knowledge of the RepRap style printers. The build was clearly way simpler than the Prusa, granted the Prusa is a better machine, but that doesn’t matter if I fail to get it going. Additionally the Kickstarter guaranteed that there would be dozens if not hundreds of people assembling them at roughly the same time so help should be readily available. So I signed up for the 3d printed kit variant at $499usd, I’m backer 452 out of 1800.

That was December last year. Understandably Brook wasn’t at all prepared for the project blowing out it’s goal by 3300% so there were some delays sourcing and manufacturing parts in the volumes now needed to fulfill the backers orders. And then we decided to move to Britain, the day I gave notice at work I also email Printrbot HQ and had my shipping address changed to a friends place in London. In the end it actually beat us to London. After the move we were in temporary accommodation for a while and then when we found an apartment I started into full time work again. But a little bit of time weekends and evenings got it assembled and running.

The build really was quite straight forward and what issues I did have mostly related to lack of appropriate tools. Turning it on the first time was quite something. The assembly process made it really clear that this is a very simple machine made from a bunch of off the shelf motors, rods and screws and a stack of cheap plastic bits. There is nothing flash or impressive in the hardware. After the effort of assembling it the physical device was almost disappointing and I procrastinated before turning it on, I think out of fear that it wasn’t living up to my hopes. I pushed on and worked through the calibration process, by the end of that it seemed highly unlikely that this pile of bits was actually going to work. And then it was time for the first print, I loaded up the model, waited for everything to heat up and hit the go button… and then the software injected it’s special magic and my pile of bits became something really cool.

“It’s like having a little bit of science fiction right in our lounge” – Andrea

Contrary to what was said on G+ and FB, the first print wasn’t a shot glass, that was the second print, the first print was a one Euro calibration piece and the Euro fit perfectly. I think that’s enough for this post. I’m going to throw up a couple more images for interest sake.

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Roof Table

by tolomea on August 17, 2012

Roof Table
GXR P10, 49mm (35equiv), ISO 800, 1/36s, f/4.3, 2012-06-23

I presume this was in one of the pubs around Angel, but I don’t recall which, maybe it was the Winchester. Regardless it’s one of the odder lights I’ve seen.

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Fox

by tolomea on August 17, 2012

Fox
GXR P10, 119mm (35equiv), ISO 336, 1/125s, f/4.9, 2012-06-23

While we were out flat hunting around Angel one day we spotted this guy nosing around someones garden. It’s interesting seeing a wild animal in this size range in the city, there’s really not much around Angel that isn’t urban.

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Moonlight Eye

by tolomea on August 17, 2012

Moonlight Eye
GXR P10, 222mm (35equiv), ISO 800, 1/4s, f/4.8, 2012-06-22

The new place doesn’t have a long view, lots of interesting street life to watch instead but nothing like this.

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Giant Earth Sculpture

by tolomea on August 13, 2012

Giant Earth Sculpture
GXR P10, 28mm (35equiv), ISO 500, 1/32s, f/3.5, 2012-06-22

With an escalator through it, cause… well just cause they can.

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Foyer Mezzanine

by tolomea on August 13, 2012

Foyer Mezzanine
GXR P10, 28mm (35equiv), ISO 176, 1/32s, f/3.5, 2012-06-22

This is the mezzanine level of the museum foyer.

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