Wednesday, April 1, 2015

Easter present: a pattern generator for everyone

My husband made something amazing for the eggers again!
He programmed a pattern generator that enables you to create triangle or square-based patterns. The output is an svg file that can be plotted on an egg.

Link to the generator:

The egg-pattern-generator has many parameters that can be set before generating the file. First you have to choose whether you want triangles or squares, then you can specify the size and number of the rows, if you want to have the shapes random sized or not. And many more tiny modifications... Have a look and create your own pattern!

I made a few eggs based on the generated designs:

Small squares

You don't have to print all the layers

Vivid colors look great

Large squares

And of course many more can be and will be made... :)

Tuesday, March 31, 2015

New designs on Thingiverse

During last weekend I printed sooo many eggs for Easter and finally finished some of my half-made designs.

I published three more designs on Thingiverse (links are under the pictures):

Flower pattern
Panda made for a friend
Wild flowers inspired by a napkin
Happy Easter egg making for everyone! :)

Thursday, March 5, 2015

Various prints and a strange pen behaviour

Some more prints from a couple of days ago. They look very good, I only discovered a few slight problems with them. 

Design from Thingiverse

The 3D cubes one is not perfect, but you can still see the 3D in it. 

Design from Thingiverse

I made these 2 eggs just as an example that how easy is to make a new printable design in Inkscape. I used my Google men file (now uploaded to Thingiverse) and the Hershey text extension.

During the printing of the 3D cubes I discovered a new anomaly. My ultra fine Sharpie pen became thicker by the end of the printing. Have you ever experienced anything similar?

Tuesday, March 3, 2015

Making of a new distal pen arm

Guest blog from tml

As you may already know, eggs are mainly drawn upon by using Sharpie pens.  The pen holder piece of the EggBot is designed to hold ultra fine point Sharpie pens. This is quite a good decision as Sharpie pens are both cheap and available everywhere.... except for Hungary. We don't have them.

On our recent trip to London we checked out a stationery and were lucky enough to find a 24-pack of fine point Sharpie pens at a very discounted price. Their lines are not as thin as those of the ultra fines but Kitti thought that they were good for painting infills so we bought them.

Back in Budapest  she tried using them, without much success; as it turned out, fine point Sharpie pens are somewhat thicker than the ultra find point pens, so they did not fit into the  pen holder arm that came with the EggBot Deluxe kit, as seen on the picture below.

Fail. After taking a look at the pen arm I thought that drilling could help but I am not a big fan of destructive methods and drilling a larger hole would have made the pen arm for the ultra fine point Sharpie pens less ideal.

3D printing to the rescue!

My next idea was that I just 3D print that particular part of the pen arm using my emaker Huxley 3D printer I have since 2011. 

The pen holding piece of the EggBot is an L shaped piece consisting basically of 2 wooden pieces, both screwed to an L-shaped, bent metal piece.

The original 

At first I thought that I would only print the particular piece holding the pen, but after looking at the part  for a while I decided that it would be better to print the entire L-shaped pen holder arm in  one piece. That way there are no bolts and metals, and plastic sheets, no unnecessary dimensions of freedom. 

I did not feel like redesigning it too much so I decided to copy the idea of the  arm's design completely. I used a pink ruler to take approximate measurements of the original piece. As it is not a very complicated part, I decided to use OpenSCAD for creating a 3D model of it. I use OpenSCAD whenever I can as you can create 3D objects in a programmatic way, by writing a simple basic-like code for generating primitives and applying transformations and boolean operations. The main advantage of this is that you can use constants and variables which makes it easy to generate multiple versions of the same object with slightly different parameters, like one arm for the fine Sharpie, one for the ultra fine Sharpie, which are basically the same, only the pen diameter changes.

I had to make a few changes to the original design, like I had to rethink the way the thumbscrew is fitted (as the original EggBot Kit part had a metal piece there which I didn't). I solved it by using a nut and bolt.
Alternative thumbscrew. The plastic is housing an M3 nut. 
There was  only one conceptual  modification I made to the original design: I wanted to create a pen holder which can fit both kinds of Sharpies nicely and that switching between the 2 kinds of pens does not require a screwdriver. I also wanted the pens to fit tightly. You can see on the picture what I came up with: I modularised the part of the arm that has the hole for the pen and made it replaceable.

The final, printed piece, glued together, with the servo motor mounted.
One pen extension for the ultra fine point Sharpie (diameter = 11mm)
and one for the fine point Sharpie (diameter = 11.5 mm)
After the design was done, I started the usual iterative process; print, try, adjust variables, print, try again, adjust variables, until everything is perfect. I needed about 4 iterations to find the perfect numbers. The biggest challenge was to get the size of the shaft for the nut that holds the thumbscrew correct I also ended up with cutting my one-piece pen arm into 2 pieces and gluing them together. The reason for this is that vertical holes print much nicer than horizontal holes.

Here is a picture of what it looks like when fitted on the EggBot:

Eggbot with custom pen arm

The thing files are available on Thingiverse.

Monday, March 2, 2015

Monday, February 23, 2015

Lots of prints and the solution to my misprinting problems

Today evening my husband's friend came over to see my EggBot in action. I showed him how it is printing but as usual we have seen the filling and outline misprinting problem. Since he is a nerd too we decided to debug it finally!

Do you remember these problems I mentioned in my previous posts?

Lines are going crazy

Filling is totally out of the outline
We have done about 10-12 prints today. Most of them was for testing purposes but on the bright side I could use my new "fat" Sharpie pens because the new pen holder piece is done! My husband printed it out with his 3D printer a few days ago but we just didn't have time to test it yet. (He also promised a post about how he made it, so stay tuned!)

Test prints
First, we tried to set the shape of the egg by lifting up and down the motor. It didn't make much change. Then we tried to print out some examples to see if only my designs are bad or it happens with the other ones too. It wasn't my designs. You can see that the prints look good from the distance. But once you look closer the lines are not aligned properly, some filling is not placed right, etc.

The next idea was to create a drawing with only squares to see if they are aligned properly. They were. Then we just printed a line that went around the egg two times exactly. However the line never reached the end of the second round, it was too short.

Test printed egg
Since we didn't have much idea what can cause this problem at the end we decided to try to update the firmware from 2.0.1 to 2.1.5. And tadaaam, it solved everything!

Egg in the front before and the one at the back after the firmware update

Pink is after the firmware update, brown and bronze is before

Google man after the update

Google man after the update - still there is a tiny mistake with his left shoe

Tuesday, February 17, 2015

Drawing and first printing of the flower pattern

I started drawing this pattern a few weeks ago, but haven't had time to finish it lately. Today I sat down to do last lines and add fillings to the lines.

What I first realised was that I forgot how to do the filling, so I opened the EggBot Wiki tutorial I used earlier.

What I also realised was that I forgot to write about the trick I invented to make the filling and the outline match more. If after you duplicate your path you go to Path → Inset for one or two times, the filling will not cross the outline and it will look better on printing.

Once I finished, let's the printing begin!

However I put every unique pattern to a different layer, first I tried to print it with only one colour. I wanted to test the whole drawing without making any mistake in the pen changing process.

As you can see the filling is not inside the outline for some reasons. I have had the same bug with my Google Men drawing, but I haven't spent time so far to examine it. To be honest I thought I did something wrong when I changed the different pens, but in this case it happened with the first layer without any pen changes.
I decided to try Extensions → EggBot → Reorder Paths for Speed.

version 1
After the optimisation the second try looked much better! At least for the leaves... :( I'm still not sure if this setting solved the problem, probably not, but now I didn't experience the same problem, I found new ones!

Filling is not perfect
Lines are not perfectly in line
I should place the pen higher

Besides my other obvious problems, the round patterns were not round at all, so I stretched the whole picture as much as I could.

version 2
The second black print looked better, stretching made its magic, round objects look almost totally round. However I still have problems with the filling. For the colour print I try to set a bit on the fillings. Who knows, I might get it right this time.

I also removed the blue flower from the left, because on the egg it was next to the pink one on the right and it did not look good. I replaced it with the orange one and kept the colour blue. Hopefully a not-filled flower will look better next to the filled pink one.

version 3

And this is how the colour print looked:

I can see that it is still not perfect, so before I publish the .svg file on my Thingiverse page I will work a bit more on it.

Thanks to my grandparents for providing eggs to experiment!