Chairs and Spare Parts

I dropped the layer height to 0.1mm and gave the Victorian Chair another go.

Pretty good I think! See the detail in the front legs.

A closer look.

Spare parts for my Prusa i3

It's not easy to see with the while filament, but those are really thin layers!

Printing Gears

A while ago I printed a 24 tooth gear. Since I had some trouble recently with stringy prints I needed some small things to print. Gears are nice and small, don't take too long either.

First I went through slic3r settings and found that I had accidentally set retraction to zero. That caused the stringy prints.

Next was the Victorian Chair again.

The left front leg didn't make it...

And the backrest has an artifact. Still much better than the first attempt next to it.

Next was another gear, seen on the left. Until now I had printed at 0.4mm layers, so I wanted to try smalle layers: the small gear on the right is 0.1mm layers.

Two problems with the gears: the bottom has a larger diameter that the top, and the holes in the top layer. It might be an issue with the model or slic3r or the printer. Not sure which yet.

Printing... printing... printing...

I've been a bit quiet on here. Had a lot to do and not much time for writing.

I've been printing all sorts of things, mostly with failures, but we learn from our mistakes.
I tried some larger prints also. Below are some pictures of what I've done lately...

The gears and the test blocks came out beautifully, but while printing the roll of filament fell off the shelf above... 

... and broke the glass bed :-(

We found some 2mm glass and a glasscutter and got back to printing. This time some brackets for the LCD display. This is 1/3 of  http://www.thingiverse.com/thing:85644

The knob is from http://www.thingiverse.com/thing:28767

A pair of Beehive glasses... what you see it "support material" being printed.

http://www.thingiverse.com/thing:13621

Having some trouble with corner lift

Finished print. Getting the support material off was a mission and broke the print as well (the small hinges)

A little elephant, with moving legs. Had issues before with the same print curling - especially the first layers of the tusks. 

With the skirt around it things went much better, until I had some filament feed issues and ruined the print. Suddenly I have "stringy" prints too (by the ears). Working on fixing that.

The little elephant out of the box.

http://www.thingiverse.com/thing:257911

Little elephant standing, with a less succesful Victorian chair next to it. 

The "stringy" printing can be seen between the legs of the chair.

More elephant

More of the chair, it is printed in two pieces.
http://www.thingiverse.com/thing:31036

Calibration

I've done some wiring and I've been trying to figure out how to mount the limitswitches. In the end I needed to use some mechanical switches since they were the only ones I could mount such that they actually work.

Once the printer is running I'll have to design and print some custom switch brackets.

Then it was homing and setting the origin. That required some updating of the firmware config. Some of my limitswitches were inverted by default, and my X-axis movement was also inverted.

I did my calibration according to Triffid Hunter's guide. That worked out well enough for the time being, I made some wrong assumptions in the beginning, so I'll have to double check the calibration.

The Z-axis gave met some trouble. With my M5x0.8 threaded rods for the Z-axis, a 200 steps-per-revolution stepper and 16x microstepping, I get to a steps_per_mm calibration value of 4000. Once I entered that (M92 Z4000) and I give any movement commands, the steppers make a lot of noise and no movement.
I believe they were trying to move very fast, but they did not have enough power. Giving the motors more current was my least favourite option, but after trying to adjust the max speed of the Z-axis I gave up and increased the current to the motors.

I stuck some kapton tape on the glass bed. Got it on nicely with the "no bubbles" method. Use soapy water on the glass and stick the kapton tape over it. Smooth it out with a scraper and the water and air go out together. Works like a charm. And I have tape that is as wide as my glass bed, so I only had to do it once.

Fitting motors and belts

I fitted the axis-motors and got the belts in. The Y-axis (bed) went well after I used a hacksaw to widen the clamp. The clamp seems to be for a belt with a coarser pitch than my GT2 belts. Wel they are in there, pretty tight.

The X-axis (carrier for extruder) was a bit more tricky. The belt went in without too much trouble, since I now knew what to do. So I fitted the belt.
Then I took the whole assembly out to fit the Z-axis motors, and when I put it back I discovered the smooth rods didn't line up exactly. So a tap here and there got the distances better, but then the belt went slack.
So I had to pull the belt out (stuck quite well in there) and redo the belt. Got it a tight as I could.

So here's the first issue I have with this design: no way to tension the X-axis belt after fitting it. Perhaps it is just my lack of experience showing?

Anyway. The Electronics was next. Discovered that I had the support frames the wrong way around. The way I had it the Arduino and RAMPS board would be sitting inside the frame on the right. It has to go on the outside and on the left. I should have checked those mounting holes beforehand.

And then: powered up! And the motors turn, all the axis are moving. There is some software in the Taurino/Arduino that move the motors a few revolution back-and-forth.

With all the stepper motors mounted. Ready to test movement!

Position of Arduino and RAMPS board.