Wednesday, August 14, 2013

Mk V Pipe

A few days ago I thought about an easier-to-build version of the Mk III Pipe. The solution I came up with was the Mk V Pipe. It can be built much quicker because of its thinner tip.

Friday, August 2, 2013

Excalibur 2

It has been quite a while since my last post.

Although the Excalibur still performs well, there are some details that might be improved. What I dislike the most about it is the fact that the nozzle and the barrel are hold together by the heater block. As the heater block consists of aluminium the thread will get damaged on the long run that way.

So I decided to develop the Excalibur 2.

Friday, December 28, 2012

Excalibur Mini Hotend

Today I received a new fan.

Its size is 25 x 25 x 8 mm. Quite small, so to speak.

Now I am planning to design a new hotend around it: Excalibur Mini.

Btw I renamed the Organ Pipe Hotend + Mk IV to Excalibur Hotend. You can find its description here.

Here it is printing.

Wednesday, December 19, 2012

Warping - Some Findings

Today I tried some settings in Slic3r. Doing so I printed a U-shaped testcube of PLA on a heated mirror. I printed the first layer at 200°C and the subsequent layers, too. It looked quite well, but at one corner it hadn't stuck to the bed as perfectly as I wished. Actually I wouldn't call it warping already, but maybe the very very beginning of it.

So I cleaned the mirror with alcohol. Then I printed a second cube with 200°C at the first layer and the other layers at 170°C. My expectation was a reduction of the warping, as a layer with a lower temperature wouldn't shrink that much like a hotter one.

The result was puzzling. The second cube showed strong warping.

To be sure I repeated the printing and printed a third cube with 200°C/200°C and a fourth with 200°C/170°C. While the third one again showed no warping, the fourth cube warped so much that it got off the heated bed and I had to abort the print.

Obviously the reduction of temperature at the second layer weakens the bond of the first layer to the bed. Maybe the "cold" second layer cools down the first one and causes it to shrink. Once the first layer got off the bed the whole part is an easy prey to warping.

Possibly this temperature difference explains a lot of cases of mysterious warping. A little option in the slicing software turns out to be a trap ...

I guess I will repeat this with ABS soon.

Tuesday, December 11, 2012

Mk IV is printing

Today Mk IV got ready.

After making the parts

they were assembled.

It extrudes ABS very well.

For the first time I dared to bore a nozzle with a cheap 0.3 mm PCB drill on my drill press. The drill went through the brass without any difficulty.

The nozzle prints very well. Unfortunatly I broke my 1 mm center drill on Saturday, so I had to use and ordinary 3.5 mm drill for the inside of the nozzle.