Sunday, 17 April 2011

It's Alive!

Although a bit shoddy so far...

A somewhat crazy end to the week, first I get the neighbours upstairs leaking water through the bathroom light fitting and blowing it out, then British Gas take too much on my direct debit and put me through the bottom of my arranged overdraft, not making other things easy.
Nevertheless, good friends are on hand to help out. With that drill borrowed from an ex-bowyer, I made quick work of the heating resistor mounting on my reprap's printbed, and luckily had a handy friend with a soldering iron nearby.
Heated bed developed by C Gubbels. Only way available to connect that power seemed to be by splicing and soldering wires, hence the zip tie for strain relief.

A day after that was sorted, with some kapton tape on top of course, I ran it for a test with my thin-walled box design.
Here is my reprap printing out the first layer, watch to the end if you want to cringe:
Whilst that unfortunate problem was quickly sorted, the printer carried on fairly well. However, as you can see there, the settings aren't quite perfect, given the fact that the perimeter didn't lay down and that there was a bit of a gap halfway through the first layer. On the second and third layers, that gap was printed over, albeit messily. As the machine carried on, most of the vertical thin wall was printed very messily, although one of the four sides almost printed perfectly.
I worked out that the problem probably wasn't that the bed wasn't hot enough halfway through, seeing how rubbery the layer underneath the current one would be, but rather that the bed needed to cool down so that the layer below stayed still while material was being deposited on it, and that it's probably the extruder temperature that's too low. Based on that I unplugged the heated bed and tried to tell the extruder to increase temp slightly, which seemed to help a tiny bit towards the end.

I'll soon find out whether my theory is correct with another print, but here is the result of that one, from both sides:
It's not pretty, but it is kinda box-shaped. :P
Probably shouldn't ever try to print walls quite so thin anyway.

I probably won't be posting much for the next week and a bit as I approach my dissertation hand-in and final exams, but we'll see what turns up.

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