Showing posts with label Prusa. Show all posts
Showing posts with label Prusa. Show all posts

Wednesday, 28 September 2011

Hot End Fail

I’ve had a bit of a break from my RepRap project recently, mainly caused by my disappointment when my first hot end lasted all of about 1 hour continuous printing before failing. It looks like the force of the filament being pushed down into the barrel was sufficient to cause the threads to slip on the PTFE interface. Probably partly due to heat making the PTFE more compliant. It does look like some plastic has made its way into the thread, but I’m not definite that it’s not just remnants of the PTFE tape. I’ve ordered the new design hot end components so looking forward to assembling that.

Meanwhile I’ve made a couple of adjustments. I’ve moved the USB connection from the top board to the lower board next to the power connection, I’ve added a switch (salvaged from a broken kettle) to the 12V power, and also added an LED strip to the underside of the upper board which nicely lights up the build area. Although I am now starting to think that it would be better to have all the electronics encased in a project box and have the rest of the machine stand alone.

I’ve also been working on a side project; using my android phone as a remote control for my Samsung TV using an Arduino connected via Bluetooth. It worked a lot easier than I thought and showed me how simple (and cheap) it could be to add wireless capability to any Arduino project. Documentation is a little sparse at the moment but hoping to add more soon, but if you’re interested the info can be found here:


http://sites.google.com/site/jsrsprojects/androidir

Friday, 24 June 2011

X Axis Belt Tension

I noticed I little lashing on my x-axis, it looked like it was being caused by the slack in the belt. The tension is set when first using the clamps, keeping the belt tight whilst tightening the clamps is a little fiddly. So I decided to try and improvise a tensioner. I looked around the house for torsion springs that might be suitable, I found a promising one in a cheap clamp (Tesco DIY little hand clamps). The un-tensioned legs of the spring were set to about 110° apart, and had long legs that I could bend around to hook onto the belt. The spring works really well in keeping tension in the belt, I might need to do some more reshaping or use tape to ensure that it stays in position in the long term. Here are some pics:

From Mendel


From Mendel


From Mendel


From Mendel