B from B extruder hot section mods / performance

Greetings All:

So I've recently received my second bits from bytes extruder kit. (the first one was a victim of my numerous misdeeds). To counteract the low heat problem I first covered the barrel with some mica film (McMaster part# 85825K41) the mica was then secured using a coating of teflon tape to prevent film from unraveling. The heater coil was then wound directly onto the teflon / mica film, and the entire assembly was covered with the fire cement provided by bits from bytes. Another issue I had was the ability of a standard computer PSU (520 Watts with +12v 20A rail) to give me the voltage flexibility I desired. so I used the computer PSU to power everything except the heater which was then powered by a CIC PS-1930 bench PSU.

All in all I'm fairly satisfied with the performance: from a room temperature of 26 C to an indicated nozzle temperature of 253 C in 4 minutes and 12 seconds with the extruder fan blowing cool air onto the nozzle during the heating process. This was accompanied by a noticable amount of ABS flowing through the nozzle so I believe that I'm not just reading the heater coil temp. (Average heater power consumption is 39.78 Watts)

I was wondering if anyone else had tried something similar and could share their experiences with their mods...

Edited 2 time(s). Last edit at 12/27/2008 06:04PM by x2800m.

While browsing around for parts for my repstrap-to-be, I just saw Mica tape at McMasters (catalog nr 6811A22) that is both cheap ($4.56 for a 1" by 15' roll, $2.33 for 1/2" width) and rated for temperatures up to 2100F (1150 C). As this is tape, it should be possible to just wrap and secure at the cooler end.

When winding the nichrome wire directly on the teflon tape, that will burn and desintegrate although that might not matter too much because of the fire cement. I just did a search to see if anyone had tried mica, and you did! Please keep us posted on how your heater holds up with use.

Regards,
Geert

-- description from McMaster --
High-Temperature Mica Tape

Withstanding temperatures up to 2100

Edited 1 time(s). Last edit at 12/28/2008 01:59PM by GeertB.

the mica heater has been operating for no less than 4 hours a day since the 25th. Has not failed yet.