Talk:RepRap Universal Mini Extruder
Jkeegan 18:32, 14 April 2011 (UTC) Hello! Adrian, what's the purpose of the hacksaw slot on the heater block? Is it just to compensate for expansion of the brass when it's heating up? Without threads, does the heater block hold on tightly? (I imagine it'd obviously depend on the size of the hole drilled, but in your prototype, is it easily slid out for maintenance, or tight?). On this page's discussion page I asked that too (sorry for repeating myself). On that page you mentioned you based your design on this one by Alain Mouette, and his pictures show what looks like a tightening bolt through the side with the slot. Just curious if you found the bolt unnecessary but the slot necessary, or just hadn't noticed the bolt, etc. Thanks!
For the sake of documentation, here's the response from Adrian on reprap-dev:
The slot is to allow for poor machining accuracy :-) You can drill the hole accurately, of course. But you then need to turn the nozzle to get a tight fit. If this ends up too tight, the slot allows a little give in the block. If it's too lose, you can compress the block plastically in a vice and the slot closes a bit; then it's tight...
Alain Mouette also commented:
I can say about my part of it: I like the slot because I use a screw to tighten the block on the nozzle, it makes it very convenient to remove it for mantainance or changing the nozzle. I understand that Adian's idea is just for the slot to allow for a little expansion as the block is press-fited on the nozzle.
- Jkeegan 20:27, 25 April 2011 (UTC)
It's strange to see "based on: unknown" and then in the text "I based this design (loosely) on Jstkatz's extruder on Thingiverse" --MarcusWolschon 03:09, 11 May 2011 (UTC)