Joined: 16 Jun 2004
Posts: 11802
Location: Sydney, NSW
You might want to pick up one of those Bunnings heaters before they sell out - my local store hardly had any left. At $15 for a well built heater, you really can't go wrong! _________________ Australian 2015 Featherweight champion
UK 2016 Gladiator champion
Wed Jul 06, 2016 10:10 pm
Nick Experienced Roboteer
Joined: 16 Jun 2004
Posts: 11802
Location: Sydney, NSW
Ninjaflex success:
The Cocoon printer now has a Flexion extruder permanently mounted - its going to be the low temperature / soft filament printer from now on. I had a try at printing Ninjaflex filament and after eight failures and a very late night, the settings in Simplify3D are dialled in just right to create tough parts with 100% in-fill. Here are the first & final prints:
The problem is a low extrusion rate compared to harder plastic - its probably not the filament slipping in the extruder as the flow rate is very consistent. I had to increase the extrusion multiplier from 0.9 (good for PLA) up to 1.3. In the infill tab, the outline overlap was increased to 45%, the infill extrusion width was increased to 160% and I included a solid diaphragm every layer. I also turned off all the ooze control, which might sound counter-intuitive but really improved the vertical surface finish.
The difference in flex between the first and last test is huge! I can easily squish the first part flat, while the final part only deflects a few millimetres even when using both hands.
So, what's it good for?
The most obvious thing is shock protection; it might be possible to replace Mr Mangle's electronics carbon fibre carrier board with Ninjaflex or Semiflex for better isolation. Flexible cable guides and back shells for connectors are another good use. I like the foam I pack around the Lipo pack but it wears out fast - Ninjaflex might make a more durable replacement. The first project with Ninjaflex is making vibration dampers for the stepper motors on the new printer; my version of Astrosyn mounts. _________________ Australian 2015 Featherweight champion
UK 2016 Gladiator champion
I grabbed one of those heaters - they are even more adorable in person.
Thu Jul 07, 2016 11:46 pm
Nick Experienced Roboteer
Joined: 16 Jun 2004
Posts: 11802
Location: Sydney, NSW
The first custom parts are made - these mounting blocks support the Y axis rails:
Unlike the printed prototype supports, I saved a heap of time and probably increased accuracy by leaving them as blocks and using a slitting saw to cut flex grooves where the support clamps down on the rod. Now to rinse & repeat for the Z axis rail supports. _________________ Australian 2015 Featherweight champion
UK 2016 Gladiator champion
Fri Jul 08, 2016 2:57 pm
Valen Experienced Roboteer
Joined: 07 Jul 2004
Posts: 4436
Location: Sydney
I have a $20 or so ebay chinese PID controller for our (food) oven, works just fine and dandy, came with the SSR, and thermocouple and all haven't had any issues with it.
might save you a few pennies on your build. _________________ Mechanical engineers build weapons, civil engineers build targets
Sat Jul 09, 2016 11:34 am
Nick Experienced Roboteer
Joined: 16 Jun 2004
Posts: 11802
Location: Sydney, NSW
Thanks, I was stealing the controller off my curing oven but for that price I can wait. The 40A SSR will be really handy! _________________ Australian 2015 Featherweight champion
UK 2016 Gladiator champion
Sat Jul 09, 2016 12:30 pm
Nick Experienced Roboteer
Joined: 16 Jun 2004
Posts: 11802
Location: Sydney, NSW
Wow, that eBay seller is fast - the controller already shipped!
The heated enclosure is almost ready to test, I just have to decipher the manual.
The wiring is just as dodgy as it looks - exposed mains terminals and all . I am being REALLY careful around this death-trap.
The heating element doesn't get nearly as hot with the new high flow fan attached:
The ceramic elements still get up to 200 degrees but the cooling fins around them are mostly around 50 to 70 degrees. That's good news as it means I can safely replace the plastic shroud with my own compact Garolite version. _________________ Australian 2015 Featherweight champion
UK 2016 Gladiator champion
Sat Jul 09, 2016 8:39 pm
Nick Experienced Roboteer
Joined: 16 Jun 2004
Posts: 11802
Location: Sydney, NSW
(not so) Hot Stuff:
The heated enclosure is a partial success. The controller can regulate the temperature quite well at 50 degrees but the heater runs out of grunt at 56 degrees, which is well short of the 70 degrees that is supposed to be ideal. I guess it will need another heater and fan to push the temperature higher - good thing I bought an extra heater . Further testing has to wait for the new controller and SSR; the small relay in the current controller is almost maxed out with just one heater attached. _________________ Australian 2015 Featherweight champion
UK 2016 Gladiator champion
More insulation might be a cheaper solution. _________________ Steven Martin
Twisted Constructions
http://www.botbitz.com
Sun Jul 10, 2016 1:42 am
Philip Experienced Roboteer
Joined: 18 Jun 2004
Posts: 3842
Location: Queensland near Brisbane
Insulation might also keep the temperature more even inside the enclosure. _________________ So even the rain that falls isn't actually going to fill our dams and our river systems
Sun Jul 10, 2016 2:54 am
Nick Experienced Roboteer
Joined: 16 Jun 2004
Posts: 11802
Location: Sydney, NSW
The final enclosure might have worse insulation - its going to have polycarbonate front and back panels. Using two heaters isn't a big deal, I am just a bit surprised that it takes so much power to heat a small volume up to 70 degrees. _________________ Australian 2015 Featherweight champion
UK 2016 Gladiator champion
Sun Jul 10, 2016 9:32 am
Nick Experienced Roboteer
Joined: 16 Jun 2004
Posts: 11802
Location: Sydney, NSW
I just had a crazy idea about the heating - if one heater running 100% of the time by itself can get the enclosure up to around 55 degrees then that's a new ambient temperature. I can use just one heater on the temperature controller to boost the enclosure up to 70 degrees - something worth trying before the new temp. controller arrives.
I also had a think about insulation. If the enclosure needs a 1,000 watts to keep it hot, then an over-night print will use a substantial amount of over priced electricity. I already ordered some Nomex insulation felt (the stuff used in fire fighter's suits) and it will be easy to get more and make a thermal blanket to drape over the printer for long print runs. _________________ Australian 2015 Featherweight champion
UK 2016 Gladiator champion
I use a towel _________________ Steven Martin
Twisted Constructions
http://www.botbitz.com
Sun Jul 10, 2016 1:06 pm
Valen Experienced Roboteer
Joined: 07 Jul 2004
Posts: 4436
Location: Sydney
If it's a ptc heater, it'll put out less heat as ambient goes up _________________ Mechanical engineers build weapons, civil engineers build targets
Mon Jul 11, 2016 9:33 am
DumHed Experienced Roboteer
Joined: 29 Jun 2004
Posts: 1219
Location: Sydney
Are you blowing air into the enclosure with the heater, or circulating it inside the enclosure?
A well insulated box shouldn't need much power to keep it at 70° if the heater is just circulating the air inside it. _________________ The Engine Whisperer
- fixer of things
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