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Nick's 3D printer build
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Nick
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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!
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Post Wed Jul 06, 2016 10:10 pm 
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Nick
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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.
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Post Thu Jul 07, 2016 11:36 am 
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Ondray



Joined: 06 Jul 2015
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I grabbed one of those heaters - they are even more adorable in person.

Post Thu Jul 07, 2016 11:46 pm 
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Nick
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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.
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Post Fri Jul 08, 2016 2:57 pm 
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Valen
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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.

http://www.ebay.com.au/itm/100-240V-Digital-PID-Temperature-Controller-40A-SSR-K-Thermocouple-Sensor-/201592348693?hash=item2eefd72015:g:YCYAAOSwUfNXSBIq

might save you a few pennies on your build.
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Post Sat Jul 09, 2016 11:34 am 
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Nick
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Thanks, I was stealing the controller off my curing oven but for that price I can wait. The 40A SSR will be really handy!
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Post Sat Jul 09, 2016 12:30 pm 
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Nick
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Wow, that eBay seller is fast - the controller already shipped! Very Happy

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 Laughing. 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.
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Post Sat Jul 09, 2016 8:39 pm 
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Nick
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(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 Smile. 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.
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Post Sun Jul 10, 2016 1:13 am 
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marto
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More insulation might be a cheaper solution.
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Post Sun Jul 10, 2016 1:42 am 
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Philip
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Insulation might also keep the temperature more even inside the enclosure.
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Post Sun Jul 10, 2016 2:54 am 
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Nick
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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.
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Post Sun Jul 10, 2016 9:32 am 
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Nick
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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.
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Post Sun Jul 10, 2016 11:43 am 
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marto
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I use a towel Razz
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Post Sun Jul 10, 2016 1:06 pm 
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Valen
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If it's a ptc heater, it'll put out less heat as ambient goes up
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Post Mon Jul 11, 2016 9:33 am 
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DumHed
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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.
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Post Mon Jul 11, 2016 9:58 am 
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