Extruders

WillAdams
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Re: Extruders

Post by WillAdams » Mon Jul 21, 2014 2:45 pm

Okay, I think I have my machine conversion (Wade's reloaded extruder from kbot3d and Jhead v5 hot end) together and working --- except that it feeds a certain length of filament and then stops.

What is one supposed to do to manage the transition from the extruder to the hot end?

I simply assembled things and assumed that it properly lined up....
Shapeoko 3XL #0006 w/ Carbide Compact Router w/0.125″ and ¼″ Carbide 3D precision collets

Ironaxe
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Re: Extruders

Post by Ironaxe » Mon Jul 21, 2014 3:32 pm

Anyone tried one of these Extruders?
http://www.ebay.de/itm/201114514667?ssP ... 1423.l2649
eShapeoko 1.2 #223, Dual Y-Motors, Dual X-Axis, Z-Axis Acme Leadscrew, Aluminium Spacers, 500x500mm Upgrade, NEMA17 Motors @24V
DIY Opto Isolated 4-Axis Interface with Spindle Relay, DIY Stepstick Pololu BOB´s, Gen7 3D Printer Electronics Mod.

SnapFracturePop
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Location: Davenport, IA

Re: Extruders

Post by SnapFracturePop » Mon Jul 21, 2014 4:27 pm

Looks a lot like the Qu-Bd design with a spring upgrade. Without handling it I can't really say if they've fixed the issues that plagued the Qu-Bd design, but at 45 euros, I doubt it. The extruder & hot end are the core of a 3d printer, and going cheap doesn't pay off in the end. I learned that the hard way. I've also switched to a Reprap frame - the 'Oko had too much bounce.

My current setup is the E3D bowden hot end & Wade's extruder. The all-metal E3D also means you could print higher temperature plastics should you choose and some really good design ideas have eliminated jams entirely for me in ABS.* Wade's extruder is a good design, though there are dozens of good designs for extruders to choose from.

http://e3d-online.com/E3D-v6/v6-1.75mm-Universal-Bowden

* - Since I say this, I expect Murphy's Law to kick in & make my printer jam tonight. Even so, it's been months since I've had an issue. I do give half of the credit to buying filament from a reputable source, http://www.Makergeeks.com.
Shapeoko #384: dual-Y, outside-belt, ACME-Z,1000mm Y, drag chain cable management, insert-nut style base board, 800mw IR laser cutter, & 3d-printing with Qu-Bd & Printrboard.

WillAdams
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Location: Pennsylvania --- south of the Turnpike, East of US-15
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Re: Extruders

Post by WillAdams » Mon Jul 21, 2014 4:46 pm

SnapFracturePop wrote:The extruder & hot end are the core of a 3d printer, and going cheap doesn't pay off in the end. I learned that the hard way.
Understood. I tried hard to get the best quality there.
I've also switched to a Reprap frame - the 'Oko had too much bounce.
Interesting. I guess this detracts from the quality /usability of the prints? Any ideas on addressing this w/in the scope of a converted machine?

Any thoughts on the viability of the conversion? I'm hoping it's still valid as:

- inexpensive way to try out 3D printing
- suitable for occasional use if swapped in / out w/ a milling head
- straight-forward way to bootstrap a 3D printer
Shapeoko 3XL #0006 w/ Carbide Compact Router w/0.125″ and ¼″ Carbide 3D precision collets

SnapFracturePop
Posts: 67
Joined: Fri May 04, 2012 5:13 pm
Location: Davenport, IA

Re: Extruders

Post by SnapFracturePop » Mon Jul 21, 2014 6:12 pm

I think some of the mods since my 'Oko from the original Kickstarter may have helped, like the dual beam on the gantry. The trouble is that 3d printing speeds tend to be higher compared to milling - each layer is 0.2mm or so tall, and the width is only slightly larger than that on each pass. You can keep the 'Oko speed down but prints will take a long time.

Bounce makes the edges wavy after a turn. Too much bounce can mean the layer doesn't sit flat, doesn't adhere to the layer underneath, or doesn't leave a flat surface for the next layer, which builds with each layer & deforms the piece. Acceleration adjustments should help, though that will increase the print time.

I can't tell much about the extruder you're suggesting, but what I've found is that the main problem with extruders is cooling, not heating. When you push filament through, it melts as soon as it's warm enough. In the Qu-Bd, heat traveled up the barrel & the PLA was becoming soft halfway up the shaft. More PLA pushed behind it, causing it to expand, push into the sides & stick. ABS does this too, but to a lesser extent, and requires a heated print bed. A good hot end will cool all but ~5mm of the barrel quickly, so there's almost no temperature transition zone. The filament doesn't have a place to get squishy, so it flows as expected.
Shapeoko #384: dual-Y, outside-belt, ACME-Z,1000mm Y, drag chain cable management, insert-nut style base board, 800mw IR laser cutter, & 3d-printing with Qu-Bd & Printrboard.

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