My Latest Project -- Introducing The TiEnd

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My Latest Project -- Introducing The TiEnd

Postby JeremyBP » Fri Mar 01, 2013 3:45 pm

Hi all.

So I've been gone a while. But I'm back now. I've spent the last couple months dreaming about hot-ends, what I like, what I don't like. What's worked, what hasn't. And so I took my last design (http://reprap.org/wiki/Odd_End), and started to update it. The Odd-End currently lives in Madison, where it's been running almost non-stop since July, and I wanted to keep that reliability. But I also wanted to try printing in polycarbonate, which would just melt the PEEK/PTFE thermal barrier. And so I got to thinking about using a stainless thermal barrier, when the thought hit me. Titanium.

Earlier this year, I was dismantling and repairing a stratasys dimension 1200st (which I broke) when I noticed something odd about the extruder design. The heater blocks were made of stainless steel. The cartridge heaters were about an inch from the filament tube, and the filament was being melted at 300ºF, according to the thermocouples. The area only an inch away where the cartridge heater lived was bluing from the heat. Stainless starts to blue at around 500ºF. Clearly, there was some serious thermal gradient going on there, but this machine was designed by people who know what they're doing, so it must be like that for a reason. Best I can figure, here's why. The stainless steel acts like a resistor in an oscillator circuit; it's a damper. It helps smooth out thermal oscillations by slowing down and limiting heat transfer between the cartridge heater and the filament tube. So why not apply that to my new hot-end? Except with titanum instead of stainless, because titanium is awesome. :twisted:

The nozzle has remained mostly the same. I's short and steep, with a very short extrusion length to reduce the possibility of jams. Oh, and it's also made of titanium.

Because of the high cost of prototyping this, I've decided to try crowdfunding it. I'd really appreciate it if you'd take a look, and I'd love to hear your thoughts.
http://www.gofundme.com/25v5ng

Thanks!

EDIT: I can English, I promise.

SON OF EDIT: Pictures!
Image.png
Thermal barrier. The top section has since been updated to fully threaded.


Nozzle.png
Nozzle.


Assembled.png
All assembled!
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Re: My Lstest Project -- Introducing The TiEnd

Postby AVRC » Fri Mar 01, 2013 5:27 pm

What filament diameter is this for?
I'm guessing 1.75 based on the 6mm thread diameter?
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Re: My Latest Project -- Introducing The TiEnd

Postby JeremyBP » Fri Mar 01, 2013 5:29 pm

Yes, it is designed for 1.75mm filament.
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Re: My Latest Project -- Introducing The TiEnd

Postby AVRC » Fri Mar 01, 2013 5:33 pm

Awesome. I'm in.
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Re: My Latest Project -- Introducing The TiEnd

Postby JeremyBP » Fri Mar 01, 2013 5:36 pm

Thanks! This is going really fast, and is going to be awesome! I'm really excited!
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Re: My Latest Project -- Introducing The TiEnd

Postby SystemsGuy » Fri Mar 01, 2013 6:08 pm

I'll be in - would you mind posting some pictures of the one you have running? I'm assuming you are using an MBI/QU-BD style fan mounted block?

Also - the last Dimension I dissected had a serious insulation between the nozzle and the heaterblock - I always assumed this was to keep the heat away from the printed part....
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Re: My Latest Project -- Introducing The TiEnd

Postby JeremyBP » Fri Mar 01, 2013 6:14 pm

I don't have a TiEnd running yet, this the first run of prototypes. However, my last version looks like this.
oddend.jpg
The Odd-End, partially assembled.


This is also just the hot-end, it doesn't have a drive. But it would thread straight into a qu-bd drive block.

The stratasys extruder does have a pretty serious heat shield between the heater block and nozzle. I was referring more to the space in the heater block between the cartridge heater and the melt zone of the filament. I can't find a picture, but I'll try to take one next time someone is crazy enough to let me mess with their $35K+ machine.

EDIT: Here's the thread the original design came out of. viewtopic.php?f=33&t=1123&start=178
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Re: My Latest Project -- Introducing The TiEnd

Postby SystemsGuy » Fri Mar 01, 2013 6:34 pm

LOL - I know the feeling w/regard to playing with expensive toys. I've got a standing appointment at the lab any time one of ours is services, just so I can watch! :-)

I'm assuming you are outsourcing the machining since - as you say - it *is* TI? ;-P
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Re: My Latest Project -- Introducing The TiEnd

Postby JeremyBP » Fri Mar 01, 2013 6:47 pm

It is Ti. The heater and nozzle are both grade 2, the thermal barrier is Ti6Al4V. I will be doing the machining myself for the prototypes, and if they work and I decide to do a larger batch, then I will outsource.

Ti isn't as bad as people make it out to be if you aren't going for production speed. The only nasty thing is tapping, ad there's only two holes to tap (both of which are fairly large, so I'm not worried). And Ti-Specific taps help a lot.

By way of a machining resumé, I've spent the last several years apprenticing in machining, and I was hired last summer to work as a fabricator in a lab at UW-Madison making parts for fluid dynamics research apparatus. Here's a two-speed shiftable transmission I made last year.
20120531_124108.jpg
Transmission with 2800W brushless motor mounted.


I hope I have your trust to make these.
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Re: My Latest Project -- Introducing The TiEnd

Postby Enraged » Fri Mar 01, 2013 6:58 pm

where does the thermistor mount? One of the more frustrating "features" of the qubd is no spot to put it (plus they wrapped the thermistor in silicone heatshrink??), so I ended up taping it as close to the nozzle as I could.

edit: also, assuming this is successful, what are your plans for full production? discount for backers?
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