Milled transparent extruder This is the extruder I made for converting my DIY CNC mill [forums.reprap.org] into a repstrap (the mill was designed for this since the beginning). mod_embed_images_loadimage('665c49c2b92e576461f829491f55ba5d', '/forum/thumbcache/0d2/8a3/15d/183/a5d/438/926/7b2/ecf/63e/a6_800x400.png', 'http://forums.reprap.org/file.php?70,file=5334,filename=extruder_1.jpg', 'https://reprap.org/forum/addon.php?70,module=embed_images,check_scaling=1,url=http%3A%2F%2Fforums.reprap.org%2Ffile.php%3F70%2Cfile%3D5334%2Cfilename%3Dextruder_1.jpg', '', 98049, 800, 400, 'Loading image ...', false); [attachment 5335 extruder_2.jpg] The extruder is mostly made from polycarbonate, other parts are standard screws and bolts or parts salvaged from epson printers. Milled parts : [attachment 5333 extruder_parts.jpg] The extruder is composed by 9 parts milled in polycarbonate and held together by M3 screws. The ball bearing (13mm ext, 5mm int 4mm width) used as idler came from an old hard drive. Instead of springs, I use small rubber tubes, they came from the rollers of the printer. [attachment 5336 extruder_idler.jpg] The axle and bushings came from the same model of stepper used to drive the extruder. The pinch wheel is a timed pulley from an Epson D88 printer. [attachment 5337 extruder_pinch.jpg] The grip looks good: [attachment 5338 extruder_grip_abs.jpg] I'm working on the hot-end now. https://reprap.org/forum/read.php?70,98049,98049#msg-98049 Mon, 18 May 2026 11:36:43 -0400 Phorum 5.2.23 https://reprap.org/forum/read.php?70,98049,109562#msg-109562 Re: Milled transparent extruder https://reprap.org/forum/read.php?70,98049,109562#msg-109562 Petrus Plastic Extruder Working Group Sat, 10 Dec 2011 08:22:30 -0500 https://reprap.org/forum/read.php?70,98049,109203#msg-109203 Re: Milled transparent extruder https://reprap.org/forum/read.php?70,98049,109203#msg-109203 Nice work. I feel your pain in having to drill through stainless! :) I wouldn't have tackled a shaft as long as you manged to drill through though! I eventually found the best approach to drilling stainless was lots of pressure and low speed, no lubricant. Just get the drill to bite in and keep the pressure on as it peeled away.

What I wanted to mention was that my little experimenting with a stainless insulator concluded that the best tweak by far I made was actually narrowing the neck of the tube, just above the heater, removing the thread and part of the shaft, to reduce the cross-sectional area of the tube. You could do this with in a lathe, or just with a small grinding wheel in a Dremel. This have a termendous impact on how the flow rate of heat up the tube. It creates a bottleneck. It helps greatly keep the heat where you want it, rather than having to expend energy cooling it after it migrates up the tube.

Hope this helps. Best of luck with your design and printing.
Regards,
NumberSix]]> NumberSix Plastic Extruder Working Group Wed, 07 Dec 2011 17:17:29 -0500 https://reprap.org/forum/read.php?70,98049,106151#msg-106151 Re: Milled transparent extruder https://reprap.org/forum/read.php?70,98049,106151#msg-106151 [attachment 5855 extruder_v2.JPG]]]> Petrus Plastic Extruder Working Group Mon, 14 Nov 2011 12:11:00 -0500 https://reprap.org/forum/read.php?70,98049,99559#msg-99559 Re: Milled transparent extruder https://reprap.org/forum/read.php?70,98049,99559#msg-99559 [attachment 5459 extruder_4.jpg]
[attachment 5460 extruder_5.jpg]
[attachment 5461 extruder_temp.GIF]

The heating wire is a kapton insulated alumel wire from a K thermocouple.
The result are even better than I expected, with the heater at 7V (I=1,3A) the temperature of the tip rise up to 250°C, and the entrance of the hotend does not rise above 50°C with the fan turned off.
With the fan at 6V (low speed) the entrance fall below 30°C.
I pushed it to 400°C, the entrance was only 61°C with the fan turned off and 31°C with the fan at 6V.

I also extruded some ABS and PLA by hand without any issues.]]> Petrus Plastic Extruder Working Group Fri, 30 Sep 2011 16:11:21 -0400 https://reprap.org/forum/read.php?70,98049,99520#msg-99520 Re: Milled transparent extruder https://reprap.org/forum/read.php?70,98049,99520#msg-99520 the post is here

And my blog on it is here

Rich.]]> richrap Plastic Extruder Working Group Fri, 30 Sep 2011 08:42:20 -0400 https://reprap.org/forum/read.php?70,98049,99461#msg-99461 Re: Milled transparent extruder https://reprap.org/forum/read.php?70,98049,99461#msg-99461
The first vertical lathe I made was too high to drill the barrel, so I made a new one much more flat with a brushless motor from a laser printer : [attachment 5455 vertical_lathe_2.jpg]

The stainless steel rod was very hard to drill, I had to reshape a cobalt drill-bit with a dremel : [attachment 5454 drillbit.jpg]
I also had to sharpen the drillbit several times during the drilling.
With the original shape, even if the drill was new, it just slide on the surface without removing any material.

Now I need to wind the heater and drill the tip to complete the extruder.]]> Petrus Plastic Extruder Working Group Thu, 29 Sep 2011 19:18:36 -0400 https://reprap.org/forum/read.php?70,98049,98213#msg-98213 Re: Milled transparent extruder https://reprap.org/forum/read.php?70,98049,98213#msg-98213 A very clean design overall...nice job!]]> mc_n_g Plastic Extruder Working Group Mon, 19 Sep 2011 18:13:23 -0400 https://reprap.org/forum/read.php?70,98049,98135#msg-98135 Re: Milled transparent extruder https://reprap.org/forum/read.php?70,98049,98135#msg-98135 I was using fibre glass insulated nichrome wire on a brass barrel with a thermal coupler temperature sensor. the assembly was wrapped with kapton tape. This assembly gave off a really bad smell. Dismantling the unit, both the fibre glass insulation as well as the kapton tape were very charred. The nichrome wire heater didn't fail. Another issue I had was the a delay when extruding and ooze after stopping even with reverse feed.
I played around with making some barrels out of brass. I believe that PLA has a problem with sticking on the inside of the brass barrel. Also the inside drill hole in the barrel has to be very smooth. I ended up deciding the designed using an PTFE insert was a good design and purchased one.

The reason for the large extruder stepper motor was it was free, I also like direct drive rather than gears. I still have more of the smaller stepper motors that I used for the X , X, Z but don't think they have enough horse power for direct drive. The minus side is there is more mass to move. I currently use acceleration.]]> RepRot Plastic Extruder Working Group Mon, 19 Sep 2011 03:51:52 -0400 https://reprap.org/forum/read.php?70,98049,98066#msg-98066 Re: Milled transparent extruder https://reprap.org/forum/read.php?70,98049,98066#msg-98066 james glanville Plastic Extruder Working Group Sun, 18 Sep 2011 09:02:23 -0400 https://reprap.org/forum/read.php?70,98049,98063#msg-98063 Re: Milled transparent extruder https://reprap.org/forum/read.php?70,98049,98063#msg-98063 www.thingiverse.com]
With wire heater too.
What was the problem with your nichrome wire heater ? Did you found why it failed ?

I think we can improve the design by using a brass insert to increase the thermal mass and by winding some copper filament on top of the heating wire to improve the thermal conductivity.

RepRot, Nice design, very clean and it looks indestructible, but why a so big stepper for the extruder ?]]> Petrus Plastic Extruder Working Group Sun, 18 Sep 2011 06:23:18 -0400 https://reprap.org/forum/read.php?70,98049,98056#msg-98056 Re: Milled transparent extruder https://reprap.org/forum/read.php?70,98049,98056#msg-98056
See write up at - [www.reprap.org]

Just upgraded it with a Makebot MK6+ extruder that has stainless steel barrel lined with PTFE - had to use a fan to cool the PLA filament to stop it going soft and benting before it entered the extruder assembly.]]> RepRot Plastic Extruder Working Group Sat, 17 Sep 2011 23:06:37 -0400 https://reprap.org/forum/read.php?70,98049,98052#msg-98052 Re: Milled transparent extruder https://reprap.org/forum/read.php?70,98049,98052#msg-98052
[picasaweb.google.com]]]> james glanville Plastic Extruder Working Group Sat, 17 Sep 2011 21:09:02 -0400 https://reprap.org/forum/read.php?70,98049,98049#msg-98049 Milled transparent extruder https://reprap.org/forum/read.php?70,98049,98049#msg-98049 forums.reprap.org] into a repstrap (the mill was designed for this since the beginning).

[attachment 5335 extruder_2.jpg]

The extruder is mostly made from polycarbonate, other parts are standard screws and bolts or parts salvaged from epson printers.

Milled parts :
[attachment 5333 extruder_parts.jpg]
The extruder is composed by 9 parts milled in polycarbonate and held together by M3 screws.

The ball bearing (13mm ext, 5mm int 4mm width) used as idler came from an old hard drive.
Instead of springs, I use small rubber tubes, they came from the rollers of the printer.
[attachment 5336 extruder_idler.jpg]

The axle and bushings came from the same model of stepper used to drive the extruder.
The pinch wheel is a timed pulley from an Epson D88 printer.
[attachment 5337 extruder_pinch.jpg]

The grip looks good:
[attachment 5338 extruder_grip_abs.jpg]

I'm working on the hot-end now.
]]> Petrus Plastic Extruder Working Group Sat, 17 Sep 2011 19:39:33 -0400