Arcol blog Just another RepRap weblog


Summary of 2012, 220% steam ahead

What a year. Read and remember the biggest moments of 2012.

And at the end get to know of a completely new product, the best way to finish a year.

Lets greet the new family member, the mini-hyena v2.0 and also regular hyena v2.0!

Achievements in 2012

Just a quick recap before we advance to the next big thing:) hotend v4 — 2012 January

Although the initial version of the v4 hotend went live at the end of 2011, many later improvements came this year. So it is a really 2012 product. Grab one here. hyena v1.0 — 2012 April

I started with v1.0, do you remember?:

M8 nut with M3 grubscrew — 2012 April


When a simple nylock M8 nut is not enough, and you need more torque.
Documentation here. Available here. hotend v4.0.5 — 2012 May

Bugfix release over v4.0. Announcement here.

Grooved 608 bearing — 2012 May

Tiny, but useful improvement. Original announcement here. mini hyena v1.0 — 2012 June


Discovering the need a reliable drive gear for direct drive mechanism, I launched the mini hyena campaign.

I gathered many feedbacks from this campaign, which helped to redesign the whole hyena family. See at the end of this article:) hotend v4.1.1 — 2012 October


I improved v4.0.5 more, and came out with v4.1.1:
It is not only bugfix (set screw), but also a real improvement (aluminium mounting) and aesthetic (black tubing) over v4.0.5 design.
Grab one here. hyena v1.1 — 2012 October


It is basically a usability improvement. Now you can counter-tighten with a 6mm wrench instead of a pliers.
For announcement, read here.
Grab one here.

Spring kit — 2012 November


Original announcement here. Grab one here.

Maglev fans — 2012 November


Maglev fans move more air with less noise; a small but nice improvement.
It is available for sale with the complete extruder (see next point).

Complete extruder — 2012 December


Original announcement here. Grab one here.

The Hyena family v2

The campaign helped me get the manufacturing done and gather much feedback.
Which kickstarted the design of v1's successor!

Asymmetric tooth profile - Hyena v2

To come up with this tooth profile it had taken countless hours and numerous versions.

Did you think the hyena was a great product? Then you'll think v2 is the best product ever!

The v2 outperforms v1 by 220%. That means at a given force where v1 has already slipped and chewed up your filament, v2 is still pushing it through happily!



For the tech-savvy out there, here is the drawing:

Unified size

One of the main discoveries from the campaign was
that the four different sizes did more confusion than good.

The conclusion is to make one size with either a 5mm or 8mm bore.
It makes everyone's life easier and one size fits all!

Here is a picture to demonstrate this handy property:

Regular hyena adjusted — Hyena v2.0

This news itself would deserve a separate article, as it is a huge milestone.
For v1.0 announcement, read here, and for v1.1 read here.


The shorter, the better

You don't need worry about the length of your motor shaft. Or particular extruder design,
because the mini hyena was designed to the shortest length possible: 10mm!

One size fits all

A picture worth a thousand words:)


Mini hyena fits on either 5mm or 8mm motor shafts.

Final look

When the extruder is properly set up the hyena accumulates absolutely no plastic chips over time.

Here is a photo after two weeks of continous printing:

If there are some chips inside, clean the Hyena with a needle not a file.
Never use heat especially not a blowtorch.

Printing achievements

I should compile an another article, where we are currently quality-wise, since I teamed up with a professional graphic artist (hey QNLaca!:)).

Until that article, here is a photo for the impatients:

Hall of fame

People, who made the mini hyena and also the v2 development possible:

  • Anonymous
  • dazed.dnc
  • Anonymous
  • atntias
  • Sefi1
  • fdefoy
  • harmonicity
  • hewball
  • houde.jeff
  • Anonymous
  • whosawhatsis
  • Intrinsicallysublime
  • bjoern5
  • contribute1334329857
  • cjmekeel
  • ckaosatom
  • scott.a.maher
  • wat_willy
  • raldrich
  • nop.head
  • device2003-kst
  • RobPovey
  • repraphd
  • justin.hawkins
  • Anonymous
  • contribute1338394611
  • vastempty
  • contribute1338413084
  • Anonymous
  • Inc0me
  • gary.s.hodgson
  • Anonymous
  • Anonymous
  • MattS
  • hoani.cross
  • boman22
  • lincomatic
  • Anonymous
  • colin22
  • m.feherpataky
  • DerekAnderson1
  • proto.user
  • Anonymous
  • SteveKelly
  • contribute1338109472
  • Pazu1978
  • AlessandroRanellucci
  • reprapdiscount
  • paranya2
  • Anonymous
  • Anonymous
  • labmat
  • maxinux
  • kurtis.burr
  • Anonymous
  • maik1
  • clem.taylor
  • Anonymous
  • Anonymous
  • JordanRoss
  • logxen
  • Anonymous
  • Anonymous
  • logxen
  • jax1000
  • reprapdiscount

It's Party-time! See you guys in 2013!:) Can't wait to show you my latest stuffs!:)
I change slightly the commenting policy. I will close the commenting after a week of the date of publishing to prevent spams leaking through.

But in all occasion, please prefer the mailing list.

After the above deadline, any further discussion can only happen on the mailing list, in this thread.


Recommended extruder setup


Grab the complete setup here.

Many people ask me what setup I am using with the v4 hotend,
or what setup I recommend for it.

I bit the bullet, and I wrote this detailed article.

I am always trying to push the envelop of 3D printing, therefore my machine
is evolving all the time, so you can expect more articles in the future:)

The extruder shown here will also be available as a kit through the website.

This recommendation is for 2012 december, although it could have been built since around 2012 march.

Partlist (with pictures) hotend v4.1.1:

Go grab one! or Grab the complete setup! hyena v1.1:

Go grab one! or Grab the complete setup!

M8 nut with M3 grubscrew:

Go grab one! or Grab the complete setup! spring kit:

Go grab one! or Grab the complete setup!

40mm fan:
Are you wondering why is a cap there?: Maglev carriage fan

Wade's accessible extruder body:

Carriage with 2 fan holders:

Satchet of nuts and bolts:

608 bearings and linear bearings (LM08UU):

Just to see it in perspective:)

Downloading the .stl file of the RP parts

All of the RP parts, are from thingiverse.
However I have modified almost all of them. I will publish one .stl file per
week on thingiverse, referring back to the original thing and its author.

Assembly of the carriage

Here is the carriage one more time:

The linear bearings goes in there:

The two fans on the sides, and it looks like this when mounted on a machine:
(Note: There is one bar clamp missing from the above picture)

The modell of this print is available on thingiverse, as thing:39923. It is basically a touchup of thing:15534, which is based on thing:9869.


This is the idler of the Wade extruder pusher:

It has an integrated guide, so you dont need the grooved 608 bearing,
to guide the filament, its mere cost saving.
You can still have the grooved 608 bearing, it does not make things worse, this idler just duplicates the grooved 608 bearing feature.

The modell of this print is available on thingiverse, as thing:39933. It is basically a touchup of thing:17030 and thing:6703.

I have RP parts available in three different colors: white, green and black.
Here is a comparison between green and white print:


Here is the gears I use:

You may be wondering why I am not using herringbone gears.
Herringbone gears run a little quiter, and have a tiny bit less backlash.
Also they can handle higher torque.

However it does not affect print quality.
The filament has a backlash due to its inertia, and we compensate
for backlash anyway. It has the same number of teeth, so no additional
resolution either (not that we need it).

But the main reason is that it is more troublesome to print out, for no real
advantage, so I kept the traditional spur gears. You can print a
herringbone if you wish as an upgrade.

Wade pusher (extruder upper body)

Here we go:

It is a modified Accessible Wade extruder, mainly the holes were adjusted.
It is more accurate and compatible with
v4 hotend.

Here is how the gears, idler and wade upper body will come together:

The complete setup

The complete extruder assembled with carriage. Everything mounted:

You can see the setup is standing on two M8 nuts, so the
hotend is lower by just enough distance then the two fans.
It is optimised for the minimum height, so you have the
maximum printing height possible*.

Here are some more pictures, it is kind of rotating:)


You could have build this extruder setup from about february of this year (2012).
If someone would have published this extruder setup back in time, it
would have saved me some unnecessary circles.
So I hope you (dear Reader) find this article equally useful,
what I would have found it, if it was existed back then.

Printing quality

If you want to check what is possible
with our v4
hotend in regard of printing quality, or you want a trouble free
extruder setup, then go get one!

As a remainder, here it is the wade pusher printed in white:
(the white is the easiest to photograph, every irregularities are shown)

Im fairly happy with the overall printing quality, you can see it as
our current state of the art at 0.3mm layer height.

No worries, even finer layer height is possible, so it is not the
limit of what v4 is capable of.


Grab the complete setup here.

I think Im able to print one full set per week, and for start I have
3 full sets. I know it is limited, but it is not intended for general
public, just for the quality enthusiastic and those who want
a working printer first and a DIY machine second.

I have some leftover pictures, which would be too bad to miss out:)

And even moar:

I change slightly the commenting policy. I will close the commenting after a week of the date of publishing to prevent spams leaking through.

But in all occasion, please prefer the mailing list.

After the above deadline, any further discussion can only happen on the mailing list, in this thread.