[arcol.hu] Arcol.hu v4 for Rapman machines

[Laszlo KREKACS]

Hi,

Seems like from all the todo list laying around, this is the first one
to tackle.

I expect to be finished still this week.
A bit in more detail:
As you may are aware, the v3 version of the hotend (the PEEK based, so
not the all metal one),
was compatible mechanically and electrically with Rapman machines.

Starting from v4, it was not the case anymore. I kept the thermistor
for a bit of time,
discontinuing the mechanical compatibility, then I migrated to
Honeywell thermistor
to be able to leave out the firecemet from the picture.
In the result the v4 hotend (v4.2 at the moment) is neither
mechanically nor electrically
compatible with rapman machines.

I still keep around the older heater block design which suits the
104-GT2, 204-GT2 thermistors
(see http://wiki.arcol.hu/product:thermistor-100k and
http://wiki.arcol.hu/product:thermistor-200k),
but I don't advise to new buyers, because the firecement is still
timeconsuming to apply (around 50mins).

Lately I have been approached by 2 people to get manufacture a fully
compatible hotend for Rapman.
And you know 2 people, is almost a crowd:), so I thought over it
(in plus one of them ordered and payed for a regular hotend, so kind
of pressurized me to finish soon),
and I think I came up with a solution,
and I already sent out to manufacturing (lathe and cnc).

In detail:
The regular v4 hotend is pretty short. And Rapman machines needs a
longer hotend, as the
full hotend is 73.0mm tall.

So the modification is basically a modified heatsink, which is
mechanically compatible with rapman.
For full detail see this v3 hotend assembly page:
http://wiki.arcol.hu/arcol-hu-hot-end-v301-assembly

Specifically this picture:
http://www.flickr.com/photos/48806889@N05/6132800160/

The heatsink modification will be consisted of two parts:
The heatsink itself, which is 15.5mm longer then standard, and a disk,
which goes
on top of it, mimicking the upper disk shown on the above photo. (two
5mm holes for the M5 bolts going into).

The lower part of the hotend needs no modification, except it is
reverted back to the firecement version
for using the 204-GT thermistor.

I do hope it will serve well all the rapman users, who are still out there.

I will post a photo once I fully assembled the first one. Hopefully
until sunday.

I should also cook up some announcement article and
fill the wiki page with some additional documentation.

Best,
Laszlo

[Laszlo KREKACS]

Hi,

Took longer, then expected, but here we go, the Arcol.hu v4 hotend for
Rapman is ready.

I extruded with it the whole morning, I have to say, I'm impressed.

Although I say it is made for rapman, but in fact it is only a
different mounting, so it can go to any Reprap machine too.
So it may be interested to you too.
It features a way longer heatsink, so even less problem of warming up.

The rapman machine is really enclosed from the bottom, so the bigger
heatsink helps there,
but also it needs a longer hotend also (mechanical limitation).

If you are curious, please check the WIP announcement blogpost:
http://wiki.arcol.hu/blog:arcol-hotend-v4-rapman

I'm preparing more photos too.

Any ideas, especially proofreading or collaboration on the wiki is appreciated.
I suck both at english and marketing so helping hand is welcome.

Best,
Laszlo