MK5 hot end has 6.5 mm bore??

[Jordan Miller]

Hi,

I'm looking at the MK5 hot end in MakerBot SVN repo:
http://svn.makerbot.com/tags/plastruder-mk5/hot-end/thermal-barrier-tube.dxf

and it looks like the central bore is 6.5 mm wide. How does this make sense, as the filament is only 3 mm in diameter.

I'm trying to build one of these instead of waiting for them to release... please help me figure it out!

jordan

[Prober]

On Aug 6, 9:12 am, Jordan Miller <jrdn...@gmail.com> wrote:
> Hi,
>

> I'm looking at the MK5 hot end in MakerBot SVN repo:http://svn.makerbot.com/tags/plastruder-mk5/hot-end/thermal-barrier-t...

>
> and it looks like the central bore is 6.5 mm wide. How does this make sense, as the filament is only 3 mm in diameter.
>
> I'm trying to build one of these instead of waiting for them to release... please help me figure it out!
>
> jordan

A friend of mine was looking for Makerfaire Detroit info and found
these great pics:

http://picasaweb.google.com/beermaker74/MakerfaireDetroit2010#

the mk5 plastruder goodness Pics 50 +

Let us know how it turns out.

[beverageexpert]

hey those are my pics :)

I believe it has a ptfe tube insert
That would explain the big bore

bryan

[Jordan Miller]

aahhhhh. now you're talking. Ok, great! I'll make a ptfe tube insert too.

thanks!
jordan

> --
> You received this message because you are subscribed to the Google Groups "MakerBot Operators" group.
> To post to this group, send email to make...@googlegroups.com.
> To unsubscribe from this group, send email to makerbot+u...@googlegroups.com.
> For more options, visit this group at http://groups.google.com/group/makerbot?hl=en.
>

[Michael Rule]

wasn't one of the biggest problems with the Mk4 hotend the use of PTFE
in the insulator barrel ? is this somehow different ? I was hoping
this would be corrected.

[Jordan Miller]

the problem with MK4 as i can tell is that the threading is way too small for a good grip in PTFE (can be overtightened easy and the threads are too small for mechanical stiffness when warmed) and PTFE is allowed to expand laterally away from the filament due to feed pressure.

Shoving a smooth PTFE tube down the steel cylinder keeps the PTFE from expanding away from the filament and also means there are no threads to rip through the PTFE.

should solve both problems (and I think they've tested the design for several hundred hours now, no leaks). i'm just impatient.

jordan

[beverageexpert]

bre said they have over 500 hours on the mk5 design
looks solid

bryan

On Aug 6, 8:53 pm, Jordan Miller <jrdn...@gmail.com> wrote:
> the problem with MK4 as i can tell is that the threading is way too small for a good grip in PTFE (can be overtightened easy and the threads are too small for mechanical stiffness when warmed) and PTFE is allowed to expand laterally away from the filament due to feed pressure.
>
> Shoving a smooth PTFE tube down the steel cylinder keeps the PTFE from expanding away from the filament and also means there are no threads to rip through the PTFE.
>
> should solve both problems (and I think they've tested the design for several hundred hours now, no leaks). i'm just impatient.
>
> jordan
>
> On Aug 6, 2010, at 8:42 PM, Michael Rule wrote:
>
> > wasn't one of the biggest problems with the Mk4 hotend the use of PTFE
> > in the insulator barrel ? is this somehow different ? I was hoping
> > this would be corrected.
>

> >>> For more options, visit this group athttp://groups.google.com/group/makerbot?hl=en.

>
> >> --
> >> You received this message because you are subscribed to the Google Groups "MakerBot Operators" group.
> >> To post to this group, send email to make...@googlegroups.com.
> >> To unsubscribe from this group, send email to makerbot+u...@googlegroups.com.

> >> For more options, visit this group athttp://groups.google.com/group/makerbot?hl=en.

[Zach Smith]

Don't worry.  The MK5 has been thoroughly tested.  We've literally run it for days on end and this thing literally WILL NOT JAM.

There is still PTFE in the design, but this time we're using it intelligently and properly.  Instead of relying on PTFE for its mechanical properties, we're using stainless steel to keep it from deforming.  We use off the shelf PTFE tubing inside a stainless steel tube.  The PTFE provides an extremely low friction path for the filament... all the way to the nozzle.  The steel keeps everything nice and sturdy.  It also prevents heat from creeping up to the filament drive.

The result is a plastruder that is reliable, simple to build, and simple to operate.

We're waiting on the final parts for this bad boy, and its looking like a release of any day now.  :)

Zach

Zach Smith
Director of R&D
MakerBot Industries

[ddurant]

> We're waiting on the final parts for this bad boy...

We are too!!!

Will this be a drop-in replacement for people who already have
makerbots? Will a new extruder controller be required?

On Aug 10, 10:52 am, Zach Smith <z...@makerbot.com> wrote:
> Don't worry.  The MK5 has been thoroughly tested.  We've literally run it
> for days on end and this thing literally WILL NOT JAM.
>
> There is still PTFE in the design, but this time we're using it
> intelligently and properly.  Instead of relying on PTFE for its mechanical
> properties, we're using stainless steel to keep it from deforming.  We use
> off the shelf PTFE tubing inside a stainless steel tube.  The PTFE provides
> an extremely low friction path for the filament... all the way to the
> nozzle.  The steel keeps everything nice and sturdy.  It also prevents heat
> from creeping up to the filament drive.
>
> The result is a plastruder that is reliable, simple to build, and simple to
> operate.
>
> We're waiting on the final parts for this bad boy, and its looking like a
> release of any day now.  :)
>
> Zach
>
>
>
>
>
> On Fri, Aug 6, 2010 at 8:42 PM, Michael Rule <mrule7...@gmail.com> wrote:
> > wasn't one of the biggest problems with the Mk4 hotend the use of PTFE
> > in the insulator barrel ? is this somehow different ? I was hoping
> > this would be corrected.
>

> > makerbot+u...@googlegroups.com<makerbot%2Bunsubscribe@googlegroups.c­om>
> > .

> > >> For more options, visit this group at
> >http://groups.google.com/group/makerbot?hl=en.
>
> > > --
> > > You received this message because you are subscribed to the Google Groups
> > "MakerBot Operators" group.
> > > To post to this group, send email to make...@googlegroups.com.
> > > To unsubscribe from this group, send email to

> > makerbot+u...@googlegroups.com<makerbot%2Bunsubscribe@googlegroups.c­om>
> > .

> > > For more options, visit this group at
> >http://groups.google.com/group/makerbot?hl=en.
>
> > --
> > You received this message because you are subscribed to the Google Groups
> > "MakerBot Operators" group.
> > To post to this group, send email to make...@googlegroups.com.
> > To unsubscribe from this group, send email to

> > makerbot+u...@googlegroups.com<makerbot%2Bunsubscribe@googlegroups.c­om>
> > .

> > For more options, visit this group at
> >http://groups.google.com/group/makerbot?hl=en.
>
> --
> Zach Smith
> Director of R&D

> MakerBot Industries- Hide quoted text -
>
> - Show quoted text -

[Zach Smith]

Its mostly drop-in.  We are using a 2.5ohm heater to heat it, so its highly recommended to get a relay board to control it.  Or you can use a larger resistor and wait longer for it to heat up.

Zach

To unsubscribe from this group, send email to makerbot+u...@googlegroups.com.

For more options, visit this group at http://groups.google.com/group/makerbot?hl=en.

[ddurant]

Thanks for the info, Zach.. I soldered up my relay board this past
weekend so I'm good to go there!

What did you say the expected price was again?

> > <makerbot%2Bunsubscr...@googlegroups.c­om>

> > > > .
> > > > >> For more options, visit this group at
> > > >http://groups.google.com/group/makerbot?hl=en.
>
> > > > > --
> > > > > You received this message because you are subscribed to the Google
> > Groups
> > > > "MakerBot Operators" group.
> > > > > To post to this group, send email to make...@googlegroups.com.
> > > > > To unsubscribe from this group, send email to
> > > > makerbot+u...@googlegroups.com<makerbot%2Bunsubscribe@googlegroups.c­om>

> > <makerbot%2Bunsubscr...@googlegroups.c­om>

> > > > .
> > > > > For more options, visit this group at
> > > >http://groups.google.com/group/makerbot?hl=en.
>
> > > > --
> > > > You received this message because you are subscribed to the Google
> > Groups
> > > > "MakerBot Operators" group.
> > > > To post to this group, send email to make...@googlegroups.com.
> > > > To unsubscribe from this group, send email to
> > > > makerbot+u...@googlegroups.com<makerbot%2Bunsubscribe@googlegroups.c­om>

> > <makerbot%2Bunsubscr...@googlegroups.c­om>

[Zach Smith]

no word yet on the final pricing.  that's something we typically do the day of the launch.  it keeps it exciting for us.  it should be close to the MK4 design.

To unsubscribe from this group, send email to makerbot+u...@googlegroups.com.

For more options, visit this group at http://groups.google.com/group/makerbot?hl=en.

[JohnWasser]

Wait... A relay board for the extruder? Doesn't that go crazy with
the 490Hz PWM output of the Extruder Controller?

Note: The HBP output of the Extruder Controller is not PWM so a relay
works fine there.

Perhaps a clip-on heat sink for the Extruder Controller MOSFETs would
be a better solution.

On Aug 10, 1:39 pm, Zach Smith <z...@makerbot.com> wrote:

[Marty McGuire]

According to the code, the heater is managed with digital writes (0V
or 5V), not with PWM.

http://github.com/makerbot/G3Firmware/blob/master/ArduinoSlaveExtruder/Heater.cpp#L122

Thanks,
Marty

[Rob Giseburt]

That makes sense with a large heated mass, like the HBP, the changes
would be slow enough that PWM would be overkill.

-Rob

[beak90]

Actually to me it does look like its controlled with PWM. You're
looking at the debug pin which of course uses a digitalWrite. The
output pin is controlled with an analogWrite and the value is
controlled by the temp_update function which outputs the PID stuff
constrained between 0 and 255. In other words, it looks like the
heater is in fact controlled with PWM. So I'm also wondering how the
relays like that...

On Aug 11, 8:39 am, Marty McGuire <schmartiss...@gmail.com> wrote:
> According to the code, the heater is managed with digital writes (0V
> or 5V), not with PWM.
>

> http://github.com/makerbot/G3Firmware/blob/master/ArduinoSlaveExtrude...
>
> Thanks,
> Marty

[Jordan Miller]

oh don't worry, it still goes crazy. MakerBot calls it the clackerator, amongst other names:
http://store.makerbot.com/relay-board-kit-v1-0.html

if you want a quiet relay board ask Rick from MakerGear, he's got some SSRs that fit the bill.

jordan

[beak90]

Maybe put it in under a pillow or something to keep it quiet :) SSRs
are pretty expensive so I see why they went with regular relays.

On Aug 11, 9:38 am, Jordan Miller <jrdn...@gmail.com> wrote:
> oh don't worry, it still goes crazy. MakerBot calls it the clackerator, amongst other names:http://store.makerbot.com/relay-board-kit-v1-0.html
>
> if you want a quiet relay board ask Rick from MakerGear, he's got some SSRs that fit the bill.
>
> jordan
>

[Jordan Miller]

SSRs are not that expensive from Rick from MakerGear... i still need to test them but, well, it's the only sensible way to go methinks. we have a very dense lab environment and all that clickety-clack is not all that great.

jordan

[ddurant]

> SSRs are not that expensive from Rick from MakerGear...

I don't see SSRs or his relay board in the MG store.. Is he not
selling them yet?

> > For more options, visit this group athttp://groups.google.com/group/makerbot?hl=en.- Hide quoted text -

[Marty McGuire]

Whoops! Stopped reading when I saw a "digitalWrite". :) Thanks for
the catch, beak90.

Wow, so, PWMing a relay... seems like a good way to wear out the
contacts. At best, a ton of PWM resolution is lost when the relay
can't keep up.

My guess: once this goes into production and MK5s are in the wild,
someone will patch the firmware to expect a relay.

--Marty

[Jordan Miller]

just ask him directly: Rick Pollack <ri...@makergear.com>

jordan

[Mike Payson]

You can get SSR's pretty cheap from Futurlec: http://futurlec.com/RelSS.shtml

[beak90]

Oh wow that is pretty cheap. The 5 amp ones would just barely work.

On Aug 11, 11:39 am, Mike Payson <m...@dawgdayz.com> wrote:
> You can get SSR's pretty cheap from Futurlec:http://futurlec.com/RelSS.shtml
>

> >> > For more options, visit this group athttp://groups.google.com/group/makerbot?hl=en.-Hide quoted text -

[Nathan Hilderman]

I don't think using relays is a good idea. If trying to maintain a
constant temperature with little hysteresis, these relays will be used
too often and will wear out (stick on).

[Jordan Miller]

I thought SSRs don't wear out because there are no mechanical parts...

jordan

[Nathan Hilderman]

True, I misread the post.