Hot end mod

[Aaron Double]

So, my resistors died finally on my MK5 after about 10 months. I had never really been able to do PLA because it would overheat and mushroom at the top of the hot end tube.

Just assembled my cartridge heater and thought I would try something. I cut temperature releaving slits in the stainless steel tube to block heat propagation.

Seems to have worked, photo is of the hot end at 220C with me holding the tube! Even better, it was at that temp for 20 minutes. Not even hot.

I'll fill you folks in when I get it up and printing later tonight.

Aaron Double

[Luis E. Rodriguez]

You mean I can use these rolls of PLA I have here! Sweet! YES please do keep us informed! Nice slits, dremel?

Luis E. Rodriguez

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[Aaron Double]

Jewelers saw, like a hacksaw but tiny, can cut through almost
anything.

Ask Rob to bring his over to the hackerspace on Thursday, I convinced
him to get one after he was over here.

You want them to be as narrow as possible so the PFTE doesn't bulge
out.

Aaron Double


On Aug 10, 3:36 pm, "Luis E. Rodriguez" <lrodriguezm...@gmail.com>
wrote:

> You mean I can use these rolls of PLA I have here! Sweet! YES please do keep
> us informed! Nice slits, dremel?
>
> Luis E. Rodriguez
>

> Are you a Maker? <http://www.makerfairekc.com/>

[Matt Smollinger]

Brilliance as always. Looking forward to the prints. I'm just
finishing dialing in my Cupcake so once the other mods are in place
(Pololu, Lowrider, Wobble Arrester, etc.) I'll have to do this!

Is that a cartridge heater you're using on a mark V? So I'm guessing
you also picked up a new block to hold it, yah? Are you still using
your crazy 62lbs of force unknown extruder?

--MS--

[Garth Kidd]

I'm having trouble reading the picture. Did you cut through just over half the tube three times with ~4mm spacing, alternating direction each time? 

[Aaron Double]

It's kinda hard to see, here's an illustration and a better photo.

The cuts start around 12mm away from the threaded end and are spaced 3mm apart. There is a cut from each side with a 3-4mm space between them. There are 5 sets in total.

As I said in an earlier email, use the thinnest saw available, you don't want the opening to be big, if it's too big, the plastic might make the PFTE bulge into the cut.

I used two heatsinks, one on top and one on the bottom. I did that because I had two:-)

Aaron Double

[Garth Kidd]

Wow. 

Ok, obvious question time: how's the structural integrity after doing that? I know it's not a supporting member, but the cuts look scary to my inexperienced brain.  

 – Garth

[Z LeHericy]

by the looks of it, that tube is only there to keep the PFTE tube from bulging out under the pressure of molten filament...so, it should be fine as long as the slots are narrow enough (hence why a jewler's saw is usefull)
-Zeno LeHericy

//((=:Z:=))\\
INVENTIONS
Technologies
zinventions.com

--

[Aaron Double]

Just getting ready to fire it up.

Aaron Double

[Rob Giseburt]

Eagerly awaiting the results. :-)

I've had the PLA fail anywhere from 5 minutes in to an hour. 

  -Rob

[Aaron Double]

What do people think I should do as a test?

Aaron Double

[Aaron Double]

Just ran the first calibration cube, After the print, I got my finger up and touched the upper heatsink, still good!

Aaron Double

On Aug 10, 2011, at 9:43 PM, Rob Giseburt wrote:

[Rob Giseburt]

Sweet. How long of a print?

  -Rob

[Rob Giseburt]

Also, as a stress test print at 100%. In case you weren't already...

  -Rob

[Aaron Double]

Just the calibration cube.

Going to do this next, heh.

http://www.thingiverse.com/thing:4317

Not going to be able to run it until tomorrow though.

Aaron Double

[Rob Giseburt]

That will definitely stress it. The reversal may kill it. It will draw the heat up the tube...

Perhaps reverse less, faster? That way it doesn't draw the heat up as much? Only if it fails, of course...

How did the cube look? 

  -Rob

[Aaron Double]

Cube was perfect except I think I need to up the time in cool.

Reversal has to work or I don't want to use PLA, I don't think I can go back to having to clean up strings, ugh.

Aaron Double

[Aaron Double]

Hey Matt,

I switched to the MK5 setup a year ago and to the Stepstruder when that came out.

That being said, I have been resurrecting the strong filament drive to attach my makergear head on it. I like how the strong drive needs no tensioning. Found out that all of the CAD files were trash because at the time I accounted for wobble and inaccuracies that I don't have anymore.

Aaron Double

[Matt Smollinger]

Very cool. Yeah I am hating cleaning up the strings on my MK5. Sounds
like my upgrade path is HBP (skipping the ABP) -> Pololu -> Gen4
(piecemeal to use the pololus) -> Mk6. Not having the HBP is wrecking
any intricate prints I've been trying (even the wobble arresters
warped like crazy). I'll probably pickup a jeweler's saw somewhere in
that mix and do this mod now too. Might try it out on my Mk5 tube as I
have a roll of PLA and have been scared to try it :)

--MS--

[Aaron Double]

Two hours into my test print and all seems to be going well. The print looks like crap, but that's not the calibration's fault, that file is a bear, makes me really want different support material... can someone write a skeinforge plugin for that??? please?

Some calibration details:
.3mm head
3mm filament

layer height of .2mm w/t of 1.75 making the thread width .35 mm wide speed at 30mm/s

reversal on with a pullback distance of 2.7mm

Aaron Double

[Bruce Jones]

This may be a stupid question, Did you take the PTFE tubing out when
you did this? I'm wondering if it can be done without taking too much
apart as I'm feeling lazy.

>  Screen shot 2011-08-11 at 10.54.05 AM.png
> 1351KViewDownload

[Aaron Double]

Sorry, I took it out.

I would take it out if I were you.

As an aside, I don't use the red tube anymore, you can get PFTE tubing for $2.29 per foot at www.mcmaster.com search for 8547K23

Aaron Double

[Z LeHericy]

I would definitely take it out... you want the inside of that tube to be as close to perfectly smooth as mechanically possible (which is one step up from humanly possible :-{) ) and if PLA liquified up to the first slot, it'd start flowing out there, which could be even more dificult to fix than a mushroom top...

-Zeno LeHericy

//((=:Z:=))\\
INVENTIONS
Technologies
zinventions.com

[Aaron Double]

Slowest print ever.

3 hours, cool was set to take at least 25 seconds per layer.

Now to flip to ABS! 

Aaron Double

[Bruce Jones]

Ok this will be my project for saturday. Any advice on getting the
PTFE tube out of the metal tube? I had to stick it in the freezer for
an hour before it would fit on the way in. Also does anyone know of a
source for suitable PTFE tubing in the UK?

Bruce

On Aug 12, 2:31 am, Aaron Double <aad...@gmail.com> wrote:
> Slowest print ever.
>
> 3 hours, cool was set to take at least 25 seconds per layer.
>
> Now to flip to ABS!
>
> Aaron Double
>

> On Aug 11, 2011, at 5:17 PM, Z LeHericy wrote:
>
>
>
>
>
>
>
> > I would definitely take it out... you want the inside of that tube to be as close to perfectly smooth as mechanically possible (which is one step up from humanly possible :-{) ) and if PLA liquified up to the first slot, it'd start flowing out there, which could be even more dificult to fix than a mushroom top...
>
> > -Zeno LeHericy
>
> > //((=:Z:=))\\
> > INVENTIONS
> > Technologies
> > zinventions.com
>
> > On Thu, Aug 11, 2011 at 1:22 PM, Aaron Double <aad...@gmail.com> wrote:
> > Sorry, I took it out.
>
> > I would take it out if I were you.
>

> > As an aside, I don't use the red tube anymore, you can get PFTE tubing for $2.29 per foot atwww.mcmaster.comsearch for 8547K23

[Bruce Jones]

Ok this will be my project for saturday. Any advice on getting the
PTFE tube out of the metal tube? I had to stick it in the freezer for
an hour before it would fit on the way in. Also does anyone know of a
source for suitable PTFE tubing in the UK?

Bruce

On Aug 12, 2:31 am, Aaron Double <aad...@gmail.com> wrote:

> Slowest print ever.
>
> 3 hours, cool was set to take at least 25 seconds per layer.
>
> Now to flip to ABS!
>
> Aaron Double
>

> On Aug 11, 2011, at 5:17 PM, Z LeHericy wrote:
>
>
>
>
>
>
>
> > I would definitely take it out... you want the inside of that tube to be as close to perfectly smooth as mechanically possible (which is one step up from humanly possible :-{) ) and if PLA liquified up to the first slot, it'd start flowing out there, which could be even more dificult to fix than a mushroom top...
>
> > -Zeno LeHericy
>
> > //((=:Z:=))\\
> > INVENTIONS
> > Technologies
> > zinventions.com
>
> > On Thu, Aug 11, 2011 at 1:22 PM, Aaron Double <aad...@gmail.com> wrote:
> > Sorry, I took it out.
>
> > I would take it out if I were you.
>

> > As an aside, I don't use the red tube anymore, you can get PFTE tubing for $2.29 per foot atwww.mcmaster.comsearch for 8547K23

[Bruce Jones]

I got the mod done this morning, using a hack saw. I did an hour long
print and have absolutley no problems to report :)

On Aug 12, 9:37 am, Bruce Jones <bruce.david.jo...@gmail.com> wrote:
> Ok this will be my project for saturday. Any advice on getting the
> PTFE tube out of the metal tube? I had to stick it in the freezer for
> an hour before it would fit on the way in. Also does anyone know of a
> source for suitable PTFE tubing in the UK?
>
> Bruce
>
> On Aug 12, 2:31 am, Aaron Double <aad...@gmail.com> wrote:
>
>
>
>
>
>
>
> > Slowest print ever.
>
> > 3 hours, cool was set to take at least 25 seconds per layer.
>
> > Now to flip to ABS!
>
> > Aaron Double
>
> > On Aug 11, 2011, at 5:17 PM, Z LeHericy wrote:
>
> > > I would definitely take it out... you want the inside of that tube to be as close to perfectly smooth as mechanically possible (which is one step up from humanly possible :-{) ) and if PLA liquified up to the first slot, it'd start flowing out there, which could be even more dificult to fix than a mushroom top...
>
> > > -Zeno LeHericy
>
> > > //((=:Z:=))\\
> > > INVENTIONS
> > > Technologies
> > > zinventions.com
>
> > > On Thu, Aug 11, 2011 at 1:22 PM, Aaron Double <aad...@gmail.com> wrote:
> > > Sorry, I took it out.
>
> > > I would take it out if I were you.
>

> > > As an aside, I don't use the red tube anymore, you can get PFTE tubing for $2.29 per foot atwww.mcmaster.comsearchfor 8547K23

[Aaron Double]

Nice.

Aaron Double

[Jetguy]

Trust me, if you have had the hot end hot even once, the previously
tight PFTE tube is going to slide right out. It melts and deforms to
the stainless tube over time.

On Aug 12, 4:37 am, Bruce Jones <bruce.david.jo...@gmail.com> wrote:
> Ok this will be my project for saturday. Any advice on getting the
> PTFE tube out of the metal tube? I had to stick it in the freezer for
> an hour before it would fit on the way in. Also does anyone know of a
> source for suitable PTFE tubing in the UK?
>
> Bruce
>
> On Aug 12, 2:31 am, Aaron Double <aad...@gmail.com> wrote:
>
>
>
> > Slowest print ever.
>
> > 3 hours, cool was set to take at least 25 seconds per layer.
>
> > Now to flip to ABS!
>
> > Aaron Double
>
> > On Aug 11, 2011, at 5:17 PM, Z LeHericy wrote:
>
> > > I would definitely take it out... you want the inside of that tube to be as close to perfectly smooth as mechanically possible (which is one step up from humanly possible :-{) ) and if PLA liquified up to the first slot, it'd start flowing out there, which could be even more dificult to fix than a mushroom top...
>
> > > -Zeno LeHericy
>
> > > //((=:Z:=))\\
> > > INVENTIONS
> > > Technologies
> > > zinventions.com
>
> > > On Thu, Aug 11, 2011 at 1:22 PM, Aaron Double <aad...@gmail.com> wrote:
> > > Sorry, I took it out.
>
> > > I would take it out if I were you.
>

> > > As an aside, I don't use the red tube anymore, you can get PFTE tubing for $2.29 per foot atwww.mcmaster.comsearchfor 8547K23

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

[Matt Smollinger]

Aaron, what temps are you running your PLA at, out of curiosity? Seems
to be this big debate on what temperature to set in SF.

--MS--

On Aug 12, 4:37 am, Bruce Jones <bruce.david.jo...@gmail.com> wrote:

> Ok this will be my project for saturday. Any advice on getting the
> PTFE tube out of the metal tube? I had to stick it in the freezer for
> an hour before it would fit on the way in. Also does anyone know of a
> source for suitable PTFE tubing in the UK?
>
> Bruce
>
> On Aug 12, 2:31 am, Aaron Double <aad...@gmail.com> wrote:
>
>
>
>
>
>
>
> > Slowest print ever.
>
> > 3 hours, cool was set to take at least 25 seconds per layer.
>
> > Now to flip to ABS!
>
> > Aaron Double
>
> > On Aug 11, 2011, at 5:17 PM, Z LeHericy wrote:
>
> > > I would definitely take it out... you want the inside of that tube to be as close to perfectly smooth as mechanically possible (which is one step up from humanly possible :-{) ) and if PLA liquified up to the first slot, it'd start flowing out there, which could be even more dificult to fix than a mushroom top...
>
> > > -Zeno LeHericy
>
> > > //((=:Z:=))\\
> > > INVENTIONS
> > > Technologies
> > > zinventions.com
>
> > > On Thu, Aug 11, 2011 at 1:22 PM, Aaron Double <aad...@gmail.com> wrote:
> > > Sorry, I took it out.
>
> > > I would take it out if I were you.
>

> > > As an aside, I don't use the red tube anymore, you can get PFTE tubing for $2.29 per foot atwww.mcmaster.comsearchfor 8547K23

[Aaron Double]

I run it around 185C,

Don't forget to change your start gcode to match the temp you set.

Aaron