Stepstruder MK6

[JohnA.]

Is in the store:

Upgrade: http://store.makerbot.com/stepstruder-mk6-upgrade.html

Regular / full kit: http://store.makerbot.com/toolheads/stepstruder.html


Looks like lead time on both is 3 weeks.

JohnA.

[Luis E. Rodriguez]

Sorry John, ya beat me!

Luis E. Rodriguez

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[JohnA.]

I happened to be reading the group when I saw it in my RSS feed.
With it showing up on Thingiverse today, release had to be imminent.

No talk of using it with Gen 3 electronics though, that part is
curious. Anyone have details?


JohnA.



On Feb 15, 12:05 pm, "Luis E. Rodriguez" <lrodriguezm...@gmail.com>
wrote:

> Sorry John, ya beat me!
>
> Luis E. Rodriguez
>

[Matt Mets]

Marty McGuire has put together these experimental instructions on how to do it:
http://wiki.makerbot.com/stepstruder-mk6-with-gen3

[Aaron Double]

The other thing that is interesting is RepG24 without any machine profiles for a steptruder + cupcake
Aaron

[ddurant]

> I'm going to stay out of this until someone's found a rock-solid
> solution...

There's been a rock-solid solution for cupcakes and ToMs for a while
now over at.. that other place which I'll probably get yelled at for
mentioning too often here. It works great, it costs less, it has
support from the actual company that makes it, if they find something
wrong later they will admit it and send you a fix.

On Feb 15, 12:30 pm, coasterman <coaster...@live.com> wrote:
> > The other thing that is interesting is RepG24 without any machine profiles for a steptruder + cupcake
>

> ...Which kinda dissapoints me...
>
> I'm going to stay out of this until someone's found a rock-solid
> solution...

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

[Aaron Double]

What I've been waiting for is the software to make a stepper work without having to monkey about. Look's like It's here! Can't wait to play.

About the machine profile, It's not hard to make a new one.

[JadeKnight]

I've been running my own built RepG24 + latest firmware on my Gen3/Mk4
Cupcake for about a week now (with a printed geared Stepper-
Brutstruder).

I just followed the Wiki entry on stepper extruders for hooking/
setting it up ( http://wiki.makerbot.com/stepper-driven-extruder ),
and it works great!

The SF35 reversal tool is awesome and has nearly eliminated all ooze
for me. I just need to do a little more minor tuning.

The only issue I'm now having with SF35 is the first layer height
(which no-one here seems to know how to adjust... *sigh*).

If there was a better solution for the heater resistors (I hear they
keep failing), I'd consider upgrading to the Mk6...

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

[Marty McGuire]

There are instructions for making the new machine profile on the "stepstruder with gen3" wiki page:

http://wiki.makerbot.com/stepstruder-mk6-with-gen3

Running a stepper extruder on gen 3 electronics is probably never going to be "rock solid" - the boards were just not set up to easily plug in a fourth stepper driver.

The tricks with running the gen3 electronics with any stepper extruder are:

• You need to either give up two H-bridge ports to drive the stepper directly OR:
• You need to make a goofy cable or jumper several connections to control an extra stepper driver.
• You'll also need a hacked firmware to drive the stepper based on which method you chose above.
  

The Stepstruder MK6 kit comes with a v3.3 stepper driver board, and I have loose instructions and some pictures for how to make one on the page listed above.  It's based on the "Using an external driver with the 2.X firmware" section on this page: http://wiki.makerbot.com/stepper-driven-extruder#toc12 which some folks seem to be using successfully with other stepper extruders.

I am personally running Gen3 electronics with a Stepstruder MK6 driven by the included v3.3 stepper driver board on MakerBot #131, and it is working great!

Thanks,
Marty

[ddurant]

> - You'll also need a hacked firmware to drive the stepper based on which
> method you chose above.
> ...

> I am personally running Gen3 electronics with a Stepstruder MK6 driven by
> the included v3.3 stepper driver board on MakerBot #131, and it is working
> great!

Which firmware are you using on your gen3 EC?

On Feb 15, 12:58 pm, Marty McGuire <schmartiss...@gmail.com> wrote:
> There are instructions for making the new machine profile on the
> "stepstruder with gen3" wiki page:
>
> http://wiki.makerbot.com/stepstruder-mk6-with-gen3
>
> Running a stepper extruder on gen 3 electronics is probably never going to
> be "rock solid" - the boards were just not set up to easily plug in a fourth
> stepper driver.
>
> The tricks with running the gen3 electronics with any stepper extruder are:
>

>    - You need to either give up two H-bridge ports to drive the stepper
>    directly OR:
>    - You need to make a goofy cable or jumper several connections to control
>    an extra stepper driver.
>    - You'll also need a hacked firmware to drive the stepper based on which

>    method you chose above.
>
> The Stepstruder MK6 kit comes with a v3.3 stepper driver board, and I have
> loose instructions and some pictures for how to make one on the page listed
> above.  It's based on the "Using an external driver with the 2.X firmware"

> section on this page:http://wiki.makerbot.com/stepper-driven-extruder#toc12whichsome folks

> >http://groups.google.com/group/makerbot?hl=en.- Hide quoted text -

[JadeKnight]

You can bootstrap it with KoenKooi's precompiled firmware:
https://github.com/koenkooi/G3Firmware (download)

You can also compile your own (which is what I did):
http://wiki.makerbot.com/v2-firmware (how to get and compile firmware)
http://wiki.makerbot.com/stepper-driven-extruder (compile settings and
wiring)

> > >http://groups.google.com/group/makerbot?hl=en.-Hide quoted text -

[tmo]

i was sort of bummed that they didnt mention all of the work that that
company had put into the thinner filament and steppers. surely
makerbot has been watching what they have been doing for the past 2
months. what ever happened to acknowledging the shoulders you stand
on in the open source community?

it also wont overheat like the mk6 seems like it might (extra fan on
the stepper??? really?) seems like another use of an item that is
pushed beyond spec to save 10 bucks. wonder how it will work when the
ambient temp in summer is 90º+

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

[Zip Zap]

I just looked at this new beast.  This is pie in the face to all you doubters.

---

From: tmo <tmop...@gmail.com>
To: MakerBot Operators <make...@googlegroups.com>
Sent: Tue, February 15, 2011 10:35:42 AM
Subject: [MakerBot] Re: Stepstruder MK6

> > > >>> makerbot+unsub...@googlegroups.com.

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[Stan Seibert]

There's no point in being coy: we can say "MakerGear" in this group
without fear of lightning bolts. :)

The MK6 announcement says this has been in development for 9 months,
and the first blog post on MakerGear about their compact stepper
extruder is from 8 months ago. These two extruders were developed
concurrently, with MakerGear getting to market quicker by using a
geared stepper and a simpler design, I suspect. It's not like
MakerBot suddenly saw the MakerGear stepper extruder and banged out
the MK6 right then. Convergent evolution has been pushing the
community this way from multiple directions.

I don't think we need to make this into a MakerGear vs. MakerBot
fight, really. Once upon a time I thought it would be useful if they
joined forces, but actually I think we benefit more this way since the
market can clearly support both companies and now they can do
different things.

Pricewise, these aren't so different: $209 gets you the the full MK6 +
stepper controller board. The MakerGear stepper extruder is $165
without electronics, so maybe ~$190 if you throw that in (can't check
price there since they are sold out).

So now the real field test is to see if a direct driver stepper is
worth the extra $20 or not.

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

[James McCracken]

I'd just like to chime in and say that makerbot, makergear, and all
the others form an ecosystem of suppliers, which is always a healthier
market than one dominated by a single supplier.

The "correct" free-market attitude is to welcome the competition, and
start proclaiming how your product is brighter / cheaper / better /
more ethical / kinder to children / kills less angels / whatever...

[Owen M Collins]

I am just waiting for the extruder that you put straw in and it would extrude gold filament.

Maybe I am spending too much time reading bedtime stories to my kids...

O.

[Brent Crosby]

tmo wrote: (extra fan on the stepper??? really?)

I agree, why would they not use the geared stepper that MakerGear
chose instead of a huge heavy stepper at what has to be the limit of
its current and the limit of its torque.

The fan is ridiculous. See this post:

http://groups.google.com/group/makerbot/browse_thread/thread/1f1efbbff9d38c28

[ddurant]

> There's no point in being coy: we can say "MakerGear" in this group
> without fear of lightning bolts. :)

Probably true. Then again, they're a business and this is their
offical google group. If I went over to the MakerGear google group and
started talking about how great MBI products were, they would have
every right to give me a virtual slap upside the head. Or maybe just a
polite request to keep to the charter.

This being sortofa central place for discussing things not directly
related to MBI hardware makes it difficult to stay on-topic. Maybe a
vendor-agnostic "3D Printing" google group or the forums JohnA started
over at http://3dprinterforum.org/ would be a better place for topics
not specific to one company...

[Luis E. Rodriguez]

Ultimaker. There I said it.

Luis E. Rodriguez

[ddurant]

> Ultimaker. There I said it.

I'm printing up one of these, right now, just for you.
http://www.thingiverse.com/thing:6331

On Feb 15, 4:33 pm, "Luis E. Rodriguez" <lrodriguezm...@gmail.com>
wrote:

> Ultimaker. There I said it.
>
> Luis E. Rodriguez
>
>
>
> On Tue, Feb 15, 2011 at 3:24 PM, ddurant <dduran...@gmail.com> wrote:
> > > There's no point in being coy: we can say "MakerGear" in this group
> > > without fear of lightning bolts.  :)
>
> > Probably true. Then again, they're a business and this is their
> > offical google group. If I went over to the MakerGear google group and
> > started talking about how great MBI products were, they would have
> > every right to give me a virtual slap upside the head. Or maybe just a
> > polite request to keep to the charter.
>
> > This being sortofa central place for discussing things not directly
> > related to MBI hardware makes it difficult to stay on-topic. Maybe a
> > vendor-agnostic "3D Printing" google group or the forums JohnA started

> > over athttp://3dprinterforum.org/would be a better place for topics

> >http://groups.google.com/group/makerbot?hl=en.- Hide quoted text -

[tmo]

why did they have a stepper "custom manufactured to the makerbot
specs" and then have to run it in a way that it overheats and needs a
cooling fan?

wouldn't it be better to have a stepper manufactured with specs that
wont overheat during normal operation?

somewhat confused by that one..

> http://groups.google.com/group/makerbot/browse_thread/thread/1f1efbbf...

[RyanP]

You can't buy the custom stepper from amazon like you could for all
the non printable parts of the unicorn?

seriously, lower part count equals better reliability. Not sure about
the cooling fan.

[Stan Seibert]

We can read between the lines of this quote from the announcement:

"We were all set and ready to go when we learned under testing that
the motor gets pretty hot during printing."

i.e. They probably had the manufacturer all tooled up and ready to
produce these steppers when they discovered the problem. At that
point, their choice was either delay further (and possibly lose some
cash depending on how far into production they were), or patch the
problem with a fan.

The other possibility is that it is difficult to achieve this amount
of torque in this form factor without running hot, and this is the
design tradeoff for deciding not to have a gearbox.

Another thread mentioned earlier today that this problem could be
solved without a fan by increasing the voltage and lowering the
current. However, I assume that this is a non-starter for an upgrade
kit due to a lack of anything above 12V on the PSU.

On Feb 15, 5:36 pm, tmo <tmoph...@gmail.com> wrote:

[Zip Zap]

So would you recommend the Makergear setup?

---

From: Stan Seibert <st...@mtrr.org>
To: MakerBot Operators <make...@googlegroups.com>
Sent: Tue, February 15, 2011 3:24:28 PM

Subject: [MakerBot] Re: Stepstruder MK6

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[Stan Seibert]

Having no experience with either, I'm not in a position to recommend
either.

I'm probably going to buy the MK6 upgrade for my MK5 once I see how
the Generation 3 electronics support issue sorts itself out. If I was
already on Gen4, it would be a no-brainer for me. Although big and
bulky, I really like working with (and sometimes dismantling) the MK5,
so the stepper upgrade makes sense.

On the side, I'm working on building a SAE Prusa Mendel. In a few
months when I'm ready to fire it up, I'll get a MakerGear stepper
extruder. Their stuff is very good (PEEK saved my MK4 extruder!) and
Rick's support is excellent. I personally like the power resistor
heater in the MK5 better than the MakerGear design, but neither is a
deal breaker.

Honestly, I'd love to see someone get ahold of both extruders and
abuse them both for our education (and entertainment). :)

On Feb 15, 6:53 pm, Zip Zap <zzap...@yahoo.com> wrote:
> So would you recommend the Makergear setup?
>
> ________________________________

> From: Stan Seibert <s...@mtrr.org>

> makerbot+u...@googlegroups.com.

[Brent Crosby]

> Another thread mentioned earlier today that this problem could be

> solved without a fan by . . .

The increased voltage _only_ helps develop the current more quickly at
higher speed.

To get the torque (magnetic) you need the current. To get the current
in the largely inductive stepper coils quickly, you need big voltage
( V=L*(dI/dT) ). So to maintain good torque at high speed, you need a
high source voltage.

At low speeds it is all about current, since you are just against the
DC resistance of the coil and the inductance does not come into play
for a static load.

The MBI design would have to use a large current to generate the
torque required to hold and push the filament without mechanical
advantage.

But now you are against the "I square R" losses (heat). Let's guess
MBI is running that big stepper at 12v and 2A. Now you have 24 watts
of heat to try to dump out of that motor, all while keeping the
internal coil temperature low enough that the insulation does not
break down. Not to mention that it is mounted in plastic.

I think the MakerGear decision to use the smaller stepper geared down
for torque is more solid. This allows the motor to run at lower
current for the same torque.

The complexity goes up for the geared motor, but in theory the gearbox
properly manufactured and sized should have a long lifetime. Even
though Kysan makes both the geared DC motor and the geared stepper,
the geared stepper appears to be much better build quality than the
geared DC motor:

http://groups.google.com/group/makerbot/browse_thread/thread/e7bc97a66209e36b/a57fefc20f7e5dcf

Only time will tell on the durability of the geared stepper compared
to the non-geared stepper design. It might be that the MBI design
works just fine, the fan keeps it plenty cool, etc.

[Jordan Miller]

How much torque does that MK6 motor put out? There are no specs available that I can find.

i dunno i am just very confused when looking at the MK6. it seems like a NEMA 23 motor would actually have been more standard and also smaller and lower in temperature and almost certainly would have more torque. I can't tell for sure from the pics. i get it that the holes were already there for a NEMA 17 but man that motor has a fat ass. That will put a lot more strain on the holes the MK5 is mounted in. The fan on top confuses me too. All the heat from the hot end comes up there, and now we will be blowing it back down again? Why not blow the heat to the side?

The MK5 shatters eventually when used with PLA. Delrin and PLA have too much friction so it is really unworkable in my experience (we printed a Prusa on a ToM and then wham, shatter city). Am looking at printable replacement parts now. But FWIW we got a stepper plastruder from MakerGear to be able to get printing asap again. Then maybe we will print the printable MK5 on thingiverse. But we are very pleased with MakerGear so probably won't try for a delrin-PLA combo again.

jordan

[Luis E. Rodriguez]

Starno 
100 oz-in holding, 0.8A, and 1lb.

From the Thingiverse thing about it: http://www.thingiverse.com/thing:6300

Luis E. Rodriguez

[Rob Giseburt]

I mounted it fan facing up. I agree that it doesn't make sense to blow
the heat down against it's natural flow.

I've been testing one, and it works great. I also have a makergear
stepper extruder and I love it too. They really are complimentary.

The Mk6 has heat issues. I've done a few 1.5 hr builds, and it seemed
to peak temperature early and the fan maintained it fairly well.

The MG has less issue with that, but that is at a sacrifice for speed.
To step fast enough to print at 40-50mm/s (x-y) with 1/8th
microstepping, a 13.6:1 gear ratio, and 1.75mm filament (which
requires faster extrusion for the same output volume) is really
pushing the ability of the Gen4 MB, let alone the Gen3 EC. It works,
but the electronics are close to a tipping point.

You can't do what you cab with a stepper extruder with a dc-motor extruder:

http://www.tinkerin.gs/2011/02/tilted-cube-test-print_05.html

In particular, watch the video, and see how well cool/slow-down works. :-)

The software was really the holdup on stepper extruders, for both MG
and MBI. I helped port the Gen3 to support a stepper with RPM, and
hope to make it support 5D (well, probably without the feedrate
interpolation, so 4D) as well. The Gen4 didn't have any stepper
support when it came out, and RepG needed a fair amount of work to get
everything ironed out. Then there was testing of the profiles and
getting all of the stuff ready, since the limitations of a dc motor
are gone, and a lot of assumptions in the skeinforge config needs to
be rethought.

This is a great time to be 3D printing! The stepper extruder can do so
much more than is being done now. Even the RepRap 5D and the
derivative Ultimaker firmwares don't take full advantage yet, and
they've had a bit of a jump-start.

Now, go to MakerBot or Makergear and order a stepper extruder. Go!

Trust me, you'll love it.
-Rob

[Jordan Miller]

thanks Luis! ok ya so then a basic nema 23 is equivalent or stronger torque, maybe slightly heavier but not as "long" so the moment arm is not as big that is trying to torque the MK6 out of the holding bolts.

very interesting...
http://www.linengineering.com/line/contents/stepmotors/5618.aspx

jordan

[Andrew Plumb]

Which PLA were you using?  I've been running my beta Stepstruder MK6 for about a week now with my old 4032D.

The PLA stickiness makes the stepper skip a step on the default fast reversal settings, but I haven't seen any strain on the laser cut plastic.  The more serious caveat is DO NOT let this particular 4032D PLA filament sit still in a warm barrel for any length of time.  It doesn't take long for it liquify all the way up and "mushroom" at the top.  Not fun cleaning that out.

Heat is deflected out the back off the thermal cape.

Aside: I had to improvise a fan mount out of MakerBeam because the fan mount part hadn't arrived in time for my beta kit: http://www.flickr.com/photos/aplumb/5426445125/

Sure is nice not having to deal with strings of ooooooooze anymore!

Andrew.

--

Makerbot Number Nine... #9... 0x09... 0o11... 0b1001... 
http://clothbot.com/wiki/MakerBotNumberNine

[Jordan Miller]

wow Rob that's amazing!!! Am so excited to see this one more.

For the Makergear one i don't do microstepping since you're already at 2720 stepsperrev with full motor stepping (200*13.6). This is close to equivalence to a 1/8 stepped NEMA 17 (1600 stepsperrev). The difference is that with a planetary gear you have increased torque while with microstepping you are losing torque with each "step" in microstepping. Which I guess is why we will need to start with 100 oz-in before microstepping to get good filament drive force.

Dunno for sure though, haven't tested it myself. But I can attest to the fact that the makergear motor is still room temperature even after an 8 hour print session with this setup.

jordan

[Jordan Miller]

hmm. we use 4043D. It printed fine with the MK5 on the ToM for the first two mendel build plates:
http://www.flickr.com/photos/19255751@N00/sets/72157625659622653/

then it would start to pause halfway through multi-hour prints. let me tell you that was very frustrating. I suspected that the DC motor was just fatiguing. So we had to keep increasing pressure from the delrin to ensure consistent printing. this eventually will get cracks in the acrylic. eventually it will shatter.

a stepper motor there, especially the MK6 motor, will probably not have this problem. But alas our acrylic already shattered so we'd have to buy a whole new setup or find someone to lasercut the pieces for us.

I guess the long hot end on the MK5 is what is making your PLA liquify all the way up the barrel? I think because the makergear hot end has such a tiny thermal transition it does not have any qualms sitting at extrusion temperature for a long while.

I am using 20 RPM rapid reversal for 100 ms. That works really well for me:
http://vimeo.com/19071041

Nooooo ooooooozing. Steppers are DEFINITELY the way to go.

I think MK6 and MakerGear stepper extruder are nearly the same price out the gate. So the MK6 upgrade path may be less expensive for many. And having it already shipping/included with a new bot is definitely plus.

jordan

[Stan Seibert]

On Feb 15, 9:04 pm, Jordan Miller <jrdn...@gmail.com> wrote:
> I guess the long hot end on the MK5 is what is making your PLA liquify all the way up the barrel? I think because the makergear hot end has such a tiny thermal transition it does not have any qualms sitting at extrusion temperature for a long while.

I'm also seeing this in the MK5 with PLA as well. I can print just
fine, but as soon as I stop for a few minutes, the PLA softens above
the teflon tube and will deform to jam the top of the barrel when I
start the next print. I'm not sure if a well-placed fan could fix
this or not.

(Fortunately, you can clear blockage in the MK5 fairly easily if you
pop off the four nuts holding the hot end and pull out the PLA while
everything is still hot. Requires multiple needle-nose pliers and
some care not to touch anything with your fingers.)

[Sonny Mounicou]

I agree.  I have had 50 hours of oozeless, jamless printing with it.  You can't go wrong with the "other" combo.

> > >> Luis E. Rodriguez
>

> > >> On Tue, Feb 15, 2011 at 10:54 AM, JohnA. <john.abe...@gmail.com> wrote:
> > >>> Is in the store:
>
> > >>> Upgrade:  http://store.makerbot.com/stepstruder-mk6-upgrade.html
>
> > >>> Regular / full kit:  http://store.makerbot.com/toolheads/stepstruder.html
>
> > >>> Looks like lead time on both is 3 weeks.
>
> > >>> JohnA.
>

> > >>> --
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> - Show quoted text -

[tmo]

wow that is an incredible video. never thought that was even
possible. so it printed the lower layers pretty fast then slows down
as the layer time goes down?

[Jordan Miller]

if you like that then look here:
http://bothacker.com/2010/06/22/keep-it-cool/

this is from june of last year...

skeinforge really is an amazing piece of code. We are all still catching up with it on the hardware side!!! i only got a stepper extruder a few weeks ago =D

jordan

[Rob Giseburt]

Yeah, since the print came to a point, as it got closer to the top it
got slower.

I was amazed enough to start shooting video.

I also suspect that I need to tune my stepper driver, it should be a
little smoother than that. ;-)

-Rob

[Rob Giseburt]

I should probably point out that this isn’t a problem. The Cupcake, Thing-o-Matic, and various RepRaps all have other limiting factors to how fast it can print. The MG motors work great, and will not slow you down.

The only device I can think of that might see a limit in these motors would be the Ultimaker, which is printing at 300mm/s. We’re nowhere close to that with a makerbot or reprap AFAIK.

  -Rob

—

MakerBot Operator

Member of CCCKC Hackerspace

Member of KC Fabricators Google Group

[James McCracken]

I've heard substantiated rumors that one of the suppliers is working
on a 300mm/s drive. I won't name names to protect the innocent, but I
hear they're coming.

[Jordan Miller]

heh, that's nothing. lasersaur was recently demonstrated at 666 mm/s running on arduino and grbl firmware. who's gonna help me slap a stepper extruder on this puppy:
http://flickr.com/photos/stfnix/5415891178/

<insert joke about 666 here>

jordan

[tmo]

i have seen the bothacker stuff, that project seems to be completely
dead. i have tried contacting the people working on it for a while (6
months+) and have never gotten a reply.

this is completely different and so much more advanced than anything i
have ever seen. being able to control the platform speed and flow
rate depending on the time it takes to print a layer is absolutely
incredible (faster speeds and flow for big layers and crawling speed
and trickle flow on tiny layers)

[tmo]

the cool plugin on the bothacker page is totally different i think.
the printer prints the layer then the nozzle orbits around the part
waiting for it to cool, you can do this with any cupcake or thing o
matic. the variable for it to kick in is the time it takes for a
layer to be printed. if it is lower than the specified value then the
machine orbits for a while while the part cools down. as far as i
know there is no variation of the flow rate or the platform speed.

[ddurant]

> the cool plugin on the bothacker page is totally different i think.
> the printer prints the layer then the nozzle orbits around the part
> waiting for it to cool,

The newer versions of skeinforge (30+ or so?) have an option in Cool
that lets you set Orbit or Slow Down. Orbit does what you've seen - it
orbits around the print until the min layer time is reached. Slow
drops feed & flow rates way down so printing slows to the point where
the layer takes the right min amount of time to complete.

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

[Jordan Miller]

look in skeinforge it is there. it is the "Cool" plugin.

we have never been able to use it with makerbot stuff because nearly everyone's motor stops turning below 255 PWM (or close to 200 PWM).

now that we have stepper extruders, you can enable that plugin with the slow down feature.

re-read that bothacker page they explain the Cool plugin a bit more. Use the "Slow Down" version of it in the popup menu.

The genius is in Skeinforge.

jordan

[Jordan Miller]

i guess part of my huge confusion about doing 1/8th stepping for extrusion is because of this:
http://blog.reprap.org/2009/02/rp-pinch-wheel-extruder.html

zach's lasercut MK3 inspired the direct drive stepper extruder two years ago. Is the 1/8th stepping so you get super high precision of the extrudate? adrian's video looks pretty good though so i'm not sure where the 1/8th stepping need is coming from:
http://blog.reprap.org/2009/02/rp-pinch-wheel-extruder-ii.html

thoughts?

jordan

[The Ruttmeister]

On Feb 17, 7:19 am, coasterman <coaster...@live.com> wrote:
> Smoother operation, more accurate start/stop... Much quieter...
>

Far more important than any of those (all of which are actually fairly
debatable at normal extruding speeds) is that the higher resolution
stepping lets you extrude smoothly at the slowest speeds. And to get
down to 0.1mm layers requires very slow extrusion speeds!

[ddurant]

> And to get
> down to 0.1mm layers requires very slow extrusion speeds!

Or very fast feed rates...

It will be interesting to see what having stepper extruders at MBI
means for the skeinforge profiles they ship with repg.

[tmo]

wouldn't gearing it down accomplish the same thing? or even do it
better? 1/16 step has much less torque than a 1/8 step driver.

a 1/8 step that is geared to 13:1 is much finer resolution than even a
1/16 stepper driver.

or at least it seems that way to me, i might be wrong.

[The Ruttmeister]

On Feb 17, 12:26 pm, ddurant <dduran...@gmail.com> wrote:
> > And to get
> > down to 0.1mm layers requires very slow extrusion speeds!
>
> Or very fast feed rates...
>

Yep, but cupcake tops out around 60mm/s on average. I haven't tried
higher speeds with my own ultimaker inspired cupcake upgrade yet.

>wouldn't gearing it down accomplish the same thing? or even do it
>better? 1/16 step has much less torque than a 1/8 step driver.
>
>a 1/8 step that is geared to 13:1 is much finer resolution than even a
>1/16 stepper driver.
>
>or at least it seems that way to me, i might be wrong.

Actually I doubt that you would need to go below half stepping or even
full stepping with a 13:1 gearbox, I'm running with a 6.375:1 gearset
and can get low enough extrusion speeds that its almost
indistiquishable from ooze!
I think higher feed speeds are where more work is needed right now.

[Jordan Miller]

yes that is what I'm getting at. most of the torque of that huge motor is wasted on microstepping. a smaller motor with a couple gears would have been more torque and not required a new air flow plan. I just can't say how it will operate with a huge ToM fan sucking lots of air out of the area. presumably you wouldn't need the motor fan?

a 0.45 step angle nema 23 that is then set for half stepping would be more torque and more accurate, too. it would have been a stock motor buy, not custom manufactured. just guessing...

jordan

[The Ruttmeister]

Microstepping only makes sense when you don't need high torque, or
can't fit in gearing, or don't want the added complexity (and fail
point) of a gearbox.
Gearing makes sense for the extruder as you get more torque by giving
up speed (which we don't need), and if you want to you can always add
micro stepping for added resolution.
I have to admit that I don't see the MBI answer to a stepper extruder
as that good an idea, if you need to actively cool your motor, then
you are doing it wrong (ignoring water cooled EV motors etc). I think
that one of the many printed gear designs on thingiverse would be a
better bet. And the MG option if you want to spend the money (and
don't already have a mk5).

On Feb 17, 2:53 pm, Jordan Miller <jrdn...@gmail.com> wrote:
> yes that is what I'm getting at. most of the torque of that huge motor is wasted on microstepping. a smaller motor with a couple gears would have been more torque and not required a new air flow plan. I just can't say how it will operate with a huge ToM fan sucking lots of air out of the area. presumably you wouldn't need the motor fan?
>
> a 0.45 step angle nema 23 that is then set for half stepping would be more torque and more accurate, too. it would have been a stock motor buy, not custom manufactured. just guessing...
>
> jordan
>

[Zip Zap]

I've just ordered a 5lb. silver roll from Ultimachine.com .  I've read the same thing about using the same specs for ABS.  However, I'm still not clear on whether to use a HBP or just plain acrylic.  I don't want any warping.

---

From: coasterman <coast...@live.com>
To: MakerBot Operators <make...@googlegroups.com>
Sent: Wed, February 16, 2011 9:33:31 AM
Subject: [MakerBot] Re: Stepstruder MK6

On the Mk5 I run PLA just like I run ABS and it works like a charm.
Even if I leave it at extrusion temp for 15 minutes. I run at 200C,
and sometimes I just use the same SF profile as I use for ABS. PLA for
me is really just a translucent, stronger, and better-smelling ABS.

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[Anderson Ta]

ZipZap,

You can still use the HBP, you just don't have to use as much heat
with PLA. 60C should be a good temp to operate with PLA if you are
worried about warping.

- Andy
digifabindustries.blogspot.com

> makerbot+u...@googlegroups.com.

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

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[The Ruttmeister]

On Feb 17, 5:21 pm, Anderson Ta <ata0...@gmail.com> wrote:
> ZipZap,
>
> You can still use the HBP, you just don't have to use as much heat
> with PLA. 60C should be a good temp to operate with PLA if you are
> worried about warping.
>
> - Andy
> digifabindustries.blogspot.com
>

I've printed quite a few huge objects in PLA on BPT, no heat, and not
a sign of warp. Just make sure you keep the tape clean and wipe it
down with alcohol if you need a super sticky effect.

[Zip Zap]

I've read that you don't even have to use a heated platform.

---

From: Anderson Ta <ata...@gmail.com>
To: make...@googlegroups.com
Sent: Thu, February 17, 2011 5:21:47 PM
Subject: Re: [MakerBot] Re: Stepstruder MK6

> makerbot+unsub...@googlegroups.com.

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

Teaser photos of some *BETA* MK6 Assembly here:
http://www.flickr.com/photos/jabella/sets/72157626097545118/

First test print, showing reversal: http://www.youtube.com/watch?v=Eoz9gTs6htg

More complicated print - no strings!: http://www.youtube.com/watch?v=e4Bp11fx5PY


JohnA.




On Feb 15, 8:47 pm, Andrew Plumb <and...@plumb.org> wrote:
> Which PLA were you using?  I've been running my beta Stepstruder MK6 for about a week now with my old 4032D.
>
> The PLA stickiness makes the stepper skip a step on the default fast reversal settings, but I haven't seen any strain on the laser cut plastic.  The more serious caveat is DO NOT let this particular 4032D PLA filament sit still in a warm barrel for any length of time.  It doesn't take long for it liquify all the way up and "mushroom" at the top.  Not fun cleaning that out.
>
> Heat is deflected out the back off the thermal cape.
>
> Aside: I had to improvise a fan mount out of MakerBeam because the fan mount part hadn't arrived in time for my beta kit:http://www.flickr.com/photos/aplumb/5426445125/
>
> Sure is nice not having to deal with strings of ooooooooze anymore!
>
> Andrew.
>
> On 2011-02-15, at 7:58 PM, Jordan Miller wrote:
>
>
>
>
>
>
>
>
>
> > How much torque does that MK6 motor put out? There are no specs available that I can find.
>
> > i dunno i am just very confused when looking at the MK6. it seems like a NEMA 23 motor would actually have been more standard and also smaller and lower in temperature and almost certainly would have more torque. I can't tell for sure from the pics. i get it that the holes were already there for a NEMA 17 but man that motor has a fat ass. That will put a lot more strain on the holes the MK5 is mounted in. The fan on top confuses me too. All the heat from the hot end comes up there, and now we will be blowing it back down again? Why not blow the heat to the side?
>
> > The MK5 shatters eventually when used with PLA. Delrin and PLA have too much friction so it is really unworkable in my experience (we printed a Prusa on a ToM and then wham, shatter city). Am looking at printable replacement parts now. But FWIW we got a stepper plastruder from MakerGear to be able to get printing asap again. Then maybe we will print the printable MK5 on thingiverse. But we are very pleased with MakerGear so probably won't try for a delrin-PLA combo again.
>
> > jordan
>
> > On Feb 15, 2011, at 7:40 PM, Brent Crosby wrote:
>
> >>> Another thread mentioned earlier today that this problem could be
> >>> solved without a fan by . . .
>
> >> The increased voltage _only_ helps develop the current more quickly at
> >> higher speed.
>
> >> To get the torque (magnetic) you need the current. To get the current
> >> in the largely inductive stepper coils quickly, you need big voltage
> >> ( V=L*(dI/dT) ). So to maintain good torque at high speed, you need a
> >> high source voltage.
>
> >> At low speeds it is all about current, since you are just against the
> >> DC resistance of the coil and the inductance does not come into play
> >> for a static load.
>
> >> The MBI design would have to use a large current to generate the
> >> torque required to hold and push the filament without mechanical
> >> advantage.
>
> >> But now you are against the "I square R" losses (heat). Let's guess
> >> MBI is running that big stepper at 12v and 2A. Now you have 24 watts
> >> of heat to try to dump out of that motor, all while keeping the
> >> internal coil temperature low enough that the insulation does not
> >> break down. Not to mention that it is mounted in plastic.
>
> >> I think the MakerGear decision to use the smaller stepper geared down
> >> for torque is more solid. This allows the motor to run at lower
> >> current for the same torque.
>
> >> The complexity goes up for the geared motor, but in theory the gearbox
> >> properly manufactured and sized should have a long lifetime. Even
> >> though Kysan makes both the geared DC motor and the geared stepper,
> >> the geared stepper appears to be much better build quality than the
> >> geared DC motor:
>
> >>http://groups.google.com/group/makerbot/browse_thread/thread/e7bc97a6...
>
> >> Only time will tell on the durability of the geared stepper compared
> >> to the non-geared stepper design. It might be that the MBI design
> >> works just fine, the fan keeps it plenty cool, etc.

>
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