[Arm-netbook] Existential 3D Printing Moments

Luke Kenneth Casson Leighton lkcl at lkcl.net
Wed May 31 05:45:18 BST 2017

On Tue, May 30, 2017 at 9:02 PM, David Niklas <doark at mail.com> wrote:

>>  only by going to a 32-bit processor running at say 100mhz can you get
>> the timing synchronisation back.
> I understand now. I thought that the arduino was faster...

 neeeh.  they're.... well... not very good, basically.  also the
arduino base code.... *sigh* it does timing loops to get accuracy by
hand-coding them in assembler with NOOPs (no operation).

 as a programmer, you know what that means... :)

>> >> david crocket (dc42) has specifically designed the duet series so
>> >> that you can consider exceeding PWM rates of 150 khz, which is what
>> >> you need if you want to sustain 500mm/sec for example (and do not
>> >> want problems to occur at speeds well below that).
>> > Link?
>>  google it please.
> This looks like it:
> http://forums.reprap.org/read.php?147,33082,471483

 yehhh that'd be about right - a good example, and really highly
technically informative and insightful.  good find.

>> >> also i forgot to mention that i've been using the E3Dv6 "volcano"
>> >> which, when you use a 0.5 to 0.8mm nozzle can easily do flow rates of
>> >> something mad like.... 200c^3/min - particularly when combined with
>> >> the huge 40:1 gearing of the flex3drive which can *accurately*
>> >> deliver the kinds of torque needed.  the volcano basically turns the
>> >> heat chamber round, so that the heat area is 20mm long instead of
>> >> the usual 10mm.
>> > Torque for what?
>> > Again, maybe a link would help us stay on the same page.
>>  google them, please.  i have a lot else to take care of.
> <snip>
> I thought you were waiting for the PCBs to get done (which was going to
> take another week I think),

 yehyeh.... still waiting: mike has family issues as well as pressing
production to deal with, he's got one side of the PCBs done, the other
side is next.

> and had nothing better to do than play with
> that oh-so-giggly-and-fun little girl in the youtube vids?

 :)  my daughter's currently in the US, her grandmother's 80th
birthday was this month.

 ok so i re-read what i wrote a bit, one of the reasons why you can't
push extruders beyond a certain point is because the heat chamber
can't keep up with melting the filament fast enough, but also it takes
quite a lot of pressure to do that.  if you can get higher torque out
of the motors by having a 40:1 gear ratio instead of the usual "direct
drive" or maybe 3:1 or 4:1 as is usual even with the mendel90,
lulzbots and so on, you have enough torque to be able to do it.

 that's what i meant.


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