Building a lasersaur
Riley
I've heard about your lasersaurs from Rob Ristroph and am very interested in building one. I've got some exp with homebrew CNC and a 40w laser assembly organ donored from a cheap Chinese engraver as well as Arduino, raspberry, open builds extrusion/steppers/controllers & such. AND LinuxCNC PCs that work great milling via LPT in spite of Danny's views :-p
Basically I should already have all the parts on hand.
Is there any chance I could come take a look at your setup and chat a bit?
My schedule's flexible, whenever's convenient for you works for me.
Thx
Riley Cassel
512-545-0711
This email was sent from my KLü Tablet
Steve Baker <st...@sjbaker.org> wrote:
>
>dan...@austin.rr.com wrote:
>
>> Atmel controllers are NOT well-suited for being a motion controller unless
>> you're talking about a super low-performing machine though. All the
>> effective controllers are FPGA based, which is not a big deal.
>
>I'm surprised that you say that. The relatively low-powered Atmel chip on
>the original Arduino does a great job for our laser cutters - and lasers
>are amongst the faster CNC platforms.
>
>What do you base your assessment of that on?
>
> -- Steve
>
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Steve Baker
Sure - we'd be happy to show you our lasersaur collection!
We live out in Crystal Falls, Leander - I'm home most evenings any time
after about 5pm if you want to drop in - just let me know which day.
We have two 100w lasersaurs:
* "The Death Ray of Ming the Merciless" is a version 11 machine that's
currently in pieces pending an upgrade.
* "Illudium Q36" is a heavily modified v13-ish machine that's in heavy use
by my wife for her home business. http://RenaissanceMiniatures.com
We mostly use them for cutting 1/8" plywood - but with a 100w tube, they
can cut up to maybe 1/2" acrylic or plywood S-L-O-W-L-Y.
The "standard" lasersaur build uses a 100w laser tube (which costs around
$1000 with shipping) and has a 2'x4' bed...so the entire machine is about
4'x6' and weighs something like 400lbs.
The v11 Lasersaur uses a PC to run high level stuff - interfacing via USB
to a regular Arduino board with a custom shield board to interface to the
stepper controllers and laser power supply. Sadly, the shield board is no
longer available.
Since v12 Lasersaur, we switched to a larger custom board with an AtMel
controller built into it instead of an actual Arduino board - and added a
BeagleBoneBlack piggybacked onto that to do the high level stuff - which
makes for fewer and simpler interconnects - which is good for reliability.
Both v11 and v12/13/14 machines present a web-based interface to the world
- so you can hook them up with Ethernet and use anything with a browser to
talk to them. I added a BeagleBone to my v11 machine so it can run the
v12 and later software.
Both setups use a pair of GeckoDrive motor controllers - they aren't
cheap, but they are REALLY good and, again, very reliable.
The v12/13/14 controller board has pins to let you use a RaspberryPi
instead of the BeagleBone - but not many people did that because the 1.xx
version of Raspberry Pi was a bit too slow. I'd expect the Pi 2 or Pi 3
would work...but I think maybe the pinout changed a bit.
To use a 40w laser tube would require you to make up some custom brackets
to hold it - but otherwise shouldn't be a problem. With so much less
power, you could use cheaper mirrors than the molybdenum/copper ones we
need - but I think the same mirror holders work OK. I don't know what you
intend to do about cooling it - I think with a 40w tube, you can get away
with a bucket of water and an aquarium pump - with 100w, you need an
industrial chiller! Venting the system is also an issue - I can show you
what we have.
The biggest issue with picking a not-standard tube is that you'd be using
a not-standard laser power supply - and we've seen some problems with
doing that because some of them have frequency and 'maintenance power'
demands that the Arduino/AtMel controller isn't set up to handle.
The good people on the lasersaur mailing list would doubtless help you to
resolve that one. My recollection is that you might need to hack the C++
code in the AtMel chip - depending on what laser tube and what laser power
supply you have.
IMPORTANT NOTE: If you're new to messing with laser cutters - please be
VERY VERY CAREFUL with the laser power supply. It generates something
like 20,000 volts and is very capable of producing 2" sparks with enough
energy to kill you! They also have a bunch of big capacitors inside that
maintain that voltage long after you unplug the power supply - so treat
them with extreme respect!!
I presume you already know how dangerous the light from the laser is for
your eyesight - even the reflection of that light from nearby surfaces is
dangerous - so don't turn the laser tube on unless it's inside a
UV/IR-tight enclosure or you have the right kind of laser safety goggles
on.
Let me know which day you want to come over.
-- Steve
Riley wrote:
> Hi there I'm Riley from the hackerspace, robot group, microcontroller
> Monday and such.
>
> I've heard about your lasersaurs from Rob Ristroph and am very interested
> in building one. I've got some exp with homebrew CNC and a 40w laser
> assembly organ donored from a cheap Chinese engraver as well as Arduino,
> raspberry, open builds extrusion/steppers/controllers & such. AND
> LinuxCNC PCs that work great milling via LPT in spite of Danny's views :-p
>
> Basically I should already have all the parts on hand.
>
>
> Is there any chance I could come take a look at your setup and chat a bit?
>
> My schedule's flexible, whenever's convenient for you works for me.
>
>
> Thx
>
> Riley Cassel
> 512-545-0711
>
>
>
>
>
>
>
> Steve Baker <st...@sjbaker.org> wrote:
>
>>
>>dan...@austin.rr.com wrote:
>>
>>> Atmel controllers are NOT well-suited for being a motion controller
>>> unless
>>> you're talking about a super low-performing machine though. All the
>>> effective controllers are FPGA based, which is not a big deal.
>>
>>I'm surprised that you say that. The relatively low-powered Atmel chip
>> on
>>the original Arduino does a great job for our laser cutters - and lasers
>>are amongst the faster CNC platforms.
>>
>>What do you base your assessment of that on?
>>
>> -- Steve
>>
>>--
>>You received this message because you are subscribed to the Google Groups
>> "ATXHS Discuss" group.
>>To unsubscribe from this group and stop receiving emails from it, send an
>> email to atxhs-discus...@googlegroups.com.
>>To post to this group, send email to atxhs-...@googlegroups.com.
>>Visit this group at https://groups.google.com/group/atxhs-discuss.
>>For more options, visit https://groups.google.com/d/optout.
>