Experiments in sintering
Tim Schmidt
granule sintering.
There's some initial work on a gridbeam-based design here:
http://objects.reprap.org/wiki/Eiffel
The idea is to use a ball mill
(http://en.wikipedia.org/wiki/Ball_mill) to produce a fine plastic
powder from plastic scraps, to fill a hopper in the machine. The
machine would then lay down thin even layers of the powder, and after
each layer is deposited, use a 2 or 3 axis gantry to move a relatively
weak laser (as compared to laser cutters) over the powder, turning it
on and off when necessary to sinter the powder into a solid object.
Despite recent successes with my new hot end design, we feel the
sintering design has certain advantages which should be explored -
particularly with respect to ease of recycling.
The Candyfab project (http://en.wikipedia.org/wiki/CandyFab) has a
working mechanism for the powder spreading, and is open source, so we
can borrow that wholesale.
I have stripped the laser out of an otherwise dead DVD-RW, which I
hope will be powerful enough to sinter dark plastics, at least. If
anyone would like to pitch in, I'd encourage you to post more
information, or edit the Eiffel wiki page.
--tim
Tim Schmidt
layer spreading mechanism, and found this:
----
How do you add the next layer?
Manually, with a scoop of sugar. The machine spreads the pile of sugar
uniformly over the build region, and then lowers the piston slightly--
to clear the spreader bar -- before the next layer is melted.
----
Simple enough. We just need a bed that moves in the Z axis, and a
wiper mechanism for leveling the plastic dust. Can do.
--tim
beverageexpert
to use it. I wanted to put it on my makerbot but havent found a cheap
pair of safety goggles.It was strong enough to melt my black abs scrap
rafts and burned anything dark. If you have access to goggles you can
borrow my laser for tests if you loan me the goggles for my tests. Do
you have the schematics on the candyfab? I wanted to do some sugar
printing and couldnt figure out the airflow rate to melt the sugar. My
air pump was too strong and the sugar blew away. I would love to
build a small version of the candyfab to do some crazy confections.
Please keep me informed on your progress
bryan
Tim Schmidt
> I have a 290mw 780nm near infrared laser but I don't have any goggles
> to use it. I wanted to put it on my makerbot but havent found a cheap
> pair of safety goggles.It was strong enough to melt my black abs scrap
> rafts and burned anything dark. If you have access to goggles you can
> borrow my laser for tests if you loan me the goggles for my tests. Do
> you have the schematics on the candyfab? I wanted to do some sugar
> printing and couldnt figure out the airflow rate to melt the sugar. My
> air pump was too strong and the sugar blew away. I would love to
> build a small version of the candyfab to do some crazy confections.
> Please keep me informed on your progress
Do you mind if I ask where you got your laser, and how much it cost?
--tim
Dean Piper
Here is that same laser power and wavelength on ebay with a Buy it now of $56.00 with free shipping and it comes with the driver!
http://cgi.ebay.com/High-Power-Laser-Module-----290-mw----Cutting-Burning_W0QQitemZ180468786545QQcmdZViewItemQQimsxZ20100215?IMSfp=TL100215122005r29504
Not too bad at all. I have to get one!
-Daen
--tim
--
You received this message because you are subscribed to the Google Groups "reprap-michigan" group.
To post to this group, send email to reprap-...@googlegroups.com.
To unsubscribe from this group, send email to reprap-michig...@googlegroups.com.
For more options, visit this group at http://groups.google.com/group/reprap-michigan?hl=en.
Nicholas McCoy
beverageexpert
the 260mw 1 but was sent the 290mw 1 instead for 44 bucks.
http://cgi.ebay.com/High-Power-Laser-Module-----290-mw----Cutting-Burning_W0QQitemZ180468786545QQcmdZViewItemQQimsxZ20100215?IMSfp=TL100215122005r29504
I wish I had goggles to use it
bryan
On Mar 6, 8:20 pm, Nicholas McCoy <mcc...@gmail.com> wrote:
> Here is a link <http://www.repairfaq.org/sam/laserfaq.htm> to a website that
> contains tons of information about lasers, including a list of
> suppliers<http://www.repairfaq.org/sam/laserlps.htm>
> .
>
> On Sat, Mar 6, 2010 at 6:21 PM, Dean Piper <dean.pi...@gmail.com> wrote:
> > Tim,
>
> > Here is that same laser power and wavelength on ebay with a Buy it now of
> > $56.00 with free shipping and it comes with the driver!
>
> >http://cgi.ebay.com/High-Power-Laser-Module-----290-mw----Cutting-Bur...
>
> > Not too bad at all. I have to get one!
>
> > -Daen
>
> > On Sat, Mar 6, 2010 at 6:08 PM, Tim Schmidt <timschm...@gmail.com> wrote:
>
> >> On Sat, Mar 6, 2010 at 5:12 PM, beverageexpert <beermake...@gmail.com>
> >> wrote:
> >> > I have a 290mw 780nm near infrared laser but I don't have any goggles
> >> > to use it. I wanted to put it on my makerbot but havent found a cheap
> >> > pair of safety goggles.It was strong enough to melt my black abs scrap
> >> > rafts and burned anything dark. If you have access to goggles you can
> >> > borrow my laser for tests if you loan me the goggles for my tests. Do
> >> > you have the schematics on the candyfab? I wanted to do some sugar
> >> > printing and couldnt figure out the airflow rate to melt the sugar. My
> >> > air pump was too strong and the sugar blew away. I would love to
> >> > build a small version of the candyfab to do some crazy confections.
> >> > Please keep me informed on your progress
>
> >> Do you mind if I ask where you got your laser, and how much it cost?
>
> >> --tim
>
> >> --
> >> You received this message because you are subscribed to the Google Groups
> >> "reprap-michigan" group.
> >> To post to this group, send email to reprap-...@googlegroups.com.
> >> To unsubscribe from this group, send email to
> >> reprap-michig...@googlegroups.com<reprap-michigan%2Bunsu...@googlegroups.com>
> >> .
> >> For more options, visit this group at
> >>http://groups.google.com/group/reprap-michigan?hl=en.
>
> > --
> > You received this message because you are subscribed to the Google Groups
> > "reprap-michigan" group.
> > To post to this group, send email to reprap-...@googlegroups.com.
> > To unsubscribe from this group, send email to
> > reprap-michig...@googlegroups.com<reprap-michigan%2Bunsu...@googlegroups.com>
Keith Mc
> I would love to build a small version of the candyfab to do some crazy confections.
> [looking at diode lasers, and laser goggles for safety...]
Why do we need coherent light for this??? Instead of a laser or a
hot air gun, how about going a little lower tech, like a Hot Point?
You can create a Hot Point in many ways:
1) An old toaster element heating a rod
2) A modified hair dryer - add a standard RR Extruder Heater Controller to close
loop the temp. Switch the 120VAC heater element with a standard LED opto brick.
3) a heater element, a tube, and a TINY computer fan to make Low Flow heat.
But my favorite:
4) A bright lamp, and a focusing system of some kind, such as a
simple magnifying lens or a focusing reflective surface. Easy Breezy...
IOW, think basic telescope optics, like a Newtonian Reflector.
We are just scaling up the power...
EX: a Lamp Hot Point may appear as a simple horizontal PVC tube above your RR.
Your light is on one end of the tube, and a dish reflector is on the other endcap.
(Use a PVC screw cleanout end cap for focus fine adjustments... :-)
At the right point, there is a small dollar store 45 degree mirror chunk to bounce
it "down" through a hole, or even another PVC pipe on a T-Coupler.
The beam then runs through a simple mag glass to focus it to a point.
Modulate lamp brightness, and make a controllable shutter shield anywhere
along the light path to block the light, and you are in business. The hot end is
far enough away from the business end to keep it from being a problem.
Faster: Simply re-purpose an old hobby Newtonian Reflector Scope for this... <grin>
Even simpler:
- Hang a theater stage Klieg Light, a halogen worksite light, or even a desk arm halogen over it.
- Focus with either a dime store round "magnifier lens on a stick", or a Page Magnifier.
If you use a line style halogen work lamp you may have to use two lenses/reflectors
to map the line to a point, and/or vignette it with a cutout, but I can't imagine that
would be too difficult. Try something like adhesive backed mirror surfaced mylar as a
reflector. Stick it on a RR'd (or milled) plastic parabolic curve for the line-to-point focusing curve.
Light/lens method benefit: Cheap and easy, and VERY LOW TECH. It is made
mostly from big box dept store (Meijer/Target/Warmart), garage sale, university
surplus, astronomy hobby store, Dollar Store, and/or hardware store items,
vs mail ordered specialty scientific parts that MAY require goggles that probably
cost a LOT more than the laser itself!
The K.I.S.S. Principle at work here...
- Keith Mc.