I have a couple of 3D printing questions for anyone in the group with
experience or answers

+ If you are printing on a glass bed, where did you get your glass? I tried
scribe and break on some mirror class from Lowes, but this is not working.
Its is really hard to scribe and break to size, and glass tends to crack as
soon as you heat it.

+ I am trying to print ABS for the first time, and it keeps curling off the
bed. Is this a size of a bed temp that isn't high enough? What is high
enough?

+ When I try to heat my bed, I can get to about 102 C as long as the nozzle
is off. When I heat the nozzle, the temp drops to 85 C, like there isn't
enough current. Anyone seen this?

+ Brad, you said you were having good luck with the window tinting plastic.
Where did you say you found it?

1.  Westlakes will cut to whatever size you need.  I had good luck with
that.  You can also get pre-cut borosilicate (Pyrex) sheet online.

2.  Definitely play with bed temps.  ABS is notorious for warping and you
need a really good bond between part and bed.  Try a higher temp especially
for the first layer.  Also can try heat plus painters tape for better
adhesion.

3. Your power supply isn't big enough.  Get a bigger one.  I recommend
www.circuitspecialists.com

4.  If you want to try kapton, you can get the 3" tape at
www.ultimachine.com

Good luck!
On Sep 3, 2012 3:29 PM, "Scott" <scott.kovale...@gmail.com> wrote:

1. I use the glass from a cheap-o WalMart frame. 8x10 cut down to size. The
frames are $2 each when purchased separately for $1.25 each in sets of 12.
The nice thing about this glass is it has a little flex to it so it's
easier to break the parts off.

2. For ABS I set the bed to 125C. It is also a good idea to clean it off
right before you do a print. I wipe it down with 100% acetone followed by
70% isopropanol.

3. what he said :). I'm using a 680W PC supply and it has plenty of oomph.
Most people recommend a 25-30 amp supply like this one:
http://www.ebay.com/itm/New-12V-DC-30A-360W-Regulated-Switching-Power...

4. Kapton is by far the best surface I have tried. I buy 120mm from
http://www.makerfarm.com/index.php/superwide-120mm-kapton-tape-33-met... .
It ends up costing about 40 cents to cover a 20x20cm plate.

I bought a bunch of pre-built PanelMax kits for RAMPS 1.3 or higher boards
and would make you guys good deals on them if you are interested. Let me
know and I can bring some to the meetup.

I've heard borosilicate is pretty expensive.  Folks online have warned that
regular untempered window glass can shatter with heat because internal
stress is uneven.  I've never seen it happen though.  I had four sheets cut
and heat treated by a local glass place and they were about $10 a piece.

I've been using window tinting film from Tiger Tint.  For me, it's been
working great and is pretty cheap. The first time I went, they gave it to
me, The second time they charged me a bit.  I have some extra I'll share if
you want it.  It has an adhesive on one side.  You peel the backing, mist
water onto the adhesive and the (very clean) glass and float it on.  Then
squeegee out the water.  If you're in a hurry, put it in the toaster oven
for a a while at about 200 to dry out.

Something else worth noting - by far the best resource for 3d printing
questions is the #reprap channel on Freenode IRC (irc.freenode.net).  I
have gotten and given piles of advice there over the years; it's an awesome
community.
On Sep 3, 2012 6:12 PM, "Brad Dudenhoffer" <urban...@gmail.com> wrote: