Build
Platform
Design
& Suppliers
The Build Platform consists of a sandwich (from
top to bottom) of:
Build surface -
Borosilicate (Low Expansion Coeficcient) Glass (Pyrex) is popular
Heat spreader - typically .040 (1.016mm) aluminum sheet
Bed Heater - either kapton film or silicone heaters have
been used
Insulator - a layer of "pellet stove" insulator (rock wool)
Frame - typically .25in/6mm aluminum plate
Corner Clips & Bed Leveling - a way to hold
everything in place and level it wrt to the extruder
Design Decisions
The Build Platform is conceptually simple, but in reality
there are complexities that are easy to overlook.
For
ABS printing it
needs to be heated to 110 degrees C. While bed heaters can be made in
any size it is very expensive to have one custom made. As a result, the
size of the build surface becomes a function of what is available in
off the shelf heaters. Right now I'm leaning toward 2x(8x8) for a 16x8
surface. The other custom part then becomes the build surface but
getting glass cut to size is not as difficult.
I purchased two of the qu-bd 200mm x 200mm (8x8) bed heaters (see
below) - they are actually 200mm square, which is not the same as 8 in,
but slightly smaller.
[note - Integrated Thermistor Beta Value 3950K - see smoothie board instructions for setting thermistor beta value] [need thickness at edges! using 2mm ]
We decided to make the platform & build surface have an
additional 6mm edge all around, so the final dimensions are 212mm x
412mm!
In order to make a mock up of the platform we cut a piece of .220 HIPS
to that size. Once the design is complete we'll replace the HIPS
with an aluminum plate.
for
corner clips I'm going to try to bend thin sheet stainless steel (24ga
.024" (.61mm) #304 stainless steel) pieces to wrap around the sides and
give both retention and height adjustment.
I've done a limited amount of price comparison and Brunner's Bits -n- Pieces http://www.pelletblowers.com/bbandp/index.php
comes in as the low cost provider at ~$20 for 2 pcs of 1/8 in material
8.5 x 17 including shipping. YMMV.
Build Surface
See the thread - Borosilicate Glass source? -
https://groups.google.com/forum/#!topic/deltabot/vIXyUzIx8t0
Lowes - Replacement Glass - 3/32 thick - Replacement Mirror - 1/8 thick
- none tempered, but all cheap - $5 clear $10 mirror
Elite Custom Glass - http://www.replacementglass.co ~ $40/pc
- not boro or
tempered glass
Elite Custom Glass - http://elitecustomglass.com - prices
cheaper ~$25/pc - same business as above - ship from ca ~$20
McMaster-Carr - http://www.mcmaster.com/#glass-sheet-stock -
nothing larger than 12x12 - expensive!
Cincinnati Gasket & Industrial Glass - www.cincinnatigasket.com
- http://www.cgindustrialglass.com/
40 Illinois ave - Cincinnati Ohio 45215 - Phone-513-761-3458
Mike Robbins - Sales Department
Quoting the
Schott Borofloat Borosilicate glass. We do **not**
offered flat polished edges.
Per our discussion we would cut the parts by hand and swipe
all (4) edges on a sanding belt to remove the sharp edge.
8"w x 16"lg (+/-.030") edges cut and swiped. I was aware of
the $50 minimum (from forum notes).
They stock a variety of thicknesses around 3mm (I did not
ask about the 2.75mm thickness)
|
| thick |
q1 |
q2 |
q3 |
| 3.3mm |
50.00ea |
25.00ea |
22.00ea |
| 3.8mm |
50.00ea |
35.00ea |
28.00ea |
| 5.0mm |
50.00ea |
38.00ea |
31.00ea |
John C. Ernst Co., Inc. - www.sightglass.com
21 Gail Ct. Sparta, NJ 07871 USA - PH
888-943-5000 973-940-1600
Matt Santolla - Inside Sales - matts@johnernst.com - minumum
order $30
1 Each 531
8.00-16.00 - Size: 8” x 16” x thickness below
Maximum Temp Rating: 446°F (230°C) - Pressure Rating: Not
Available
| Thick |
Q1 |
|
|
| 3.3mm |
72.00 |
|
|
| 3.8mm |
80.00 |
|
|
| 5mm |
86.00 |
|
|
F.J.Gray &CO. - Gray Glass CO. -
http://grayglass.net/glass.cfm/Industrial-Products/Borosilicate/catid/4/conid/79
Glass Fabricators – Authorized Distributors Corning Glass, Kopp Glass,
and AFG Industries
Chris Viggiano
- sales@grayglass.net
a 3.3mm thickness of the borosilicate sheet glass.
8" x 16" parts would be $45.00 each.
it would be a three piece minimum,
plus boxing and UPS to Jackson NJ of $58.00 for a total of
$193.00.
Bed Heaters
Maker's Tool Works - Bed Heater, 240 mm x 310 mm Kapton - 24v - 220W -
$24.95 (optional heat spreader $10)
http://store.makerstoolworks.com/bed-heater-240-mm-x-310-mm-kapton/
Panucatt Devices - helios 200 heated bed (200mmx200mm) - $40 - .125
thick pcb heater - 10A - ??V
http://www.panucatt.com/product_p/hbp200.htm
ebay - http://stores.ebay.com/consumertronics
MINCO KAPTON 9" X 7" POLYIMIDE THERMOFOIL HEATER PANEL, 10 OHM,
HK5528R6.2L12B - $69.95
LulzBot - http://www.lulzbot.com
24v 8-10a 360w
silicone heater 298x298, mk1 pcb heatbed 214x214
RigidBotBig 12"x16"x10" - Invent-A-Part, INC - http://www.inventapart.com/rigidbot_tech_info.php
claims a heated
bed - 300x400 - can only order/quote - no on-line 'store'
Quintessential Universal Building Device, Inc. - was
qu-bd.com points to q3dprinter.com - http://quintessentialuniversalbuildingdevice.com
- one up/two up/revolution 3d printers - parts
Heat spreader
Speedy Metals - .040 assumed
sheet 6061 - 12x18 $12.76
sheet 5052 - $9.18
sheet 3003 - h14 - $9.18
Insulation
For
the A1, I used an insulating blanket used for Pellet Stove Gasket
Material. Generically I believe it's called Rock Wool.
According to the post here:
http://www.hearth.com/talk/threads/pellet-stove-gasket-material.109274/
The trade name of the material is Lytherm or
Fiberfrax. It comes in
sheets 1/8 and 1/4 inch thick.
suppliers include
http://heiligkuh.com/bbandp/product_info.php?products_id=51 (he is also
on eBay) - $7/sqft
http://woodheatstoves.com/lytherm-gasket-by-square-foot-raw-material-p-12444.html
- $18/sqft!!
http://www.woodmanspartsplus.com/442265/products/High-Temperature-Kaowool-Paper-Gasket.html?d_id=63012
- $6.20/sqft
for info on Kaowool see:
www.fabricationspecialties.com/pdf/kaowoolpaper.pdf
I'm going to use two layers between the
structural support and the underside of the heated bed. The layer
directly against the bed will have to be trimmed to allow for the power
and thermistor wiring which bulges out from the surface of the heater.
My eBay auction was
http://www.ebay.com/itm/High-Temperature-Gasket-Material-/201003583687?pt=US_Replacement_Parts&var=&hash=item2eccbf48c7
Build
Platform Structural
Speedy Metals - 'flat' - limited widths - 'plate' - can be cut to size
plate 6061 3/16 thick - 12x18 - $28.01 - 12x24 - $35.51
Miscelaneous
The
kapton heater in the A1 came with an adhesive layer that held it to the
heat spreader. The Silicone rubber heater I'm using dosn't come that
way so I'll buy some double sided kapton tape and use that to hold the
heaters to the heat spreader.
Contact
Information
Contact me using: fpirz (at) media (dash) conversions (dot)
net