Posted by control guy at 03/11/2001 11:40 PM EST
Student on team #250 from HVCC.
There may be some of you out there who have the belief that lexan does not break, that it is indestructable.
It DOES break.
Thank you.
This has been a public service announcement.
Posted by Chris Hardman at 03/12/2001 12:38 AM EST
Student on team #111, WILDSTANG, from Rolling Meadows and Wheeling High schools and motorola.
In Reply to: Lexan, the wonder material
Posted by control guy on 03/11/2001 11:40 PM EST:
: There may be some of you out there who have the belief that lexan does not break, that it is indestructable.
: It DOES break.
: Thank you.
: This has been a public service announcement.
depends on what thickness your using. we use lexan on our shipping crate, and it’s sweet
chris hardman
Posted by Matt Leese at 03/12/2001 8:36 AM EST
Other on team #73, Tigerbolt, from Edison Technical HS and Alstom & Fiber Technologies & RIT.
In Reply to: Re: Lexan, the wonder material
Posted by Chris Hardman on 03/12/2001 12:38 AM EST:
Well, anything thickness polycarbonate (stupid corporate terms 
will break after you apply enough stress to it. Although it does tend to bend a lot more than it will break in thinner sizes.
Matt
Posted by Chris Hardman at 03/12/2001 5:59 PM EST
Student on team #111, WILDSTANG, from Rolling Meadows and Wheeling High schools and motorola.
In Reply to: Re: Lexan, the wonder material
Posted by Matt Leese on 03/12/2001 8:36 AM EST:
: Well, anything thickness polycarbonate (stupid corporate terms will break after you apply enough stress to it. Although it does tend to bend a lot more than it will break in thinner sizes.
: Matt
polycarbonate does not equal lexan different products
chris hardman
or am i wrong?
Posted by Matt Leese at 03/12/2001 8:14 PM EST
Other on team #73, Tigerbolt, from Edison Technical HS and Alstom & Fiber Technologies & RIT.
In Reply to: Re: Lexan, the wonder material
Posted by Chris Hardman on 03/12/2001 5:59 PM EST:
Lexan is GE’s brand name for polycarbonate. They’re exactly the same thing. You call it potato, I call it patato. You call it Lexan, I call it polycarbonate.
Matt who realizes he really needs to get out more…
Posted by Travis Covington at 03/13/2001 2:58 AM EST
Student on team #115, MVRT, from Monta Vista High School and 3com - NASA-Xilinx-Hitachi Data Systems.
In Reply to: Re: Lexan, the wonder material
Posted by Matt Leese on 03/12/2001 8:14 PM EST:
technically polycarb doesnt break…
it shears and will fracture if you have a square inside cut…
it weakens at the corner and if slammed by something will break…
BUT…if you round the corners it is VERY strong…almost impossible to break…
it on;ly breaks when you didnt design your part to be made out of lexan (sharp corners inside corners tight angle cuts etc)
and im pretty sure lexan is a diff product entirely…
slightly diff physical prperties i know for a fact…
be sure to use polycarb tho…lexans not on add hardware
TC (geek who thinks hes a nerd)
Posted by Matt Leese at 03/13/2001 9:29 AM EST
Other on team #73, Tigerbolt, from Edison Technical HS and Alstom & Fiber Technologies & RIT.
In Reply to: Re: Lexan, the wonder material (hopefully u mean polycarbona
Posted by Travis Covington on 03/13/2001 2:58 AM EST:
No, Lexan is most definately polycarbonate with the exact same physical properties. This is from GE’s web site: “LEXAN sheet, manufactured from GE Plastic’s proven LEXAN polycarbonate resin”. And even if your parts are well designed, polycarbonate can still break. It is not indistructable eventhough it sometimes seems as if it is. Rounding corners, etc. just makes a stronger end product. All polycarbonate is breakable given enough stressors in the right directions. I’ve even seen 1/16" polycarbonate (which you would assume would just bend a whole lot) break after a lot of force (okay, someone was hitting it repeatedly with a hammer).
Matt
Posted by Andy Baker at 03/13/2001 10:29 AM EST
Engineer on team #45, TechnoKats, from Kokomo High School and Delphi Automotive Systems.
In Reply to: Polycarbonate=Lexan
Posted by Matt Leese on 03/13/2001 9:29 AM EST:
Matt,
You are very correct.
GE Plastics invented polycarbonate back in 1963 (Dan Fox), and their version is called LEXAN.
There are other types of polycarbonate, and all are legal.
Sheffield Plastics = HYZOD
Westlake Plastics = ZELUX
Ato Haas N. America = TUFFAK (this may be a glazing, I dunno)
Ensinger = ENSICAR
GE Plastics = LEXAN
Andy B.
Posted by Travis Covington at 03/14/2001 7:34 PM EST
Student on team #115, MVRT, from Monta Vista High School and 3com - NASA-Xilinx-Hitachi Data Systems.
In Reply to: Polycarbonate History
Posted by Andy Baker on 03/13/2001 10:29 AM EST:
errr
me feel dum dum
oh wells…
-TC (ill shut up now)
Posted by Anton Abaya at 03/15/2001 3:56 PM EST
Coach on team #419, Rambots, from UMass Boston / BC High and If only we had free donuts…
In Reply to: Re: Polycarbonate History
Posted by Travis Covington on 03/14/2001 7:34 PM EST:
Andy? u seem knowledgable about plastics…?
i think i read it somewhere…
-anton
Posted by Dave… at 03/17/2001 12:27 AM EST
Engineer on team #5, Robocards, from Melvindale, MI and AFL (Alcoa Fujikura Ltd).
In Reply to: Anyone hear about the new conductive plastic ?
Posted by Anton Abaya on 03/15/2001 3:56 PM EST:
Conductive plastics are somewhat misleading. The base resin material (polycarbonate, nylon, polyethylene, etc.) is not conductive, but rather the fillers which are added. Most plastics have some sort of additive(s) for strength, stiffness, or other material properties which are desired. A conductive plastic simply adds fibers or flakes of carbon or stainless steel. The plastic resin just holds the stuff together.
Dave…
: Andy? u seem knowledgable about plastics…?
: i think i read it somewhere…
: -anton
Posted by Adam Krajewski at 03/12/2001 4:15 PM EST
Engineer on team #221, MI Roboworks, from CCISD and Michigan Tech…
In Reply to: Lexan, the wonder material
Posted by control guy on 03/11/2001 11:40 PM EST:
Yes, Polycarbonate breaks… But so does everything else. We are very happy with the polycarbonate gears in our drivetrain this year. I myself was skeptical to how well they would work, but it has worked flawlessly so far… The side panels, front ‘drive’ wheels (including the green spokes) and spur gear off the drill motor are all polycarb.
Going back to the previous gear thread, if you have access to a waterjet, large polycarb gears are fairly easy to make from raw materials.
Adam
Posted by Patrick Dingle at 03/12/2001 8:54 PM EST
Coach on team #639, Red B^2, from Ithaca High School and Cornell University.
In Reply to: Lexan, the wonder material
Posted by control guy on 03/11/2001 11:40 PM EST:
polycarbonate == Lexan
polycarbonate != acrylic
acrylic == plexiglass
Patrick
: There may be some of you out there who have the belief that lexan does not break, that it is indestructable.
: It DOES break.
: Thank you.
: This has been a public service announcement.