Reply
 
Thread Tools Display Modes
  #1  
Old 05-26-2016, 09:39 AM
brossa brossa is offline
Guest
 
Join Date: Feb 2005
Posts: 911
What kind of cutting mechanism is this?

There's a Kickstarter for a widget to slice plastic bottles into long thin strips, which can then be used for a variety of purposes.

The cutting action of this widget seems to be performed by two wheels that overlap slightly. If you don't want to click on the link, I'll try to describe the setup:

Take parallel axles, and place one wheel on each axle. The wheels have broad, flat metal 'tires' like on an old-fashioned wagon wheel. The edges of the metal 'tires' have a hard 90 degree angle, probably ground so as to be flat on the sides. The two wheels are staggered on the axles, and arranged such that the rim of one wheel slightly overlaps the rim of the other wheel, and the wheels are in contact along their sides. If you feed a sheet of material into the wheels, one wheel pushes the sheet down and the other wheel pushes the sheet up, and the sheet gets sheared or sliced at the point where the two wheels touch each other. It's kind of like a pair of scissors of infinite length, with two blades always sliding past each other.

Is there a name for this kind of setup? The widget on Kickstarter looks like it's made of off-the-shelf parts, but googling 'rotary cutter' or 'rotary shear' doesn't seem to pull up the right sort of mechanism.
  #2  
Old 05-26-2016, 10:00 AM
GaryM GaryM is offline
Charter Member
 
Join Date: Jun 2000
Location: St. Louis, MO 50mi. West
Posts: 4,445
I'd just call it a rotary shear. We had a larger version in sheet metal shops years ago and I'm sure still today. I have a plastic handled small version used for cutting wrapping paper that I bought in WalMart or maybe Hobby Lobby.

A Google search for "rotary shear" brings up thousands of images from massive machines to handheld electric or smaller.
  #3  
Old 05-26-2016, 10:19 AM
TriPolar TriPolar is offline
Guest
 
Join Date: Oct 2007
Location: rhode island
Posts: 37,388
It's often an additional feature for a bead roller used to make impressions in metal. Slightly larger wheels cut the metal instead of just bending it. Rotary shear sounds like a good name.
  #4  
Old 05-26-2016, 10:38 AM
GaryM GaryM is offline
Charter Member
 
Join Date: Jun 2000
Location: St. Louis, MO 50mi. West
Posts: 4,445
Same cutting action as scissors actually except you move the work rather than the tool.

Sent from my LG-V495 using Tapatalk
__________________
GaryM
  #5  
Old 05-26-2016, 10:55 AM
Gary T Gary T is offline
Member
 
Join Date: Mar 2002
Location: KCMO
Posts: 11,122
At the 1:23 point the text says "Can be used for demonstration purposes only and not for advertising or sales promotion." Why? What kind of demonstration purposes might one use it for? What kind of advertising or promotion might one use it for? What's the problem with using it for the latter?

I assume they don't mean demonstration, advertising, or promotion of the product itself in the context of trying to sell it, as it seems totally nonsensical to have such a prohibition.
  #6  
Old 05-26-2016, 11:30 AM
naita naita is offline
Guest
 
Join Date: Jun 2002
Location: Norway
Posts: 4,896
Quote:
Originally Posted by Gary T View Post
At the 1:23 point the text says "Can be used for demonstration purposes only and not for advertising or sales promotion." Why? What kind of demonstration purposes might one use it for? What kind of advertising or promotion might one use it for? What's the problem with using it for the latter?

I assume they don't mean demonstration, advertising, or promotion of the product itself in the context of trying to sell it, as it seems totally nonsensical to have such a prohibition.
It doesn't say "Can be used", it says "Cans used". They're promoting a device for cutting plastic bottles and plastic cans and inform you that this part of the video, where they are cutting metal cans, has been included for demonstration purposes, and is not meant to advertise and promote the device as suitable for cutting metal cans.
  #7  
Old 05-26-2016, 06:33 PM
Gary T Gary T is offline
Member
 
Join Date: Mar 2002
Location: KCMO
Posts: 11,122
Quote:
Originally Posted by naita View Post
It doesn't say "Can be used", it says "Cans used". They're promoting a device for cutting plastic bottles and plastic cans and inform you that this part of the video, where they are cutting metal cans, has been included for demonstration purposes, and is not meant to advertise and promote the device as suitable for cutting metal cans.
I'm glad one of us read that carefully! Thanks.
  #8  
Old 05-26-2016, 07:10 PM
Channing Idaho Banks Channing Idaho Banks is offline
Guest
 
Join Date: Mar 2015
Location: beautiful Idaho
Posts: 2,083
This makes me think of the Monty Python 'String' sketch. Now that you have miles of plastic strips, what are you going to do with them?

Last edited by Channing Idaho Banks; 05-26-2016 at 07:11 PM.
  #9  
Old 05-27-2016, 12:48 AM
Projammer Projammer is offline
Member
 
Join Date: Apr 2006
Location: SW Arkansas
Posts: 5,771
Quote:
Originally Posted by Channing Idaho Banks View Post
This makes me think of the Monty Python 'String' sketch. Now that you have miles of plastic strips, what are you going to do with them?
Use it as cheap filament for your 3D printer.

I saw a tech article on that once but can't be arsed to look it up now.
Reply

Bookmarks

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is Off
HTML code is Off

Forum Jump


All times are GMT -5. The time now is 04:07 AM.

Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2017, vBulletin Solutions, Inc.

Send questions for Cecil Adams to: cecil@chicagoreader.com

Send comments about this website to: webmaster@straightdope.com

Terms of Use / Privacy Policy

Advertise on the Straight Dope!
(Your direct line to thousands of the smartest, hippest people on the planet, plus a few total dipsticks.)

Publishers - interested in subscribing to the Straight Dope?
Write to: sdsubscriptions@chicagoreader.com.

Copyright 2017 Sun-Times Media, LLC.

 
Copyright © 2017