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psomero
02-14-2005, 04:16 AM
ok, well i'm planning on building a sheet metal brake. the best guidance i've found so far was at http://bd-4.org/bendingbrake.html . this is a great guide (there's schematics on the link at the top of the page), however it does not specify how to locate the pivot pin center. i've been playing with it a bit in solidworks, but i have no idea what i'm trying to accomplish with the apron (i think that's the term. the piece the handle's attached to...) travel.


anybody got any idea?

Paul Alciatore
02-14-2005, 11:03 AM
I've never built one but it is my understanding that the axis of rotation should be horizontally displaced from the inside corner of the bend by the thickness of the metal being bent. That puts it at the outside edge of the finished bend. It's possible that a small vertical displacement (downward?) from there might help by lessing the amount of slippage as the bend is made, but I don't know.

This distance, of course, changes with the thickness of the metal being bent. If you elect for a fixed distance, use the largest thickess you are designing for. If you want an adjustment, it is easier to adjust the position of the hold-down to achieve this.

Paul A.

happy02
02-14-2005, 11:03 AM
I have the plans to build a brake in a 1955 Popular Mechanics magazine article. It's one of those things I'd like to build if I ever get a Round Tuit. They show the pivot pin to be located exactly on center between the bending bar and the bed. Also it shows the clamp bar to be ground back at 10* so it will allow stock to be bent over 90* to allow for spring back. If I can be more help, let me know. Good Luck. Joe
The article I have is for a brake for 20ga.metal.

[This message has been edited by happy02 (edited 02-14-2005).]

SGW
02-14-2005, 12:09 PM
Dave Gingery published plans for a bending brake, available from Lindsay Publications www.lindsaybks.com (http://www.lindsaybks.com) that may give some of the design theory.

G.A. Ewen
02-14-2005, 02:33 PM
<font face="Verdana, Arial" size="2">Originally posted by psomero:
ok, well i'm planning on building a sheet metal brake. the best guidance i've found so far was at http://bd-4.org/bendingbrake.html . this is a great guide (there's schematics on the link at the top of the page), however it does not specify how to locate the pivot pin center. i've been playing with it a bit in solidworks, but i have no idea what i'm trying to accomplish with the apron (i think that's the term. the piece the handle's attached to...) travel.


anybody got any idea?</font>

If you would like to contact me by e-mail I will send you some photos that might help. I....er.... borrowed these photos so I would rather not post them here. http://bbs.homeshopmachinist.net//redface.gif

m_kilde
02-14-2005, 05:13 PM
You are welcome to look in my photobucket, this is just a small brake, but great fun to build

http://photobucket.com/albums/v127/m_kilde/

Mogens

Fred White
02-14-2005, 08:11 PM
I bought these plans off eBay and upgraded the materials to be able to bend about 24" of 16 Ga material.

http://www.how-to-plans.com/sheet_metal_bending_brake_18in_.html

What I really like is it uses my bench vise for support so I don't tie up shop space with the tool when I'm not using it.

The plans specify the axis of the bend as Happy02 described it. If you want to bend more than 90 degrees, then the clamp bar will have to be ground even more. Most commercial brakes probably allow around 120 to 135 degrees of bend.

[This message has been edited by Fred White (edited 02-14-2005).]

psomero
02-15-2005, 12:43 AM
G.A. Ewen, check your mail

radish1us
02-15-2005, 03:42 AM
<font face="Verdana, Arial" size="2">Originally posted by m_kilde:
You are welcome to look in my photobucket, this is just a small brake, but great fun to build

http://photobucket.com/albums/v127/m_kilde/

That is one sweet bender there, any chance of getting some drawings of it???????.

Mogens</font>

shaque
02-15-2005, 11:44 AM
While we are on this subject, has anyone got plans for a finger brake sometimes called a box brake eh? or should it be huh? http://bbs.homeshopmachinist.net//biggrin.gif http://bbs.homeshopmachinist.net//biggrin.gif http://bbs.homeshopmachinist.net//biggrin.gif
Jim http://bbs.homeshopmachinist.net//smile.gif
Thanks George

By the way, that's one awesome machine Mogens, please give us some more information on it...

[This message has been edited by shaque (edited 02-15-2005).]

J. R. Williams
02-15-2005, 11:54 AM
Psomero
Check with (webmaster@homemetalshopclub.org) as he has prepared a formal set of plans for a small sheet metal brake I designed and built many years ago.
JRW

m_kilde
02-15-2005, 01:22 PM
Hi radish1us

You can see my web-site

I know it is on the edge of advetising

------------------
Mogens Kilde
www.mogenskilde.1go.dk

Chester
02-15-2005, 02:12 PM
The link below shows a slightly modified GINGERY 24" brake that was made from 1/4 X 2" angles. Doing it again, I'd make the clamp leaf adjustable (back and forth) to compensate for various metal thicknesses. But as is, it is adequate for 18Ga full width bends for tool trays, autobody pieces , etc. Anyone that has access to Princess Auto in Canada should look at that 36" red unit (#8043690) they sell for around $300. Many well thought out features such as an adjustable clamp leaf and lock down, that could be re-used.


http://community.webshots.com/photo/263051141/274872199rTlLCz

[This message has been edited by Chester (edited 02-15-2005).]

Fred White
02-15-2005, 05:40 PM
Chester-

That link shows a jointer.

??????

Chester
02-15-2005, 09:33 PM
Hit the "view full size" link on the bottom and you'll see the brake in the center photo. It is on the back of that stand.