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Harvey Melvin Richards
04-15-2010, 12:39 PM
I have a 36" Pulford sheet metal brake. The bending part is 15/16" thick. Is there a way I could bend a part that looks like this with this brake? I'm not visualizing a solution.

http://i811.photobucket.com/albums/zz35/HarveyMelvinRichards/Bend.jpg

RKW
04-15-2010, 01:07 PM
That appears to be a pretty standard set of bends. Are you looking to do it in one operation or something like stamping? Otherwise I think you can make one bend to 90, turn the part over and then make the other. Am I missing something about your particular brake possibly?

Harvey Melvin Richards
04-15-2010, 01:18 PM
That appears to be a pretty standard set of bends. Are you looking to do it in one operation or something like stamping? Otherwise I think you can make one bend to 90, turn the part over and then make the other. Am I missing something about your particular brake possibly?
My problem is the bending part of the brake is too thick. I have a small pocket milled on one end and the bending part (name?) is only 1/2" thick and I'm able to easily bend this part. However the part I need to bend is 30" long and the pocket is 6" long.

I am able to bend a "J" with these dimensions, but I can't figure out how to do an "S".

RKW
04-15-2010, 01:29 PM
I think you may be referring to the adjustable "fingers" on your brake that are too thick and not the part itself, right?

http://www.bii1.com/images/sheet%20metal%20brakes/BB-3616E-large.jpg

Each of the segments of this brake are fingers. This type of brake is a box or finger brake.

How about a picture of two?


My problem is the bending part of the brake is too thick. I have a small pocket milled on one end and the bending part (name?) is only 1/2" thick and I'm able to easily bend this part. However the part I need to bend is 30" long and the pocket is 6" long.

I am able to bend a "J" with these dimensions, but I can't figure out how to do an "S".

bborr01
04-15-2010, 01:45 PM
Does your break open far enough to bend the first 1/2 inch tab, then slide the part in from the back and bend the long tab? Then pull it out from the back.

Brian

Harvey Melvin Richards
04-15-2010, 01:46 PM
This is the brake.

http://i811.photobucket.com/albums/zz35/HarveyMelvinRichards/P4151023Large.jpg

This is where I can make the bend I want, but not 30" long. It's the 6" pocket on the right end.

http://i811.photobucket.com/albums/zz35/HarveyMelvinRichards/P4151021Large.jpg

This is where the bender part is too wide.

http://i811.photobucket.com/albums/zz35/HarveyMelvinRichards/P4151020Large.jpg

The scale is being held by the adjustable fingers. They open about 1" so I can put something under them if I need to.

bborr01
04-15-2010, 02:05 PM
Sounds like the break will open to 1 inch so my solution of inserting the partially bent piece from the back will work.

Brian

DR
04-15-2010, 02:55 PM
Yep, you will have a problem bending it on that brake.

What I've seen done with similar brakes is to mill the "leaf" (or is it the apron?) thinner all across like the 6" area. For stiffness a solid bar is bolted in the milled recess when you aren't bending parts like shown.

My DiAcro finger brake will bend with only 1/4" between bends when it's factory stiffener bar is removed.

Harvey Melvin Richards
04-15-2010, 03:29 PM
Sounds like the break will open to 1 inch so my solution of inserting the partially bent piece from the back will work.
Brian
I'm still not following. I bend an "L" with a 1/2" leg, with the 1/2 leg pointing down, my next bend has to be at least 1" because my leaf (?) is 1". If I start with a 1" L, it doesn't work either. It would seem like the middle portion of this bend can only be as wide or wider than my leaf.

Harvey Melvin Richards
04-15-2010, 03:30 PM
Yep, you will have a problem bending it on that brake.

What I've seen done with similar brakes is to mill the "leaf" (or is it the apron?) thinner all across like the 6" area. For stiffness a solid bar is bolted in the milled recess when you aren't bending parts like shown.

My DiAcro finger brake will bend with only 1/4" between bends when it's factory stiffener bar is removed.

This makes sense to me, as I can bend what I need on the thinner section. This is a 1 or 2 item bend, so it's not worth modifying the brake. Thanks.

Jim Stabe
04-15-2010, 04:04 PM
You either need to find someone with a lighter duty brake that has a 1/2" thick apron or someone with a press brake with a narrow lower die.

Harvey Melvin Richards
04-15-2010, 04:46 PM
You either need to find someone with a lighter duty brake that has a 1/2" thick apron or someone with a press brake with a narrow lower die.

That's kinda what I thought. I'm going to go with option #3, redesign the part for my brake.

camdigger
04-15-2010, 05:14 PM
I have a 36" Pulford sheet metal brake. The bending part is 15/16" thick. Is there a way I could bend a part that looks like this with this brake? I'm not visualizing a solution.

at 15/16" thick, you ain't bending nothin' with that brake. Find some thinner material or seek other means.

IMHO, YMMV

Thiiner material could be done with a homemade pressbrake punch and die, 100$ press and 40$ hyd jack.

Harvey Melvin Richards
04-15-2010, 05:42 PM
at 15/16" thick, you ain't bending nothin' with that brake. Find some thinner material or seek other means.

IMHO, YMMV

Thiiner material could be done with a homemade pressbrake punch and die, 100$ press and 40$ hyd jack.
By bending part, I meant the piece of the bake that moves, thus bending the work piece.

I still haven't come up with a definitive name for what that part of the brake is called.

Ries
04-15-2010, 05:57 PM
Here in the USA, it is usually called the "leaf".

On a straight brake, you have a top leaf and a bending leaf.
On a box and pan brake, sometimes called a finger brake, like yours, you have fingers on the top leaf.

Many brakes have a removable bar on the lower, bending leaf, full width, that can be taken out for problems just like yours, making the thickness of the bending leaf less.
You bolt it back in when you are bending thicker material at full width, and need the mass and leverage of the full thickness.

Unfortunately, yours was not built this way.
If you look at the picture of the Connecticut brake here-
http://roperwhitney.com/bending/1-17.cfm
you can see the white colored bar, and the bolts that hold it on.
Remove it, and the bending leaf is thinner, allowing reverse bends to be tighter together, just like what you want.

Harvey Melvin Richards
04-15-2010, 06:20 PM
Here in the USA, it is usually called the "leaf".

On a straight brake, you have a top leaf and a bending leaf.
On a box and pan brake, sometimes called a finger brake, like yours, you have fingers on the top leaf.

Many brakes have a removable bar on the lower, bending leaf, full width, that can be taken out for problems just like yours, making the thickness of the bending leaf less.
You bolt it back in when you are bending thicker material at full width, and need the mass and leverage of the full thickness.

Unfortunately, yours was not built this way.
If you look at the picture of the Connecticut brake here-
http://roperwhitney.com/bending/1-17.cfm
you can see the white colored bar, and the bolts that hold it on.
Remove it, and the bending leaf is thinner, allowing reverse bends to be tighter together, just like what you want.

Thanks, that's some good info.