My Press Brake DIY

[cpl]

Press Brake i'm doing to work in the press. Not complete yeat, need to weld the knife into the tubes and the V into the base... but already tested with 1/2" - bended like paper.

Bonus:

 

[sscustom]

looks good man

 

[racingtadpole]

1/2" bent like paper.. How big is the press then?

 

[cpl]

i dont know exactly.. something around 60tons..

How i can calculate that ? Someone can teach me?

 

[ilovevocs]

Looks awesome.

Can you form a 90? Most brakes I have seen built like this allow you to slightly over bend to Compensate for spring back. Before getting a press brake with commercial made dies I had contemplated building one like yours until I realized that the angle iron approach would not compensate for re over bend required to compensate for spring back.

That said I'm more accustomed to bedding gauge thickness and do not posses a practice understanding of
bending and /
Or forming thicker materials. I find while working with gauge thicknesses that thicker materials tend to have less spring back. When you bent the .5" did you get very close to a 90?

Not trying to be negative or point out flaws in what your doing, just attempting to verify / invalidate my own thoughts.

 

[astroracer]

I bought a press brake kit from Swag Offroad. Welded it together in a few hours and did test bend on a piece of 3/8ths plate.

Test bend went to a perfect 90degrees.

The kit uses standard C channel and angle iron and is well worth the price.

It did the 3/8ths like paper and it will do 5/8th's plate 3"wide...
Mark

 

[A_Pmech]

cpl,

You can calculate the tonnage required by using a bending tonnage chart:

http://www.smithmachinery.com/docum.../pressbrake20tonnage20chart_14E7017915276.pdf

First, determine the width of the die opening. Then measure the material thickness. Slide down the die width column until you arrive at the material thickness and the number in the box is tons of pressure required per foot of bend.

 

[cpl]

Looks awesome.

Can you form a 90? Most brakes I have seen built like this allow you to slightly over bend to Compensate for spring back. Before getting a press brake with commercial made dies I had contemplated building one like yours until I realized that the angle iron approach would not compensate for re over bend required to compensate for spring back.

That said I'm more accustomed to bedding gauge thickness and do not posses a practice understanding of
bending and /
Or forming thicker materials. I find while working with gauge thicknesses that thicker materials tend to have less spring back. When you bent the .5" did you get very close to a 90?

Not trying to be negative or point out flaws in what your doing, just attempting to verify / invalidate my own thoughts.

Hmm indeed, i forgot about that!!
I havent check the spring back effect on my press but the plate i bended i got it a little over 90degrees.. My channel is 90degrees.. maybe because of the plate thickness?
I should have done the channel with a larger angle ~93degrees

The idea for this press is to bend thick metal (1/2 ~ 1").
To bend thin metal - above 1/2" - here in my business we bought a real bender - 175tons / 3meters... waiting to be delivered.

I bought a press brake kit from Swag Offroad. Welded it together in a few hours and did test bend on a piece of 3/8ths plate.

Test bend went to a perfect 90degrees.

The kit uses standard C channel and angle iron and is well worth the price.

It did the 3/8ths like paper and it will do 5/8th's plate 3"wide...
Mark

Nice! And how much tons are you using?

I based mine in yours saw few pictures on google hehe

cpl,

You can calculate the tonnage required by using a bending tonnage chart:

http://www.smithmachinery.com/docum.../pressbrake20tonnage20chart_14E7017915276.pdf

First, determine the width of the die opening. Then measure the material thickness. Slide down the die width column until you arrive at the material thickness and the number in the box is tons of pressure required per foot of bend.

Hi A_Pmech, thankz..
I know about that, i have an excel sheet here to calculate that..
What i mean i need to calculate is my press power.. how much tons my press apply.. cause we dont really know How to calculate this ?




Here in my business i work with steel cutting by Oxy / Oxy CNC / Plasma CNC.. do you guys want pictures of the machines?
We have three machines here.. one that cuts by oxygen reading the printed drawing.. one that is oxy-cnc.. and another that is plasma-cnc-400A

 

[astroracer]

Nice! And how much tons are you using?

I based mine in yours saw few pictures on google heh

My press is rated for 30 tons but I am only using a 20 ton bottle jack to run it. The 20T jack had no issue with a 5/8th x 3" test piece.
Pics would be appreciated.
Mark

 

[PCO6]

cpl - That looks great! Did you have the knife point machined and what angle is it? Thanks.

 

[gorilla]

The allowance for spring back is made by making the punch (upper die) less than 90*. I just measured a typical goose neck punch out of curiosity and it measured 891/2*.

 

[PCO6]

^^^ That's about what I figured (88* or 89* but I'm splitting hairs). The one pictured looks to be even less but it probably isn't that critical. Thanks for measuring it.

 

[cpl]

Hello everyone.

The knife i made from ASTM 1050 steel... i cutted a retangle by oxycut then i did the bevel by oxycut torch too.

Then i sended it to be milled - since i dont have a milling machine yeat
Just received:

 

[Kevin54]

The allowance for spring back is made by making the punch (upper die) less than 90*. I just measured a typical goose neck punch out of curiosity and it measured 891/2*.

^^^ That's about what I figured (88* or 89* but I'm splitting hairs). The one pictured looks to be even less but it probably isn't that critical. Thanks for measuring it.

On punch and dies, you want your die to be 90 degrees and the punch to be 85 degrees. This will allow for springback after the forming. 9 times out of 10, a punch and die both at 90 degrees will not give you a 90 degree part. The punch can always be less than 85 degrees also. Even a 60 degree punch will give you a 90 degree part. You just control the bend by the amount of pressure you use.

 

[gorilla]

You can reliable get 90*bends with 90* tooling if you use enough force to coin the material. This is not likely to happen in a home shop with a 20 ton press. The shape of the nose of a punch determines the radius of the bend to some extent so a variety of angles and radius's are used there is no fixed rule other than allowing for some spring back.

 

[Kevin54]

You can reliable get 90*bends with 90* tooling if you use enough force to coin the material. This is not likely to happen in a home shop with a 20 ton press. The shape of the nose of a punch determines the radius of the bend to some extent so a variety of angles and radius's are used there is no fixed rule other than allowing for some spring back.

Yea, you can do it if you use enough force, but why would you want to "coin" it in the first place? And yea, the shape of the nose DOES determine the radius. I don't dispute that. But I've ran enough press brakes and have made enough punch and dies, and also made enough dies, that the majority of parts, you don't want to have to coin them to get the angle desired. For one, when you coin them you stand the chance of thinning the material, depending on the material and the thickness.

 

[gorilla]

Yea, you can do it if you use enough force, but why would you want to "coin" it in the first place?

I would never commend coining if it can be avoided. My point was that there are other methods besides air bending. If you are ever in California I'll buy you a beer and we can swap press brake stories.

 

[Kevin54]

Yea, you can do it if you use enough force, but why would you want to "coin" it in the first place?

I would never commend coining if it can be avoided. My point was that there are other methods besides air bending. If you are ever in California I'll buy you a beer and we can swap press brake stories.

Very true. There are other methods. And I'll hold you to that beer if I ever get out that way And if you ever make it to Ohio, although I don't know why you would want to visit the state, the beer's on me

 

[ilovevocs]

Very true. There are other methods. And I'll hold you to that beer if I ever get out that way And if you ever make it to Ohio, although I don't know why you would want to visit the state, the beer's on me

Kev, im an ex. cali resident. Their are a few positive aspects of living in ohio. No smog checks, less VOC compliance, much less traffic, lower cost of living, no smog in the afternoons, and half the state doesn't catch on fire on a regular basis... Sadly that's about it.

When I moved to so cal my first trip the local autobody jobber left me frazzled. Half the products I was used to working with were not / could not be sold their.

 

[porschedude996TT]

Kev, im an ex. cali resident. Their are a few positive aspects of living in ohio. No smog checks, less VOC compliance, much less traffic, lower cost of living, no smog in the afternoons, and half the state doesn't catch on fire on a regular basis... Sadly that's about it.

When I moved to so cal my first trip the local autobody jobber left me frazzled. Half the products I was used to working with were not / could not be sold their.

Slowly Sinking and Stinking into the Drain. Stop California, I want off!

 

[gorilla]

The US Air Force museum at wright-Patterson AFB is one good reason to visit Ohio. I got to spend an afternoon there some years ago and I plan on returning someday.

 

[machinesales]

Hows the press brake project coming along? I kinda got in on this a little late,but would love to see the end results of your project.