Press Brake Tooling Help

Got a Pneuco 6' 30 ton up acting pneumatic press brake. Haven't fired it up yet as I don't have tooling for it. Looking to pick some up used if I can as I'm just playing around at this point - but may consider ordering some new and picking up at Fabtech in Chicago in November.

Looking to send this machine up exclusively for 90 degree bends in 18 ga CRS.

Should I use a 90 degree punch then to make repeatability as good as possible?

3/8" V die opening? or?

Any help is appreciated.
thanks

Sounds like what you will be needing is for someone to come over and help you get set up. I'd hate for you to spend a bunch on tooling and end up with the wrong stuff.

Die opening is usually chosen based on bend radius. Punch is narrower and more acute than the die. The punch is stopped short of pinching the work ( air gap. ) Not a good idea to try for a coined bend ( no air gap. ) Hard on the tooling and marks up the work.

Your local used press dealer will probably have racks full of press tooling. I see press tooling on ebay all the time; problem is in finding the lengths that you need. Tooling can be mild steel and also can be fabricated, though you are probably looking at a hardened punch at least. Making something six feet long with some accuracy may be outside the capabilities of the small shop however.

Repeatability is usually a function of material temper and accurate gauging. You are going to be settting the stops to fix the air gap. A good press operator can gauge each piece and if it's under or over he can adjust the stock in the die and punch it again to compensate. A good press operator is worth what you'll be paying him.

IS this to make money or hobby stuff?

Money- then invest in good tooling.

Simple open sided bends or boxes?

Will you need to swap punches a lot?

Simple bends, buy planer tooling, if needed cut to size.

Want a lot better setup, use Wila tooling.

Ultimate in setup, top quality.

Have no connection to Wila other than a rack full of the stuff and totally satisified with the product. Worth every penny.

Part numbers that would would perfect in 18 ga would be:

OZU-911 bottom die
BIU-904 top punch

This set will give a nice radius on the part.

Need to do a larger box flange then a BIU-902 will work.

bending tooling

thanks for input. I'm trying to learn - coin/air/bottom bending - can someone explain these in practice to me. I know the definitions, but not sure of best applications? First tooling company I talked to recommended a 3/8" V die and a fairly sharp punch as I recall (17 degree?). Second one I talked to said if I was doing same bends/same material to go with a 89/90 degree punch to increase repeatability/accuracy - guessing this would be "coining"?. I am looking to do small (25 pc) runs of sign cabinets. For profit parts (hopefully) and to learn more about process - grow into bigger/better brake later.

I start with a Laser cut blank, 1" 90 degree bend on 4 sides (all up), followed by 5" 90 degree bend on 2 long sides (both up). The 2 short ends are rolled up by hand and welded. Blanks are approx 22x55 in the flat.

I don't understand the big difference in tooling (wila vs planar) - I'm not making rocketships- but want to be reasonably consistent in bends so the "boxes" fold up nicely and weld together consistently.

Should not need to switch tooling at all (I hope). The press operator will be me for the foreseeable future. Don't have a lot of $ in this machine and want to get my feet wet, learn, and hopefully be able to make some parts without having to depend on someone else and their schedule.

thanks so much for all the input!

This may work for you...my experiment, it's done quite often apparently.

If you have your blanks laser cut you can have your tooling cut as well. Someone linked to a similar patent that is actually a better idea. I should have something working this week.

Laminated press brake idea. New? - Pirate4x4.Com Bulletin Board

I foresee a few problems, tool marks being one of them, but they make a film for that.

Used die prices are very high from what I've seen, but you may want to call a bunch of these places. They're heavy too.

18 ga only? I might consider a 6-8' leaf brake for the long side and 48" box and pan for the rest. (esp if tooling is going to cost $2k and your volume is low).

-James

Simply put:

air bending-the punch pushes the material down into the die but the punch, material do not bottom out.

Coining- the upper punch pushes the material into the die, the upper punch drives the material into the die, bottoming out, forcing the angle of the bend.

Air bending takes much less "tons per foot" to operate.
Coining will add 50 % plus in required tonnage for the same bend.

Wila is sectional, you buy a secton, 20" on average.

Use clips to hold the punch in place, real nice when changing.

Tooling is hardened, and ground to size. All punches, dies are all the same size.

Just go to Wila on google, read up.

Planer tooling is what it says, made on a planer. Can be good or bad depending on the machine that cuts it out.

I used planer tooling for a while then made the switch to Wila, would never go back. Wilson makes sectional also but they don't harden as deep , for basically the same cost.

bending

Thanks for replies everyone. So is air bending generally going to yield a larger radius bend than coining? Would seem to me with a 3/8" die opening and 18ga material you'd have a "large" radius? I'm looking for fairly tight bends - and am most worried about consistency. My machine has mechanical stops that are adjustable and as far as I know that's how I control stroke or depth of bend? Last supplier I talked to seemed to think that by using a 90 degree punch I would get more consistency - does this make sense?

jamscal - thanks, I have a leave and finger brake - but I want something I can set up back gauges/stops on and get 100 repeatable bends in a row - can't see me doing that on those machines. Could be done I suppose - but I'm looking to automate a little more than that -but appreciate the suggestions. I've seen the sectional tooling done on laser for unique/short run apps - good idea.
thanks all

18 ga carbon takes about 3 tons per ft to air bend over a 3/8 die.

So at 55" part length your need 18 tons.

Radius will be a tad "bigger" air bending but probably not what you think.

If I get a chance tomorrow I'll take a picture of 18 ga air bent 90

Repeatability is all about the brake, not the tooling.

Once the tooling is set then the mechanical aspects of the brake take over, loose pivots show up, flexing rears it's ugly head, crowning may or may not happen.

Depending on the brake where you place the part can affect the bend.

And the material thickness will change the angle of bend as material is not the same size , sheet to sheet. One sheet could be .043 the next .048

Welcome to the world of press brakes

Hey don't pass up a good finger brake to make those parts.

Have two press brakes and still hold on to the ol' manual brake.

Took the brake and made a table in the rear with a backgauge.

Once the top clamp, material clearance, fingers were set, we pumped out a lot of parts , 30 x 44 in 20 gauge.

Made a lot of beautiful corners, rival any press brake.

Plus, there is no material flying in air, no chance to get that reverse bend just back from the edge by not following the dies fast enough.

Totally quiet

And 18 ga is a piece of cake to pull.

Huskerz said:

The 2 short ends are rolled up by hand...

Click to expand...

Why? Make a station and hit them also.

gbent
I thought the same thing but the ends must have a curve /radius.

Bends

precisely on the ends - 5" radius - roll & tack as you go and then continuous tig weld & finish. Would love to be stamping these, but my quantities are no where near paying for a die like that!

Would love to see the air bend photo if you get a chance- also please note tooling specs.

Definitely never get rid of my 10' x 16 whitney apron brake or my smaller finger brake- but haven't been able to set them up for quick/easy repeatable degree of bend? Backstop I can handle - but don't know of an easy way to get exact 90s every time? Plus that's a lot of beam to swing by yourself a few hundred times in a day???

Still would love a detailed explanation on how to select V die opening width and punch angle - and how it affects parts/consistency.
Thanks so much everyone!

there are standards in die/punch selection.

Example the 911/904 setup I use gives a nice tight bend with 18 ga material.

The die is 3/8 between tips, the punch has a .031 tip

You could use a die with a 1" wide opening, same .031 tip punch and bend 18 also, except the radius will be very large.

Dies may be chosen by the required flange length needed, you couldn't make a 1/4 " lip on the material using a 1" wide die.

The wider the die the less tonnage per foot required to make the bend. a 3/8 die, .031 tip punch is about 3 tons per foot, as I said before. Using a 3/4" wide die the tonnage drops to around 1.4 per foot.

So...........you ask again about consistency.

It all the brake, not the tooling. It doesn't make any difference if you have a 3/8 die or 1/2 die, the travel of the ram must be the same to produce like parts, with air bending or coining.

Air bending the brake must stop at the same point, coining, the brake must produce the same pressure.

if the brake cannot repeat itself you will never get like parts.

As you mentioned one guy said to use a 90 deg setup, fine, except the brake must be able to "push" the same every time or the angle will be different.

Need to edit my previous post(was watching TV) bottom bending will take about 4 times the tonnage, coining about 10 times.

So your 30 ton brake isn't going to bottom bend 55" (3 tons ft x 4=12 tons ft ///12x4.58=54 tons)

Everyone has an opinion, mine would be to air bend.

read this http://archive.metalformingmagazine.com/1998/03/Hurco/hurc.htm

Huskerz said:

...
Still would love a detailed explanation on how to select V die opening width and punch angle - and how it affects parts/consistency.
Thanks so much everyone!

Click to expand...

I can't really help much there, not a press operator, just a hack fabricator who has spent some time around pressmen. This is all in a book somewhere. I've seen some huge tombs on sheet work. Don't have any titles for you. The tooling MwTech has recommended will get you as close as you are going to get. Accuracy is determined by the repeatability/stability of the machine and spring-back in the material. Your machine is what it is and the material is what it is.

While reducing the die opening reduces the material effect on the bend angle it also increases the bending force which adversely effects the machine repeatability. This trend continues to it's extreme when the material is coined. Then you have taken the material variable out as much as you can but the press has to apply a lot more pressure so you have maximized the machine's contribution to the error. It's a tradeoff.

If accuracy is really all that important, ( and why can you just tap it in? ) then you need to look to your material chain. Getting material that is calendared and tempered would do more for accuracy than fiddling with die openings. 'course you are talking a big increase in price and you are going to be captive to your sheet processor.

I used to make a radiused part out of sheet that had to have a particular radius and tension. We bought 4130, calendared and normalized, with certs. A bit of premium over stock but not too bad as the stuff is used in airplanes. Problem was that if the processor's oven was down for maintenance, which was rarely on schedule, we had no material. I ended up having to stock several months worth of material. The premium for which I had to eat when the customer failed.

Another factor; your part has two different type right angle bends to do. One long ( twice ) and one short. One is going to have to be against the grain. The spring back on that is going to be different than the spring back on the long one. Bending against the grain takes more force and is less repeatable than bending with the grain.

MW
thanks for your patience- and sticking with me. I understand what you are saying on the die openings widths- and I'm good with 3/8" die and giving air bending a try (after seeing your numbers - I don't really have an option . I will look at link you referenced and try to do my homework.

I'm still fuzzy on punch selections. My previous information was leading me to believe that a 90 degree punch would be more consistent than a more acute punch (all other things being equal)? Is this accurate?

What do I look for in used tooling - a tool distributor here just got a bunch in from a big factory that closed. How do I know if it's wila/wilson planar etc....

Will try to read up - thanks again

The punch doesn't make a difference, 90 or acute.

Its how the machine can squeeze those things together

Super accurate bends are made all day with air bending.

As starboilin added the brake will see more stress bottom bending/coining, so expect worse bending with these methods if the brake flexes, can't repeat the pressure, etc.


Today was crazy, will try again tommorrow

The inside bend radius will be .156 of the lower die width. Lower die width should be 8x material thickness for air bending. Buy the book Fundamentals of Press Brake Tooling by Ben Rapien, great book and will answer a lot of questions.

Its easy to make up some crude tooling using heavy pipe and a simple 2 roller type bottom V to do large radius bends in thin materials. Yep its hard to get spring - bend start -finish perfect but its a far quicker starting point to then pull to shape as you weld.

dirk said:

Buy the book Fundamentals of Press Brake Tooling by Ben Rapien, great book and will answer a lot of questions.

Click to expand...

+1

The book has been recommended here before. I bought it based on those recommendations, and I don't even have my press brake installed yet. Its about $100. IIRC. But it sure doesn't take long to scrap out $100. worth of material or spend $100. on tooling that won't do the job you need.