punch and die set

[winklershop]

Hello To All

Here is the latest die set that I am planning on building. YouTube link of the auto cad drawing.

https://youtu.be/o0Qgv6fgu3Q

It is a die set that I plan on building to punch out these parts out of 1.5" by 1/4" aluminum t6 6061 flat bar on my Niagara number 3 punch press.

I used the 10% generic rule of thumb for the clearance on the die with a die land and 3 degrees of taper below the land.

Do you see any red flags in my design?

The yellow is the punch holder plate

The green is the two round punches (these will be purchased)

The pink is the cut off punch, (i am going to put quarter inch chamfers on the corners)

The dark blue is the stripper plate

The white with red is the die block white shows the land and the red is the 3 degrees of relief (it will be one piece of tool steel)

All of which will be mounted in a danly guide pin die shoe set

I plan on using D2 tool steel and sending it out for heat treat.

I also think I will heat treat the d2 tool steel and then send them to a EDM shop to cut the die base and the chop off punch.

The chop off punch has a thin cross section and I think heat treating it after word would cause some cracking.

The light blue is the strip and the part produced, will be punching out about 400 of these once a quarter

The strip will be hand feed until it hits a stop, then press hits, stop swings out of the way, remove finished part, reengage the stop.

any ideas, input would be much appreciated.

Thank you!

 

[memphisjed]

exercise in die design more than production/cost reasoning? It wouldnt take long to just punch a hole, spin part, punch again. Being that you are doing 1600 a year it would be just as fast. Laser shop Would be faster. Angle line would be fastest.
I have no idea what the giant blocks are on the sides of your blade. Shear blades normally cut from one out from the web, on flat stock that means cutting from left to right or right to left on the radio dial - not from edge in to center, or center out. You will have cupping with this approach.
All of our shears are stock blades just bolted to a36 or a50 plates. You can get those for near the price of just the stock- machined/sharp with holes already in place.

If it is die design project, add in dynamic stripper to hold down material as punches and blade approaches. Shorten your punches- a lot. have the dies for each punch separate from the bed plate, they wear out. have the blades on your bed plate separate, they wear out and no matter what you will need to tune the clearances with shims or push pull bolts.

 

[winklershop]

Thank you for your input memphisjed. you are correct there are faster ways to make this part, like water jet or laser, (im not familiar with angle line?) the goal to make these parts the cheapest possible per part. also notice that there is 1/8" radii on the corners of these rectangles. so there is 2 holes, 4 fillets and two end cuts (that is a lot of setups for a manual setup) one of the ways to make these cheap as possible is to use a high speed punch press, which is my goal, eventually i would add a air feeder and auto stop system which would drop these into a bucket a second per part. the material costs around a dollar per part. trying to get the price point under 2 dollars a part. i forgot to mention that even after these hit the bucket, they have to be post processed as the holes need to be chamfered counter sunk. i spend a weekend making 400 of these parts using conventional methods.

i have no official training in die design, i have 4 different books, and a great uncle that used to be a die maker that i am getting my knowledge from. the giant blocks on the sides of the blade contain the 1/8" radius fillets and mounting provisions, also they enter the die block before the cutting starts so everything is supported and no side loading/misalignments can happen. it does look and sound ridiculous... this is why i am here, there is always a better way. i put the curve on the shear blade, to reduce the amount of tonnage required, should i make it straight flat or angled one way or the other? i would be interested to learn more about this. if there is stock blades that can be bolted on that would be great, but i have the corners to take off as well.


dynamic stripper to hold down material as punches and blade approaches, i like the sound of that. would eliminate the need for my giant blocks. this press has a 1-1/2" stroke.

i have lots to learn,,, any pictures, videos, links, commercially available products that are out there that can be shared, would really open my eyes to attack this project with modern day efficiency.

 

[wood2steel]

Winkler, I am clueless to punch press type work, but am curious if the older style Danly Die press sets are even still used. Asking because I hv a small collection of those used Die sets and they need to be in the hands of someone who could even still use them.
Never hurts to ask!!
Johnny

 

[AD Design]

I agree with what memphisjed has posted. I don't know how using the other process he's mentioned fits into your plans so I'll address this from the perspective of using a progressive stamping die per your design.

Your design uses a box stripper, no real benefit to using one in this application other than guiding the stock. Simple guide rails (common to use these) control lateral movement of stock in the width but also control how high the stock raises up of the die face. Box strippers can have stock feeding trouble if bow/warp in the strip exceeds the "mouth" of the opening in the stripper. Guide rails can be popped off and clearance added if need be much easier than a box stripper. Spring loaded tension to reference stock strip edge can be added in a guide rail rather easily and while there's a few more components to be machined far less material is used to control stock strip movement. A spring stripper will work just fine with die springs used to change the pressure required. Transfer pins, gas shocks, and pressure pads all offer options if needed. It's all about options rather than struggle with a design that locks you into limitations IMO.

Punches should be likely be shorter, can't tell what the dimensions are. Shorter punch length means less expense and less chance for deflection/misalignment to the die. Won't go into the difference/preferences of back mount vs. face mount for now. Agree with separate mounting for punches for ease of alignment, re-sharp, replacement of components, change in design.

Removable die sections could be used for all cutting edges in the die plate and less expensive 4140 PH can be used for the die plate. Catastrophic die failure from unexpected events occurs daily. One big chip-out or a need to adjust clearances means a re-work/replacement of a large piece of expensive tool steel. Removable die buttons/sections does mean more components to be machined but often makes a big difference in operating costs. Stamping dies are often designed (where possible) to have cutting edges that can be removed/replaced/adjusted while the die is still set up in the press and production resumes. Clearance adjustment is just add/subtract a shim, larger/smaller ID of buttons are much less expensive/risky than changing the hole size in a large piece of tool steel.

That "H-shaped" cut-off/parting blade will be one expensive punch to make and will be a PITA to sharpen while deriving little benefit from controlling deflection across the width of the die. The relatively thin cross section could be increased by stock progression and punch placement. Scrap from cut-off and punch needs to be considered in die taper (stacking/flipping). Use 1/4 to 1/2 degree through the die section as a starting point. A simple blade punch for parting that's pocketed/captured and secured with fasteners will eliminate cost of your current design and allow for clearance adjustment as well as ease of sharpening and/or replacement. Ejector pins in any punch are my preference, there are other methods for slug/scrap control.

I see no pilots to set/control the stock location/progression. Even when limiting the stock feed, like a "French" stop, the strip can/will move due to gravity/stock warp/bow all by itself and results in scrap parts. A pilot will locate/lock the strip in position once the press ram is lowered enough for the pilot to enter the hole and can give a visual assurance that the strip is correctly located. Misfeed is common when fed by coil or long unsupported strip blanks that hang out the end of the die.

There's several more things to point out/consider but this is long winded enough already. My suggestions do add complexity to the design but the benefit would be in running the die with less trouble. Costs are not only in design hours and machining time but also in operating costs. Your current design may work well enough for what your targets are. It's all about how many pieces you expect the die to produce over the life of it. If your part numbers ramp up a problem with small batch production may be a big PITA for longer runs. Maybe small batch problems are no big deal for you, only you can say.

I hope this was of some help, good luck with this.

 

[Kalispel]

Building the die seems to be a lot more work than making 1600 parts. Definitely a good learning exercise if you really want to try it.

I would not expect good edge quality on laser cut 1/4" 6061. Maybe someone knows how to do it well. Waterjet would make a nice part, but it would be costly. We would probably setup our 70-ton "Metal Muncher" to make them in several operations.

 

[BT Fabrication]

contact cleaveland tool , they make everything for every iron worker and could probably do it for cheaper then you can build it for. they do multi setups like this all the time, might cost $2000+ but you only pay for it once.

 

[TDegenhart]

Your thinking reflects my concepts of a stamping die of mu youth 50 years ago. One stroke, one part complete. Then I learned about progressive dies.

What you are proposing is simple on first glance but expensive to run and maintain.

First order of business is what are the requirements of the part dimension wise and can you get material that meets width requirements without having to trim? As the width varies, does that affect the placement of the holes and the trimming of the corners? Can the corners be trimmed to 45 degrees or a curve but not full radius. If full radius is required, then trimming the part to width is almost a certainty. Bow and warpage of the part. How flat must the part be? What are the burr requirements, will the part need to deburred after punching? These questions need answers before designing the die.

If you don't have a copy, I suggest you get a copy of 'DIE MAKERS HANDBOOK' by Jerry Arnold, published by Industrial Press. Lot of good stuff.

Assuming that the width and hole locations requirements are simple and stock width is ok, then the biggest problem is the corners. Do the corners just need to be broken which could be handled by tumbling or true corners. Tumbling would also correct pierce and cuttoff burrs. True corners almost certainly means either special width material ($$) or trimming the stock.

Consider making the die three stages with spring pressure/stripper plate. The first operation is a French trim and stop, pierce two holes. Second trim the corners and partially cuttoff leaving tie piece, pilot off of the two holes. Third, cuttoff.

This is a much bigger die and more complex but it is also a simple die to build and maintain.

An alternate solution is an NC mill

Tom

 

[memphisjed]

AD, I learned a little from your post on unrelated material movement. Thank you. As for other processes a angle line is two punches oriented 90 degrees from each other and then a shear. Material moves thru, (angle) and gets punched on web, then flange, then sheared. Also used for flat bar. Not a one off tool speed like a stamp setup, but versatile and cheap to run. Still fast.
Back to op, Adding in the second handling changes the math quickly in my brain. Drilling al can be done almost the same speed as punching- likely faster depending on press. You can drill and countersink with the same bit, in just fractions of time more- depending on drill. If relatively slow drill then the same time. You also have countersink aligned with the hole by tooling. Slightly offset countersink are noticeable and reflect bad back to you. We all rough neck it sometimes letting countersink self center... bad habit and practice to get into. Always have worked clamped on a drill.
Making a punch holder and die block for the press that accepts a standard system would be useful everyday, a single use fancy tool is good for one item. Have Cleveland tool or American punch send you their off the shelf catalogs.

 

[AD Design]

Several part details affecting the design of the die have not been supplied by the OP. Hole spacing tolerance, width of the part, flatness, allowable burr, what's important and what can be changed in the part design for ease of manufacturing. I didn't bring these up because the OP had to evaluate and decide whether to machine the part, change the die design or not. But others have brought these up and I agree that these considerations need to be addressed before metal is cut. Die design pushed in expediency will disappoint in production settings but by then it's usually too late or too expensive to correct. Planning is just as important as production and it's easier to think through with a CAD design than retro-fit a solution. I still applaud the effort of the OP (and the contributions of the collective) but die design and operation is not a casual endeavor.

To the OP: You decide what you want to do after reading all the suggestions. If you want advice there's several people here with the knowledge that are willing to help. Ganbatte.

 

[rogertoolmaker]

Hello To All

Here is the latest die set that I am planning on building. YouTube link of the auto cad drawing.

https://youtu.be/o0Qgv6fgu3Q

It is a die set that I plan on building to punch out these parts out of 1.5" by 1/4" aluminum t6 6061 flat bar on my Niagara number 3 punch press.

I used the 10% generic rule of thumb for the clearance on the die with a die land and 3 degrees of taper below the land.

Do you see any red flags in my design?

The yellow is the punch holder plate

The green is the two round punches (these will be purchased)

The pink is the cut off punch, (i am going to put quarter inch chamfers on the corners)

The dark blue is the stripper plate

The white with red is the die block white shows the land and the red is the 3 degrees of relief (it will be one piece of tool steel)

All of which will be mounted in a danly guide pin die shoe set

I plan on using D2 tool steel and sending it out for heat treat.

I also think I will heat treat the d2 tool steel and then send them to a EDM shop to cut the die base and the chop off punch.

The chop off punch has a thin cross section and I think heat treating it after word would cause some cracking.

The light blue is the strip and the part produced, will be punching out about 400 of these once a quarter

The strip will be hand feed until it hits a stop, then press hits, stop swings out of the way, remove finished part, reengage the stop.

any ideas, input would be much appreciated.

Thank you!

Three degrees die clearance is excessive. Use 1/4 to 1/3 degree. Once the land at the top of die opening is sharpened into the die relief the die opening gets larger and larger until the parts are no longer in tolerance. The greater the relief angle; the sooner the tool is going to produce out of tolerance parts. The relief is required to relieve the blanking pressure, so the die block does not crack. One degree is .01745 per inch of length. Your suggesting .052 in a one-inch-thick die block. If we have more clearance than necessary; we build shortened life into the tool. A Poor Die-Making Practice!

If your set on doing this in your shop with only 1600 a year. Look at purchasing Unipunch C-frame Tooling for low production tooling. With so few parts, it will be difficult to recover the cost of the tooling.

All the Best.
Roger

 

[AD Design]

To echo what Roger has posted, excessive die taper produces no benefit and hastens the end of parts within tolerance. Excessive die taper can also allow for the slug to flip, turn sideways, and prevent the following slugs from exiting the opening as they entangle with all the others to follow. This can result in "slug packing" and can break the punch, crack the die section, and/or mangle the stripper. Quite a few times I'd get a die that required me to use brass drifts and a hammer or a drill to clear the mass out. This was often because of excessive taper or too large a clearance in the die shoe. What is ideal is to have a smooth, continuous pathway/surfaces from below the die land to the exit out the bottom of the shoe so all the slugs are in a uniform single stack with just enough clearance along the sides to slide down the exit path without room to tumble/turn. Slug control is from die face to scrap chute and beyond. This isn't always possible to do and step drilling is often employed in the shoe but a bigger hole and excessive clearance can do more harm than good. JMO.

 

[AD Design]

I wasn't going to bother posting again in this thread until the new thread of a "non professional" forum was brought up recently. The OP in this thread doesn't really seem to know what he's doing and I would regard him as a rank beginner based upon a poor design conceived by a relative. It's been almost a month without a reply from him/her, got some information from others and is off his/her merry way.

On the surface this bothers me that there wasn't even the courtesy to say thank you to all the input from the collective trying to help present better solutions. I've grown somewhat accustomed to ingrates wanting to benefit from the years of experience I've paid dearly for. Still, there's often a lingering resentment I sometimes feel for the newb that has a casual disregard for what that knowledge has cost me in time/sweat and even humbling myself to others that would debase me. If you've never worked in a real machine shop then you don't know what "Type A" characters are or the pecking order that always seems prevalent. Far too many amateurs saunter in and expect to benefit from that hard won knowledge without regard for how valuable that knowledge/experience is. To make matters worse far too many can't be bothered to try researching their own questions or even using the search function on this site. Little wonder that many of us are so damn grumpy.....ok maybe it's just me that's grumpy.

However, this thread and many others like it have rendered a service in creating a discussion for the collective to chew on. Maybe I should just speak for myself here but if I've shared something the more experienced members found useful then it was worth my time and trouble to post. The rest of the collective have posted in many threads I often found to be valuable reading. If I can offer something in return to somebody here then my meager contributions are just my way of saying thank you to those that may never know how it helped me. The OP for threads like this can go take a flying f*ck at a rolling doughnut for all I care, they seldom reciprocate or offer anything besides their own wants/needs. Yet they, in their own way have rendered a service in bringing others to the table to share/explore how a problem can be solved. Some do not suffer fools gladly, I think even fools can serve a purpose if I can learn to get past the irritating aspects they bring. Easier said than done.

 

[michiganbuck]

"can go take a flying f*ck at a rolling doughnut f..."
Wow, I haven't heard that since the 60s
I thought my friend Bob K made it up.

I see flaws in the design and think the Op should pay a die guy to sketch a design.

Better yet, post the part and ask how best to make it.

For the number needed farm it out may be best.

 

[winklershop]

I apologize from my late response. I understand how this looks, sorry about that….

I do appreciate everyone’s input and want to thank everyone for their input.

Your right I don’t know WTF I am doing and that’s why I am here, sorry….

To paint the picture or write the book to convey everything you need to know would be the size of billboard or thick as a phone book.

The information that has been provide has pointed me in the right direction and I thank everyone here for that.

Since I my last post I reflected on all the information and decided to go with the iron worker die set approach and have been working with Piranha and Cleveland to get everything I need to do that. About $3000 in investment, the stuff is ordered and on the way, might not see anything until late march.

 

[AD Design]

I apologize from my late response. I understand how this looks, sorry about that….

I do appreciate everyone’s input and want to thank everyone for their input.

Your right I don’t know WTF I am doing and that’s why I am here, sorry….

To paint the picture or write the book to convey everything you need to know would be the size of billboard or thick as a phone book.

The information that has been provide has pointed me in the right direction and I thank everyone here for that.

Since I my last post I reflected on all the information and decided to go with the iron worker die set approach and have been working with Piranha and Cleveland to get everything I need to do that. About $3000 in investment, the stuff is ordered and on the way, might not see anything until late march.

=I'd like to retract my comments about the OP, apparently he's not like the college students wanting others to fill in the blanks on his project assignment. They're soooo much more clever than us.

To the OP: You stood tall on that one, please accept my apologies for underestimating you. It's hard to tell intentions in a long distance format.

 

[AD Design]

"can go take a flying f*ck at a rolling doughnut f..."
Wow, I haven't heard that since the 60s
I thought my friend Bob K made it up.

My formative years in Detroit machine shops left an indelible mark on me.

 

[rogertoolmaker]

You're doing this for a learning experience. You could take another look at your punch design. As designed, it is just OK, it will work, but the design could be much better. Also, why D2 for 1600 Aluminum parts/yr. Match your design with annual requirements. We don't need to kill a flea with a sledge hammer.
Roger

 

[rogertoolmaker]

You're doing this for a learning experience. You could take another look at your punch design. As designed, it is just OK, it will work, but the design could be much better. Also, why D2 for 1600 Aluminum parts/yr. Match your design with annual requirements. We don't need to kill a flea with a sledge hammer.
Roger

 

[Garwood]

I've seen (I think I own some) very simple/elegant die sets built to do almost exactly what the OP wanted.

I've CNC machined a lot of bar ends with corner radius' while leaving the sides of the bar untouched. I fake the radius and extend it away on a tangent from the part sides. I'd think if you were OK with a the look of sheared 1/4" 6061 you'd be just peachy with an imperfect radius on your stock.