'Wrap' Or 'Cap' A Punch To Increase Bend Radius

Hellcat,

I have not heard of this process. It sound Ok for producing a prototype (if there is no other option), however, as a production solution- unless it was very very low volume I do not see how the sheet metal punch (which it is in effect) can deal with the wear and therefore the repeatability of the bend.

Surely if your customer is asking for change to the original product they will be expecting tooling costs which would be quoted or added to the per piece price or set-up cost.

Regards

Jon

Yes, low volume. I was told the prototypes they wasn't probably are the production run based on thier history of purchases. I use 300 series stainless to cap. It holds up quite well.

Why does manufacturing engineers have any say in the processes. Let the fabricators do what they need too to get the job done. There's a difference between sitting at autocad all day to actually working the material and getting it to form the way you want too.

Sometimes you just have to tell them, "Tell me why it won't work, because if you can't give me a good reason, I'm doing it."

It's a matter of meeting production needs, not who gets credit for coming up with the solution. If they don't have a better solution they they can just keep their noses to their monitors.

As far as the engineers are concerned, you are their customer and they are to produce the drawings and information needed for you to do your job, you are the expert in getting it done, not them.

I just have a sore spot in that area because I've bumped heads with our lead engineer, who thinks he has all the answers. One time he had all his latitude stripped from him by the production manager, but now we have a different production manager and he's at it again. He's not a bad guy at all, but sometimes he gets a little carried away.

Without a picture of what you are wanting to do I'm not clear on what you are describing.

My company manufactures machinery used in produce packing houses. Sometimes our engineers come up with ideas that require more then our typical dies can handle.

We've made ties using our own resourcefulnesses to accomplish. We also have a machinist, I don't know if you employ one but it helps.

We've taken top dies and welded round bar along the length of it produce a wider radius. We've gotten large square cold finished material and machined it to fit as a bottom die and machined the top with a grove and a top die to fit in the grove so when they meat, it keeps the material flat leaving a crease along the sheet metal as a stiffener. We've made dies that create a long countersink with a flat bottom with a slot inside that, keeping the material flat, so we can bolt it down with a flat head bolt.

Using a punch die seems a little risky to me. A punch die is only as strong as it's narrowest point. Making the die work in a way that it wasn't designed for could cause it to start bending or weaken it for normal use.

Furthermore, dies are expensive to replace.

Thanks for the feedback.

They moved me from mfg. eng. to the vague world of R&D Engineering and even though my "experiments" work they would rather not go there. I am not the fabricator, so to speak, on a regular basis. I do some of the machining myself for tools / protos on the older manual machines we have (The M.E. group took my programming access away, lol.), but we also have a resident Machinist.

Yes the die opening 'v' needs to change accordingly with the increase in punch 'V'. I was always more concerned with safety where this is concerned.

Agreed.

Someone bid and accepted the job. That person should provide you and management with the answer to the problem. How did they plan on making the part and obtaining the required result.

I am not able to inform you of how to fix the problem from a technical view. But, it would seem you have done so, if only for the time being. As for a long term resolve it seems to me where folks need to sit down together and establish a 'moving forward' plan.

Good luck with that,

cr3

That sounds like Par for the course.

Our sales department often pickup jobs that seem outside our capabilities. It goes through engineering and from there handed off to fabrication "Here, you figure it out."

And Ta da, an new die is born.

lmao, yeah... *poof* here it is! I miss the days where I could have the freedom to do that, now it seems to be smoke and mirrors rather than real magick

Make a tool to check the bend radius after every bend. The cap will thin out on every bend. The result may not matter but who gonna pay for the rejected parts? As long as you can prove you can maintain the required tolerance on the bend radius by checking and changing the cap when necessary, the engineer will be happy. At least I would.

Pineapple

Yes, good advice. But I happen to be the engineer and they refuse to make me happy

They occasionally ask for my help but seem reluctant to use the solutions I come up with, maybe if I fed the ideas through another source it would get better reception...

In the mean time they are asking the customer to modify the radius in thier solid model.

Thanks for your support

I guess maybe I miss the old days when I could design, program, proto and ship in one day when needed.

My favorite line was: 'damn it! I'm an engineer not a miracle worker!' (stolen from Bones on S.T. with modification) but I'd get it done.

Salesman sells the job. Manufacturing engineer designs how the product is to be made. Manufacturing produces it.

Sounds like you are trying to cover their butts.

Now that thats said can the punch end be reduced so that different radius end can be made to the customers specs. Changed out as the job demands. Would be limited tooling change.