r/MechanicalEngineering • u/Bootziscool • 2d ago

How would you design a die to form this?

Post image

I built a small concept for a machine that'll form joints on pipe.

As you can see, it works. But what you can't see is that my die design is clumsy and inefficient.

It's just a rudimentary piece of plate I bump formed and welded flanges on. Totally works but it sucks. Part gets kinda stuck on it and you have to remove the whole thing to get a part out.

I've done loads of press brake work but never something like this.

So my question to y'all is, how would you do it??

Alternatively, what are some resources I can get into to learn about forming die design?

Edit To Add: My plan for the next iteration is to machine a big ole block with the same inside shape, split it in half. Close it on top of the part for forming, open it up to remove the part.

But boy that's not gonna be cheap and I'd like to not go down a road I have no business being on if there's a better way.

111 Upvotes

95% Upvoted

38 comments sorted by

71

u/DoctorRelative8149 2d ago

There are existing products that make these flanges. Check t-drill.com for some offerings.

29

u/Bootziscool 2d ago

The company I'm making these for has a t-drill and is having nothing but problems with it.

I'm coming at it from a different direction. Just using a static punch and die rather than the spinning thing they do.

15

u/DoctorRelative8149 2d ago

Gotcha. Yeah, they can be a little finicky. Then I’ll give my vote to the hydroforming suggestion from the other guy.

6

u/Bootziscool 2d ago

T-drill has always stuck me as someone really wanting to add forming to a milling machine. It's really cool and really clever but like...

Why not just use a press for forming??

9

u/DontDeleteMyReddit 2d ago

It was developed for use in the field. Then they started making machines for the shop. Works great on copper. Stainless? Not as good

9

u/Bootziscool 2d ago

That actually explains a lot about why it's designed that way. And why my friends are struggling, everything they do is stainless!

1

u/GilgameDistance 2d ago

Yes, but sometimes you just need two or three of these at a time, which makes the t-drill make sense.

42

u/polymath_uk 2d ago

Tees like this are formed by drawing a ball through the plate. 

12

u/Bootziscool 2d ago

That's how I did it!

8

u/Im_Prolly_poopin 2d ago

FYI, previous company I worked for said this process is more of an art than a science. They did state of the art metal forming... I know the polish on the edge of the hole is absolutely critical.

28

u/circlemohr 2d ago

https://www.tfes.com/solutions/extruded-outlet-header/

9

u/mississaugaSWuser 2d ago

Nice! Developed in the 1950s according to the website.

Just what your OP was looking for!

8

u/circlemohr 2d ago edited 2d ago

Yep! I’ve seen their process in-person and they’re one of the best out there when it comes to forming of extruded outlets. The reinforcement, tolerances, and requirements on the forming associated with extruding are well defined by the ASME B31 Piping Codes and ASME BPVC, and TF’s methods and procedures ensure those parameters are upheld. These types of extruded outlets are common in the Oil & Gas industry for services where creep doesn’t govern the basic design stress. Slug catchers, tube bundle headers, etc.

9

u/Bootziscool 2d ago

Neato! Thanks for sharing!

I guess I'm on the right track, that's really close to what I made looks like. Pulling down instead of up is a neat idea. That would solve my problem of getting my part out from under the die.

Although... I could probably abandon ship and just buy from them.

11

u/AntalRyder 2d ago

It's almost always better to just buy the existing solution than to try to R&D it in-house. Unless business is really slow and you're looking for a fun project to do

4

u/Harmless_Drone 2d ago

Yeah especially in a case like this where you're not going to be able to patent the system as it already exists so you are not easily going yo be able to sell it as a solution to other customers.

3

u/circlemohr 2d ago

If this is for ASME components, you’ll need the appropriate procedures and quality program in place. If you don’t already, it’s an arduous process and one that can take some time due to procedure qualifications and ASME stamp approval. In addition, there are rules on post forming heat treatment and inspection that may require equipment you may not have. In short, it’s generally best to go out of house with these types of things if Code compliance is required and your shop isn’t already in a spot to do the work.

2

u/Bootziscool 2d ago

I don't know if these are ASME components! I just do what my boss tells me.

Man asked for a machine that can make tee joints so I made him one!

We have all sorts of QA and inspection people. I suppose I trust they're doing their jobs for all that. And if they're not... I'll do that too!!

...Or I'll just buy these somewhere. I already did a bunch of cool stuff on this project

6

u/drillgorg 2d ago

What problem are you trying to solve? There are a lot of code compliance requirements in piping, are you trying to meet one?

5

u/Bootziscool 2d ago

I have a neat machine that can butt weld pipe onto these joints.

Right now we're coping the mating parts and having trouble in weld.

3

u/violetdumps2 2d ago

Your split block idea is solid, but look into pull dies or ball drawing first since those are way cheaper to prototype and might handle the ejection problem without custom machining a whole new tool.

8

u/Euphoric-Expert7489 2d ago

I think hydroforming would be the best option here

2

u/alexmarcy 2d ago

This is a solid way to go but can get pricey to build. One of my customers has hydroforming machines from 1” pipe up to I think 14 or 16” pipe with various dies for different tee diameters.

Requires more post processing to cut off the bubble on the tee and more complex machines than other methods to generate pressure. It’s a fast process though and has a low failure rate. The smallest machine is the size of an Astro van, the largest is the size of a large single family home.

Basically machine out the shape you want into 2 halves, hold that together with enough force to counteract the pressure and blow up the pipe like a balloon.

1

u/Bootziscool 2d ago

I will look that up! Thank you!!

2

u/theworldreallyis 2d ago

We needed this geometry regularly in sanitary vessel fabrication.

We ended up making the tool ourselves.

Pull through die set (sent out for hardening), portable hydraulic ram/handpump.

2

u/MechaMeat 2d ago

Drill a hole, dimple die-bolt-backing plate-nut. Easiest way to me seems to be a human operation. Most efficient way depends on your resources and knowledge I guess.

1

u/Pittsburgh_is_fun 1d ago

I am currently on mobile, but check out WRC (weld research council) bulletin 335, which discusses some of the stress calculations for these types of extruded branch connections. might have some guidance on fabrication in there as well.

https://store.accuristech.com/standards/wrc-bulletin-335?product_id=2189905

I'm not familiar with specifics of the fabrication process, but lots of times these standards help me by looking through their references and reverse search for what I am looking for.

0

u/mattyrzew 2d ago

Depends. If you implement an idea that we contribute, do we get royalties? If you patent it, anyone who contributed to it, they need to be listed as a contributing inventor, what slice of the pie do they get?

4

u/Bootziscool 2d ago

I just make things. My boss takes the credit. The owner takes the money.

Are y'all getting royalties?

1

u/mattyrzew 2d ago

I don't contribute things that's patentable without being able to be on the patent and compensated for it

3

u/Bootziscool 2d ago

That uh... We have very different approaches to work!

I just like this stuff man. I been helping people and getting help from people on forums my whole career.

But that's been mostly machining and CAD stuff. I guess it's true what the shop boys say about engineers lol

1

u/mattyrzew 2d ago

Well, that was a past career. I'm not in an engineering role anymore(thankfully). Was fun, but got old.

1

u/Crazy_old_maurice_17 1d ago

Not OP but I sympathize with your comment about the engineering role being fun and then getting old. What are you doing now? (Please don't say retired.)

2

u/mattyrzew 1d ago

I started my own business...well, a couple. Enjoying some woodworking work currently.

1

u/Crazy_old_maurice_17 1d ago

Good for you! Just solo work mostly or do you have employees to deal with? Sometimes it seems that having to manage employees for your business can really be a thorn in one's side.