Sheet metal die cost reduction

[_malek]

Hello friends,

can you help me reduce the die cost of the part (3mm alloy steel):

the die workshop gave me a quotation of a four stages die:
1- forming the (plate like shape).
2- cutting center radius.
3- cutting half of the (small size cuts) on edge.
4-cutting other half (the rest of them).

he advises to separate the last stage into two stage to avoid work piece collapse due to fatigue.

and also he told me to prepare a pre-cut square sheets in order to eliminate a preparing cutting stage.

the annual production plan for this die is around 1000 per month, so, the die economics will fail the product.

i'm thinking of making the production plan as follows:
1-one forming stage.
2- laser cutting or the inner and outer small size cuts.

is this doable? one of my friends told me that i need to make it in a variable (z) laser cutting machine or a CNC punch machine.

kindly your advice will be most valuable.
Thank you.

 

[dvd]

How many are you making and how big is the part? Quantities are going to dictate process.

Some parts are capable of being formed and blanked in a single die with a fineblanking press and die, maybe not yours, though -

https://www.feintool.com/fileadmin/PDF/Broschüren/SystemParts_Europa_EN.pdf

I am not sure if you will find the die expertise on this site to get a good answer.

 

[_malek]

Dear Dvd,

Thank you for your reply, the outer diameter is 220 mm. inner diameter is 170mm.
General tolerance is +-0.05mm.
I'm planning to produce 1000 part per month.

Thank you for sharing this valuable supplier, I will contact him but I think the cost plus shipping will be over budget.
I'm in a start up business and i have very limited budget.
I can manufacture a die single stage(forming) locally in around 2500 EUR.

 

[dvd]

malek - you would have to use a special press also, very high capital expenses for the die and press.

I would also be curious if the formed blank could be completed with all other operations done with laser. Do you have assurances on the 1000/month quantities? Can you increase tolerances by modifying mating parts?

 

[hendersdc]

What is your cost target for the part? That many small holes will take a while to cut on a laser so it might not end up being cheaper.

3mm steel is very thick for non-structural parts, what does the part do? Can you decrease the material thickness at all?

 

[JayMaechtlen]

You could form the step portion, then laser cut the rectangular holes then the inside and periphery.
Fixture it with the outer flange 'up' so the laser can reach the inner edge of the rectangles.
There could be some damage to the side of that vertical section when cutting the rectangles - possibly. If you did get damage, can either apply some kind of protection or perhaps have a protective sleeve - copper, perhaps - that would slip in place prior to the laser cutting.
1000 a month - only 50 a day, should easily do that on a single flat cut laser machine.
Actual cycle time will depend on the specific machine and size of the part.

Of course, economics of hard tooling are affected by how many months or years you expect to make these and if the quantity will increase or not.
The laser approach is likely the best way to start out. That way you only have the forming dies for initial outlay, and if you need to adjust the hole size or other parameters it is very easy when laser cutting. Eventually, if everything goes really well, you may transition to hard tooling.

Jay Maechtlen

http://www.laserpubs.com/techcomm

 

[JayMaechtlen]

I intended to add to the post -
The distance from the rectangular holes to the step could be a real issue for hard tooling.
But possibly a punch/die for a single rectangle, and punch each hole individually. Have a fixture to rotate the disk into each position.
Punch, index, repeat.
Mor tooling than the laser solution, but shoudl be a lot cheaper in production.
That might work very nicely, and not require a multi hundred-thousand dollar laser system with its own issues.

But anyway - start by forming the step and laser cutting the rest.
Then develop additional hard tooling if/when economic, while you can actually produce parts and generate revenue.


Jay Maechtlen

http://www.laserpubs.com/techcomm

 

[itsmoked]

Except tying up a $200K laser for 50 a day every day makes the parts expensive to make.

What about punching everything flat then drawing the part?

Keith Cress
kcress -

http://www.flaminsystems.com

 

[SwinnyGG]

What about punching everything flat then drawing the part?

You're going to get some tearing and undesired deformation. With the inside of the rectangular punched openings so close to a hard 90 degree bend, you have to bend before you punch.

 

[_malek]

@ dvd:

Thank you for your reply.

it's a client request to have 1000 piece per month but nothing is written yet.

also, tolerances can be +- 0.1 mm. after checking with the part mating and application.

 

[_malek]

@ hendersdc:

Thank you for your support.

sorry the thickness is 2 mm. (my bad)

my target cost is to reach 1.6 USD Per Piece.

yes you are right the lase guy told me it will cost tribble the target cost if i cut 1000 piece in one time.

also he advised to make the laser holes first then bunch the parts in a die. which is a fault process sequence.

i learned from the dies man that this will lead to make the holes elongation and may tear up during bunch.

thank you for your tips.

 

[_malek]

@JayMaechtlen:

Thank you for your valuable feedback.

I'm Happy to know that my assumption is doable.

but i think i'm going to need a variable (Z) laser machine, in order to maintain the head close to the workpiece square holes as well as the center hole (two levels).

and this type of machine is hard to reach around me, a friend of mine suggests a (CNC Bunch) machine to make the square holes. but i didn't follow this lead to the end.

for your suggestion of making a small punch/die with a single square holes (100 holes) i think it is a better idea: to make a die with a 1/8 of the holes to be distributed to 1/4 of the circumference, results to make 8 strokes to produce the 100 holes.

this suggestion will affect productivity of the shift. but will increase quality of the square.

I will walk through the three assumptions (CNC bunch-laser with a mounting die and two dies ) and compare economics.

Thank you for your support.

 

[dvd]

Is $1.6/ea including material? There is at least 1.0 kg of material in the blank (probably more like 1.5 kg), sheet metal will exceed that price just for the raw material.

 

[John Donlan]

Malek, I am no expert on either laser machining or CNC punch machining. My experience is in metal cutting (manual and CNC lathes, milling machines, screw machines).

That being said, I'm not sure which of the different processes would work out for you economically.... But I think you should give serious consideration to burrs. If laser machine leave you with no burrs around the top or bottom of the rectangular holes.... That may be the way to go. If CNC punch press leaves you with burrs (and I don't know if it will) you may have to put in a secondary deburring operation (extra $$$).

So I guess when I'm getting that is that you should consider whichever process will give you the "finished part" the quickest.