[Mark Green]

I am considering upgrading our sheet metal facility.
Currently we do everything by hand and subcontract laser cutting.

I was looking at CNC turret punches and came across a combined punch laser. Why would I need a CNC punch if I can LASER cut ??

What top ten tips are there for buying used sheet metal equipment. ( The budget won't run to new gear.)

We would want to work on 2.5mx1.25m (8'x4') sheets upto say 3mm stainless (also m-steel and aluminium.)

What should I expect to pay for a useable machine - nothing pretty or lightning fast but reliable and accurate.


thanks


Mark

[PhoenixMetal]

Hi Mark,

The benefit of the turret punch portion is that they are faster and cost less to operate.

The reason you would want the laser portion of a punch/laser machine is for cutting odd shapes, odd angles, etc.

Turret punches are great and very fast, however every time you need to punch an odd angle, you need to buy a specially keyed tool. A feature called Auto-Index on some turrets eliminates this need to a certain extent, however this is generally only on a few of the tool stations.

A laser on the other hand, requires no special tooling to cut any sort of angle. Also, if you were cutting unusual contours (imagine a wavy pattern), a laser could do this well, whereas a turret could not do so cleanly or easily.

So basically, a combo punch/laser gives you the speed and low operational cost of a turret punch, with the flexibility of a laser.

Another benefit of the turret punch portion is that you could work on materials like galvanized steel cleanly. I have not used a laser, but I have heard that the heat makes a mess of the zinc coating (galvanization).

[metalworkz]

Hi Mark,
The benefits of having a laser are basically as PhoenixMetal has stated. On the other hand if you don't need the special options that it provides there are consumable costs involved with the laser that need to be taken into consideration such as the gases needed and lenses etc.
A turret punch press(Amada etc.) is much faster than a laser in most cases, and if you get a turret with auto-index stations included they can be programmed to any angle. Some Amada turrets only have 2ea 'B' station auto-index but some of the newer turrets have 2ea 'B' stations and 2ea. of the 6.5" 'E' stations also.
For the sheet size of 4' x 8' and up to .118 stainless I would recommend an Amada Pega372 which you should be able to find in the 'Used' variety. This model has a 30ton punching capacity, 48" travel in the Yaxis, and 72" travel in the X axis. It will also do repositioning of a full sheet(120" x 48") for blanks larger than 72". The turret I believe holds 52 tools(various sizes A,B,C,D and E staions,usually 2 each D stations, 2ea E stations, and 4ea C stations) with 2ea. of the 'B' size auto-index stations. You will need extra clearance dies for the stainless and thick aluminum but the std. .008" clrearance dies will work for most of the regular jobs. Use 10% of the material thickness for clearance calculations. I am not sure what one would cost today but I was thinking somewhere around $50,000, I may be way off. You will have to do some searches for used machinery to see what is available and the costs. Try to find a package that includes at least the standard tools as tooling can be a big cost also. I am currently running the Amada EMK 3610NT pictured in my avatar.
Regards,

[chenry]

another benefit of the combined unit is being able ot use form tools in the punch for louvres and such

[metalworkz]

You don't need the punch laser combination machine to use form tools. Most form tools including louver tools, card guides, lances, extrusions, halfshears, and dimples can be used in a punch without the need for laser cutting. Any holes or cutouts that need to be in the sheet before using the forming tool can be pre-punched. Having the laser option is great, but the cost is going to be too high compared to a turret punch.
Regards,

[gridley51]

I went through this exercise five years back.Compared Plasma,Punch and Laser.
It is impossible to justify a new laser unless you have enough work to keep it loaded.This will be backed up by the main laser manufacturers.You are looking at an investment of several £100,000`s,probably about £500,000.Used lasers are available and due to the recession there will be several good buys coming up.But again,the guys with these machines and a lot of debt round there necks are all working very cheaply.I see a lot of jobs that a few years back would have been sheared and punched but are now lasered by firms seeking work to cover machine costs.
Leaves Plasma and Punch.I went punch,buying a wide beam LVD Shape.It was the right decision at the time.Now five years down the road the work has changed and a Plasma would be better for us.
What you have to look at is the volume you are subcontracting,compare current costs with quotes from two other suppliers.This is a good time to get work requoted as a lot of companies are quiet.
What is your monthly spend on sub contract?Will it cover the payments on a machine?
What thicknesses and materials are you working with?If mainly above 3mm you may want to consider plasma,most punches will go to 6mm but finish and punch size becomes a problem.
Don`t worry too much about angular shapes as most modern punches have at least fout auto index heads capable of something like 0.001 of a degree.
Want to give us more info?
Mark.

[Independent CNC]

A few more things to consider are the types of material you’re going to be cutting. As an example I prefer to punch Aluminum material because it is slow / expensive to laser. Also I prefer Trumpf machines to any turret because EVERY tool is an auto index tool. Don’t get me wrong turrets have their place I am just stating an observation form a programming stand point.

Before you make a selection I would have documented cycle times of cutting your product.

Independent CNC Programmer
http://www.independentcnc.com/

My mission is to share CNC programming innovations for a lifetime.

[PhoenixMetal]

Hi IndependentCNC - I never realized that Trumpf punching machines aren't quite "turret" punches. I just took a look at ther website. The concept is the same in that it is a cnc punch with a toolchanger, but instead of keeping the tools in a turret, it looks like it keeps the tools aside and changes them in/out of the punching station more like the toolchanger in a cnc milling machine. At least that's my take based on its pictures. Having autoindex capability on every tool sounds like a dream.

On the other hand, we have an Amada turret, and all I can say is that these things are workhorses! They seriously last forever and require near zero mainainence.

[Independent CNC]

PhoenixMetal, you may find Salvagnini’s interesting too. They have no tool change time and you program a part not having to worry about clamp dead zones. The right angle shear also allows for nesting parts butted next to each other.


Independent CNC Programmer
http://www.independentcnc.com/

My mission is to share CNC programming innovations for a lifetime.

[metalworkz]

The downside for the Trumpf machines is the cost for repairs/service and parts.
It is awesome to have the ability to rotate/index any tool, but most of the older machines use an old outdated DOS type control software. Also the Trumpf model I used to run had a small 10 tool turret near the front of the machine that folds down and inside a cover when not in use and the rest of the tools are stored on a rail behind the toolhead towards the back of the machine. The other thing that no-one mentioned is the fact that the Trumpf has a vacuum on the tool head so all the tools are like 'air-blow' and the vacuum does work well.
Another thing that should not be a problem is the Safety light and mirrors that surround the machine; if the mirror stands ever get bumped out of alignment it can be a 'pain-in-the-rear' to get them aligned again. Best to have a metal barrier to prevent the mirror uprights from being bumped. It can be awkward getting used to setting up the tools and the adapter that loads them into the machine also. It is a great machine but these things are different from say the Amada turret presses and personally I feel the Amada turrets are easier for tha average operator to learn.
Regards,

[kreb]

I just started thinking of a punching machine as an alternative to a plasma. I'm trying to get a handle on a few things:

-How quickly are you going to run through dies before they need sharpening/replacement? - This relates to the nibbling feature in particular

-How smooth are the arcs?

-My shop is old school. What are the best resources to learn how to properly set-up, run and optimize these things?

[Independent CNC]

Tool sharpening depends on how well maintained you machine is and making sure your using the correct die clearance. You also have tools made by Mate, Wilson, Trumpf and maybe some others with all different qualities.

For outside arcs I use a small square that seems to work well.

I would talk to some of the machine resellers and ask these questions also.

Independent CNC Programmer
www.independentcnc.com

My mission is to share CNC programming innovations for a lifetime.

[metalworkz]

I just started thinking of a punching machine as an alternative to a plasma. I'm trying to get a handle on a few things:

-How quickly are you going to run through dies before they need sharpening/replacement? - This relates to the nibbling feature in particular

-How smooth are the arcs?

-My shop is old school. What are the best resources to learn how to properly set-up, run and optimize these things?

The dies will last for years before they need replacement. You only sharpen them when they need it. If you use the correct clearance and don't cross the tools they will perform very well and for a long time. Nibbling is not so bad on the tools if you don't try to overdo it. Keep the feed pitch at the recommended values and use just a little more clearance when possible to avoid the punch wiping out on the die. Nibbling will usually leave some mismatch on the parts but with some creative deburring strategies it can be cleaned up fairly quickly. The arcs are very smooth, but there is some mismatch. For smaller radiuses it will be best to have some 4way corner radius tooling, or even a single radius tool and it can be used in the auto-index station.
I don't think there is a lot of information readily available about setting up and running these machines, but for Amada machines you should be able to find some information. I would be glad to help with Amada machines as well and you can contact me for more info if needed.
Best regards,