Laser cut Vs. Water cut 1

[Darioun]

Hallo everybody,

I'm in the process of selecting the machinery for a brand new plant for my company (we manufacture conveyors systems) and I'm evaluating the possibility to buy a machine to produce internaly all of our steel plates for drive and idle ends of conveyors.

I would like to understand the ups and downs of laser cutting machines versus water cutting machines.

Is there some place on the web where I could find some technical details on the two processes and other info for what concerns price differences and environmental impact
(I guess laser machines may have some gas exaust problems while some care must be taken in dumping the water after the use).

Thanks.

Luca Fontana

 

[unclesyd]

Here is place to start. Just remember they sell water jet cutters.

Look in the left hand column.

http://www.omax.com/compare.php

 

[MikeHalloran]

I used to work for a shop that _farmed_out_ both kinds of cutting, mostly in 12ga and 14ga stainless steel. The parts differed as follows:

- The waterjet cut parts always arrived with a coating of fine grit all over them. The particular shop we dealt with is a startup, and the cutter is the only machine he has, so he doesn't have a way to wash the parts. Just be aware that the water stream is augmented with fine abrasive, and you have to remove it from the parts, and do some housekeeping around the cutter. The actual water flow rate is quite modest. I don't think he regularly dumps the water from the catch tank.

- The laser cut parts always arrived clean. I don't know if the shops we dealt with just always clean them, or if the process leaves them clean.
- The laser cut parts have a heat affected zone. It's very narrow, but it's enough to interfere with welding the edges. We found that out after some expensive product was rejected for ugly welds. The (experienced) welder who joined them remarked, _after_ the peanut butter hit the fan, that the metal 'welded funny'. So we bought another four $1000 sheets of metal, got them cut, and just touched the cut edges with a snag grinder, and they welded beautifully.

One thing that can have a big effect on your costs is nesting. Contract shops are typically not motivated to squeeze a lot of pieces out of the metal you send them. They will just array a pattern over the face of a sheet, but they won't take the time to, e.g. rotate some of the shapes and nest them close together. A lot of our parts were large rings. You can't get many out of a sheet ... unless you split them into quadrants. which are very nestable.



Mike Halloran
Pembroke Pines, FL, USA

 

[Darioun]

Thanks guys! That was very helpful. Now I have an idea thet will help me to chase the best solution form my needs!

Luca Fontana,
Milano, Italy

 

[btrueblood]

Mike,

We have the opposite experience, laser cut parts arrive dirty (covered with fine oxide slag), water cut parts arrive clean. Both processes generate debris, so it comes down to how the parts get washed afterwards.

 

[MikeHalloran]

Thanks. I suspected as much re the detritus.



Mike Halloran
Pembroke Pines, FL, USA

 

[twinny]

Cost is the diference!
Waterjets are expensive to run. Typicaly 50HP pumps.
Garnet £200 or $400 american per metric ton and you will consume 1Kg every 2 minutes.
£40 for a "cheap" orifice made of saphire lasts 40 hours.
£40 for a "cheap" focusing tube lasts 50 hours.
£100 for a good focusing tube lasts 100 hours.
You have to get rid of the sludge afterwards and the pump spare parts are also expensive. I believe you buy a waterjet to make money for the guy who is selling you the parts for the pump.
Laser cutting time cycles are MUCH faster also.
Its a no-brainer. Laser for me. 1/10 of the running costs and 10 times the cutting performance.