Open Format Laser ???

[brian fithian]

My business is starting to get very busy and I am almost grown out of my lil 40W Epilog Laser. Looking to move up to an open format laser to increase production, X10. Would like to hear others' input on the pros and cons of different Open Lasers. Most of my work is cutting 1/8" acrylic but, would also want to be able to open up more possibilities.

[Dave Sheldrake]

Pro's

• They are easier to align (the tubes are fitted in the gantry and have two fixed mirrors)
• You can get full sheets into a 2400 x 1200 machine
• Bigger tubes can be totally enclosed

Cons

• Difficult to focus accurately as the lens tube has to be moved as all full sheet sized machines have fixed beds (or half bed risers)
• You have a limited working depth, usually around 100mm
• They are slower due to the much heavier gantry weight
• They tend to run 75mm focal lengths so have bigger spot sizes
• The mirrors are 30mm and the lens's 25mm (quite a bit more expensive)
• It's a pain to change sheet thickness from say 3mm to 6mm easily (Focus as above)
• Open beds need powerful extraction, figure on 2 x 3hp extractors to pull enough air through

Few other niggles as well but nothing that really matters much

[Patrick Gardner]

We have 2 of the Kern lasers. Both are the class 4 type. They are rather pricey, but for cutting out plex, they cant be beat. Our see heavy use cutting plex daily. Had one machine for almost 3 years now with almost zero issues.

[Kev Williams]

if you want to increase production x10, you're gonna need x10 more machines

[John Lifer]

Or x10 larger in size....... a 4x8 Kern would be x20 in area .........
Just say'n. (probably what 15x price?)

[Kev Williams]

-- 10 or 15x more size means you can do 10 or 15x bigger stuff, which DOES allow you time to do other stuff between jobs, BUT, you still only gots one or maybe two laser beams producing at any given time...

It's why I have 15 small machines instead of one huge one

[Rich Harman]

Pro's

• They are easier to align (the tubes are fitted in the gantry and have two fixed mirrors)
• You can get full sheets into a 2400 x 1200 machine
• Bigger tubes can be totally enclosed

Cons

• Difficult to focus accurately as the lens tube has to be moved as all full sheet sized machines have fixed beds (or half bed risers)
• You have a limited working depth, usually around 100mm
• They are slower due to the much heavier gantry weight
• They tend to run 75mm focal lengths so have bigger spot sizes
• The mirrors are 30mm and the lens's 25mm (quite a bit more expensive)
• It's a pain to change sheet thickness from say 3mm to 6mm easily (Focus as above)
• Open beds need powerful extraction, figure on 2 x 3hp extractors to pull enough air through

A friend recently purchased a large flatbed G.Weike machine. Based upon my experience helping him get it set up I disagree with some of the cons listed.

Focus is by sliding the tube, but it is extremely easy to do.
Work depth definitely is limited, but for cutting strictly sheet goods - it is not an issue.
Not slower than mine, maybe slower than a Kern but it moves faster than I expected. Personally, I would feel better slowing it down - seems like excessive accelerations for that gantry mounted tube, but I guess it does just fine like it is.
Uses a 2-1/2" (63.5mm) lens (or whatever focal length you want), as easy to replace as on my machine.
Not sure of the mirror and lens diameters but they are priced like other Chinese mirrors and lenses.
It does use two blowers, but they are not 3hp each, just two regular ones.

The landed price of his machine was close to what I paid for mine several years ago, under eight grand.

As far as increasing production, I think you would be better off with multiple smaller machines. A larger machine won't cut any faster, it'll just cut more before having to change material. I would size the machine based upon the size of the parts that you need to cut, then add more machines to increase production.

[Dave Sheldrake]

Each to their own Rich, I have 4 of them and am going by what mine are like

Spot on about the price, imported a Sinjoe flatbed is still under $8k easily, for their size they are almost throwaway machines (I think the sinjoe is $5,600 + the usual stuff)

[brian fithian]

Thanks for all of the points of view. The larger capacity i think i would like, i could accomplish more while cutting. Maybe a flat bed plus keeping my epilog as well might be the answer...

[Bert McMahan]

Brian, I don't have a flatbed laser nor do I do the kinds of production runs you do, but would you say you're more limited by waiting on the laser to cut stuff, or in how fast you can load or unload your machine and start new jobs? It might help you figure out if one BIG machine or a few small machines are better.

In other words, if you're constantly loading and unloading machines and moving files around, having a large format laser might really help since you can cut the loading and unloading time down a lot. If, instead, you're doing 1 hour runs with 5 minutes worth of material swapping in between, you're not going to save a whole lot of time.

Good luck with your decision whichever way you go.

[brian fithian]

Yeah, im constantly loading/unloading. It takes 30 mins to run ea sheet and 10-15 mins in between. I know that time is going to be the same ultimately. Trying to figure on another small one (the Epilog is about 10 years old but still runs good) or an open laser. Im thinking the open laser may allow me to do a little more. I have had to turn down quite a few jobs in the past because of the limitation of the enclosed epilog.
Then, there is $$$$...lol... thts going to be the ultimate decision maker

[Terry Swift]

From what I've seen at shows and read - the Kern, while pretty darn expensive is the way to go. They offer several sized beds from what I remember and once you get above 150+ watts - you can go into some metal processing as well with that kind of power. Like in most lasers - the more power, typically the faster you can engrave and if you had a 4' x 8' bed set-up with several sheets of acrylic to run your file(s) on - then it would be a pretyt quick thing to do. Many of the bigger shops that do lots of acrylic and even wood / etc. run the Kerns and I've never heard any of them complain - except on PRICE. Yet, you get what you pay for and considering many Class 4 lasers like Epilog, ULS, Trotec, and others are easily over $25k for a modest machine - if you've got the production to pay for the Kern or other large format ones - you'd be crazy NOT to invest in one versus going several smaller models. Yet, that is IMHO!

[Dave Sheldrake]

Last quote I got for an 8x4 Kern 250 watt was $180k, my original 260 watt Chinese 8x4 was $12,500

Kerns are excellent machines but there isn't a practical justification for the $170,000 difference for the work I do

The largest acrylic processing company in the UK (Gilbert Curry Plastics) uses a fleet of Chinese flatbeds

Power is rarely the limiting factor for engraving, the linear speed tends to be more of a constraint. Even when running flat out my gantry engravers rarely run over 25% power when running at top linear speed

Kern prices will get you an 8x4 2.5kw fibre from China

[Rich Harman]

"you get what you pay for", I disagree.

For example you can pay about $20k for a mainstream laser with a small bed. If you want a bed twice the size you'll pay about twice as much, even though the laser tube, motion control, software, electronics etc. are all the same. You aren't just paying for longer belts, a larger bed and a larger enclosure - you are paying what the manufacturers can get you to pay. "Don't leave money on the table", that is a common saying here and the mainstream manufactures feel the same way. If you need a larger table they are going to make you pay big.

The Chinese lasers don't follow the same pricing structure. If you want a larger work area you'll end up paying for the extra labor and materials required to build the larger machine and that is it - they don't add tens of thousands of dollars more to the price just because they can.

[Dave Sheldrake]

The Chinese lasers don't follow the same pricing structure. If you want a larger work area you'll end up paying for the extra labor and materials required to build the larger machine and that is it - they don't add tens of thousands of dollars more to the price just because they can.

^^^^ Exactly this