Laser Options - Making choices

[Bob & Elaine Robinson]

Hi, I'm new to the forum. Although this is my first post, I've spent some time going through the archives regarding subjects that I need information on – specifically regarding the selection of a laser. Without going into the brand vs. brand thing, after months of talking to many friends, and looking at ULS and Epilog, I've settled on a ULS. It was not an easy choice, even given the fact that most of the people I know use a ULS. I have a couple issues with both, but the ULS would be best.

I haven't made my final choice on two things: whether to get 360 or 460 and the question of the optional optics package. On the size issue, initially I would like to have the extra space for production. I would be cutting 1/16" Basswood, chipboard in various thicknesses varying from .030 to .060, and plywood (used for miniatures) of 1/64" to 1/16" thickness. My contemporaries' keep advising me to stay with the 12" x 24" format because many materials come in 12" x 24" and the extra space is just wasted. I find this is to be so not so much the case for me, as I use some custom stock sizes. The other argument against the larger table I have been hearing is that larger tables can have accuracy problems at the outer corners. I'm curious to hear anything about this. Repeatability/accuracy are extremely important in what I do, so this may be a concern (?)

I've been considering the High Power Density Focusing Optics. I don't envision this as a production tool, but as something to use for prototyping parts for molding processes. I also make parts for casting in metal (centrifugal rubber mold casting) and urethane (silicone molds) A lot of these parts use curves and circles. For example, imagine (for you architects) a fancy, curved dentil on a roof parapet. This part may be only 1/4" high. I need a part that is precise, with no steps and a uniform kerf. This pattern will then be molded once or twice as part of a master pattern. I've been doing things like this on a mill, but the ability to do rapid changes to experiment with size/shape on a laser has me excited. I would assume running at slower speeds, etc. would prevent stepping and provide a uniform kerf. I think I heard that the Aztec Calendar demo is done with the HPDFO option. Anyway, I may get that option now or later, but for now I know I will at least get the 1.5" lens and see how that works first.

Let me know if you need any more information about what I am doing. Any help/advice based on your experience would be appreciated.

Bob

[Rodne Gold]

Large tables magnify lens and laser alignment issues and often power drops at the ends of the table. you wouyld find you can cut at the top left but not at the bottom right without significantly upping power.
Reducing spot size will give less kerf but will reduce your cutting thickness.
I do masters for moulds , the laser is not ideal for this , it does not leave smooth surfaces where you hog material.
i wouldnt get the 1.5" lens either unless you sure you need it , the stock 2" does incredibly fine detail as it is and has more cutting depth than a 1.5"
1.5" lenses are great for thin substrates like paper and card.
Get the frilly bits IF you need them , don't anticipate the need.

[Bob Cole]

I have to disagree with Rodne on the optics. I've been using the 1.5" and don't have any issues with cutting 3/8 acrylic. The spot size is .003 on the 1.5.

The laser comes standard with 2.0. I had them add the 1.5 so I could test with both to determine which one works best for the application. If you are mostly cutting 1/16, the 1.5 should work fine and give you the smaller spot size.

There is a creeker who has the HPDFO and loves it. There was a post a few weeks back.

The Aztec calendar I got from ULS has both the 1.5 and the HPDFO (1.5 on one side and the HPDFO on the other). It looks very impressive. I just couldn't justify the 2-3k for the HPDFO lens for the items I was doing.

If you truly have a need for the larger table size, then get it. My table is 32X18 and haven't really used any more than the 12x24 due to the supplies. When purchasing custom sizes, I was able to cut out a few puzzles on one sheet instead of multiples. If I had to do it over again, I would save the money on the table size and put towards more juice.

Keep us posted on your purchase.

[Mike Hood]

I also disagree on the "problems" with larger tables. I think these are mainly experienced by those who don't have them.

I use the full table in a large portion of my work. I've never seen anything that is a large concern. Great for cutting larger sheets without having to reload, or larger pieces (pass-through REALLY helps in that respect as well).

Get the size that best suits your needs. Just like with the power of your laser ... size DOES matter. :)

[Scott Shepherd]

It really depends on what you plan to do with it, doesn't it? It's a question none of us can really answer. It depends on what you plan to do and what your sales plan is. If you plan on doing a certain product range and never deviating from it, then that's one thing, or if you plan to go out and try and get every thing you can to keep the laser busy that's another thing. If you plan to tap into markets you haven't even thought of yet, then the larger table could play into it, but if you have a specific plan and it doesn't involve branching out on products, then the smaller table with a larger wattage may be better.

To me, it's quite a personal decision that involves a lot of factors only you know. I'm always amazed (and I have probably been one of them) how quick people can tell you what you should do without knowing a thing about your business plan and your objectives. Figure out what your plans for it are, short and long term, and then see which size and which options meet that need the best.

Just my opinion (and that's not even worth two cents!)

[Bob & Elaine Robinson]

I would like to thank everyone who weighed in. I've been looking at these pretty closely for about three months. I have a friend who lasers who lives nearby. I've learned a great deal from him and by talking to everyone else I know who has a laser.

My friend has 3 ULS lasers, a 25w, a 50w and a 100w. The first two are 12" x 24" and the 100w is a 32" x18". All have down draft tables and 1.5" lenses. The 25w is 7 or 8 years old. The other two are newer.

He uses the same materials I do and the only difference in our work style will be that I am less into production (but still mainly using the laser for production) and will be doing some pattern making, too. I came to the conclusion that his favorite of the three (the 50W 360) is the one for me. His least favorite is the 100w. It may be fast, but like Bob C, he almost never uses the extra table size for the same reasons.

On the optics, I have to concur with Rodne, for now. I did talk to one friend who has a 360 with the HFDPO optics. He is very happy and claims he is getting the precision he is striving for with his setup. On the other hand, he informs me that one person whose work he admires for it's precision is that of my friend with the three machines. He attributes this to the combination of using the narrow beam of the 1.5" lens and the operator's experience in using the correct settings (speed isn't everything).

One last thing. When I first looked into this and was considering the Epilog, I could not get a decent answer from ULS on air assist. Specifically, why Epilog provides a back sweep air assist as standard and you can use your own oil-less (with filters) compressor. ULS, on the other hand has you spend 5k or more. In any case no one I talked to is using air assist with their ULS, yet it seems, from reading old posts that it does aid greatly in keeping the lens clean. ULS is still vague on this with my discussions with them. They have attributed the need for an air assist set-up on the Epilog to the brand of tube, construction, etc. as creating a greater potential for flare-ups. I'm not sure what to make of that answer and whether I should consider doings something regarding air assist in the future. I guess time will tell.

Bob

[Bill Cunningham]

They have attributed the need for an air assist set-up on the Epilog to the brand of tube, construction, etc. as creating a greater potential for flare-ups. I'm not sure what to make of that answer

Bob

I do! It's called Bovine Scatology!

Many jobs will benefit from air assist regardless of what machine your running.. I'm sure if you search through this forum, you will even find a do-it-yourself air assist for the ULS.. Any air system from the manufac. is going to be E x p e n $ i v e

[Nancy Laird]

Bob,

I'm weighing in on this with our own experiences. We have two ULS machines. The M-20 (20W) was built in 1996 and is still on the original tube and going strong. We also have an M-360 (40W) that was built in 2005 and bought last year. We use the M-20 regularly and in some instances we are running both machines on jobs, like the plaques we recently did for the State Fair.

We regularly use the 2" lenses on both machines without problems, and don't use any air assist unless we are cutting acrylic with the 1.5" lens on the 40W. We clean the lenses regularly and have had only one instance when the lens got so dirty that we were having rastering problems.

You do NOT have to purchase the compressor from ULS - our M-360 came with a small Gast compressor that the original owner had purchased. It's about a 1/15 hp compressor and is sufficient for the purposes.

We do have downdraft tables on both lasers, which help in keeping the lenses clean because they draw the smoke down and away from the material (and the lens).

The other big expense you will have with the laser is the exhaust system, as you'll need a good blower and, if you have the machine set up in a residential area, you'll want to put a muffler on it. Ours is so quiet when it's running that one has to be within 10 feet of it to hear it running.

As far as table size is concerned, only once have we wished for a table larger than 12x24, but the 18x32 wouldn't have been large enough either. Since most stuff comes already cut to 12x24, a table larger would be a waste.

I don't know anything about the HFDPO optics, so I can't weigh in on that issue. I do agree with Scott's post - you have to know what you want to do with the machine and have a business plan to make the right decision for you on which machine to purchase.

Nancy (106 days)

[Dennis Perry]

Hi Bob I have a 660/100w, I purchase a compressor for about $200 works great. ULS has room to work with you make your best deal, like dealing with a used car salesman.

Have fun Dennis

[Rodne Gold]

I have 6 lasers , 3 of them have 980 x 510 tables , the other 3 are smaller, I also have a selection of lenses and collimators - Im not talking about bigger tables without having the experience of em or owning em.
There is a definate downside to using big tables , the longer the beam path , the more chance of misalignment there is and the more one has to undertake alignment procedures. if you do have power losses across the table (and all lasers will exhibit this) you then have to use the incorrect power over the table to achieve a consistent result. That generally involves overpowering certain areas to get the right results where the power drops.
We often dont use the full table for production run type jobs cos of the fact that the chances of incomplete cuts are radically enhanced.

In terms of a short lenses , if you wanna argue that their cutting ability is as good as longer - well so be it , but the physics of it all will disprove that assertion as their depths of "focus" where there is sufficient power density is much smaller. You might find with perspex which is a wave guide , you will be ok , but with other stuff you wont!!!

I find it really odd that folk would consider add ons that cost a lot and could compromise general ability before they actually discover they need em.
HDPO optics and different lenses can easily be bought AFTER you have your laser. These are items for SPECIFIC purposes , there are no free lunches , buy a short lens and some collimator and you WILL have some downside.
No 1 priority with a laser is to reduce cycle times to as short as possible with acceptable results , using lenses with smaller spot sizes will often be counterproductive in this regard especially with large areas of solid engraving where lenses with smaller spoit sizes will give you radically worse surface areas in terms of ridging etc.
I can tell you this , we use our specialised lenses for very specific jobs and the purchase of them was merely to serve customers in these specific applications to retain our customer base , they have never really made us a whole lot of extra money. If i didnt have them , i doubt I would have lost any significant business. As to table size , the times we have had to turn work away cos its too big to fit into the laser are minute. In many years of lasering I have used my pass thru facility a handful of times and the profits I have lost in turning away "big" stuff are not even near the cost of the bigger table.

As to air assist , it is a vital component of lasering , it does a whole lot more than just keep optics clean. The direction of the air , the pressure and airflow are all components of the lasering process. If you go to the synrad site , you will see that they specify air assist figures with all their other specs for lasering various materials. It all depends on the material and how it reacts to the heat generated by the beam. for example to get the best quality and speed in terms of cutting pex , one has to direct airflow so it ejects the melt thru the back of the kerf as well as modulating airflow so you dont cool the melt and get a less than polished edge and it cant be so low so as to allow more melt and thus edges sticking together.
Apart from that , the air assist clears the smoke and debris from the next area the laser is firing at , something that evacuation system cant do as effectively.
I would install an air assist way before even considering hdpo and short lenses.
At any rate , what you need to do is take an actual job you are contemplating doing and ask the mnfgrs to run it for you in front of you , if the std configuratiuon doesnt work , THEN consider speciality options.
You indicated you want to cut wood , well I can tell you this , that more power is the key for clean wood cuts , nothing much else is. The analogy is this.
Which would make a cleaner hole in piece of paper , a bic lighter or a pencil soldering torch?
Lower powers will enable you to cut , but your HAZ (heat affected zone) will be majorly worse than using high powers which will tend to vaporise more then "burn".
In terms of making money , we have found multiple smaller lower power machines far eclipse the potential of a single large high powered one as the time when you use the limits of a larger machine are small.
In terms of stock sizes , buying a machine based on that is folly , a small table saw will enable you to cut to size and the cost of materials is generally a minor factor in terms of price charged. You save by buying larger sheet sizes and have a ton more flexibility if you use exactly what you need.
Bob , I have a huge amount of experience in making spin cast masters with the laser , so if you want explicit info , dont be hesitant to ask.
Your biggest problem in this regard is the fact that that the laser will engrave totally perpendicularily and very fine detail will cause the moulds to tear as there is no angled shoulders to these areas. (for examplk=e , you will find the rubber tween small letters in bass relief (where they stand proud from the surface) will not last) so sometime achieiving the precision you want will actually make things worse. The other problem will be larger surface areas of engraving which are very rough.

[Scott Shepherd]

I was told that Grainger (www.grainger.com (http://www.grainger.com)) part number 4Z024 is an acceptable compressor. It's about $300. You'll just have to turn it on and off yourself. You assign air assist flow and flow rates through the driver and the colors. For instance, you might want the "wash" of air to be at 25% flow while rastering, and then bump it up to 100% when vector cutting. However, if that is selected and you haven't turned the air on, it'll just sit there. It won't cut if the air requirements you specified are not met. The ULS model turns it on and off automatically. If I recall reading correctly, there is a wire that's in the machine that controls that, that you could wire into a switch yourself.

[Richard Rumancik]

. . . I would be cutting 1/16" Basswood, chipboard in various thicknesses varying from .030 to .060, and plywood (used for miniatures) of 1/64" to 1/16" thickness. My contemporaries' keep advising me to stay with the 12" x 24" format because many materials come in 12" x 24" and the extra space is just wasted. I find this is to be so not so much the case for me, as I use some custom stock sizes. The other argument against the larger table I have been hearing is that larger tables can have accuracy problems at the outer corners. I'm curious to hear anything about this.

Bob, I have done quite a bit of basswood for a customer that makes kits. With all due respect to those that really like the 2" lens, I use the 1.5" lens for basswood, veneer and 1/64" plywood. I find that the kerf is narrower and it just gives me a better product. I have a special fixture to hold down 4" x 24" sheets of basswood flat, and I cut in air so there are no reflections on the backside.

As far as table size: to be honest I was disappointed after I got my laser and learned that cutting and marking quality in the lower right corner (maximum x and y) was not very good. The beam travels the longest through air and so is attenuated and loses beam quality. As a result I would get parts that did not cut fully in that corner and engraving was fuzzy. In some cases you can compensate but it is usually a messy work-around. My table is 18 x 25 wide but I generally use either the "top" half or the left half, but rarely the right lower quarter of the table.

As Rodne suggested, you can increase power in the lower corner but you have to spend a lot of time playing with colors and figuring out appropriate power levels. Power and speed are difficult enough to optimize and set once, never mind having to set it for table location. And if you are cutting a single large piece, you would have to make breaks in it to change colors (power levels.) Maybe some users here can cut a whole sheet of tags in an 18" x 24" sheet of material but I wouldn't try. (As an aside, at one point I thought it would be interesting if the driver could be programmed to add a linear boost to the power density when working in the lower right corner - increase power or drop speed - so as to avoid manually compensating for attenuation loses.)


I suppose I could probably do most things with a 12" y-axis, but I do like the flexibility the 18" x 25" table gives me. However, I really did expect that the laser would be able to cut and engrave consistently anywhere on the table and I find that it does not. I highly recommend anyone buying a laser to do tests in the lower right corner to see how consistent the laser is over the whole table. Cut and mark a part near the origin (0,0) with minimal power margin, and then repeat at maximum x,y and compare the results. Hopefully some models are better for this; in my case I have learned to live with the limitations and compensate when needed.

One comment on air assist - the Mercury feeds the air through a sealed chamber and it is expelled more-or-less co-axially with the beam. This implementation appeals to me a lot more than the air assist tube on the Epilog that is aimed at the workpiece from an angle. I have never used an Epilog, but intuitively I think that blowing debris, smoke, and vaporized acrylic straight through the cut would be better than blowing air at the cut from the side.

[Mike Hood]

Any air system from the manufac. is going to be E x p e n $ i v e

Unless you buy a Pinnacle (or GCC), they come with air assist built in... :)

[Mike Hood]

I was told that Grainger (www.grainger.com (http://www.grainger.com)) part number 4Z024 is an acceptable compressor. It's about $300. You'll just have to turn it on and off yourself. You assign air assist flow and flow rates through the driver and the colors. For instance, you might want the "wash" of air to be at 25% flow while rastering, and then bump it up to 100% when vector cutting. However, if that is selected and you haven't turned the air on, it'll just sit there. It won't cut if the air requirements you specified are not met. The ULS model turns it on and off automatically. If I recall reading correctly, there is a wire that's in the machine that controls that, that you could wire into a switch yourself.

My Explorer II has a switched AC output for the air compressor. I don't use it for the air compressor itself, but for a MAC valve (actually a pair of them) that switches on the airflow when I select "air" in the properties for that color. I use a second MAC valve to switch in reduced air pressure manually. I flip a switch and can drop the air pressure to a second regulated flow rate for more intricate stuff. The valves are about $30 each at Grainger and can be used for any number of shop air automation circuits. I use another to dump the compressor air at the end of the day to keep condensation down, and another to flow air into an aux tank to keep compressor run times down in the evenings.

[Bob & Elaine Robinson]

Apparently my email stopped notifying me of new posts.....You have all been incredibly helpful and just about universally verified what I have been finding here and off-forum. I do know that the 12" x 24" 360 will be best for reasons stated. I have also talked to many folks off the forum who have had problems in the lower right hand quadrant on the larger tables. I've seen two large machines with the lower 1/3 and right hand 1/3 semi-permanantly masked off. The 100w results in wood, however, were impressive. Regardless - not practical for me.

I can appreciate not going option crazy. I have done tests on my friend's ULS to see what the diff. is with lens sizes, and on that basis, I favor the 1.5". Another benefit with the narrower beam that I found was that I did not have to be so picky when calculating offsets. As for the $$$ stuff, ( HDPO optics) I think time and a big "show me" will have to to occur before I part with more $$.

I found all the comments about air assist interesting. The consensus seems to be it is easier to assign a plus to that than expensive optic options. The challenge will be (as I have been wrestling with for 3-4 months) is to come to terms with ULS and their policies when it comes to deal time (probably in a week). We'll see what happens there - currently, the only option I am committing to is the down draft table.

Nancy, we also have a woodworking shop and a knife making operation, so we do have a variety of dust collection and exhaust solutions - from a full cyclone system to a small powered vent for getting rid of talc dust. For the laser, I'm resurrecting my Penn state 1.5 hp 2 bagger. I've pulled the 4" hose off the bags and vented out the wall using a Tjerlund vent. Both Penn State and Grainger (and others) have just the blowers available to make your own. Most of the people I know in my field have been using these with their ULS & Epilog lasers. The only change I'm going to make is to convert mine to 220.

Rodne - thanks for your offer on help on the CRMC. I'll be contacting you as time goes on.

Richard, you have confirmed for me a lot of what I have heard.

Bill, "Bovine Scatology" can sometimes get pretty deep when one negotiates a purchase. It's actually kind of fun...

Bob

[Bill Cunningham]

Bill, "Bovine Scatology" can sometimes get pretty deep when one negotiates a purchase. It's actually kind of fun...Most, if not 'all' of the B.S. you will hear, will probably come from the sales people with the least experiance, in both sales, 'and' lasers. Even if they make the sale, they don't understand that any B.S. spread during the pitch may very well come home to haunt them.. At the very least, they would find your trust in them somewhat diminished as you gain experience with these machines and recognize just 'what' was B.S. when you heard it.. It's all part of the learning cycle.. Have fun!