Posted by Jim Earman ● Tue, Feb 13, 2018 @ 08:00 AM
Laser Marking System Q&A
Recently, a manufacturer of Class 1 medical devices contacted me with some questions about integrating advanced laser marking systems with their products. The system needed to satisfy FDA and customer marking requirements, and they were looking for a supplier who was willing to work closely with them to provide support.
During our initial conversations, the manufacturer provided me with a list of capabilities that they were looking for in their laser marking system and asked some really good questions. While every application will have unique requirements and specifications, I thought that these initial Q&A sessions might benefit others looking for a laser marking system.
Jimani: Let’s talk about the capabilities you are looking for. Just go down your capabilities wish list, and I’ll address each item on it.
Manufacturer: Ok. First, we’re looking for a system with the ability to mark a variety of materials including multiple types of stainless steels, titanium, anodized aluminum, some plastics (Radel), phenolic and silicon.
J: We build 1064 nm fiber laser marking systems. 1064 nm laser light is the wavelength of choice for all metals, and it works well for some, but not all, plastics. My typical response to people is that if marking a particular plastic is an essential requirement, let’s test it first.
M: How about optional dual laser heads for marking steel and plastic?
J: Not available from Jimani. The only dual head systems that I am aware of are flying optics gantry type systems made by companies such as Universal, Trotec, and Epilog. If there are dual head galvo driven systems on the market, I am not aware of them.
M: A system that will compliment a safe, clean environment?
J: I believe that Jimani Fiber Laser Marking Systems comply with that request as well as any systems on the market.
M: How about an on-board reader/verifier and character verification? These are optional for us, not necessary.
J: We do not offer this option as an integrated system component, and I am of the opinion that reading and verification should be standalone operations.
M: We’d like a user-friendly interface.
J: We use Prolase Laser Marking Software. You can download a demo copy of it at www.laserware.com, and it will run on any Windows desktop computer. You can look at this video here which was intended to jump start new Prolase users. It will give you an idea of the steps that one has to go through to create a basic laser marking job file.
M: Will the system be user serviceable and easy to maintain?
J: Jimani Langolier systems are user serviceable to the point where any component can be replaced by the user and identification of any failures can almost always be made over the phone. Having said that, the major optical components in the system, laser module, and scan head, are not user serviceable and, in the event of a failure, must be returned to the manufacturer for repair. Laser modules and scan heads are purchased components and not manufactured by Jimani. With the exception of cleaning and occasional lubrication of lead screw or rotary components associated with part or focus movement, there is no maintenance.
M: Will it have the ability to work with a variety of file types.
J: Does this refer to graphic files to be marked? Prolase will accept dxf, dwg, plt, ai, eps, and a few other vector format graphic files. It will also accept and mark 1 color jpeg files although it is important to realize that galvo driven markers perform best with vector graphic images, not bitmap graphic images.
M: We just need to know what type of file types can be imported or exported.
J: Prolase is not a graphic generation or modification program. Text, serial numbers and machine-readable codes are all marking object types that can be created in Prolase but graphical images, such as logos, must be created in some other program and imported into Prolase. Prolase is authored by American Laserware and Keith Cudebec is the founder of American Laserware and the creator of Prolase. Keith’s comments about this subject are twofold:
No one’s laser marking software will ever do as good a job of creating graphics as will the dedicated graphics programs such as Engravelab, Illustrator, CorelDraw, and various CAD programs.
It doesn’t make sense to tie up a $60K marker for work that could be done on a $3K graphics workstation. Markers get their payback by marking parts, not editing graphics.
Prolase does not export file types. Laser marking job files are saved in an American Laserware format and can only be used in Prolase.
M: Can the system be integrated with the network? Will it provide data such as who, where, what, and when pertaining to manufacturing? Will it provide variable data?
J: Prolase can input and output some data types, but a detailed answer to this question is probably better coming from Keith Cudebec, the founder, and president of American Laserware. I can put you in touch with him if you like. Prolase Server software will let you control data in any way, shape, or form that you desire although it requires a front end from you to define how you want to control that data.
M: Can you provide a system with automatic focus?
J: When a Langolier is equipped with a servo motor Z axis, the focus position can be programmed with a resolution of 40,000 encoder counts per inch. This is not the same as 3D marking which requires a 3D marking image and hardware and software to move the lens in real time over a 3-dimensional part. Prolase does not support 3D marking.
M: We’d like simple character location at set-up.
J: Does this refer to the location and setup of characters to be marked? We use Prolase Laser Marking Software and marking setups are simple and straightforward.
M: We’d like the ability to remark parts with no discernable ghosting.
J: Ghosting generally occurs when the original marking has been removed from a part, and it is placed back into the marker to be marked again. If a ghost trace remains after the original marking has been removed, unless the part is placed under the lens such that the new mark is perfectly superimposed over the original mark AND the marking information is the same, I don’t know how ghosting can be avoided.
M: Let’s circle back to automatic focus, simple character location, and ghosting.
There are several companies that offer auto focus by means of an on-board camera. I see it as similar to a vision system that is coordinated with the laser system. Also, at present, we are looking at a couple of systems that claim a more accurate way of picking up locations at set-up.
As for ghosting, I have in the past been able to remark parts with almost no ghosting when they had been fixtured properly. Some systems with on-board cameras claim that they can eliminate or reduce ghosting dramatically.
J: These topics all sound related to the camera subject that you brought up. First of all, let me tell you how our motorized focus works.
When we use a motorized Z axis, we connect a servo motor to the precision Z axis lead screw. We use internally encoded Teknic servo motors. The motors have 2000 encoder counts per revolution, and the pitch of the lead screw is .1 inch per revolution. Our systems are calibrated such that, upon startup, the Z axis finds a very accurate home position. That position can be anywhere, but we normally set it to home at the top surface of the fixture plate that parts will be placed on for marking. If a part is placed on the fixture, then the operator or setup person must know the distance from the top of the fixture plate to the mark location on the part, and that distance is put into Prolase for a Z axis position of that particular mark. As many Z axis distances, as necessary can be put into a marking job file for different Z axis marking positions on a part. This technique is extremely accurate, but it requires that information about the part be known to the operator or setup person.
We have experimented with vision systems and prox sensors for focus and part location. This can all be done and made to work although it is a technique that best serves applications in which a marking system runs one type or a few types of parts for long periods of time. The reason for this is that camera systems must be “taught” to correctly see and interpret the part that they are marking and, my experience is, this can be a lengthy and tedious process. For applications that have relatively short runs of parts and may include many different parts in a day, the camera technique is not efficient at all. As a rule, we stay away from camera systems for part location and alignment.
If an integrated camera system is a requirement for you, then we are the wrong company. If I needed a system with the type of camera system that I believe you are describing, I would look to XXXXXXXXXX. I believe that this is the kind of technology that their systems have evolved to and I think that they probably do a better job of that than anyone else in the business. I’ve also heard that their software is difficult to use, but I have only used their reader software, not their marking software.
M: How about marking in hard to reach areas?
J: Please explain this requirement in more detail. The area of the part to be marked must be in the field of view of the lens, and the lens must be able to be positioned such that the marking area is within the depth of focus of the lens.
M: Inside the leg of a channel, between features on a part, etc.
J: If the location to be marked is in the field of view of the lens then it can be marked. The exception to this might be very deep, very narrow channels that are near the edges of the marking field. This can be addressed by using a telecentric lens, but that starts getting really expensive.
M: Will it have a precision 5C rotary axis with a through hole?
J: This feature exists on the Langolier fiber laser marking system.
M: Laser must be capable of achieving results compliant to FDA and GS1 requirements regarding the DPM/UDI marking used in the medical industry.
J: Prolase Laser Marking Software is capable of meeting any FDA/GSI DPM/UID marking as long as the specific marking requirement can be defined by the user.
M: As far as safety goes, we want to ensure that any and all safety measures are up to date, and easily kept in place for the life of the machine.
J: Regarding safety: It sounds like you would want an enclosure on a marker. If you simply specify a Class I enclosure, then you have an enclosure that by definition allows “No human access to laser exposure.” Class I is very specific, and I’ve seen many systems that put some type of enclosure around their marker and call it Class I. Many of those are not truly Class I. Just be aware.
Having said that, a true Class I enclosure can make your life a bit difficult. No human access to laser exposure also means that, if the system has an internal red alignment laser, that must also be disabled when the door is opened. Alignment lasers are extremely useful for setups and part locating. I could go on for a long time about laser safety and what is or isn’t necessary for a safe system, but I won’t. Your safety people will probably have some say so about what they will or will not allow in your factory and getting them involved in an early stage might save you some grief downstream.
M: Can you recommend settings for all material types common to our industry?
J: We can help with specific settings for various materials. If you are looking for a “recipe book” of all laser settings for all materials, it doesn’t exist.
M: Can you provide solid technical support for all software, hardware, and processes that can be utilized in the programing, set-up, and the operation of the Laser Marker?
J: I believe that Jimani and American Laserware (the authors of Prolase Laser Marking Software) have the best reputation for support in the industry. That does not mean, however, that either Jimani or American Laserware will accept the responsibility for programming all of your laser marking job files.
M: Demonstrable results.
J: I am a firm advocate of the “Show me what you can do” philosophy. We will not sell a system without having done samples or having a clear understanding of what the system is expected to do.
Contact Jimani and see what they can do for you with a state of the art laser marking system.