MakeArmy

Afternoon LE Crew (Kyle?)

I have some follow-up questions on the galvo lasers. How “important” is having a MOPA? Or is it just the need/desire to have a JPT laser source (See kyle previous comments) because it seems a lot of the MOPAs have a JPT and the others are Raycus Q-switch sources? If I'm marking, wattage isn't as important unless you're doing deep engraving or want coloration? Can I get a 20-w mopa and still do colors at the same speed as a 60-w mopa?

I'm looking at commarker units. The cost of a regular 50W is almost the same as a 20W MOPA JPT.

Sincerely, Undecided in New Jersey

Hey Again Undecided, great questions!

MOPA Sources

The importance of a MOPA laser source (and by that we really mean a pulse width unlocked MOPA, like the M7 sources from JPT) is dependent on your use case and goals. For basic marking, you absolutely do not need it. I find its helpful if you're doing a lot of deep engraving or marking since being able to modify your pulse width and tune that into your marks can significantly speed up deep engraving if you're willing to invest the time and material into tuning for it. The inverse use case, as you mentioned, would be color marking. In this scenario, you'd do the opposite, dropping your pulse width in order to control heat rather than ablate.

While MOPA can be helpful, it doesn't mean deep engraving is impossible without it. Having a q-switched source, such as a MAX or Raycus, simply means you may invest a little more time into getting those deeper marks. One thing that q-switched fiber sources suffer from is a lower static pulse width, typically in the 80-130ns range, often shifting automatically based on the frequency selected. That inherently means you can only apply so much power at a time per pulse, so there are limits on how quickly you can work through material. You'll also notice those LP sources from JPT are listed as MOPA. They are technically MOPA sources. They come with a 200ns locked pulse width – where similar wattage sources from other brands are much lower, as mentioned above. The difference between the LP and M7 source series is the pulse width being locked vs unlocked. The M7's can go from 1-500ns pulse width.

Wattage Considerations

Wattage, when it comes to color marking, is kinda irrelevant. Colors are a byproduct of heat, not ablation, meaning you can get serviceable color marking even at lower wattages. Typically, applying surface color marks – at least to titanium or stainless – will be a slow process because if you push more power to speed up the process you'll probably ablate and remove any color you gain or ruin the finish.

Use Cases

I can't really answer how important MOPA or a pulse width unlocked laser will be for you. Ultimately what matters is how you plan to use your machine and how much time you plan to dedicate to tuning it. If spending large amounts of time marking colors on stainless steel or titanium is important to you, and variety with colors is the spice of life, then its probably worth considering. Additionally if you plan to spend a lot of time deep engraving, it can also save you some time to both move up in wattage, and consider the MOPA.

If you value color marking, the M7 MOPA source would carry more value. If deep engraving, or working with highly reflective materials like copper, gold or silver, the cost difference between the 20W JPT M7 vs a 60W JPT M7 justifiable. Depending on where you order from the price difference could potentially be negligible (at least when considering 60W or less). 60W lasers are the tipping point in cost effective value for most people. The cost rapidly begins to go up if you push into the 80, 100, 120w+ range and if you aren't seriously using that power to accomplish something specific it could easily be a wasted investment.

A 50w Raycus q-witched source is a great way to save money on the source itself if you really just want general marks. If colors are on the table and you needed the wattage for deep stuff, I'd personally opt now to go with a 60w M7 instead. Upgrading a laser you have with another source is rarely worth the cost and effort. It's regularly cheaper to buy an entire new laser than it is to just buy the source. This also leaves you with the option of having a spare machine as a business backup. Of course it's not the most cost effective regularly purchasing new lasers either.

Comparing Options

For the record there is no 50W M7 source. Really you should be weighing the cost of 20W, 30W, and 50w LP sources (for non color emphasis) vs 20W, 30W, and 60w M7 sources. If any of those are on your list and you're checking multiple manufacturers it's worth knowing just in case you see one marked as MOPA but have no idea if its an LP or M7 source (locked vs. unlocked pulse width).

The 60W M7 can handle just about anything well. The price of going with a 60W vs a 20W or 30W M7 isn't a huge difference. My guess is 60w units probably sell more frequently as an all-rounder for mixed use, so manufacturers often win the scales of economy buying that source to use in the units being sold.

Current Pricing and Suggestions

I just double checked the cost from 20W MOPA ComMarker against the 30W MOPA ComMarker. It's a $100 difference bringing you to about $2899. I think a 50% increase to power on tap is well worth the ~3% cost increase. going to 60w MOPA ComMarker is around another $1000 upgrade to ~$3999 depending on rotary and accessories. Honestly, those prices are pretty wild since they are all the M7 source. The lower LP sources in most units, at 20W or 30W started at around $5K just a year or two ago for most brands.

If it was me between these options, I'd probably go with the 30W ComMarker for general purpose, or the 60W ComMarker if I ever wanted to handle any kind of deep stuff. I'd rule the 20w option out just based on cost being too close to the 30w. It's ABSOLUTELY worth the extra $100 to have the power on tap, no question. The prices on the 30W and 60W are totally reasonable and its a brand that seems to be backing up their warranty and helping people out from what we've seen.

Kind regards, Kyle + The LE Team

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