I’m etching the same material on Thunder & Donner. Checked laser before & after my job on Thunder no visible change. Same job next day on Donner had to clean lens halfway into the job.
The difference is the tube opening. Thunder is narrow. Donner a wide tube opening. To reduce lens replace time let’s use a narrow tube on all the lasers.
Thanks
Shaun
The small nozzle was the default when we started. The issue is alignment of the laser. It has become substantially harder if not impossible to keep them aligned with the small nozzle now.
That said, yes we should get the narrow nozzle on the lenses. This just takes some hard work making them aligned.
@Team_Laser
1 Like
We really can’t use the smaller nozzle with the older machines. They drift out of alignment so easily, this would require someone adjusting it once a week or more per machine. It can take an hour or more to align a machine. There’s just not enough volunteer time to devote to that regularly.
As the number of laser users continues to increase, our volunteer group has stayed pretty constant. We don’t have time to align them perfectly that often. So, for the older machines, we have switched to using the larger nozzle and accepted that lenses are going to need to be changed. A lens can be changed in 5 minutes, which is more acceptable use of volunteer time. Additionally, there are only a handful of people that can properly align the machine versus a dozen or more that can change lenses. Trading the $30-40 cost of lens for an hour of volunteer time and putting the machine back in service is something I support.
I think a better long term solution is to find more durable lenses for the thunders or switch to machines that don’t drift as much. @pinewoodnut found some GaAs lenses that look promising for similar prices. In the mean time, the new big thunder is probably the only machine that should run a small nozzle. Putting the small nozzle on Donner or Blitzen is likely to result in it being taken out of service more frequently than necessary resulting in reduced use.
1 Like
They shouldn’t drift this much. Why are they drifting is the real question.
Repeatedly crashing the lens holder into your work weights isn’t likely to be handled better by more expensive equipment. We would all like to believe that the crashes don’t happen, but the combination of history, and current results suggest that they do happen.
The chinese lasers are the only ones that have a lens holder that sticks down and can run into the work piece. It’s cheap and simple, that’s why they use it. Most of the nicer machines have much better designs.
I don’t understand the community objection to buying something that is more durable. There is a reason these chinese machines are so cheap.
So what do they do to protect the lens? What do their focal lengths look like? Seems like we have contradictory requests to stay with assemblies that keep the lens better enclosed to keep fumes off, and assemblies that don’t stick down to bump into inappropriate weights placed in bad positions.
ULS, one manufacturer we’ve discussed at length in these forms, does it a bit differently.
The air assist cone is allowed to crash into the part, if you screw something up, but it doesn’t damage the laser or alignment. The carriage is on a sprung roller and pops off the gantry, takes a few seconds to place it back on. Additionally, the lens is not held in the cone, but on the carriage (closer to where the mirror is on our lasers), and is fixed in place. In practice, we crashed the carriage several times over the few years I ran one but never had it come out of alignment. The entire carriage and cone is about 1/2 the length of the Chinese assembly which probably contributes to rigidity and the ability to maintain alignment. I believe the lenses have similar focal length, but if course ULS offers many options for shorter or longer lenses.
If you’re curious about other differences, I’d suggest taking a look at the epilog, it’s set up for engraving and I believe has a different style of air assist (backsweep vs cone) but it is one of the higher quality desktop machines on the market.
1 Like
The problem is that the tube design on the thunders does nothing to get the material away from the lens assembly. We’ve got a design for a new air assist that tries to blow debris away from the workpiece at an angle rather than push air back at a solid object straight down. Right now, the design does not really allow the exhaust to extract dust, smoke and debris well.
Because the membership keeps insisting on buying low cost machines, our only options are to consider major components disposable or start designing fixes for the machines. For the larger size 63” machines, this is the only machine available in the size. It makes sense to deal with the problems of the lower cost machine to get the larger bed size. For the smaller machines that get used constantly, I think something more durable would keep them in service longer, reduce day-to-day problems and produce better cuts and rasters.
Feel free to look into it, but there’s not likely a quick fix.
I don’t have an answer for my question. I use a thunderlaser in my shop and never have to re align it.
I do understand the idea of replacing lenses being more cost effective in volunteer time. Do we have a large stock of them on hand to keep up with this demand?
As a side note, I was going to show shaun how to align the laser, but we didn’t have any thermal paper anymore so I couldn’t. Did we move the stock?
I think it’s been walking around recently… Last place I found it was the cabinet to the left of big thunders computer.
Yes, we should have some thermal labels on a black reel.
We’ve been buying 20 lenses at a time to accommodate the current use rate. It’s probably time to order some more and try out some of the GaAs ones and see if they last longer.
1 Like
Thanks Andrew. Makes sense. BTW Donner has a cracked lens.
The problem isn’t the membership, it is the salesman. None of us are confident a more expensive machine will handle the abuse of DMS significantly better. We all get caught in the “I think” this will be better hole, where we can’t really prove it will be better.
Thanks for defining the possible problem as crashing the head of the laser. It seems we would need a laser head that has clearance closer to an inch from the material while cutting to really cut down on crashes. I don’t know of one that offers that currently, but would be a game changer!
The Universal laser, is the cone that rides close to the material just a shroud? We may be able to make flexible disposable versions of those so if they hit material they would deflect or break rather than transfer the energy to the laser head.
Absolutely possible.
There’s a lot of reasons to buy a higher quality laser. It’s a hard sell because a lot of people haven’t used the laser to understand the differences. When we move into the new space, I’d love to ask for a loaner unit and have it up for a week or two and let people see the difference. That’s something for the future though.
I know there are a lot of reasons to buy one,
I’ve used a Universal and an Epilog laser at other shops and found them to be cool. But, and un-abused Thunder Laser is also AWESOME and a fraction of the price while offering the majority of the features. The question becomes is a more expensive abused laser that much better than the abused thunder laser?
Thus, I’ll circle back to my bad salesman statement, “I think it will be better” (But, I wouldn’t bet my money to check it).
I can’t recall the last time we had to change the lense on the epilog. It has it’s lense up and out of the way of all the cutting materials.
I have no doubt that the gantry on the thunders is probably bent just enough to make an actual alignment impossible. This is just from the gouges in the mesh that can be seen. I’m sure we have had worse crashes.
1 Like
Hey Shaun,
Given how much you use the machines, I think it would be a benefit for you and others for you to be trained on lens cleaning, lens changing and have access to those materials. Happy to meet you at the space and go over it with you. Let me know when you are typically at the space.
1 Like
Thanks. I would like that. I already clean the lens but would like to know how to replace. Usually there on Wed-Fri. during the day. Give me a time and we can meet
Shaun