Running Laser Too Long??

[Liesl Dexheimer]

Is it bad if you run the laser too long? I have a project that I'm working on where it has been engraving continously for over 1 hr 20 min now. Am I over working the machine? I'm guessing it will finish in 1 hr 45 min.

[Joe Pelonio]

Many of my jobs have taken longer than that and it's never been a problem.

I ran a job once that took about 30 hours and I ran it straight through. Each piece of material tool about 45 minutes to engrave then 2 hours to cut, then I changed material. Never missed a beat on that one.

[Liesl Dexheimer]

Phew, that's good to know. I'm approaching 1 hr 45 min now, I think it may run more like 2 hrs. Hardest part is not leaving it unattended, lol! Seems like it takes F O R E V E R !

[Scott Shepherd]

I agree with Joe, you're fine. I had jobs running all day today that had a 80 minute cycle times. Those jobs can be brutal if you don't have other things to do (or you can do without leaving it). I feel for you, been there, done that. It can make for a really long day.

[Liesl Dexheimer]

Yeah this is more of a personal project. It's taking MUCH longer than I thought. I was figuring 1/2 hr to an hr but I'm now @ 2 hrs 11 min & counting. Hopefully should be done within the next 15 min...not too much more to engrave. Then I need to engrave another piece that will be the same, saving that part for tomorrow. If this comes out decent (crosses fingers) maybe I'll post the result...

[Dean Fowell]

I ran a price of 24 x 36 glass family photo for 2.5 hrs come out good, very long day it felt like.

[John Noell]

I just did 26 pieces that each took over an hour. I read a couple of books and played a lot of stupid computer games.

[Gary and Jessica Houghton]

I know what you mean John. I have 48 pieces at about an hour each. Not the longest job ever, but I am about videoed out! I have to stay awake, so no books for this job....

[Jiten Patel]

We run our laser 10 hours a day, constantly. I have to stand an manually feed pieces of card every minute or so. That makes for a very long day. Aren't we all glad they are memorising to watch!

[Rodne Gold]

Jiten , you must be able to make a feeder of some sort , perhaps a tipping z table that tips to discard the cut card and uses a puff of compressed air to clear some sort of vacuum table of cut pieces , tips back and some mechanical arm arrangement (like a finger with a rubber tip) drags the next piece into place on it. It MUST be worth your while to make something like this. Im sure there must be something in the printing industry that can be utilised? Failing that , it might be worthwhile getting a cheap unskilled operator to do the tedious stuff.

[Jiten Patel]

Rodne, its something we are thinking about seriously, but as the business is growing, we are doing it ourselves for the minute. Once we get enough coming in, a full time staff member is first on the cards, then a trip to China, to get a more powerful system and a bespoke feed developed which should take our production through the roof. Something like the SEI Paper Blaster, which is an impressive bit of kit.

[Joe De Medeiros]

I agree with Joe, you're fine. I had jobs running all day today that had a 80 minute cycle times. Those jobs can be brutal if you don't have other things to do (or you can do without leaving it). I feel for you, been there, done that. It can make for a really long day.

This is the time I use to catch up on my SMC reading, and other forums

[Tammy Larrabee]

I ran 79 flasks at apx 20 min each, makes for a very long day

[Rangarajan Saravana kumar]

In my Epilog we used to engrave wood for continuously 30 hrs at a shot to complete a job, but be sure the proper ventilation, coolers etc in place all the time to run..

Else, no problem

But, running rotary for 8hrs a day, making motors more heat. So we stop a while and run... I dont know why steppers get so heat after 4/5hrs...

Regards,
Saravanakumar

[Dan Hintz]

I dont know why steppers get so heat after 4/5hrs...
You run a lot of current through the windings to get them to jump to the next step quickly, then you continue running a lot of current through the windings to get them to stay at the next step rather than rolling past uncontrolled. Lots of current = lots of heat.

[Liesl Dexheimer]

Been meaning to post a follow-up to this thread for a long time. Here's my final result:

207811

Took me over 20 hrs to complete (5 hrs of which was engraving the inlay, not to mention the time cutting the pieces of paper out). The overall size of this piece is 23 1/8" in diameter. There are two pieces of Baltic Birch plywood that were used and glued to braces on the back side. I had to use two pieces since my engraving area is only a maximum of 12" x 24". The paper is Strathmore watercolor paper that I painted and then cut. I did this mainly for a challenge, I was tired of being limited in engraving size and wanted to do something on a larger scale. Getting the pieces to line up was the hardest. Still wish I could have a larger engraver but oh well...I wanted a challenge!

This piece made it into an art show along with some other non-engraved pieces of mine.

Thanks again to people who helped me along the way! I was concerned about running the laser for a long period of time but it all worked out in the end! :)

[David Fairfield]

If you are running long stretches, I think it would be a good idea to adjust your maintenance accordingly. The schedule in the manual is based on average use, whatever that is. The tech people will be able to tell you more specifically. Before running a long job, I'd make sure all was clean and lubricated.

Dave

[Glen Monaghan]

running rotary for 8hrs a day, making motors more heat. So we stop a while and run... I dont know why steppers get so heat after 4/5hrs...


They get so hot because Epilog chose to use stepper motors rated for 24VDC but drive them with straight 48VDC and leave the coils continuously at full power. The motors are over driven (not uncommon with steppers, in order to get quick movement) but not current limited the way motor manufacturers recommend. I'm guessing that's largely why they use such a massively oversized stepper... to better handle the extra heat.

I talked with several motor manufacturers about this and all say doubling the rated voltage with constant current drive like that invalidates their warranty. In the end, I ordered a small-frame stepper with custom-wound 48VDC coils to make my own chuck-based rotary device. The motors (I bought two to have a backup/spare since it took a couple of months to get them made and delivered) just arrived so now I need to clear some time to get it wired up and tested!

-Glen

[Larry Allred]

We run our laser most of the day, 5-6 days a week. Running is better than sitting, and a whole lot more profitable.

Just make sure you have the proper forced ventilation and keep it clear & moving the air outside. Keep the laser clean and lubed. Heat and particle buildup are the two main concerns. Manage those and you can run it as long as you can stand! :)