Hi William,
>>> When a laser is left ON at what percentage of build time is the laser being used?
We had to ask ourselves the same question. We only use or laser for actual build time about 65 - 70 % of time. We actually used this percentage when calculating the ROI for the UPS. However, in our particular situation, we used to average about 2100 hours per laser when we use to shut it off after every build. Now that we have the UPS and leave the laser running we average 6500 hours. 65 - 70 % of 6500 is still 4225 - 4550 hours, which is double the laser life.
Also I think it is important to keep in mind that we do not work on Sundays and only work 10-hour days. This is management's decision. We do not come in at night nor on Sundays to start builds (thank god !).
I am sure there are some Service Bureaus out there that keep these machines running consistently in the 90% range. So again this is another economic advantage of keeping the machine running as much as possible.
By the way, to answer some questions that have been posed, we change out our laser after it has fallen under 18 mW. I would imagine, in some cases, we could probably squeak out a few more hours if we didn't, but we find the build slow down to be unjustifiable.
Mark Wynn
Yazaki North America
Canton, Michigan
Phone: 734-983-1702
e-mail: mwynn@yazaki-na.com
>>> "William LeBlanc" <leblanw@UMoncton.CA> 09/17/99 08:51AM >>>
Hi Mark,
This discussion on laser lifetimes has definitely got me going. From what I have been reading I am amazed by the longevity that is reached by several companies. A question that I have is: When a laser is left ON at what percentage of build time is the laser being used? (example: lifetime of 5500 hrs @ 70% occupation = 3850 hrs, 5500 hrs @ 50% = 2750 hrs)
Mark, I dug up my folder on the UPS that we purchased and it's a "True on-line, double conversion, power line isolated UPS". Thanks for the input on the types of UPS, this will probably help somebody someday make a more informed decision.
Markus Hitter, I too have noticed the effects of temperature on laser power. On a few occasions room temperature increased to about 25 C because of HVAC failure and oddly enough laser power decreased slightly and once room temperature was back to normal laser power slowly increased back to it's previous level.
Thanks to all, I have learned some great stuff over the past few days.
William LeBlanc, ing.
Concept + Inc.
leblanw@concept-plus.com
www.concept-plus.com
>>> "Mark Wynn" <mwynn@yazaki-na.com> 09/16 5:04 PM >>>
William,
I'm curious, what type of UPS are you using? Is it a "line interactive", an "on line", or an "in line type".
I'm not going to pretend to be an expert on this subject but here is how it was explained to me. A "line interactive" type of UPS just monitor's (and filters) the power coming in from the outlet and passes it right back out to your equipment. If it notices a disturbance that is out of tolerance, it will kick over to the power stored on the batteries which is clean. However not all UPS's have the capability to catch all irregularities.
An "on line" type UPS actually takes AC power changes it to DC, cleans it, and stores it to batteries. Then changes the DC back to AC and sends it to your equipment. This system doesn't allow any irregularities to pass to your equipment.
I am curious because we found out the hard way. We originally didn't want to spend more than we needed to. So we elected to buy the "line interactive" type. We didn't see any improvement at all. After consultation from a specialized group of our electrical company we got a refund for that UPS and put it towards an "on line" Liebert. We have had great success ever since.
Mark Wynn
Yazaki North America
Canton, MI
Phone: 734-983-1702
e-mail: mwynn@yazaki-na.com
Steve,
Believe me I have tried pretty much everything, got the UPS & filter several years ago, tried leaving the laser ON, etc, etc .... Still the same results, some good, some fair & some bad lasers. I guess that's how the cookie crumbles.
I would be curious to know the percentage of He/Cd lasers making it at X # of hours.
Regards,
William LeBlanc, ing.
Concept + Inc.
leblanw@concept-plus.com
www.concept-plus.com
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