Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Path: utzoo!utgpu!water!watnot!watmath!clyde!cbatt!ucbvax!RICE.EDU!phil From: phil@RICE.EDU.UUCP Newsgroups: mod.computers.laser-printers Subject: Re: What's a duty cycle? Message-ID: <493.phil.titan@Rice> Date: Fri, 20-Feb-87 10:33:41 EST Article-I.D.: Rice.493.phil.titan Posted: Fri Feb 20 10:33:41 1987 Date-Received: Fri, 6-Mar-87 21:44:42 EST Sender: daemon@ucbvax.BERKELEY.EDU Distribution: world Organization: The ARPA Internet Lines: 46 Approved: laser-lovers@washington.arpa > But what's > supposed to happen if we use it more heavily than its allotted 3000/month? > I.e., what does "duty cycle" measure? Not bloody much. We have an Imagen 2308 (formerly 8/300) which is based on the Canon LBP-CX engine (same as, I believe, a Laserwriter). We received it in January of 1985 and have averaged between 4000 and 6000 pages per month on it ever since. That's well over 100000 pages in two years---and that's a pessimistic estimate. Have we had problems with it? Of course! But 80% of the problems were with Imagen's processor box, not with the print engine (we've replaced the power supply and just about every board in the processor). Aside from replacing the silly plastic "paper separator" every few months, only two things went wrong with the print engine. First, we had to replace the fuser roller assembly---the very last set of rollers in the paper path. This assembly is responsible for heating and "fusing" the toner to the paper. The assembly is not designed to last more than, I think, about 50000 pages. Sooner or later, you have to replace them. Second, the clutch mechanism that drives the paper pickup roller (the roller that actually picks up paper out of the paper tray) slowly gave out over the course of several months. The result was a groaning sound accompanied with a noticeable temporary decrease in the speed of the paper path. In other words: the paper would actually slow down for a few seconds while the mechanical engine would groan and moan. For some reason, the image processor software 2.2 was able to cope with this slow-down, although Imagen technical support was very surprised by that statement (and probably didn't believe it). But the new software/ hardware, 3.3, was not. The image would come out squashed at the bottom of the page. So, we finally had to say goodbye to the 2 year old print engine and replace it with a refurbished one. I think that duty cycle is an estimate of how hard you can push your print engine and still have it perform optimally. But the estimate is purposefully a pessimistic one. We pushed our engine well past that limit, and it still lasted for two years. We could have had that specific engine repaired and refurbished and returned to us, but that would have taken longer than just having it replaced with an already refurbished one. So our two year old engine is actually still in commission---it was refurbished and sold to another customer. We just don't know where it is. William LeFebvre Department of Computer Science Rice University