servos, steppers and tubes - Engraving Etc. Forum

<body> <h1>Full Version: <a href="https://www.engravingetc.org:443/archive/index.php?webtag=EE&msg=872.3">servos, steppers and tubes</a></h1><a name="a872_3"></a><p><b>From: laserman (MIKEMAC)</b> [<a href="lmessages.php?webtag=EE&msg=872.3">#3</a>]<br /> 23 Feb 2005<br /><b>To: Dave</b> [<a href="lmessages.php?webtag=EE&msg=872.1">#1</a>] 23 Feb 2005</p> <p>Dave,</p> <p>I will give my perspective on your questions please keep in mind that I am a rep for Universal.</p> <p>With that said here goes.</p> <p>Servos VS Steppers this has been a on going debate for years Servos have better ramp up / down speeds than the stepper motors do. I think that speed and engraving quality should be the point here. You maid the statment "How fast can you really go" This is all material and laser power dependent. When you engrave too fast some things will be sacrificed and that will be quality.</p> <p>Vector cutting in my opionin is better with stepper motors when you are vector cutting speed makes no difference between the two motors because you have to get through the material before you can move. More laser power would allow you to cut faster.</p> <p>However when you are dealing with Vector lines the movements are extremly fast and with the stepper motors you will get better accuracy. A simple test to try is cut a circle on both systems chances are you will see a nub on the one cut with the servo versus the one cut with the stepper. This nub is the start stop point servos have a difficult time ending up where they start.</p> <p>Another point to make here regarding servo motors. Servo motors are great on large field size systems because they can take advantage of the area. Most laser systems that use Servo motors are not going to be high end motors or encoders the MFG's simply can not afford to use these types of set-ups in this price range of equipment it is not economically smart.</p> <p>What this means is that you will not get perfect acuracy and repeatibilty.</p> <p>Most users won't ever notice this but if you ever put them to the challange you would see.</p> <p>Enough said on this topic I am sure that I will be crucified for some of my statements and please remember these are just my opionins.</p> <p>Next topic Laser tubes:</p> <p>Again a highly debated subject I would like to point out a few facts regarding the laser tubes.</p> <p>ULS used to use the Synrad, and Coherent tubes in there early systems.</p> <p>They learned a lot when trying to make these tubes preform the way they wanted them to. They spent years of developing special optics packages, power supplies, and cooling methods to try to accomplish this. They had a lot of sucess but as time went on it became imparent that is was to costly to continue this way.</p> <p>This is when the ULS tubes were developed They took all of there efforts working with the Brand X tubes and packaged them into there own.</p> <p>I don't know if many people are aware of this but ULS hold several patents on the laser tube both U.S. and International. What this says to me is "Pretty Impressive" when this little system manufacturer took on the big boy's and made there own tubes. In fact they were one of the first to come out with the air cooled laser tubes.</p> <p>They now offer laser tubes from 10 watts up to as much as 150 watts for the OEM Market.</p> <p>The last statistics had ULS selling a larger volume of OEM laser tubes<br /> than some of the other MFG's of tubes. In fact the ULS tubes are used on several OEM laser engraving/cutting systems.</p> <p>What does this all mean well "Cost and Control" Uls has the control on the quality and cost of manufacturing as well as the re charge or repair costs this all trickles down to the end user.</p> <p>Drivers:</p> <p>Personaly I think this is a huge advantage ULS writes there own drivers. They have stayed up to date with the Operating systems and graphic software programs. They continue to add or improve the functions and flexibility all the time and most of the ULS systems can use the newest drivers even on there older systems (some are not able to use the XP Drivers systems that are 12 to 15 years old).</p> <p>Cost of replacement parts:</p> <p>ULS has to be the easiest system to maintain and service. The cost of the parts are minimal for example.</p> <p>Set of X Axis bearings $90.00 <br /> X Axis belt 35.00<br /> Lens $230.00<br /> Laser Tube recharge $850.00</p> <p>These are the parts that if not maintained properly will need to be addressed. It is important on any laser system to keep it clean and maintained.<br /> These costs are controlled by the end user the better they take care of the system the less the replacement costs.</p> <p>I hope this is just plain old information on the ULS I highly recommend that you get a demonstration and meet your local rep so you will be able to see first hand what I am saying. It is worth the time and effort good luck with your decision.</p> <p>ÃƒÆ’Ã†â€™ÃƒÂ¢Ã¢â€šÂ¬Ã…Â¡ÃƒÆ’Ã¢â‚¬Å¡Ãƒâ€šÃ‚Â </p><p class="edit_text">EDITED: 23 Feb 2005 by MIKEMAC</p> <hr /><a name="a872_4"></a><p><b>From: Harvey only (HARVEY-ONLY)</b> [<a href="lmessages.php?webtag=EE&msg=872.4">#4</a>]<br /> 23 Feb 2005<br /><b>To: Dave</b> [<a href="lmessages.php?webtag=EE&msg=872.1">#1</a>] 23 Feb 2005</p> <p>On the subject of drivers.</p> <p>I own a NH Optima, made by ULS. It is an old machine, out of production. I got it used.</p> <p>It is a sweet machine and ULS still is putting out updated drivers and firmware for this machine. Continued support is important, they do it.</p> <p>When I switched my computer to XP Pro, one phone call and I received the new driver free by email. It is a much improved driver to boot.</p> <p>I do not have any experience with other companies. Why should I? ULS has addressed every need in a very professional manor with me.</p> <p> </p> <hr /><a name="a872_5"></a><p><b>From: shari (APPLIK)</b> [<a href="lmessages.php?webtag=EE&msg=872.5">#5</a>]<br /> 23 Feb 2005<br /><b>To: Dave</b> [<a href="lmessages.php?webtag=EE&msg=872.1">#1</a>] 23 Feb 2005</p> <p>Dave,<br /> Just thought I would tell you about my experience with ULS. I bought a 25 W unit in April of 97. I use it every day, five to six days a week. Their manual is easy to understand and their training was awesome. Sometimes very loooong days. I mostly do vector cutting with a smidge of other things thrown in. I have never had a problem with accuracy on my machine. I cut appliques for computerized embroidery designs and they have to be <u>exact</u> every time. Absolutely no room for error or variance. I keep it very clean and have never needed to replace anything except the lid shocks (from opening and closing the lid so much). When I bought a new computer with Windows XP, they emailed me the newest driver. Works great and I am a real control freak when it comes to my settings. I just purchased a new larger field 50W unit. They are very nice people to work with. If you need an answer to a question, just ask. They are very prompt about getting back to you and they have never made me feel like I have ever asked a "dumb" question, although I'm sure I have. Good luck on your purchase. Lasers are one of the most fun tools you can own. <br /> Shari</p><hr /><a name="a872_6"></a><p><b>From: Rodney Gold (RODNEY_GOLD)</b> [<a href="lmessages.php?webtag=EE&msg=872.6">#6</a>]<br /> 23 Feb 2005<br /><b>To: Dave</b> [<a href="lmessages.php?webtag=EE&msg=872.1">#1</a>] 24 Feb 2005</p> <p>Hiya Dave<br /> Steppers are not a good option at all , they are generally not closed loop systems and can lose position easily , just about NO cnc machinery of note is supplied with a stepper motir barring the cheapest. I have experience with both , we run stepper and dc servo and closed loop servo machinery. Stepper machinery , unless using micro steppers cannot extraoplate a circle as a circle , its a series of straight lines as the motors have discreet steps. Whatever motor you use , you will have to replace it at some time if you use your machine heavily. Most of them are negligably priced compared to a mother board or source. Personally I would never ever buy a stepper driven machine. You can NEVER recover if you have an error with a stepper , it doesnt know where it is. Both are accurate and the repeatability depends on other stuff like bearings etc.<br /> As to speed , in terms of lasering , speed is money , we upgraded or 3 slower 25 w machines to faster 30 w machines and our productivity rose almost 2 fold. Speed and power are king in terms of lasers (provided of course the motion system has the precision to let you use the speed)<br /> Iv'e used synrad and Coherent DEOS sources , The coherents seem a little better to me in terms of beam quality and power density<br /> We have had failures on both , tho the synrads we used were very prone to blowing the RF cards. Synrad actually sent me a repair manual and the parts required to repair the source were pennys , problem is the RF boards need to be tuned and you need an offboard laser controller to do so which we didnt have. A local guy here in South Africa fixes em so its real cheap. You will find that tubes generally fail cos of small stuff , like a blown component and they don't fail totally. Generally most of the repair costs of a source are postage. Make sure your laser supplier has a replacment source at hand and get a machine with a no quibble warrantee on the source. A year is the minimum and there should be no hour counter etc. I have NEVER paid for a blown source , but I have a 3 yr warrantee on my machines and all thats not covered is the lenses and mirrors (and obviously abuse) Key to conserving your source is the cooling and the Power supply to the source. Overheating is a problem and considering we live in a very hot country , we spent the money and installed an air conditioner in our laser room.<br /> As to drivers , well they are the heart of the machine and will determine the effectivity. You should have drivers for XP and for 98 , don't expect much support for 95 with new and current models. Older lasers might not have drivers that work with newer O/S's, but this is not much of a problem as you can use an old puter as a sort of print server and still work in the newer OS. A lot of software will not have support or work under old Os's like Corel 12 , so if you want to use it , check your laser has the matching driver.<br /> The biggest cost in a laser will be the tube , we have had motor failures , but they are generally only in the Y axis and are very rare. On my lasers they cost about $150 at worst and are a snap to replace. We run at the highest speed about 8 hrs a day continually and sometimes longer. I have had to replace ALL my y axis bearings and rails (the ones the head rides one) but that was due to us not knowing that the bearing had to be lubricated (wasnt specified in the manual and these were new machines even to our local agents) It was covered under warrantee and took about 1/2 an hour to do.<br /> I have never had to replace a mother board/belt or anything like that , we have replaced mirrors and lenses both of which are quite expensive , a lens comes in at about $500 or so in our part of the world. We have also replaced 1 ribbon cable to the heads that developed an intermittent fault and we have replaced many focus probes and that was due to user error , mostly cos the probe hit something and broke off. I use GCC lasers but have no affiliation to them or to any dealer. I live in south Africa so it doesnt matter to me what laser you get.<br /> I agree a lot of dealers are biased , they HAVE to be to promote their product. Just apply the 1/2 x2 rule and you will be safe , IE halve performance claims and double quoted costs and if it is still financially viable under those circumstances, go for it</p><hr /><a name="a872_7"></a><p><b>From: Ken D. (KDEVORY)</b> [<a href="lmessages.php?webtag=EE&msg=872.7">#7</a>]<br /> 24 Feb 2005<br /><b>To: Rodney Gold (RODNEY_GOLD)</b> [<a href="lmessages.php?webtag=EE&msg=872.6">#6</a>] 24 Feb 2005</p> <p>I wanted to comment on your stepper motor comments. If someone is always going to run at the highest speed for throughput, then get a servo. If they will be slowing the machine for diminishing returns on quality, a stepper should be considered.</p> <p>In the past I designed pumps used in the medical industry. Some used stepper motors, others a servo approach. It is true that stepper motors usually don't provide feedback to the controller. Therefore if it gets out of sync the controller won't know. (I've noticed my ULS machine re-homes itself prior to every run.) </p> <p>Why might it loose its position?<br /> 1) If the controller tries to accelerate or decelerate quicker than the motor can handle given its load. <br /> 2) A change in load that was not accounted for. </p> <p>If the engineers knew what they were doing #1 should not be an issue.<br /> Regarding #2, if the unit is not properly cared for and the moving optical head gets stuck, or your running with the cover off and bang it, Yes the controller will not know to compensate. </p> <p>With a stepper motor the laser bed is like a grid (a raster image.) Each step moves one position. The controller knows where its engraving by keeping track of step counts. The speed is steps per unit time.</p> <p>With a servo system you have an encoder to tell where the motor is. Knowing where it is, where you want it to be, how quickly you want it there, and its current velocity, the controller calculates how to adjust the power going to the motor.</p> <p>A stepper can hold a fixed position, a servo will oscillate around a fixed position overshooting & compensating. Controlling a server is much more complex. A servo approaching a point from different directions will cause an overshoot in different directions. </p> <p>A servo is constantly compensating for not being where it should be. A stepper is driven so its location and speed/acceleration are always known. You can calculate stepper motion for future use, servo motion must be calculated live.</p> <hr /><a name="a872_8"></a><p><b>From: Jon C (JONCASHMAN)</b> [<a href="lmessages.php?webtag=EE&msg=872.8">#8</a>]<br /> 8 Mar 2005<br /><b>To: Dave</b> [<a href="lmessages.php?webtag=EE&msg=872.1">#1</a>] 8 Mar 2005</p> <p>OK - I like hearing what a lot of the sales guys have to say about servomotors and steppers. It's always good for a laugh. The best answer I ever got was from a guy that said that if you took a stepper and a servo and put them next to each other, which is better? Neither. They need electronics and code connected to them in order to function. It is not the motor design, it is the design around the motor that counts. Don't let these people fool you. Steppers can run just fine and are less complex, more reliable (ask me how many servos I went through on my old Epilog) and less expensive to replace. The machines need to be repeatable as well. Go test the machines yourself and have them run the same vector engraving file two or three times on the same piece of acrylic. You might be shocked how bad the encoders locate the beam on some of these servo driven machines.</p> <p>Laser tube differences? What matters is if they are consistent, pulse properly and are easy and inexpensive to replace. It's a difficult question to answer, but the bottom line is that this is blown out of proportion by the sales types in order to push their products. Lasers that are in these machines today all pretty much do a good job.</p> <p>Operating Systems. Universal seems to be on the ball with updated drivers that work well. </p> <p>Warranty and afterwards. In my experience, I replaced servos quite often. It seems as though many people have this problem. I haven't replaced the steppers on my Universal. It gets a lot of use.</p> <p>In the end, it's a total design package and the service and support that I receive that makes me happy. You probably will be happy with any US made machine, but I've run into more people that ended up with a Universal after owning another brand than the opposite. </p> <hr /><a name="a872_9"></a><p><b>From: Rodney Gold (RODNEY_GOLD)</b> [<a href="lmessages.php?webtag=EE&msg=872.9">#9</a>]<br /> 8 Mar 2005<br /><b>To: Jon C (JONCASHMAN)</b> [<a href="lmessages.php?webtag=EE&msg=872.8">#8</a>] Unread</p> <p>Actually you arent really comparing steppers and servos , you are comparing closed loop feedback systems with no feedback type systems. Whatever the merits of the motor , the feedback system is always a far more flexible system and is undoubtedly better in just about every application. Any poor system will act poorly , damning feedback systems on the basis of poor implementation is a little unfair, apart from which stuff like bearing and motion system tolerances would come into play in terms of repeatability.<br /> I don't have any repeatability problems with any of my machinery that uses encoder based systems and that includes my real cheapo epson printers which manage exceptional registration.<br /> In terms of tubes , beam quality is very important as are the tubes optics , the way the laser pulses , peak power , beam diameter etc all come into play. </p> <p>There is a tendency for these type threads to devolve into a my brand is better than yours type thing , or folk get a little aggrieved when perhaps a feature on their brand of machine is slagged off which is a little unfortunate. All of these type lasers have issues and some are stronger than others in areas , but at the end of it all , all the laser engravers in the same size/power/price class do the same stuff and do it well.<br /> I don't think the comment that if its USA made its better than other non usa brands , some of the stuff from China is excellent and innovative and best of all good value and the Trotec machine is no slouch either. The rofin source too is as good if not better then offerings from synrad or coherent. <br /> Apart from technical issues , I agree fully with what you say in that it is the total package that counts and IMHO , the deal breaker is the support and warrantee.</p><hr /><a name="a872_10"></a><p><b>From: Engravin' Dave (DATAKES)</b> [<a href="lmessages.php?webtag=EE&msg=872.10">#10</a>]<br /> 9 Mar 2005<br /><b>To: Rodney Gold (RODNEY_GOLD)</b> [<a href="lmessages.php?webtag=EE&msg=872.9">#9</a>] 9 Mar 2005</p> <p>Rodney,</p> <p>These are the types of threads, although very technical to some, that get a bit competitive, but are the most valuable to forum members. My opinion about servo vs. stepper motors has not changed because of this thread, but I am much wiser because of the open dialogue. </p> <p>Both sides of the aisle have some very good points and you have brought it all together.</p> <p>This discussion does add credence to what is brought up often, the manufacturer rep and support is often the deal breaker.</p> <p>Thanks for all the great information.</p> <hr /><a name="a872_11"></a><p><b>From: Peter</b> [<a href="lmessages.php?webtag=EE&msg=872.11">#11</a>]<br /> 9 Apr 2005<br /><b>To: Engravin' Dave (DATAKES)</b> [<a href="lmessages.php?webtag=EE&msg=872.10">#10</a>] 9 Apr 2005</p> <p>Nothing is is more important than after sales service....not sales service.</p> <p>We were caught by an Australian distributor of french software and American Lasers engravers, that would not accept responsibility for the breakdowns and lost time encountered by the machinery and software/dongles they sold.</p> <p>They continually blamed the providers of the software/ dongles and the manufacturers of the Laser engravers in the USA.</p> <p>In the end it cost our firm over $18,000 cold hard cash lost in sales.</p> <p>The company in question in Sydney Australia, blamed us, the software company and the Laser engraver manufacturers and in the end supplied us with damaged loan machines...which we had to buy before they would send it out....Yes sign a sales agreemant..then they sent us a smashed machine and wouldnt give us credit until their tech flew in to work out whether " we broke it, or it was done in transit"</p> <p>all this over several months</p> <p>We asked them what they would do to help us out..and they offered us 5% off of photograve ( which we could buy anywhere else in the world for more than 30% better than their price) </p> <p>The end result was the company basically absolved themselves of any responsibility, blamed every one else for their problems and left us out of pocket. They also had the temerity to blame us for all the problems.</p> <p>We have subsequently found out from trips interstate, that the same company has done the same thing to other Engraving companies, that have told us they will, never deal with them again....ever!</p> <p>Funny that the only other purchaser of this particular companies products in Adelaide Australia, ( whos employee we have just taken on board) has given us the same story as well...<br /> " oh " we just have to email America because its not our problem".</p> <p>What the "Universal" problem is that the company in the USA dont realise is the damage being caused by the Australian Distributor of their product is..that, many are choosing other products..</p> <p>the end result is, you must purchase on local dealer warranties, guarantees and support, ask for it in writing, dont believe the snake oil salesmen..get em to put it down in black and white...coz at the end of the day..the USA companies that manufacture are not going to believe a little purchaser, they will believe the Distributor that has the infrastucture, supply and purchase power to back their machines.</p> <p>So at the end of the day, whether you have a local, <b>universal</b>, Pinnacle/ GCC, Epilog, xenetech,Gravograph,Trotec dealer.<br /> If they are all about the same price...</p> <p>Go for the one that will give you the best service, back up etc..all the machines will give more or less the same result..</p> <p>service, service service....if you are only worried about about a few grand difference in purchase price....dont simply go for price, go for after market service....</p> <p>and how they will look after you when the machine they sell you breaks down and you are left with thousands of dollars of lost business..</p> <p>In Australia, it is a Universal question that must be addressed.</p> <p>regards</p> <p>Peter </p><hr /><p align="center">Show messages: <a href="lmessages.php?webtag=EE&msg=872.1">All</a>  <a href="lmessages.php?webtag=EE&msg=872.1">1-2</a>  3-11</p> <h4><a href="lthread_list.php?webtag=EE">Back to thread list</a> | <a href="llogout.php?webtag=EE">Login</a></h4> <h6>© 2026 <a href="http://www.beehiveforum.net/" target="_blank">Project Beehive Forum</a></h6> </body>