On Thursday 03 September 2015 07:50:59 Peter Blodow wrote: > Hello Gene, > I have beeen following your description of what you were doing to you > machinery for weeks now, but I must confess that I have lost track on > the way, can't imagine in most cases what you are describing. How > about mailing a couple of picture of your goodies so I can re-read > your mails and get an image of your "new" shop equipment?
I'll take my camera out with me today, and post some pix on my web page in the next day or so. I am quite likely guilty of switching the referenced machine in the word "the" in the middle of a sentence, and I'm sure that can be confusing. In re the lathes control box, has two 2M542 stepper drivers in it, with a 4" 12 volt computer fan blowing on the heat sinks of each one. Power supply is a full wave bridge, choke input filter, with about 12k uf's filter caps. To get operating voltage for the fans, an LM317 was setup to output about 17 volts, which spins the fans right up. Then from that 17 volts, a 7805 makes 5 volts for the C1G BoB. Because the sink tab on an LM317 is also the center, output terminal, and therefor electrically hot, I had mounted it with an insulator kit using the thin si rubber insulator. No grease in deferrence to the si rubbers life expectancy. Bolted to half a square foot of 1/4" thick alu plate should have been enough heat sinking, but apparently was not, particularly when, in the process of putting a pcb on the outside of the box to carry a 5 pack of 5 pin, 2.54 spaced plugs so that everything could be unplugged if I needed to move the lathe out and work on it, but I misswired the plug for the encoder creating a short on the 5 volt line from the BoB. Fairly close to instant toast for the LM317. But it did work for a couple years until the dummy sitting in this chair screwed up. I thought that LM317 was the last one in local captivity and ordered some switching buck switchers from China but they are still 10 days away. So finding a bag of 8 or 9 LM317's will rescue me till they arrive. Their improved efficiency will reduce the load on the motor supply transformer and should reduce the overall heat level in that box by at least 20 watts. But this will do in the meantime. In the meantime I used the same pwm driven servo amp that Pico sells for the spindle motor driver in the new mill, so what I learn about using a limit3 to reduce the brutality of a motor reversal will get taken back to the lathe, where I have 50 lines of hal code and about 7 code modules doing a much gentler reversal that results in several turns of overshoot from the position specified in the G33.1 command line. I added some more code to latch the spindles position when the motion module issued the reversal command, and when it had actually made a couple degrees of motion in the new direction. With a 20 lb chuck, and doing a rigid tap at 300 rpms, the overtravel was just short of 3.5 full turns of the chuck. Even with the limit3 to soften the turnaround, the mill can do that same reversal and get back to full speed in about 1 second, at 2500 rpms! So I am learning that A: Jons servo amp is one tough bit of gear, and B how to exploit it to do something that on the lathe would only have succeeded in burning up another of those plastic timing belt sprockets that I have probably burned up 20 of in the 15 years I had that piece of junk. But now I have on hand, a new head, with all metal backgears in it, and a conversion kit to change the chinese belt out for the much taller cogs XL belt, but it came from fleabay with a very small tooth count, 10 I think, and bored for the 8mm OEM motor shaft, but I had made a jackshaft to replace that motor, driven by a 3" polygroove pulley from the nominally 1" pulley on a treadmill motor. So I bought some 16 coggers with a 10mm bore to replace the 10 cogger that boring to 9mm destroyed, so now I need to make a new jackshaft with a 10mm nose for these sprockets. And I may have to order a longer XL belt if I can't lift the jackshaft enough to make this one fit. Realisticly, milling some off the top of the jackshaft frame would be quicker than obtaining the longer belt. On top of all that, the treadmill motor has now developed a rumble that says the load end bearing on the armature now has square balls in it. And the flywheel/fan/pulley I will have to remove to gain access for replacing it, is superglued to the motor shaft as its not a keyed drive, but screwed to the shaft, self tightening in the treadmill use, but I'm turning both ways so I glued it on. I hope I can get it hot enough to make the glue release. I noted yesterday that the fan has some wobble I had not noticed before, so its possible the shaft itself is bent, those polygrove belts don't slip when the chuck make a stop in about 2 degrees of rotation because the toolpost has tipped the whole carriage into the work, digging a ramp about 100 thou deep as it tips and stopping it in about 10 degrees of motor shaft rotation from 4000 rpms. That this rumble started after the last such instance is clue #2. The fix for that is to swap the rubber compound assembly for a 2x2x4 block of steel, which will allow me to bore the QC holders 10mm holddown bolthole at the right rear of the block, which in turn will place the cutting forces on the middle of the carriage as opposed to hanging off the front, making the right edge of the carriage lift a thou, tipping the tool into the work to start the the whole show all over again. Or a new lathe big enough to do what I ask this one to do. But the shops 2 layers of OSB flooring wouldn't handle that weight without picking it up and pouring a concrete slab under it. Now theres a word picture for you. :) That has me scanning fleabay for another motor, and becoming resigned to remaking the mount to the jackshaft. Sigh. As Guilda Radner was fond of saying, its always something... I'll get some newer pix & post them over the next 2-3 days. > Greetings > Peter > > Am 03.09.2015 12:59, schrieb Gene Heskett: > - snip - > > > So I might have the lathe fully functional by the end of the day > > again. Cheers, Gene Heskett > > --- > Diese E-Mail wurde von Avast Antivirus-Software auf Viren geprüft. > https://www.avast.com/antivirus > > > ---------------------------------------------------------------------- >-------- Monitor Your Dynamic Infrastructure at Any Scale With Datadog! > Get real-time metrics from all of your servers, apps and tools in one > place. > SourceForge users - Click here to start your Free Trial of Datadog > now! http://pubads.g.doubleclick.net/gampad/clk?id=241902991&iu=/4140 > _______________________________________________ > Emc-users mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/emc-users Cheers, Gene Heskett -- "There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order." -Ed Howdershelt (Author) Genes Web page <http://geneslinuxbox.net:6309/gene> ------------------------------------------------------------------------------ Monitor Your Dynamic Infrastructure at Any Scale With Datadog! Get real-time metrics from all of your servers, apps and tools in one place. SourceForge users - Click here to start your Free Trial of Datadog now! http://pubads.g.doubleclick.net/gampad/clk?id=241902991&iu=/4140 _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
