Re: [Emc-users] MESA 7i92H Saga
On Tue, 20 Aug 2019, John Dammeyer wrote: Date: Tue, 20 Aug 2019 12:47:12 -0700 From: John Dammeyer Reply-To: "Enhanced Machine Controller (EMC)" To: "'Enhanced Machine Controller (EMC)'" Subject: Re: [Emc-users] MESA 7i92H Saga Asking again. The only web link I found on this subject is 2 years old https://forum.linuxcnc.org/39-pncconf/32347-5i25-7i76-pin-axis-9-motor-pos-cmd-does-not-exist and their solution was not to use step/dir with the mesa board. So is anyone actually using something like a mesa 7i92 with step/dir to the spindle? Or can someone explain why axis.9 is defined and how LinuxCNC attaches to it? Thanks John I think the best way to do this is to use a working configuration and add the stepgen spindle control manually to the hal file. Its really not that complex to do by hand, and if the configurator doesn't not know how to make a step/dir controlled spindle and you add more stepgens by adding more axis you will just have a mess... 1. You don't need any more axis 2. You will need to enable 6 stepgens (0..5) in the driver load line 3. You need to setup stepgen 5 in velocity mode and scale it appropriately (scale will be pulses per turn if you link the stepgen rate to the spindle speed in RPS or 60*steps per turn if you use the RPM spindle speed) 4. Next you need to net the spindle speed from motion to stepgen 5s velocity command 5. You probable also should net stepgen 5's enable to motions spindle enable (so the step rate is forced to 0 when the spindle is disabled) Unless you have looked at a hal file these may seem pretty mysterious but here are some things that should help: http://linuxcnc.org/docs/html/hal/tutorial.html also man pages: man motion man hostmot2 To show actual pins/parameter/signals of a running LinuxCNC instance: halcmd show all > all.txt all.txt now has all pins,parameters, signals and functions of you current running LinuxCNC system, and can be a great copy/paste donor file so you dont need to guess at names Peter Wallace Mesa Electronics ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] MESA 7i92H Saga
On Sat, Aug 17, 2019 at 7:46 PM John Dammeyer wrote: > I thought I had set up a static IP. Although the odd thing is I can set the > mask to 255.255.255.0 and save it but when I get back into the dialog it > shows 24. Go figure. Right, because 255.255.255 is 24 ones followed by 8 zeros, and the netmasks are often described by how many bits they mask, denoted like so: 192.268.11.0 /24 ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] MESA 7i92H Saga
Asking again. The only web link I found on this subject is 2 years old https://forum.linuxcnc.org/39-pncconf/32347-5i25-7i76-pin-axis-9-motor-pos-cmd-does-not-exist and their solution was not to use step/dir with the mesa board. So is anyone actually using something like a mesa 7i92 with step/dir to the spindle? Or can someone explain why axis.9 is defined and how LinuxCNC attaches to it? Thanks John > -Original Message- > From: John Dammeyer [mailto:jo...@autoartisans.com] > Sent: August-18-19 1:30 PM > To: 'Enhanced Machine Controller (EMC)' > Subject: Re: [Emc-users] MESA 7i92H Saga > > Making progress. Dedicated Ethernet at the moment. > So far I've been able to see the charge-pump signal (stepper #04) show up > on DB25-17. Machine Enabled on DB-25-1. And all DB-25 pins for the 4 > motors show step pulses when they are jogged. Limit switches appear to > work. > > Haven't been able to get the PWM for the spindle working but that doesn�t > really matter at the moment because the Spindle AC Servo I bought takes > step/dir but not PWM. > > Instead I decided to add another step generator. Using pncconf it shows up > as StepGen #5 on pins 2,3 of the second parallel port named P1. The > problem is that the HAL file contains an axis.9 and as a result now LinuxCNC > won't run. > > ./Stretch-MESA.hal:306: Pin 'axis.9.motor-pos-cmd' does not exist > > Included with this posting is that error and the fragment of the HAL file that > defines all the spindle stuff. > > Everything for the stepgen.05 is fine until: > > # ---closedloop stepper signals--- > > net s-pos-cmd<= axis.9.motor-pos-cmd > net s-vel-cmd<= axis.9.joint-vel-cmd > net s-output => hm2_7i92.0.stepgen.05.velocity-cmd > net s-pos-fb <= hm2_7i92.0.stepgen.05.position-fb > net s-pos-fb => axis.9.motor-pos-fb > net s-enable <= axis.9.amp-enable-out > net s-enable => hm2_7i92.0.stepgen.05.enable > > As the hal and ini files were generated by pncconf what could cause this? > The axis steppers in the ini file are all defined as [AXIS_n] and the spindle > as > [SPINDLE_9] so I can see how an axis.9 might show up but no other > definition anywhere else. > Must be really simple but not obvious. > > Any ideas? > Thanks > John ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
[Emc-users] Fw: Emc-users Digest, Vol 156, Issue 87
From: emc-users-requ...@lists.sourceforge.net Sent: Tuesday, April 23, 2019 10:06 AM To: emc-users@lists.sourceforge.net Subject: Emc-users Digest, Vol 156, Issue 87 Send Emc-users mailing list submissions to emc-users@lists.sourceforge.net To subscribe or unsubscribe via the World Wide Web, visit https://lists.sourceforge.net/lists/listinfo/emc-users or, via email, send a message with subject or body 'help' to emc-users-requ...@lists.sourceforge.net You can reach the person managing the list at emc-users-ow...@lists.sourceforge.net When replying, please edit your Subject line so it is more specific than "Re: Contents of Emc-users digest..." Today's Topics: 1. Re: Servo reduction for gantry machine (Leonardo Marsaglia) 2. Re: Servo reduction for gantry machine (andy pugh) 3. Re: possibly good news for LinuxCNC (Gene Heskett) 4. Re: possibly good news for LinuxCNC (andy pugh) -- Message: 1 Date: Tue, 23 Apr 2019 10:14:01 -0300 From: Leonardo Marsaglia To: "Enhanced Machine Controller (EMC)" Subject: Re: [Emc-users] Servo reduction for gantry machine Message-ID: Content-Type: text/plain; charset="UTF-8" Well I think gluing a belt that long and wide with a proper jig or the right equipment could be a pain in the ass so I'm thinking about what Roland sugested. To machine the rack in wich the belt will be running. That way I can guarantee zero strecth and perfect engagament. I plan to make the racks (I may be can call it linear pulley? or infinite diameter pulley) out of 6061 aluminum. Then I can set them up like a normal rack but with the benefits of the servobelt system. I know this is not the quickest solution but I can machine the racks easily here in the shop so that's not a big problem. I'm also thinking about using the loop servobelt setup wich I think it's more convenient. Here's a picture of the setup: https://static1.squarespace.com/static/51396d24e4b01b4441c64c1f/51396d24e4b01b4441c64c2a/58f69bcff7e0ab3d0693dee9/1492556758738/2016-05-06+09.00.22.jpg. The only thing that I need to decide yet is the belt profile for the system, since I don't need the belts to fit into each other I can make the racks with any profile. I'm thinking about using HTD or GT2 but that's not decided yet. For the servo reduction I think the more suitable solution for me now are the planetary reducers. I found some that claim to have 5 arcmins of backlash so that's pretty accurate for my application. I plan to reduce the 750 W servos about 10 times to gain torque. Since the machine is going to be used to machine sheets of wood I think that will do the job. Also with that kind of reduction I can get rapids of about 45 meters/min wich is not bad. I still need to determine the final weight of the gantry with more accuracy (I estimate it will weight 300 kg aprox), I'll do that at the moment of purchasing the motors, and may be I'll increase the power to 1kw for the long Y axis. El mar., 23 abr. 2019 a las 5:05, Les Newell () escribi?: > I quite like the servo belt idea but I think it needs pretty accurate > clearance between the fixed and moving belts. Note that you can't clamp > the fixed belt. Clamps cover the teeth. If I was doing this I'd look > into polyurethane based adhesives. For instance the stuff they use to > bond in car windscreens sticks to just about anything and is very tough. > Devcon also make some impressive 2-part polyurethane rubber adhesives > that are very strong and adhere well to both rubber and metals. > > An unsupported belt that length will have significant stretch. I used > some kevlar belt specifically designed for positioning on a CNC drill > about 10 years ago. It was about 4m long and I saw positioning errors of > up to 0.5mm under load. As the spec was +/- 0.5mm on that job I just got > away with it after using a little bit of software compensation. On the > plus side it has been running 10+ years in a production environment with > no detectable wear. About the only issue I ever had with it was a pulley > that came loose. > > If you go for rack, look for 'precision' rack. The cheaper racks are > pretty rough. They aren't designed for accurate positioning. You > mentioned putting the feedback encoder on the pinion. This is a bad > idea. Any backlash in your gear train will make it really hard to tune > the motors and the motors will tend to oscillate when stationary or > moving slowly. This will put a lot of strain on the gear train. Gears > don't like repetitive reversal like that. I have worked on a lot of rack > driven routers and they all used encoders on the motors. Most used > direct drive to the pinion with huge motors or single stage belt > reduction. Are you looking at brushless motors? If so they will have > built in encoders. > > You are thinking of using 2 module 30 tooth pinions and your
Re: [Emc-users] Best option for modern RTAI distro
On Mon, 19 Aug 2019 at 22:46, Frank Tkalcevic wrote: > > So what are my options for building an RTAI kernel for a modern distro? Is this any help? https://github.com/andypugh/RTAI/releases (Click the "assets" arrow to see the file links) -- atp "A motorcycle is a bicycle with a pandemonium attachment and is designed for the especial use of mechanical geniuses, daredevils and lunatics." — George Fitch, Atlanta Constitution Newspaper, 1916 ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
