[Emc-users] Parport driver max expected frequency
Hello to all. I need to control a screw with an encoder mounted on it. Calculating the max rpm and the resolution I want I need a 25 khz read response for the encoder. I remember reading somewhere the maximum expected frequency of the parport software driver to read an input but I don't remember where. I would like to know please if any of you have an approximation of the frequency, because If this works I can save some money. If not, I would have to buy dedicated hardware. Thanks as always! -- *Leonardo Marsaglia*. -- October Webinars: Code for Performance Free Intel webinars can help you accelerate application performance. Explore tips for MPI, OpenMP, advanced profiling, and more. Get the most from the latest Intel processors and coprocessors. See abstracts and register http://pubads.g.doubleclick.net/gampad/clk?id=60133471iu=/4140/ostg.clktrk ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Parport driver max expected frequency
On 09/30/2013 12:05 PM, Leonardo Marsaglia wrote: Hello to all. I need to control a screw with an encoder mounted on it. Calculating the max rpm and the resolution I want I need a 25 khz read response for the encoder. I remember reading somewhere the maximum expected frequency of the parport software driver to read an input but I don't remember where. I would like to know please if any of you have an approximation of the frequency, because If this works I can save some money. If not, I would have to buy dedicated hardware. The port, itself, has no frequency limit. It takes about 1 us to read the legacy ports, and the motherboard puts the CPU in a wait state while it is doing it. But, reading a single register of the parport hardware will just take about 1 us, at the lowest level. The hal_parport driver is fairly efficient, and you only need one instance of the software encoder component should also be fairly efficient. If you need to detect position every 25 us, this could be a problem. If you just want to be sure that encoder counts are not lost, then this should work fine. Later motherboards with PCI-connected parports are a bit faster. You should be able to run a 25 us (25000 ns) base thread on a good CPU. Jon -- October Webinars: Code for Performance Free Intel webinars can help you accelerate application performance. Explore tips for MPI, OpenMP, advanced profiling, and more. Get the most from the latest Intel processors and coprocessors. See abstracts and register http://pubads.g.doubleclick.net/gampad/clk?id=60133471iu=/4140/ostg.clktrk ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Parport driver max expected frequency
Hello Jon and thanks for the quick answer. I was affraid that it would be on the limit. I guess I'm going to use a 5i20 to read it. I have one machine using it so I can test it with the TTL encoder and see how it works. Do you know if the 6i25 is already supported by LinuxCNC? I know that hostmot 2 works with it, but I don't know if there is support for that particular card on LinuxCNC. Leonardo. 2013/9/30 Jon Elson el...@pico-systems.com On 09/30/2013 12:05 PM, Leonardo Marsaglia wrote: Hello to all. I need to control a screw with an encoder mounted on it. Calculating the max rpm and the resolution I want I need a 25 khz read response for the encoder. I remember reading somewhere the maximum expected frequency of the parport software driver to read an input but I don't remember where. I would like to know please if any of you have an approximation of the frequency, because If this works I can save some money. If not, I would have to buy dedicated hardware. The port, itself, has no frequency limit. It takes about 1 us to read the legacy ports, and the motherboard puts the CPU in a wait state while it is doing it. But, reading a single register of the parport hardware will just take about 1 us, at the lowest level. The hal_parport driver is fairly efficient, and you only need one instance of the software encoder component should also be fairly efficient. If you need to detect position every 25 us, this could be a problem. If you just want to be sure that encoder counts are not lost, then this should work fine. Later motherboards with PCI-connected parports are a bit faster. You should be able to run a 25 us (25000 ns) base thread on a good CPU. Jon -- October Webinars: Code for Performance Free Intel webinars can help you accelerate application performance. Explore tips for MPI, OpenMP, advanced profiling, and more. Get the most from the latest Intel processors and coprocessors. See abstracts and register http://pubads.g.doubleclick.net/gampad/clk?id=60133471iu=/4140/ostg.clktrk ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users -- *Leonardo Marsaglia*. -- October Webinars: Code for Performance Free Intel webinars can help you accelerate application performance. Explore tips for MPI, OpenMP, advanced profiling, and more. Get the most from the latest Intel processors and coprocessors. See abstracts and register http://pubads.g.doubleclick.net/gampad/clk?id=60133471iu=/4140/ostg.clktrk ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] polyurethane resin casting
I've made quite a few resin molds, I was working as a prototype technician once upon a time and made a lot of parts in resin. We did both silicone and metal molds, but we never poured the resin manually. I used a large vacuum oven with mixing equipment inside, the internal dimensions were like a large kitchen oven, much like the american sized ovens were you can fit a turkey. Resin and hardener were placed in separate cups, vacuum applied, the hardener was poured into the resin under mixing and after 30 seconds of mixing it was slowly poured into the mold. It was a small mixing machine that did everything automatically inside the chamber, the only thing I had to do was to put the components in their cups and set the mixing/pouring parameters and close the hatch. As the mixing and pouring happened in an air free mold, every run came out perfect. i could make really gnarly molds with back angles and pockets and it didn't matter. Perfect every time. I have tried to get my hands on such vacuum chamber with no success, but it shouldn't be much of a problem to make one. /Sven 2013/9/30 Erik Friesen e...@aercon.net I have looked at similar machines, but 1 oz is about 4 or 5 oz too little. I tried some pressure casting, it seemed to work. However, a day later little surface bubbles are ruining some of the surface. It probably because the molds are platinum rtv, which caused inhibition in the ie-3075, which is possible per datasheet. The alternate 50 second gel time material is not doable to get in the tank soon enough. My vacuum system seemed like it was taking a long time to do its job, I was using one of the dessicators from bel-air http://www.belart.com/shop/42010-space-saver-vacuum-desiccator-140mm-white-base-p-42010.html?cPath=9 . I realized that the valve has a 1/16 inlet, so a quick drill has shortened the vacuum time about 2/3. I think I will try some method of using static mix pressure to pressurize the mold. On Sun, Sep 29, 2013 at 1:14 PM, Jack Coats j...@coats.org wrote: 30% hydrogen peroxide is normally available at hair dressers for bleaching hair. On Sun, Sep 29, 2013 at 11:30 AM, dave dengv...@charter.net wrote: On Sat, 2013-09-28 at 23:03 -0600, Gregg Eshelman wrote: On 9/28/2013 5:16 AM, Erik Friesen wrote: For the high speed vacuum, why not just use an external tank, with plumbing valve or equivalent to switch to whichever has highest vacuum? That's fine if you have the space and funds for a big tank, and a good vacuum pump. I bought an old but excellent condition Gast rotary vane vacuum pump, but haven't used it in some years since for the mold making and casting I do pressure has worked much better. Pulling a vacuum in a large tank takes quite a bit of time, unless you get a very high volume pump - and you'd best have a high volume bank balance to get one. ;-) Instead of one large tank some smaller ones can be ganged together with a manifold. Propane tanks with the valves removed so they can be hooked together with as large of pipe as possible will work, but getting the smelly stuff out can be a problem. I tried it with one tank, with the insides of the valve removed and opened up some with a drill to reduce restriction as much as I could. The stink would draw right through the vacuum pump and smell up the whole shop. mercaptans are soluble in sodium hydroxide soln; don't know the ideal concentration. Also Clorox should oxidize them but be careful about using on concentrated mercaptans due to rapid reaction rate. Dissolving them in sodium hydroxide and then oxidizing with hydrogen peroxide should work but the commonly available 3% peroxide may be a little wimpy. 30% works better but is hard to get and nasty to handle. YMMV HTH To sorta on-topic this, one of the tasks I plan to put my mill to is making prototypes of things in metal to use as masters for RTV molds to make plastic castings. -- October Webinars: Code for Performance Free Intel webinars can help you accelerate application performance. Explore tips for MPI, OpenMP, advanced profiling, and more. Get the most from the latest Intel processors and coprocessors. See abstracts and register http://pubads.g.doubleclick.net/gampad/clk?id=60133471iu=/4140/ostg.clktrk ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users -- October Webinars: Code for Performance Free Intel webinars can help you accelerate application performance. Explore tips for MPI, OpenMP, advanced profiling, and more. Get the most
Re: [Emc-users] polyurethane resin casting
Were you using aluminum? What type of draft did you use on the moulds? This is the aftermath of the pressure tank test. http://aercon.net/Public/pumppix/Air%20bubbled.JPG This is the static mix pressure test, not sure exactly why the top corner bubbled. http://aercon.net/Public/pumppix/Static%20pressured.JPG http://aercon.net/Public/pumppix/Static%20pressured%202.JPG On Mon, Sep 30, 2013 at 2:53 PM, Sven Wesley svenne.d...@gmail.com wrote: I've made quite a few resin molds, I was working as a prototype technician once upon a time and made a lot of parts in resin. We did both silicone and metal molds, but we never poured the resin manually. I used a large vacuum oven with mixing equipment inside, the internal dimensions were like a large kitchen oven, much like the american sized ovens were you can fit a turkey. Resin and hardener were placed in separate cups, vacuum applied, the hardener was poured into the resin under mixing and after 30 seconds of mixing it was slowly poured into the mold. It was a small mixing machine that did everything automatically inside the chamber, the only thing I had to do was to put the components in their cups and set the mixing/pouring parameters and close the hatch. As the mixing and pouring happened in an air free mold, every run came out perfect. i could make really gnarly molds with back angles and pockets and it didn't matter. Perfect every time. I have tried to get my hands on such vacuum chamber with no success, but it shouldn't be much of a problem to make one. /Sven 2013/9/30 Erik Friesen e...@aercon.net I have looked at similar machines, but 1 oz is about 4 or 5 oz too little. I tried some pressure casting, it seemed to work. However, a day later little surface bubbles are ruining some of the surface. It probably because the molds are platinum rtv, which caused inhibition in the ie-3075, which is possible per datasheet. The alternate 50 second gel time material is not doable to get in the tank soon enough. My vacuum system seemed like it was taking a long time to do its job, I was using one of the dessicators from bel-air http://www.belart.com/shop/42010-space-saver-vacuum-desiccator-140mm-white-base-p-42010.html?cPath=9 . I realized that the valve has a 1/16 inlet, so a quick drill has shortened the vacuum time about 2/3. I think I will try some method of using static mix pressure to pressurize the mold. On Sun, Sep 29, 2013 at 1:14 PM, Jack Coats j...@coats.org wrote: 30% hydrogen peroxide is normally available at hair dressers for bleaching hair. On Sun, Sep 29, 2013 at 11:30 AM, dave dengv...@charter.net wrote: On Sat, 2013-09-28 at 23:03 -0600, Gregg Eshelman wrote: On 9/28/2013 5:16 AM, Erik Friesen wrote: For the high speed vacuum, why not just use an external tank, with plumbing valve or equivalent to switch to whichever has highest vacuum? That's fine if you have the space and funds for a big tank, and a good vacuum pump. I bought an old but excellent condition Gast rotary vane vacuum pump, but haven't used it in some years since for the mold making and casting I do pressure has worked much better. Pulling a vacuum in a large tank takes quite a bit of time, unless you get a very high volume pump - and you'd best have a high volume bank balance to get one. ;-) Instead of one large tank some smaller ones can be ganged together with a manifold. Propane tanks with the valves removed so they can be hooked together with as large of pipe as possible will work, but getting the smelly stuff out can be a problem. I tried it with one tank, with the insides of the valve removed and opened up some with a drill to reduce restriction as much as I could. The stink would draw right through the vacuum pump and smell up the whole shop. mercaptans are soluble in sodium hydroxide soln; don't know the ideal concentration. Also Clorox should oxidize them but be careful about using on concentrated mercaptans due to rapid reaction rate. Dissolving them in sodium hydroxide and then oxidizing with hydrogen peroxide should work but the commonly available 3% peroxide may be a little wimpy. 30% works better but is hard to get and nasty to handle. YMMV HTH To sorta on-topic this, one of the tasks I plan to put my mill to is making prototypes of things in metal to use as masters for RTV molds to make plastic castings. -- October Webinars: Code for Performance Free Intel webinars can help you accelerate application performance. Explore tips for MPI, OpenMP, advanced profiling, and more. Get the most from the latest Intel processors and coprocessors. See abstracts and
Re: [Emc-users] Parport driver max expected frequency
On 09/30/2013 12:33 PM, Leonardo Marsaglia wrote: Hello Jon and thanks for the quick answer. I was affraid that it would be on the limit. I guess I'm going to use a 5i20 to read it. I have one machine using it so I can test it with the TTL encoder and see how it works. Do you know if the 6i25 is already supported by LinuxCNC? I know that hostmot 2 works with it, but I don't know if there is support for that particular card on LinuxCNC. Sorry, I don't use Mesa products, as they are my competitor. Jon -- October Webinars: Code for Performance Free Intel webinars can help you accelerate application performance. Explore tips for MPI, OpenMP, advanced profiling, and more. Get the most from the latest Intel processors and coprocessors. See abstracts and register http://pubads.g.doubleclick.net/gampad/clk?id=60134791iu=/4140/ostg.clktrk ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] polyurethane resin casting
How about trying a different resin? Call Smooth-On and see if they have any recommendations that may fit your needs. Or perhaps an epoxy might work better? There are many manufacturers of those. One that looks like they have some interesting products is West Systems. -- October Webinars: Code for Performance Free Intel webinars can help you accelerate application performance. Explore tips for MPI, OpenMP, advanced profiling, and more. Get the most from the latest Intel processors and coprocessors. See abstracts and register http://pubads.g.doubleclick.net/gampad/clk?id=60134791iu=/4140/ostg.clktrk ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] polyurethane resin casting
On Mon, 2013-09-30 at 18:23 -0600, Gregg Eshelman wrote: How about trying a different resin? Call Smooth-On and see if they have any recommendations that may fit your needs. Or perhaps an epoxy might work better? There are many manufacturers of those. One that looks like they have some interesting products is West Systems. West Systems is well thought of in the boating world. Nice easy ratio for catalyzing. Fairly long open times. Dave -- October Webinars: Code for Performance Free Intel webinars can help you accelerate application performance. Explore tips for MPI, OpenMP, advanced profiling, and more. Get the most from the latest Intel processors and coprocessors. See abstracts and register http://pubads.g.doubleclick.net/gampad/clk?id=60134791iu=/4140/ostg.clktrk ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users -- October Webinars: Code for Performance Free Intel webinars can help you accelerate application performance. Explore tips for MPI, OpenMP, advanced profiling, and more. Get the most from the latest Intel processors and coprocessors. See abstracts and register http://pubads.g.doubleclick.net/gampad/clk?id=60134791iu=/4140/ostg.clktrk ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] polyurethane resin casting
2013/10/1 Erik Friesen e...@aercon.net Were you using aluminum? What type of draft did you use on the moulds? Yes. Usually splitted molds or ejectors in the bottom that could be manually knock the piece out. Another simple trick is to drill a small hole and plug it with a tiny bit of clay at the mold side. Then you can pop the piece out with compressed air. Draft, depends on the part but with a ejector pin or two and a splitted mold you can go vertical. I recently made a few parts with no draft and molded in epoxy. http://farm8.staticflickr.com/7152/6686837519_9a8b65926b_z.jpg -- October Webinars: Code for Performance Free Intel webinars can help you accelerate application performance. Explore tips for MPI, OpenMP, advanced profiling, and more. Get the most from the latest Intel processors and coprocessors. See abstracts and register http://pubads.g.doubleclick.net/gampad/clk?id=60134791iu=/4140/ostg.clktrk ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] polyurethane resin casting
2013/10/1 Erik Friesen e...@aercon.net Were you using aluminum? What type of draft did you use on the moulds? Yes. Usually splitted molds or ejectors in the bottom that could be manually knock the piece out. Another simple trick is to drill a small hole and plug it with a tiny bit of clay at the mold side. Then you can pop the piece out with compressed air. Draft, depends on the part but with a ejector pin or two and a splitted mold you can go vertical. I recently made a few parts with no draft and molded in epoxy. http://farm8.staticflickr.com/7152/6686837519_9a8b65926b_z.jpg -- October Webinars: Code for Performance Free Intel webinars can help you accelerate application performance. Explore tips for MPI, OpenMP, advanced profiling, and more. Get the most from the latest Intel processors and coprocessors. See abstracts and register http://pubads.g.doubleclick.net/gampad/clk?id=60134791iu=/4140/ostg.clktrk ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
[Emc-users] Is this some kind of RPM counter?
That thing that looks like a small motor in serial. http://farm8.staticflickr.com/7421/10027375954_9ecca084b7_c.jpg /Sven -- October Webinars: Code for Performance Free Intel webinars can help you accelerate application performance. Explore tips for MPI, OpenMP, advanced profiling, and more. Get the most from the latest Intel processors and coprocessors. See abstracts and register http://pubads.g.doubleclick.net/gampad/clk?id=60134791iu=/4140/ostg.clktrk ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
[Emc-users] Holding current for a tool changer
I bought this tool changer from a guy who slaughtered a VMC. http://farm6.staticflickr.com/5550/10027456456_2434844618_c.jpg There is a vid here with the changer before he took it down. http://www.youtube.com/watch?v=8Smt54Ehh3k It has a pneumatic cylinder that locks the carousel when a TC occours, but there's nothing that holds the arm itself. On top of that there is a dampener in the end position that pushes the arm away if no force is applied. This leads me to believe that the motor that rotates the arm probably has some kind of holding current when a TC happens. Maybe in the resting position too. To complicate it even further, the end stop switch (approx sensor) is triggered before the dampener even touches the arm. I have an idea that the end switch tells the controller to go from moving to holding and the last centimetres are done with the energy of the arm itself. Possible? /Sven -- October Webinars: Code for Performance Free Intel webinars can help you accelerate application performance. Explore tips for MPI, OpenMP, advanced profiling, and more. Get the most from the latest Intel processors and coprocessors. See abstracts and register http://pubads.g.doubleclick.net/gampad/clk?id=60134791iu=/4140/ostg.clktrk ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Parport driver max expected frequency
On Mon, 30 Sep 2013, Leonardo Marsaglia wrote: Date: Mon, 30 Sep 2013 14:33:34 -0300 From: Leonardo Marsaglia leonardomarsagli...@gmail.com Reply-To: Enhanced Machine Controller (EMC) emc-users@lists.sourceforge.net To: Enhanced Machine Controller (EMC) emc-users@lists.sourceforge.net Subject: Re: [Emc-users] Parport driver max expected frequency Hello Jon and thanks for the quick answer. I was affraid that it would be on the limit. I guess I'm going to use a 5i20 to read it. I have one machine using it so I can test it with the TTL encoder and see how it works. Do you know if the 6i25 is already supported by LinuxCNC? I know that hostmot 2 works with it, but I don't know if there is support for that particular card on LinuxCNC. Yes the 6i25 is supported (it normally has 5I25 firmware installed so looks like a 5I25) Leonardo. Peter Wallace Mesa Electronics (\__/) (='.'=) This is Bunny. Copy and paste bunny into your ()_() signature to help him gain world domination. -- October Webinars: Code for Performance Free Intel webinars can help you accelerate application performance. Explore tips for MPI, OpenMP, advanced profiling, and more. Get the most from the latest Intel processors and coprocessors. See abstracts and register http://pubads.g.doubleclick.net/gampad/clk?id=60134791iu=/4140/ostg.clktrk ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Is this some kind of RPM counter?
It looks more like an auxiliary motor to run a cooling fan for the big motor. This is sometimes needed if the large motor is under speed control and running at low speed. Steve Stallings -Original Message- From: Sven Wesley [mailto:svenne.d...@gmail.com] Sent: Monday, September 30, 2013 9:32 PM To: Enhanced Machine Controller (EMC) Subject: [Emc-users] Is this some kind of RPM counter? That thing that looks like a small motor in serial. http://farm8.staticflickr.com/7421/10027375954_9ecca084b7_c.jpg /Sven -- October Webinars: Code for Performance Free Intel webinars can help you accelerate application performance. Explore tips for MPI, OpenMP, advanced profiling, and more. Get the most from the latest Intel processors and coprocessors. See abstracts and register http://pubads.g.doubleclick.net/gampad/clk?id=60134791iu=/414 0/ostg.clktrk ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users -- October Webinars: Code for Performance Free Intel webinars can help you accelerate application performance. Explore tips for MPI, OpenMP, advanced profiling, and more. Get the most from the latest Intel processors and coprocessors. See abstracts and register http://pubads.g.doubleclick.net/gampad/clk?id=60134791iu=/4140/ostg.clktrk ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
