Keyboard Shortcuts
ctrl + shift + ? :
Show all keyboard shortcuts
ctrl + g :
Navigate to a group
ctrl + shift + f :
Find
ctrl + / :
Quick actions
esc to dismiss
Likes
- CAD-CAM-EDM-DRO
- Messages
Search
Re: DRO UPDATE
A. G. Eckstein
Terry,
Thanks for the words of encouragement. I need that and hope my little bit will help. I appreciate all the words that I have gotten on the site and as things progress, will try to update it. My long term goal is to get to the magical resolution of 0.0001" Actually, when I started the goal was to get accuracy to 0.001" with no backlash. I have far exceeded that but now it is a challange. Please let me know if I can help further. Art At 11:56 PM 02/28/2000 -0000, you wrote: From: "Terry May" <tmay@...>OLDER THAN DIRT Country Bubba (Actually the inventor of Country and Bubba) |
Re: DRO UPDATE
Terry May
Art,
Just wanted to tell I have been looking at your website, great pictures!! It really helps to visualize your setup as you have been discribing it on the list. I hope my DRO turns out to be half as good as yours. Just a quick update from my shop, I didn't have any 7414's or the decrete transistors that Steve Linsay used on my bench so I just played around a bit. Hooked up the encoders to my scope and checked out the waveform and then used a freq counter to do the same. All the encoders look like they are working fine so after work tomorrow I will pickup some chips at Radio Shack and put together a board. Concerning the discussions about wires/cables for the setup, I have lots of good parts left over from a dearly departed HP plotter. Amoung the goodies are all the wires used to move the pen holder, I think they will be long enough for the Y and Z axis' of my mill/drill if not the x axis. As I was playing with the encoder still hooked to the motor and reading it with the freq counter, I realized that just one channel out of a 1000 line encoder is a very nice division factor for a tach????. I think I will experiment with that a little also. Thanks again for sharing your experiences and your website! Terry May |
Re: re - Wonderboard PC interface
D.F.S.
Here is the design I threw together over the weekend. It is not final, it is a starting point only. There is some serious proofreading and checking to be done, but the basic interface is all there. I'm out of town this week. I DO have the design and the free design package with me (Easy Trax) The problem, is on my laptop, it can only run in 640X480 Mode and That is only shown as about a 4" X 6" rectangle. I'll be seriously limited in any REAL work on in. I can generate Postscript files of the board. I have no real way to generate an image given the current situation. If anyone can convert it, and post is someplace everyone can see it. let me know. My board is external to allow lots of board space to add custom circuits. 2. All input and output lines optoisolated.My design will use opto-isolators on the Board to PC interface. The Board to device interface should probably have them where damage is likely to happen as well. I'll need about 20, about 11 outbound and 9 inbound to the PC. 3. All optos socketed.I figured on socketing all the chips. 4. Selection of optos to allow interchangability between cheap and highThe 17 Cent parts BG Micro has looked plenty fast for anythink you will ever be able to spit out of a PC. 5. Sockets for optional SS relays on control lines.I have PC mount Simgle pole Double throw Relays I planned to use. I don't have sockets for them, but leaving holes for them along with a big array of space to install them and wire them where appropriate seems reasonable. What do you mean by "SS" relay? 6. On board 5V power.I figure the power and voltage requirements could vary tremendously depending on what a person wanted to install as far as external drive and interfaces. 110 or 220V are very likely to be used by some people. I figured on running AC straight to the box, and installing a surplus regulated power supply in the box, to leave all the options open. BG Micro, all electronics amd electronics goldmine all have a good selection of regulated power supplies for under 10 bucks, many are universal and can take anything from 90 - 250 Volts. 7. DB25 and screw term capable input - your choiceMine has a 2 row 26 pin connector to the computer. I have both 25 pin Din and 26 pin header connectors that simply crimp on ribon cable. Cut the cable to length and crimp the ends on. Of course everyone has the option to crimp whatever type of connector they want on the other end, even if it only extends to a connector mounted on the outside of the case. For the IO ports, I suggest dual connectors designed onto the board and people can install the type they want. Ie. a standard header, and holes to mount whatever readily avalible type of screw connector we select. I DO have some, but they are big, they take crim on spade type connectors. There are 3 lugs on each pin, they are held down by a screw, you could always remove the screw, toss the spades and connect the wire to the screw. 8. DB9 and screw term options for step/dir lines.Good idea, both designed onto the board, install whatever you want. 9. Screw terms for limits, e-stop and control outs.Same as above. My design would isolate all the PC lines at the point the enter from and exit to the PC. That should protect the PC. People could then isolate whatever IO From they board they considered necessart to protect the "Wonderboard". I would just as soon keep the board outside of the PC case. The ISA board will now work with Laptops, Microchannel PCs and many people would be afraid to install it inside the case anyway. All the Status and Diagnostic LEDs I have designed in, are mounted on the board itself. They would need to be run outside the PC and be mounted in a project case of some sort. Marc BTW. we are still under 10 bucks in parts. Granted, additions will add to that cost, but the basic board is under 10, plus a power supply, and whatever case people want. |
Re: Wonderboard PC interface original message!
jguenthe
Doug,
toggle quoted message
Show quoted text
So what if it gets it's 5v supply from the PC and requires another cable. It would seem to me that it could also get the 5v from a wall wort or some other source besides the host PC, therefore my vote is for a separate board and optional additional power supply. This way if space is a problem and your host is a laptop, you could get the 5v from another source. John Guenther -----Original Message-----
From: Harrison, Doug [mailto:dharrison@...] Sent: Monday, February 28, 2000 3:20 PM To: 'CAD_CAM_EDM_DRO@...' Subject: RE: [CAD_CAM_EDM_DRO] Wonderboard PC interface original message! From: "Harrison, Doug" <dharrison@...> Yes, we did get a little carried away with this one. I did manage to get plenty of feedback, so much that I printed it into a big stack of paper (more trees died) and took it home to read over the weekend. Thanks to all who contributed. I still have some more research to do before I commit to the final specification. Perhaps I should clarify my goals, which have not changed. The plan was to design a board with enough dummyproofing to use in industrial applications yet simple enough to be inexpensive and quick to build. I see the potential to use this board as an interface with several parallel port step motor programs. However, CNCPro is the one program I feel comfortable enough with to support for retrofits. That is the program I am designing the board for. This is not meant to be a negative comment on other software and I would be happy to work with developers of such programs if they wish to communicate their wants and needs. The info I have on most of them is inadequate to work with. The preliminary specification looks like this: 1. Separate board - not in PC. ( I may change this again if I succeed in solving the DC-DC converter issue. Shucks! I might even go both ways.) 2. All input and output lines optoisolated. 3. All optos socketed. 4. Selection of optos to allow interchangability between cheap and high speed optos for step/direction lines. 5. Sockets for optional SS relays on control lines. 6. On board 5V power. 7. DB25 and screw term capable input - your choice 8. DB9 and screw term options for step/dir lines. 9. Screw terms for limits, e-stop and control outs. Several of you noted that it should not be necessary to use optos to drive the step/dir amp inputs because most drivers are already optoisolated. Some of them aren't. But the main reason I stuck to my guns here is that there is a tendency (and I've seen it) to use the same 5V supply for the driver optos as is used for the limit switches. The drivers are protected but the parallel port is tied to the limit lines. Not good. The data out optos will be supplied by the PC 5V supply. Yes, I know this means more than just a single cable from the PC - another argument for making the board fit into a PCI/ISA slot. Doug -----Original Message----------------------------------------------------------------------------- GET A NEXTCARD VISA, in 30 seconds! Get rates as low as 0.0% Intro APR and no hidden fees. Apply NOW! ------------------------------------------------------------------------ Welcome to CAD_CAM_EDM_DRO@...,an unmoderated list for the discussion of shop built systems in the above catagories. To Unsubscribe, read archives, change to or from digest. Go to: Log on, and you will go to Member Center, and you can make changes there. For the FAQ, go to bill, List Manager |
Re: Wonderboard PC interface original message!
Harrison, Doug
Yes, we did get a little carried away with this one. I did manage to get
toggle quoted message
Show quoted text
plenty of feedback, so much that I printed it into a big stack of paper (more trees died) and took it home to read over the weekend. Thanks to all who contributed. I still have some more research to do before I commit to the final specification. Perhaps I should clarify my goals, which have not changed. The plan was to design a board with enough dummyproofing to use in industrial applications yet simple enough to be inexpensive and quick to build. I see the potential to use this board as an interface with several parallel port step motor programs. However, CNCPro is the one program I feel comfortable enough with to support for retrofits. That is the program I am designing the board for. This is not meant to be a negative comment on other software and I would be happy to work with developers of such programs if they wish to communicate their wants and needs. The info I have on most of them is inadequate to work with. The preliminary specification looks like this: 1. Separate board - not in PC. ( I may change this again if I succeed in solving the DC-DC converter issue. Shucks! I might even go both ways.) 2. All input and output lines optoisolated. 3. All optos socketed. 4. Selection of optos to allow interchangability between cheap and high speed optos for step/direction lines. 5. Sockets for optional SS relays on control lines. 6. On board 5V power. 7. DB25 and screw term capable input - your choice 8. DB9 and screw term options for step/dir lines. 9. Screw terms for limits, e-stop and control outs. Several of you noted that it should not be necessary to use optos to drive the step/dir amp inputs because most drivers are already optoisolated. Some of them aren't. But the main reason I stuck to my guns here is that there is a tendency (and I've seen it) to use the same 5V supply for the driver optos as is used for the limit switches. The drivers are protected but the parallel port is tied to the limit lines. Not good. The data out optos will be supplied by the PC 5V supply. Yes, I know this means more than just a single cable from the PC - another argument for making the board fit into a PCI/ISA slot. Doug -----Original Message----- |
Re: resonance and controllers
Harrison, Doug
toggle quoted message
Show quoted text
-----Original Message-----Some programs are not very good at accurately spacing the step pulses. The variation in timing shows up as harmonics and the effects are significant. Doug |
Re: DRO update
Joe Landau
Thanks for those pictures. That is really helpful!
toggle quoted message
Show quoted text
"A. G. Eckstein" wrote:
--
---------------------------------------------------------- Joe Landau jrl@... VersaForm Systems Corp. (408) 370 2662 591 W. Hamilton Ave., # 201 Campbell, CA 95008 Excellence in Medical Software www.versaform.com |
Re: posting
Jon Elson
PCSHAPER@... wrote:
From: PCSHAPER@...Is that a Shizouka ? Needless to say, it is costing me a fortune to keep it working! ThisI had a similar problem, using an Allen-Bradley, and then EMC with an ancient GE servo drive with resolvers. I replaced the resolvers with 1000 cycle/rev encoders, giving 4000 counts / rev. Multiply by 5 TPI, and that is a resolution of 20,000 counts/inch, or .00005". I got these encoders for $75 surplus, they are certainly around. I also would like to know if anyone has a schematic of the resolverThere are commercial resolver to quadrature interpolator/converters. They generally include all the stuff to excite the resolvers, amplify the signals and decode them. The only chip level stuff I know about is the Analog Devices 2S80 series, which are darned expensive chips. But, I'm sure other outfits know how to do this without the expensive AD parts. Old Qume daisy wheel printers had equivalent chips for their magnetic position encoders (inductosyns are kind of planar, ironless resolvers). I never got a print so I could figure out how to reuse these chips. If you want to do web searching, you might try keywords like interpolator and inductosyn, as well as resolver. But, if you have to purchase the interpolator boxes at new prices, it might be cheaper to get shaft encoders surplus, instead. Jon |
Re: returned, returned, returned
Bertho Boman
Hello Jan,
toggle quoted message
Show quoted text
We got your site URL and the site is very nice. I have been spending too much time there already. I assume you know but when you respond to someone on the list the message will be re-mailed to everyone, including your self. So seeing your own message is normal. Bertho Boman ========================
|
Re: DRO update
A. G. Eckstein
Bertho,
Thanks for the kudos; I tried, but am no real web artist or for that matter a photographer:) For me, the performace is more than adequate. Beats the devil out of the dials and backlash in the screws. Repeatability "seems" to be very good. I have tried moving the table quite quickly and also slowly. Have learned NOT to make rapid changes in movement or especially direction as the error rate jumps rapidly. The biggest problem seems to be when you "just start" to move and I believe this is causing pulsation in both directions causing the "jitters" to indicate errors. I have had to "relocate" some of the holes especially when changeing tools for the counterbore opeations and from apperances, seems to be right on. (Hell of a lot closer than when I was using the dials and lead screws for positioning!) Will try the last idea you propositioned sometime this week. (gotta work for the money to buy toys ya know!!) At 08:52 PM 02/27/2000 -0500, you wrote: From: Bertho Boman <boman@...>and how do you wipe the cable? and then quickly back how much error do you see? OLDER THAN DIRT Country Bubba (Actually the inventor of Country and Bubba) |
Re: DRO update
Bertho Boman
Nice Job!
toggle quoted message
Show quoted text
It is not clear form the pictures but how do you keep dirt out of the box and how do you wipe the cable? How is the performance? If you set up a careful "0" mark and then move quickly to the other end and then quickly back how much error do you see? If you do the same thing but slowly? Now try really slow in one direction and then quickly back? Bertho Boman ========================== From: "A. G. Eckstein" <axtein@...> As previously mentioned, I would try to get a web site up this weekend...... |
Re: Houston HMSC
Ward M.
Jan,
toggle quoted message
Show quoted text
Here it is: Ward M. ----- Original Message -----
From: <JanRwl@...> To: <CAD_CAM_EDM_DRO@...> Sent: Sunday, February 27, 2000 1:55 PM Subject: Re: [CAD_CAM_EDM_DRO] Houston HMSC From: JanRwl@...NOT get sent, nor even "saved" on this end! I quickly loose patience with"new sites" which make communication more difficult than turning on thediscussion of shop built systems in the above catagories. To Unsubscribe, read archives, change to or from digest. |
Re: Houston HMSC
Ward M.
No problem. Besides, I can use the text link you just sent.
toggle quoted message
Show quoted text
I wasn't trying to upset you... Sorry, Ward M. ----- Original Message -----
From: <JanRwl@...> To: <CAD_CAM_EDM_DRO@...> Sent: Sunday, February 27, 2000 1:55 PM Subject: Re: [CAD_CAM_EDM_DRO] Houston HMSC From: JanRwl@...NOT get sent, nor even "saved" on this end! I quickly loose patience with"new sites" which make communication more difficult than turning on thediscussion of shop built systems in the above catagories. To Unsubscribe, read archives, change to or from digest. |
messages
<<
This keeps coming back to ME! This is one detail of what I meant! Any attempt I make to REPLY to you at the address "FROM" results, only, it it being sent, instead, to ME, again!!!>> If you hit reply on a CAD_CAAM_EDM_DRO message it will be sent to the list, ans as a member of the list you will also recieve a copy of the message. To write to a person offlist, highlight that persons name, and click on that name and then copy it, then click on write and paste that name into the send to box, this typical AOL method, also copy and paste any quotes of the message the same way. An alternate method is to hit reply, delete the list name, and cut and paste the individuals name in the address box. Hope this helps, bill |
Re: Houston HMSC
Ward M.
Where ?!?!
toggle quoted message
Show quoted text
Ward M. ----- Original Message -----
From: "Jan Rowland" <JanRwl@...> To: <CAD_CAM_EDM_DRO@...> Sent: Sunday, February 27, 2000 1:31 PM Subject: [CAD_CAM_EDM_DRO] Houston HMSC From: "Jan Rowland" <JanRwl@...>discussion of shop built systems in the above catagories. To Unsubscribe, read archives, change to or from digest. |
to navigate to use esc to dismiss