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Metalworking (rec.crafts.metalworking) Discuss various aspects of working with metal, such as machining, welding, metal joining, screwing, casting, hardening/tempering, blacksmithing/forging, spinning and hammer work, sheet metal work. |
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#1
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Okay, you guys (gals?) have been answering my questions and solving my
problems for about 5 years now. Time for possible payback. Had to get a new roll of Mylar (ouch!) for the plotter. Now that I have plenty, I am willing to make "division strips" for any and all. Give me the diameter of your chuck (or any fixture), I will multiply by 3.141592 and print you a strip of Mylar (very high linear stability) with any divisions you desire. E.g., 360, 27, 231 etc. I can number the divisions, like on a scale. I can probably print two scales (back to back on the same side), on a single 1" strip. This plotter prints very accurately (HP design jet 600) Cost? Almost free. I send you the strip and you, after receipt, send me equivalent postage. If you want two strips, the weight is almost nothing. HELP! I need ideas for shipping. Product must be rolled and not folded. I need a source of cheap shipping tubes. I used to get 24"± tubes for about $1, but I lost my source. Office Max, etc, want about $2.50 per tube. Wife says use toilet paper tubes. I will check with post office to see if TP tubes are not too small. If they work I should be able to get by with less than 2 ounces. IDEAS FOR TUBES APPRECIATED. This offer expires in about 2 moths because sig. other will want plotter out of the living room and back in the shop. Email me direct with your diameter, etc. Ivan Vegvary |
#2
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On Fri, 03 Feb 2006 16:11:38 GMT, Ivan Vegvary wrote:
HELP! I need ideas for shipping. Product must be rolled and not folded. I need a source of cheap shipping tubes. How about a film canister, put inside a small mailer? How wide are the strips, and can they be rolled that tight? |
#3
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On Fri, 03 Feb 2006 16:11:38 GMT, "Ivan Vegvary"
wrote: Okay, you guys (gals?) have been answering my questions and solving my problems for about 5 years now. Time for possible payback. Had to get a new roll of Mylar (ouch!) for the plotter. Now that I have plenty, I am willing to make "division strips" for any and all. Give me the diameter of your chuck (or any fixture), I will multiply by 3.141592 and print you a strip of Mylar (very high linear stability) with any divisions you desire. E.g., 360, 27, 231 etc. I can number the divisions, like on a scale. I can probably print two scales (back to back on the same side), on a single 1" strip. This plotter prints very accurately (HP design jet 600) Cost? Almost free. I send you the strip and you, after receipt, send me equivalent postage. If you want two strips, the weight is almost nothing. HELP! I need ideas for shipping. Product must be rolled and not folded. I need a source of cheap shipping tubes. I used to get 24"± tubes for about $1, but I lost my source. Office Max, etc, want about $2.50 per tube. Wife says use toilet paper tubes. I will check with post office to see if TP tubes are not too small. If they work I should be able to get by with less than 2 ounces. IDEAS FOR TUBES APPRECIATED. This offer expires in about 2 moths because sig. other will want plotter out of the living room and back in the shop. Email me direct with your diameter, etc. Ivan Vegvary A friend and I were just discussing ways to know the orientation of a telescope's equatorial mount. One guy wants to get 12" to 15" brass gears made and use rotary encoders. That'd work, but I was thinking that it could also be done electro-optically with a pattern on a disc or strip. I'll ping him, see if he'd like to try this. I can generate a pattern in AutoCAD and save it as a .dwg file (R-12), .dxf (R-12) or adobe .pdf but I have no way of accurately printing it. I wish I could figure out how those Chinese calipers get .0005" resolution. I took one apart. The features on the capacitive scale and reader are not nearly that small: the reader's strips are on ..025" centers and the scale's features are .100" wide with spaces between them that look like they were routed with an .0125" dia (might be 0.5 mm dia) endmill. |
#4
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"Don Foreman" wrote in message A friend and I were just discussing ways to know the orientation of a telescope's equatorial mount. One guy wants to get 12" to 15" brass gears made and use rotary encoders. That'd work, but I was thinking that it could also be done electro-optically with a pattern on a disc or strip. Don, generate your Acad dwg, or I could do same. Be more than happy to plot it for you. Ivan |
#5
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Heh.. film cannister. I was wondering a few days ago how I'm
going to get supplies of those. They're becoming rare! Maybe he should use cigar boxes. Dave Hinz wrote: How about a film canister, put inside a small mailer? How wide are the strips, and can they be rolled that tight? |
#6
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HELP! I need ideas for shipping. Product must be rolled and not folded. I need a source of cheap shipping tubes. I used to get 24"± tubes for about $1, but I lost my source. Office Max, etc, want about $2.50 per tube. Wife says use toilet paper tubes. I will check with post office to see if TP tubes are not too small. If they work I should be able to get by with less than 2 ounces. IDEAS FOR TUBES APPRECIATED. People that make fireworks use cardboard tubes that are pretty cheap. |
#7
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Don Foreman wrote:
I wish I could figure out how those Chinese calipers get .0005" resolution. The resolution is even higher. It is 1" / 20480. Theoretical. I get a few 1/1000mm out of them with overshampling and averaging. I took one apart. The features on the capacitive scale and reader are not nearly that small: the reader's strips are on .025" centers and the scale's features are .100" wide with spaces between them that look like they were routed with an .0125" dia (might be 0.5 mm dia) endmill. Have you seen what I have added to my HP in the meantime? I didn't describe how the electronics work*). But I have put a lot of material how the signals look like and about the mechanical arrangement of the couppling and shielding caps. See: http://www.motor-manufaktur.de/werkstatt/09_yadro/part_1.html *) Because I don't know. I have only a vague picture of it: It works with the vernier principle and it seems that it does enhance resolution by messuring the coupled voltage. I _guess_. Still have to laugh when I get remembered how much fun it was to use the HP-54645D Mixed signal scope. :-) Geee, and they sayed that I can keep it as long as I want. What a gem! BTW: Hopefully at the end of this month, kits for my digital scales interface will be available. Nick -- Motor Modelle // Engine Models http://www.motor-manufaktur.de DIY-DRO - YADRO - Eigenbau-Digitalanzeige |
#8
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"Mike Berger" wrote in message ... Heh.. film cannister. I was wondering a few days ago how I'm going to get supplies of those. They're becoming rare! Maybe he should use cigar boxes. Nah... you can still get them by the Hefty Bag full at any full-service film processing center. Some amateur pyrotechnicians make tiny aerial shells with them. LLoyd |
#9
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On Fri, 03 Feb 2006 12:18:10 -0600, Mike Berger wrote:
Heh.. film cannister. I was wondering a few days ago how I'm going to get supplies of those. They're becoming rare! Maybe he should use cigar boxes. I've got 2 ammo cans full of 'em, but as such, I'm getting low (film cans, not cigar boxes). |
#10
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On Fri, 03 Feb 2006 18:03:02 GMT, "Ivan Vegvary"
wrote: "Don Foreman" wrote in message A friend and I were just discussing ways to know the orientation of a telescope's equatorial mount. One guy wants to get 12" to 15" brass gears made and use rotary encoders. That'd work, but I was thinking that it could also be done electro-optically with a pattern on a disc or strip. Don, generate your Acad dwg, or I could do same. Be more than happy to plot it for you. Ivan Cool. I'll see if the guy responds. If he does, I'd be glad to send you a mailing tube with stamps on it. Just peel off the outer address label. |
#11
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Don Foreman wrote:
On Fri, 03 Feb 2006 18:03:02 GMT, "Ivan Vegvary" wrote: "Don Foreman" wrote in message A friend and I were just discussing ways to know the orientation of a telescope's equatorial mount. One guy wants to get 12" to 15" brass gears made and use rotary encoders. That'd work, but I was thinking that it could also be done electro-optically with a pattern on a disc or strip. Don, generate your Acad dwg, or I could do same. Be more than happy to plot it for you. Ivan Cool. I'll see if the guy responds. If he does, I'd be glad to send you a mailing tube with stamps on it. Just peel off the outer address label. As a word of advice onthe encoding, look up "Gray code" techniques. the reason it's important is that in Gray code, only one bit changes at any transition. That makes reading the position a lot less prone to reading errors. Just a thought... Richard |
#12
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Richard Lamb writes:
As a word of advice onthe encoding, look up "Gray code" techniques. the reason it's important is that in Gray code, only one bit changes at any transition. Encoders these days are incremental quadrature feeding a counter, not Gray code. Gray code made sense when the electronics were costly, but not so today. |
#13
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Ivan Vegvary writes:
I need a source of cheap shipping tubes. Dumpster behind carpet shop or printing plant. But I think you'd be better off coiling it into something like a 5 x 5 x 5 inch box at $0.18/each. http://www.uline.com/ProductDetail.asp?model=S-4050 If you really need tubes: http://www.uline.com/Browse_Listing_3656.asp |
#14
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Ivan Vegvary wrote:
Okay, you guys (gals?) have been answering my questions and solving my problems for about 5 years now. Time for possible payback. HELP! I need ideas for shipping. Product must be rolled and not folded. I need a source of cheap shipping tubes. I used to get 24"± tubes for about $1, but I lost my source. Office Max, etc, want about $2.50 per tube. Wife says use toilet paper tubes. I will check with post office to see if TP tubes are not too small. If they work I should be able to get by with less than 2 ounces. IDEAS FOR TUBES APPRECIATED. Ivan Vegvary Carpet store dumpster - full of tubes. _-_-bear |
#15
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"Richard J Kinch" wrote in message . .. Ivan Vegvary writes: I need a source of cheap shipping tubes. Dumpster behind carpet shop or printing plant. Richard, thanks, I've tried carpet tubes, way way too heavy. But your link to 5" cube boxes is the obvious answer. Thanks for the link. Ivan |
#16
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Richard J Kinch wrote:
Richard Lamb writes: As a word of advice onthe encoding, look up "Gray code" techniques. the reason it's important is that in Gray code, only one bit changes at any transition. Encoders these days are incremental quadrature feeding a counter, not Gray code. Gray code made sense when the electronics were costly, but not so today. Ah. I guess I've dated myself. Just wondering if I got lucky... Richard |
#17
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Richard Lamb wrote:
Richard J Kinch wrote: Richard Lamb writes: As a word of advice onthe encoding, look up "Gray code" techniques. the reason it's important is that in Gray code, only one bit changes at any transition. Encoders these days are incremental quadrature feeding a counter, not Gray code. Gray code made sense when the electronics were costly, but not so today. Ah. I guess I've dated myself. Just wondering if I got lucky... Richard Gray code was used on aircraft reporting altimeters because it was easy to determine an error in coding. If any one bit was out the thing would report wierd altitudes in sequence. John |
#18
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Why not small boxes.
If you don't need 24" why buy them. Post office has several sizes - but those are not high volume. (and a little pricey) Martin Martin Eastburn @ home at Lions' Lair with our computer lionslair at consolidated dot net NRA LOH & Endowment Member NRA Second Amendment Task Force Charter Founder Ivan Vegvary wrote: Okay, you guys (gals?) have been answering my questions and solving my problems for about 5 years now. Time for possible payback. Had to get a new roll of Mylar (ouch!) for the plotter. Now that I have plenty, I am willing to make "division strips" for any and all. Give me the diameter of your chuck (or any fixture), I will multiply by 3.141592 and print you a strip of Mylar (very high linear stability) with any divisions you desire. E.g., 360, 27, 231 etc. I can number the divisions, like on a scale. I can probably print two scales (back to back on the same side), on a single 1" strip. This plotter prints very accurately (HP design jet 600) Cost? Almost free. I send you the strip and you, after receipt, send me equivalent postage. If you want two strips, the weight is almost nothing. HELP! I need ideas for shipping. Product must be rolled and not folded. I need a source of cheap shipping tubes. I used to get 24"± tubes for about $1, but I lost my source. Office Max, etc, want about $2.50 per tube. Wife says use toilet paper tubes. I will check with post office to see if TP tubes are not too small. If they work I should be able to get by with less than 2 ounces. IDEAS FOR TUBES APPRECIATED. This offer expires in about 2 moths because sig. other will want plotter out of the living room and back in the shop. Email me direct with your diameter, etc. Ivan Vegvary ----== Posted via Newsfeeds.Com - Unlimited-Unrestricted-Secure Usenet News==---- http://www.newsfeeds.com The #1 Newsgroup Service in the World! 120,000+ Newsgroups ----= East and West-Coast Server Farms - Total Privacy via Encryption =---- |
#19
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John wrote:
Richard Lamb wrote: Richard J Kinch wrote: Richard Lamb writes: As a word of advice onthe encoding, look up "Gray code" techniques. the reason it's important is that in Gray code, only one bit changes at any transition. Encoders these days are incremental quadrature feeding a counter, not Gray code. Gray code made sense when the electronics were costly, but not so today. Ah. I guess I've dated myself. Just wondering if I got lucky... Richard Gray code was used on aircraft reporting altimeters because it was easy to determine an error in coding. If any one bit was out the thing would report wierd altitudes in sequence. John They were used a lot on simulators too, and the weird read outs were great for troubleshooting... |
#20
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On Fri, 03 Feb 2006 16:03:20 -0600, Richard J Kinch
wrote: Richard Lamb writes: As a word of advice onthe encoding, look up "Gray code" techniques. the reason it's important is that in Gray code, only one bit changes at any transition. Encoders these days are incremental quadrature feeding a counter, not Gray code. Gray code made sense when the electronics were costly, but not so today. Gray code is relevant to absolute encoders, not to incremental encoders. An absolute encoder will give correct position even if the encoder was moved during a power-down situation. However, a nonredundant n-bit binary sequence can be arranged so all adjacent states vary by only one bit, thus avoiding race conditions, and it is true that inexpensive silicon (e.g., a microcontroller or FPGA) can now easly convert those state codes to a monotonic sequence of values. Example: adjacent binary states from 0 to 7 would be 0,1,3,2,6,7,5,4. Elex can sort that out. It gets messier if there are 65,536 states (16 bits). Elex can still sort it out. Mitutoyo uses a really ingenious scheme for absolute position reading of their digital calipers. Google it if interested. It's explained (in patentese) in a patent assigned to Mitutoyo. I think the HF calipers may have ripped that off, don't recall when Mitutoyo's U.S. patent was dated. I think the HF digital calipers, at $16.99 on sale, are an incredibly good buy. I have both HF and Mitutoyo and I see no difference in accuracy, function, feel or finish between them. |
#21
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Don Foreman writes:
Gray code is relevant to absolute encoders, not to incremental encoders. An absolute encoder will give correct position even if the encoder was moved during a power-down situation. Quadrature encoders are both incremental and absolute by virtue of the index pulse, if you have cheap electronics, and you can tolerate homing in the application. |
#22
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Richard J Kinch wrote:
Encoders these days are incremental quadrature feeding a counter, not Gray code. Gray code made sense when the electronics were costly, but not so today. QEs are nothing more than 2 bit Gray code (only one bit changes) connected to a counter. Nick -- Motor Modelle // Engine Models http://www.motor-manufaktur.de DIY-DRO - YADRO - Eigenbau-Digitalanzeige |
#23
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Nick Müller wrote:
QEs are nothing more than 2 bit Gray code (only one bit changes) connected to a counter. Nick That is an intresting "observation". I never thought of that. :-) ...lew... (retired electronics engineer) |
#24
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In article ,
Don Foreman wrote: Mitutoyo uses a really ingenious scheme for absolute position reading of their digital calipers. Google it if interested. It's explained (in patentese) in a patent assigned to Mitutoyo. I think the HF calipers may have ripped that off, don't recall when Mitutoyo's U.S. patent was dated. I think the HF digital calipers, at $16.99 on sale, are an incredibly good buy. I have both HF and Mitutoyo and I see no difference in accuracy, function, feel or finish between them. The patent number is 6,005,387, according to the back of my Mitutoyo CD-8"PS. To get a pdf copy of the patent, go to http://www.pat2pdf.org. No gray codes are involved. It's an incremental encoder, and measures distance from the last zeroing. Joe Gwinn |
#25
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Lew Hartswick wrote:
That is an intresting "observation". I never thought of that. :-) I meant: looking at the signal. Of course QEs and Gray-code are two different things. Nick -- Motor Modelle // Engine Models http://www.motor-manufaktur.de DIY-DRO - YADRO - Eigenbau-Digitalanzeige |
#26
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Joseph Gwinn wrote:
The patent number is 6,005,387, according to the back of my Mitutoyo CD-8"PS. To get a pdf copy of the patent, go to http://www.pat2pdf.org. Thanks for that link/hint! Nick -- Motor Modelle // Engine Models http://www.motor-manufaktur.de DIY-DRO - YADRO - Eigenbau-Digitalanzeige |
#27
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"Ivan Vegvary" wrote:
snip HELP! I need ideas for shipping. Product must be rolled and not folded. I need a source of cheap shipping tubes. I used to get 24"± tubes for about $1, but I lost my source. Office Max, etc, want about $2.50 per tube. Wife says use toilet paper tubes. I will check with post office to see if TP tubes are not too small. If they work I should be able to get by with less than 2 ounces. IDEAS FOR TUBES APPRECIATED. Ivan, If you ship US Post Office Priority mail, you can get boxes for free. Here is a link to triangular "tubes": http://shop.usps.com/cgi-bin/vsbv/po...=24&passFlag=4 First page of lots of Priority mail stuff: http://shop.usps.com/cgi-bin/vsbv/po.../Priority+Mail The boxes, envelopes and labels are free. The USPO delivers them to your door for free. (One envelope already has Priority Mail postage paid and of course these are not free) -- Jim |
#28
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#29
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Okay, had one taker and mailed a 360° layout for a 5" chuck this morning. I
put three copies on a strip of Mylar, gives him three chances to cut and paste on to his chuck. Surprisingly with a 5"x9" soft pack envelope and toilet paper tube, the whole thing weighed in at a little over 1/2 of an ounce. Very cheap to ship. Thanks to everybody for their shipping advice. Will change to film canisters as soon as I can scrounge up some more. Anybody else want a 5" diameter scale? Any other scales? Let me know. Ivan Vegvary |
#30
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No - maybe a field office supporting a local customer. Like I used to do in Austin.
Mitutoyo Institute of Metrology is in Aurora, Ill. US offices : Michigan (motor cars maybe?) Illinois (three sites) California (city of Industry) Martin - using his Handbook of Metrology version 1.1 :-) Martin Eastburn @ home at Lions' Lair with our computer lionslair at consolidated dot net NRA LOH & Endowment Member NRA Second Amendment Task Force Charter Founder Joseph Gwinn wrote: In article , (Nick Müller) wrote: Joseph Gwinn wrote: The patent number is 6,005,387, according to the back of my Mitutoyo CD-8"PS. To get a pdf copy of the patent, go to http://www.pat2pdf.org. Thanks for that link/hint! Welcome. Interestingly, the inventor is a Swede (by the name) living in Seattle. Wonder what the story is. Does Mitutoyo have an R&D facility there? Joe Gwinn ----== Posted via Newsfeeds.Com - Unlimited-Unrestricted-Secure Usenet News==---- http://www.newsfeeds.com The #1 Newsgroup Service in the World! 120,000+ Newsgroups ----= East and West-Coast Server Farms - Total Privacy via Encryption =---- |
#31
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Just go to the US patent website and look it up.
Karl "Joseph Gwinn" wrote in message ... In article , Don Foreman wrote: Mitutoyo uses a really ingenious scheme for absolute position reading of their digital calipers. Google it if interested. It's explained (in patentese) in a patent assigned to Mitutoyo. I think the HF calipers may have ripped that off, don't recall when Mitutoyo's U.S. patent was dated. I think the HF digital calipers, at $16.99 on sale, are an incredibly good buy. I have both HF and Mitutoyo and I see no difference in accuracy, function, feel or finish between them. The patent number is 6,005,387, according to the back of my Mitutoyo CD-8"PS. To get a pdf copy of the patent, go to http://www.pat2pdf.org. No gray codes are involved. It's an incremental encoder, and measures distance from the last zeroing. Joe Gwinn |
#32
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In article ,
"everyman" wrote: Just go to the US patent website and look it up. That works, but doesn't yield a pdf file. For the record, the US patent website is at http://www.uspto.gov/patft/index.html. Joe Gwinn Karl "Joseph Gwinn" wrote in message ... In article , Don Foreman wrote: Mitutoyo uses a really ingenious scheme for absolute position reading of their digital calipers. Google it if interested. It's explained (in patentese) in a patent assigned to Mitutoyo. I think the HF calipers may have ripped that off, don't recall when Mitutoyo's U.S. patent was dated. I think the HF digital calipers, at $16.99 on sale, are an incredibly good buy. I have both HF and Mitutoyo and I see no difference in accuracy, function, feel or finish between them. The patent number is 6,005,387, according to the back of my Mitutoyo CD-8"PS. To get a pdf copy of the patent, go to http://www.pat2pdf.org. No gray codes are involved. It's an incremental encoder, and measures distance from the last zeroing. Joe Gwinn |
#33
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On Sat, 04 Feb 2006 00:04:24 -0600, Richard J Kinch
wrote: Don Foreman writes: Gray code is relevant to absolute encoders, not to incremental encoders. An absolute encoder will give correct position even if the encoder was moved during a power-down situation. Quadrature encoders are both incremental and absolute by virtue of the index pulse, if you have cheap electronics, and you can tolerate homing in the application. A once-per-rev index pulse is still ambiguous if the encoder goes thru more than one revolution in the travel range of the moving part, not an uncommon situation. A rotary encoder might well be geared up for higher resolution and accuracy. "Absolute" generally connotes being able to sense absolute position even after a power outage during which movement occurred one way or another. The absolute encoder knows immediately where it is without having to hunt for an index, a fiducial mark or a limit sense condition. |
#34
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Don Foreman wrote:
On Sat, 04 Feb 2006 00:04:24 -0600, Richard J Kinch wrote: Don Foreman writes: Gray code is relevant to absolute encoders, not to incremental encoders. An absolute encoder will give correct position even if the encoder was moved during a power-down situation. Quadrature encoders are both incremental and absolute by virtue of the index pulse, if you have cheap electronics, and you can tolerate homing in the application. A once-per-rev index pulse is still ambiguous if the encoder goes thru more than one revolution in the travel range of the moving part, not an uncommon situation. A rotary encoder might well be geared up for higher resolution and accuracy. "Absolute" generally connotes being able to sense absolute position ---------- even after a power outage during which movement occurred one way or another. The absolute encoder knows immediately where it is without having to hunt for an index, a fiducial mark or a limit sense condition. I would even go so far as to "always" . If it's not Absolute then it's only relative. :-) ...lew... |
#35
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According to Don Foreman :
On Sat, 04 Feb 2006 00:04:24 -0600, Richard J Kinch wrote: Don Foreman writes: Gray code is relevant to absolute encoders, not to incremental encoders. An absolute encoder will give correct position even if the encoder was moved during a power-down situation. Quadrature encoders are both incremental and absolute by virtue of the index pulse, if you have cheap electronics, and you can tolerate homing in the application. A once-per-rev index pulse is still ambiguous if the encoder goes thru more than one revolution in the travel range of the moving part, not an uncommon situation. A rotary encoder might well be geared up for higher resolution and accuracy. That may be so -- but I think that he may have been referring to the linear glass scales, which have one index pulse at one end, and quadrature encoding throughout the range. "Absolute" generally connotes being able to sense absolute position even after a power outage during which movement occurred one way or another. The absolute encoder knows immediately where it is without having to hunt for an index, a fiducial mark or a limit sense condition. I agree. And this makes it easy to recover from an interrupted CNC machining run. Enjoy, DoN. -- Email: | Voice (all times): (703) 938-4564 (too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html --- Black Holes are where God is dividing by zero --- |
#36
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