Glad you enjoyed it. Hope you found something in it of use for you. If you really want to go down the Toolmaker's Chair route, you may have a job to find one these days. Should you find one it will not e cheap. People have really cottoned onto Ebay these days and try to milk it for all they can get. Regards.
Thanks for the video. I do as much of my work from the center of the work piece as possible. First using a manual edge finder then if necessary an indicator to fine tune. My edge finder is consistently within .001 - .002" . I have seen edge finders with weak springs and they are less accurate.
Hi Dave, Very interesting. different methods of edge finding. I do have a machinist chair that I got with some tools I bought. never knew what it was till now found it in a wood box in a drawer. Cheers
Yes they are Paul, just had a look on ebay, nothing today. What you need is to find a retired or deceased Tool and die guy and get hold of it. Good hunting. Regards.
Hi, Dave! As you mention near the end, repeatability is also an issue. It would be interesting if you took a couple of the more popular methods and did a bunch of repetitions to see how close they are each time...
Backlash should only be an issue if relying on the dials on the machine to place the spindle in any one place. DRO's tell us the reading of the placement no matter the direction of travel and no matter the amount of backlash. In fact you could use the DRO to determine the amount of backlash. If I have this wrong please tell me why? I need to learn as I am not formally trained.
Hello Kevin thanks for the view and your comment. Yes you are correct that with a DRO any backlash is irrelevant, but I was just pointing out to those who do not have a DRO that you must always know in which direction the backlash lies and how to apply it. I have another video which shows a method of achieving that. Regards.
very informative but im confused, How do you know the chair was the most accurate, when the dti and the optical gave the same readings. my thoughts are the chair is more likely to have errors machined in it rather than (although fiddley) the dti method with a known ground flat bar. keep up the great vids
Hello Paul, thanks for the view and question. The Toolmakers chair are a high end engineering instrument and are better than 0.0002" ( 2 Tenths ) accuracy, ( hence the cost ). You then also must take into account that when you have used it that any offset error indicated is Double the actual error as you were sweeping the chair. i.e. indicated dti difference 0.0005" is only an offset error of 0.00025" With you question asking how is a chair more accurate as the other readings were the same, my simple answer is that the chances of people having the optical one is very slim; secondly as you saw the Projected Edge method is very fiddly and time consuming compared to using a chair. So that is was why I made the comment that the chair was the most accurate. Apologies if you think that my statement was incorrect. Each to our own opinions. 😊 Take care. Best Wishes.
@@daveticehurst4191 Hiya Dave, thank you for your in depth reply. As it happens I used my edge finder today for a quick and dirty job, found both edges on Y used 1/2 function on my DRO started to spot it with my center drill and it looked wrong. I got my calipers out and measured from the spot to both edges and was 0.4mm out! how the hell I've managed that I don't know, but at least it wasn't a part for a Elon Musk space ship😁
I am not convinced that the TM chair is the most accurate. All methods are compared to the original pin and paper method which probably is the most inaccurate?? The TM chair is the closest to that. As a few other measurements are very close to each other they are either more likely to be accurate, as opposed to being the worst IMHO. Happy to be wrong here but need to know why. I am an amateur so quite likely wrong I guess.
Hi Kevin, thanks for the question. Toolmakers chairs are I imagine from the early 1900's way before the edge finders we have today and provided they were accurately made were a quick, easy and accurate way to find and edge other that the Projected edge method. The wiggler / wobbler came about in the USA in 1918 and was much cheaper. see link to Patent. patents.google.com/patent/US1300428 Personally I think that the results I obtained were in general quite correct, I was showing the different methods. The trouble with wigglers and mechanical edge finders is the Human eye and hand coordination / reaction, by the time your eye sees it move, you hand could still be moving so an error occurs. Have a look at the latest video where I do a repeatability on wiggler, mechanical and electronic edge finders. For general engineering tolerances 0.005" error is more than acceptable. Thanks for watching.
@@daveticehurst4191 Thanks Dave. I don't question the results you got, they seem pretty right to me. My actual intended point is to do with the comparison with the paper /pin method. I just think the other results highlight the inaccuracy of that method. ps In regard 0.005"as a poor result generally, but it is of course regarding the desired or required accuracy eh.
Fascinating - and thorough. I particularly appreciated the cautions about backlash. Thanks!
Glad that you found it helpful. Thanks for watching. Regards.
A very instructive video David. I like the fact the Old Timey method works so well. I love these videos of yours. Cheers Nobby
Glad you enjoyed it Nobby, keeps you from becoming bored with life 😊. Stay well. Best Wishes.
Great informative video Dave. I like the idea of the toolmakers chair. Regards Peter.
Glad you enjoyed it. Hope you found something in it of use for you. If you really want to go down the Toolmaker's Chair route, you may have a job to find one these days. Should you find one it will not e cheap. People have really cottoned onto Ebay these days and try to milk it for all they can get. Regards.
Thanks you for taking the time to do this, interesting stuff!
My pleasure Robert, glad that you found it interesting. Thanks for watching. Best Wishes.
Entertaining comparison of various methods of edge finding. Tc, Mike
Interesting and informative video . Thanks. I’m subscribed and looking forward to watching more of your videos.
Welcome aboard. Thanks for watching and I hope you will get some useful information from some of my other videos. Regards.
Great stuff, really enjoying your videos,
Glad to hear it! Thanks for watching. Kind Regards.
Thanks for the video. I do as much of my work from the center of the work piece as possible. First using a manual edge finder then if necessary an indicator to fine tune. My edge finder is consistently within .001 - .002" . I have seen edge finders with weak springs and they are less accurate.
Thanks for sharing David. Glad you found it of interest. Regards.
Hi Dave, Very interesting. different methods of edge finding. I do have a machinist chair that I got with some tools I bought. never knew what it was till now found it in a wood box in a drawer. Cheers
Hi Randy, clad you found out what your "Goodie in a wooden box " was for. Hope you get a chance to use it. Regards.
Hello Dave,
Another interesting video, thank you. The toolmakers chair is news to me, shame they are so rare and expensive.
Take care.
Paul,,
Yes they are Paul, just had a look on ebay, nothing today. What you need is to find a retired or deceased Tool and die guy and get hold of it. Good hunting. Regards.
Hi, Dave! As you mention near the end, repeatability is also an issue. It would be interesting if you took a couple of the more popular methods and did a bunch of repetitions to see how close they are each time...
Thanks for the view and suggestion. May do that now whilst the camera is still set up. Best Wishes.
Backlash should only be an issue if relying on the dials on the machine to place the spindle in any one place. DRO's tell us the reading of the placement no matter the direction of travel and no matter the amount of backlash. In fact you could use the DRO to determine the amount of backlash. If I have this wrong please tell me why? I need to learn as I am not formally trained.
Hello Kevin thanks for the view and your comment. Yes you are correct that with a DRO any backlash is irrelevant, but I was just pointing out to those who do not have a DRO that you must always know in which direction the backlash lies and how to apply it. I have another video which shows a method of achieving that. Regards.
very informative but im confused, How do you know the chair was the most accurate, when the dti and the optical gave the same readings. my thoughts are the chair is more likely to have errors machined in it rather than (although fiddley) the dti method with a known ground flat bar.
keep up the great vids
Hello Paul, thanks for the view and question. The Toolmakers chair are a high end engineering instrument and are better than 0.0002" ( 2 Tenths ) accuracy, ( hence the cost ). You then also must take into account that when you have used it that any offset error indicated is Double the actual error as you were sweeping the chair. i.e. indicated dti difference 0.0005" is only an offset error of 0.00025" With you question asking how is a chair more accurate as the other readings were the same, my simple answer is that the chances of people having the optical one is very slim; secondly as you saw the Projected Edge method is very fiddly and time consuming compared to using a chair. So that is was why I made the comment that the chair was the most accurate. Apologies if you think that my statement was incorrect. Each to our own opinions. 😊 Take care. Best Wishes.
@@daveticehurst4191 Hiya Dave, thank you for your in depth reply. As it happens I used my edge finder today for a quick and dirty job, found both edges on Y used 1/2 function on my DRO started to spot it with my center drill and it looked wrong. I got my calipers out and measured from the spot to both edges and was 0.4mm out! how the hell I've managed that I don't know, but at least it wasn't a part for a Elon Musk space ship😁
I am not convinced that the TM chair is the most accurate. All methods are compared to the original pin and paper method which probably is the most inaccurate?? The TM chair is the closest to that. As a few other measurements are very close to each other they are either more likely to be accurate, as opposed to being the worst IMHO. Happy to be wrong here but need to know why. I am an amateur so quite likely wrong I guess.
Hi Kevin, thanks for the question. Toolmakers chairs are I imagine from the early 1900's way before the edge finders we have today and provided they were accurately made were a quick, easy and accurate way to find and edge other that the Projected edge method. The wiggler / wobbler came about in the USA in 1918 and was much cheaper. see link to Patent.
patents.google.com/patent/US1300428
Personally I think that the results I obtained were in general quite correct, I was showing the different methods. The trouble with wigglers and mechanical edge finders is the Human eye and hand coordination / reaction, by the time your eye sees it move, you hand could still be moving so an error occurs. Have a look at the latest video where I do a repeatability on wiggler, mechanical and electronic edge finders. For general engineering tolerances 0.005" error is more than acceptable. Thanks for watching.
@@daveticehurst4191 Thanks Dave. I don't question the results you got, they seem pretty right to me. My actual intended point is to do with the comparison with the paper /pin method. I just think the other results highlight the inaccuracy of that method. ps In regard 0.005"as a poor result generally, but it is of course regarding the desired or required accuracy eh.