I think you'll find the better light was because the un-machined perspex rod had a polished surface. When you machined it down to 10mm, you lost all the internal surface reflection, so only axial light passed through. The 10mm would have worked better if you had polished it, although diameter control would have been difficult. Also, the more rod sticks out of the top of the holder, the more light is collected and passed down to the target.
I remember one of these when I was doing fine limit work at a college when I was studying production engineering. With one you could drill a hole to within one ten thousandth of an inch. The device we used was made one of the instrument makers of the day.
Enoct The o-ring can come off pretty easily with just a straight sided cylinder to hold it. If you tapered the recess inwards, the O-ring will actually seat into the taper and be less likely to come off easily. Or you could machine a o-ring groove in the reduced end to capture the -o-ring but leave enough protruding to give you the no-slip surface you desired John
Absolute quality work mate I really enjoyed the way you made it look easy I’m a beginner in machining I’ve made a few tools but I’m gonna give this one ago if you don’t mind thanks for sharing you work god bless P.s what was the optic material you used thanks
Hi Herman I did say how to do it , put the plastic rod in the chuck and use a sharp tool set to centre hight. I used a strip of paper as a feeler gauge between the tool and plastic. Then move the tool over the face turn the chuck 90 degrees and move the tool back. over the face. use a felt tip pen to add the colour to the mark.
Hi, Alan, I see you are using a good old Set-Tru chuck, the same model as I have. Have you ever done a video showing the use of it? I have read so much mis-information about using one, and I am sure, like me , you know how to use it properly. So many people believe you need to loosen and tighten screws in the back plate, and on my own they are not even accessible!
You are correct the three screws you adjust are the 3 in the body of the chuck at 90 degrees to the chuck axis. Not the 3 screws on the back of the chuck which hold the chuck to the mounting plate
As usual I was not very clear, I meant that there are sites saying to loosen the screws that hold the two parts of the chuck together and after adjusting the conical socket screw to re tighten. I believe on later models the screws they mention are accessible, by our model has them covered by the backplate.
OK Nathan I understand by the way I feature the chuck next week when I regrind the jaws, I found that one jaw was out. That explains why I had to reset the chuck every time I used it.
Nice project - Even a centering scope has problems - a normal drill bit will want to wonder, so the dimple made by the center punch matters. What I have been thinking about is how one could make this so it could be used with an automatic-center-punch? (Rennsteig makes my favorite). Instead of a punch - one could put a collar that holds the automatic-center-punch tip. Polishing the outside of the rod matters - turns it into a light-pipe.
I think you'll find the better light was because the un-machined perspex rod had a polished surface. When you machined it down to 10mm, you lost all the internal surface reflection, so only axial light passed through. The 10mm would have worked better if you had polished it, although diameter control would have been difficult.
Also, the more rod sticks out of the top of the holder, the more light is collected and passed down to the target.
Allen, Excellent project. Something else to add to my project list. Thanks, Randall in Kentucky, USA.
Thank you, I like the center finder.
Spot on Alan 😀, it'll make a nice project. Thanks.
A great idea and well executed
Nicely done Allan.
great job,
Alan this is a very nice video,very well explained.thank you for sharing
What a great project to make thanks Alan...
Neat project! Came out very nice!
I remember one of these when I was doing fine limit work at a college when I was studying production engineering.
With one you could drill a hole to within one ten thousandth of an inch.
The device we used was made one of the instrument makers of the day.
I have seen quite a few of these made and not one of them was silly enough to drill holes to allow light in.
Thank's for this Allen, I'll be making one of these asap!
Nice project Allen. Thank you for taking the time to make the video.
Thanks for watching!
Enoct
The o-ring can come off pretty easily with just a straight sided cylinder to hold it. If you tapered the recess inwards, the O-ring will actually seat into the taper and be less likely to come off easily. Or you could machine a o-ring groove in the reduced end to capture the -o-ring but leave enough protruding to give you the no-slip surface you desired
John
good idea John
Absolute quality work mate I really enjoyed the way you made it look easy I’m a beginner in machining I’ve made a few tools but I’m gonna give this one ago if you don’t mind thanks for sharing you work god bless
P.s what was the optic material you used thanks
Hi you can use perspex or acrylic rod
Good job Alan. Unfortunately you did't show how you applied the "red cross" , because that is the primal requirement for accuracy.
I think he said, plastic in the Chuck & score with a cross slide tool.
Hi Herman I did say how to do it , put the plastic rod in the chuck and use a sharp tool set to centre hight. I used a strip of paper as a feeler gauge between the tool and plastic. Then move the tool over the face turn the chuck 90 degrees and move the tool back. over the face. use a felt tip pen to add the colour to the mark.
You could use leds and button batteries for lighting.
where do you get the perspec rod from? Not available from amazon or master-car in the us
Hi Harry I had the perspex rod from Ebay in UK if no perspex try acrylic rod
McMaster-Carr has Acrylic rods - they list as "Comparable To Perspex, Lucite, etc"
www.mcmaster.com/plastics/color~clear/material~acrylic-plastic/
I like it but I'm sure it wouldn't be long before I whacked the perspex with the hammer.
Hi, Alan, I see you are using a good old Set-Tru chuck, the same model as I have. Have you ever done a video showing the use of it?
I have read so much mis-information about using one, and I am sure, like me , you know how to use it properly. So many people believe you need to loosen and tighten screws in the back plate, and on my own they are not even accessible!
You are correct the three screws you adjust are the 3 in the body of the chuck at 90 degrees to the chuck axis. Not the 3 screws on the back of the chuck which hold the chuck to the mounting plate
As usual I was not very clear, I meant that there are sites saying to loosen the screws that hold the two parts of the chuck together and after adjusting the conical socket screw to re tighten. I believe on later models the screws they mention are accessible, by our model has them covered by the backplate.
OK Nathan I understand by the way I feature the chuck next week when I regrind the jaws, I found that one jaw was out. That explains why I had to reset the chuck every time I used it.
Nice project - Even a centering scope has problems - a normal drill bit will want to wonder, so the dimple made by the center punch matters.
What I have been thinking about is how one could make this so it could be used with an automatic-center-punch? (Rennsteig makes my favorite). Instead of a punch - one could put a collar that holds the automatic-center-punch tip.
Polishing the outside of the rod matters - turns it into a light-pipe.
I've heard good feedback about the Woodglut plans.