ed4copies
Local Chapter Manager
Last edited:
Wanna watch a boring movie?
- Thread starter ed4copies
- Start date
Signed-In Members Don't See This Ad
Signed-In Members Don't See This Ad
I think those blanks are made with a high degree of precision.
My inclination would be to use the 45-degree part of the square to mark corner-to-corner crosses on each end to determine and mark the center point on each end of the blank. . I actually draw the corner-to-corner lines from all 4 directions.
I do this all the time with "square" section blanks and even blanks which are off square. . I actually draw the corner-to-corner lines from all 4 directions. . If the blank is truly square, the cross lines coincide in pairs.
In fact, I don't use a square of the type you show, but rather a small square made expressly for this 45-degree purpose for pen-turners.
I then turn between the marked and shallowly drilled center points. . After rounding I drill as you show.
.... just my two-bits .... and my suggestion would not work well without the precision I am assuming.
My inclination would be to use the 45-degree part of the square to mark corner-to-corner crosses on each end to determine and mark the center point on each end of the blank. . I actually draw the corner-to-corner lines from all 4 directions.
I do this all the time with "square" section blanks and even blanks which are off square. . I actually draw the corner-to-corner lines from all 4 directions. . If the blank is truly square, the cross lines coincide in pairs.
In fact, I don't use a square of the type you show, but rather a small square made expressly for this 45-degree purpose for pen-turners.
I then turn between the marked and shallowly drilled center points. . After rounding I drill as you show.
.... just my two-bits .... and my suggestion would not work well without the precision I am assuming.
jttheclockman
Member
I think you are taking too much for granted Mal. Getting a straight line down a pattern is the more precise way so you are not relying on side dimensions.
I seen those blanks with bent in sides and all kinds of wacky casting. When working with patterns getting center is the key. Ed did good. A smaller machinist square would be helpful but what ever works.
John, my understanding is that these blanks are printed and not cast in the way you refer to them.
That is precisely why I used the word "precision" twice above.
I know that Ed "did good"; of course he did; he always does.
I was merely offering a possible alternative, which could be easier for some and which I have already acknowledged may not be applicable in situations where the blank is made with lower precision as you talk about.
That is precisely why I used the word "precision" twice above.
I know that Ed "did good"; of course he did; he always does.
I was merely offering a possible alternative, which could be easier for some and which I have already acknowledged may not be applicable in situations where the blank is made with lower precision as you talk about.
Last edited:
ed4copies
Local Chapter Manager
Before making the vid, I tried putting the blank in my scroll chuck, the hole would have been way off center, the end was rectangular, not square. That's what prompted me to make the video.
jttheclockman
Member
I could be off with the way the blank was made but I have seen those molds made with printers and then any color resin is added and when cast they deform. You maybe right on these type blanks but I still would not take a chance. Yor method works great for any blank that does not have a design like that in it and in fact I do it that way when finding centers. "PRECISION" is the key word when doing segmented blanks at any time of the process. Anyway nice video. My nit picking of the video was Ed doing the work on top of a movable lid of some sort when a nice solid table was under it:biggrin::biggrin::biggrin:
John, I too could be "off" in my understanding of the way in which the blank was made :biggrin::biggrin::biggrin:.
In any case, I was only presenting a method which might be applicable.
My method could very well be useful even though Ed says the blank has a rectangular cross section. . The crosses that I draw (actually scribe) on the blank ends would not coincide in the case of a rectangle. . In such a case you would have to rely slightly on your judgment to pinpoint the center of the blank end. . But eyeballing a line through the center of the pattern on the face of the blank is also an act of judgment.
The important thing is that Ed has pointed out the need to be very careful and as accurate as possible in establishing the center points on the ends of the blank and he has video'd a practical method for doing so.
He has also highlighted the advantages of "turning between centers" again in this video.
Thanks, Ed ! . Your continual attention to details like this, your support of the products you sell, and your support of your customers is much appreciated by those of us who are already your customers, as well as by many who may not yet be but will be soon due to your strong participation on IAP !!
In any case, I was only presenting a method which might be applicable.
My method could very well be useful even though Ed says the blank has a rectangular cross section. . The crosses that I draw (actually scribe) on the blank ends would not coincide in the case of a rectangle. . In such a case you would have to rely slightly on your judgment to pinpoint the center of the blank end. . But eyeballing a line through the center of the pattern on the face of the blank is also an act of judgment.
The important thing is that Ed has pointed out the need to be very careful and as accurate as possible in establishing the center points on the ends of the blank and he has video'd a practical method for doing so.
He has also highlighted the advantages of "turning between centers" again in this video.
Thanks, Ed ! . Your continual attention to details like this, your support of the products you sell, and your support of your customers is much appreciated by those of us who are already your customers, as well as by many who may not yet be but will be soon due to your strong participation on IAP !!
Don Rabchenuk
Member
The original print of the blank is done on a 3D printer and then a mold was made. P. Town Subbie (excuse the spelling if wrong) sells a mold made from the print. The first pour of white in this blank is done and after it cures it gets a second pour of the inside colors.
mark james
IAP Collection, Curator
Excellent video Ed. Tricky stuff - getting the center points for pattern retention. Even when I have confidence that the blank is square, I assume that it is not and use the method you displayed. Even then, I have a bucket of tapered patterns. (Although I do make use of this funky pink thingy...)
larryc
Member
Haven't tried any of those blanks but when I turn almost any blank I first round it off in the lathe using a Steb Center before I drill it.
https://www.amazon.com/Robert-Sorby-STB250-Original-Stebcentre/dp/B002RMH4SA
Expensive but I have had mine about 10 years so it has paid for itself.
I use it on all out of square blanks and especially curved, out of square Jack Daniels blanks.
https://www.amazon.com/Robert-Sorby-STB250-Original-Stebcentre/dp/B002RMH4SA
Expensive but I have had mine about 10 years so it has paid for itself.
I use it on all out of square blanks and especially curved, out of square Jack Daniels blanks.
ed4copies
Local Chapter Manager
Tim, on reanalysis of the blank, it appears they don't take into consideration the "bottom". If I sanded off the white bottom material, I BELIEVE (not certain) the blank would be square and would then correctly register center for drilling. HOWEVER, I don't know how structurally sound it would be, once the "bottom" is removed, so I would rather do it the way I have shown.
I have no argument with others who find an equally-accurate method that may be easier for them.
edicehouse
Member
Keep in mind there are 2 variations of how this blank is made. One is with a 3D printer doing the design, then after that is complete the other part is filled with resin and cast that way.
The other way is the design is poured into a mold, and that cures. Then the other part is filled with resin and cast.
wood128
Member
I would agree that the center should be obtained of the blank pattern. I would do that by Ed's method, but by using smaller and more accurate tools, such as a smaller straight edge and a scribe or sharp knife ( not a large ,thick square and pen or pencil ) . Also, the end 4 corners can be connected with hairline marks. Then, one of the most important steps is to get a centerpoint at each end of the blank where the lines intersect . Use a real sharp awl and small hammer to make the point for the lathe mounted centers. I also will use the drill press , small drill and vise, to just lightly start the centerpoint hole.
ed4copies
Local Chapter Manager
When I make videos, I try to use the tools I think most penmakers would have.
When I graduated with my BS degree, my first job was selling engineering drawing materials. (Bruning div. Addressograph Multigraph--no longer exists) I am very familiar with the fine line tools that were used, prior to CAD-CAM. But making a vid to show my depth of knowledge will not be terribly useful for a guy who doesn't really know what an adjustable triangle is. He DOES have a straightedge of some sort in his shop. This video demonstrates that what he has will work to get the job done.
When I graduated with my BS degree, my first job was selling engineering drawing materials. (Bruning div. Addressograph Multigraph--no longer exists) I am very familiar with the fine line tools that were used, prior to CAD-CAM. But making a vid to show my depth of knowledge will not be terribly useful for a guy who doesn't really know what an adjustable triangle is. He DOES have a straightedge of some sort in his shop. This video demonstrates that what he has will work to get the job done.