tag:blogger.com,1999:blog-6261993076995357307.post8441566013129171297..comments2023-11-05T06:16:56.961-05:00Comments on the Carpentry Way: La Menuiserie Study (II)Anonymoushttp://www.blogger.com/profile/14328401081765407624noreply@blogger.comBlogger8125tag:blogger.com,1999:blog-6261993076995357307.post-19688643856523638892016-07-18T11:53:09.237-04:002016-07-18T11:53:09.237-04:00Hi Brad,
you know the weak spot of SketchUp as we...Hi Brad,<br /><br />you know the weak spot of SketchUp as well as I do, eh?<br /><br />If you set the circle's facets to too low a number, it distorts the positions of the intersections too much. If you set it to too high a number of segments, then intersection of solids or components will not work properly a lot of times. <br /><br />I've settled on using 'circles' with 96 sides, as this seems to provide adequate accuracy, and no problem when intersecting parts.<br /><br />When I am taking a point off of a circle, I can zoom in and see whether I am meeting the middle of a segment (which is slightly less than the radius) or the arris of two segments meeting (which is the exact radius). If it is the middle of a segment, I draw a radius line through the point at the correct dimension, and go off of the tip of the radius line instead of the circle segment, if you follow.<br /><br />I've found the faceted circles mean that total precision cannot be achieve, but you can tell all the same if the geometry is correct or not. If a given intersection of line and circle is off by some tiny amount from a projection line (like 0.001mm) , then you can put it down to the issue of the segmented circle and generally have faith that the intersection is where it should be. If the line of projection is significantly off the line of the circle (by more than 0.1mm, say), then the procedure for the development/projection of the line is going to be at fault. <br /><br />If I am swinging an arc, and know the radius of that arc (which easy to measure in SketchUp), then I can first draw the projection line entering and exiting from that arc at the correct distance from the center of arc, and then draw the arc in afterwards, in which case the arc becomes more symbolic than an actual reference for a distance.<br /><br />In any case, even with a circle with 96 segments and the inherent uncertainty that brings, I think that Sketchup offers greater precision, with the capacity to zoom right in, than would pencil, compass and paper, using your unaided eye.<br /><br />~CAnonymoushttps://www.blogger.com/profile/14328401081765407624noreply@blogger.comtag:blogger.com,1999:blog-6261993076995357307.post-65819755454252599772016-07-18T10:33:14.821-04:002016-07-18T10:33:14.821-04:00How do you handle Sketchup's segmented circles...How do you handle Sketchup's segmented circles with the developed drawings?Anonymoushttps://www.blogger.com/profile/00846627293221631538noreply@blogger.comtag:blogger.com,1999:blog-6261993076995357307.post-61760659507710905972016-07-18T10:16:47.210-04:002016-07-18T10:16:47.210-04:00Phil,
appreciate the comment. It shouldn't ma...Phil,<br /><br />appreciate the comment. It shouldn't matter at all what the angle of rotation is, or the slope of the stick - either the geometrical drawing method works, or it does not. I've translated the text, and it makes no mention of a specific amount of rotation or a specific amount of slope for the piercing stick. If a specific slope or rotation were important, that would be mentioned or depicted. There is no 'butterfly effect' in this type of situation. Different slopes or rotations of the piercing stick will lead to different shapes and positions of mortises on the developed view, however, those variances will still lead to an outcome where the mortise allows for a square section stick of the correct size to pass through the post. With any variance in the axial rotation of the sloped stick, Report Line 'A' dimensions will also vary. <br /><br />Though there are no dimensions or angles provided on the text or plate 1 drawing, I do try to duplicate the drawing in the text as closely as I can, in the full light of the fact that it need not be a carbon copy. Thus, in my sketch, I still have the general arrangement of the sloped sticks arrises in the same relation to the post as the text does.<br /><br />Let's look at this idea a little more though, and see what might happen if I set the axial rotation of the piercing stick differently. If I rotated the piercing stick's section so that two of its faces were parallel to the slope, and two were therefore perpendicular to the slope, then logically the sloped stick would have its side faces plumb. That means that the plan drawing would present a print which was the same width as the stick, correct? However, if you consider how they project lines plumb from the sloped stick's section to form the Report Line 'A'', then it is immediately apparent that Report Line 'A' would be way too wide in such a case.<br /><br />In fact, the only case in which dropping plumb lines down from the arrises of the sloped stick section to make Report Line 'A' would be correct, would be where the stick were not sloped at all, but were horizontal. That would be the case where the lines are both plumb and are perpendicular to the slope of the stick. <br /><br />~CAnonymoushttps://www.blogger.com/profile/14328401081765407624noreply@blogger.comtag:blogger.com,1999:blog-6261993076995357307.post-85131978379259973942016-07-18T08:01:51.675-04:002016-07-18T08:01:51.675-04:00Hello Chris,
When I look at your result, it is as ...Hello Chris,<br />When I look at your result, it is as if you don't use the same angle of rotation(around the long axis) of the oblic piece. It seems also that a little translation will also make the book and you to be in accordance.Try to rotate it 5° to the right (when you look from left to right) and tranlate 2mm to the ..... good direction.<br />This kind of difference is very sensitive to these initial conditions (butterfly effect!). Have you got the data from the drawing or from the text. The relative position of the two parts comes from the drawing (generally in this kind of book) So it is difficult to reproduce it exactly as no information is given.<br />PhilAnonymousnoreply@blogger.comtag:blogger.com,1999:blog-6261993076995357307.post-23909194815401429222016-07-17T18:45:37.841-04:002016-07-17T18:45:37.841-04:00Hi Jamie,
thanks for the question. The free versi...Hi Jamie,<br /><br />thanks for the question. The free version has all of the functionality required for the sketches you see here. I have the pro version, however truth be told I rarely make use of the features for which you pay extra, like Layout. <br /><br />SketchUp is easy enough to learn how to use if you are starting from ground zero, and there are plenty of online (Youtube) tutorials you can check out to learn about various functions. Of the many functions built into Sketchup, I only use a portion myself, remaining a bit ignorant of the rest.<br /><br />~CAnonymoushttps://www.blogger.com/profile/14328401081765407624noreply@blogger.comtag:blogger.com,1999:blog-6261993076995357307.post-36648680354017631752016-07-17T17:37:35.237-04:002016-07-17T17:37:35.237-04:00Out of curiosity, are the "pro" features...Out of curiosity, are the "pro" features in SketchUp needed to do this work, or does the free version have all of the functionality?Anonymoushttps://www.blogger.com/profile/11714090611641801297noreply@blogger.comtag:blogger.com,1999:blog-6261993076995357307.post-6399981586987810342016-07-17T10:14:25.239-04:002016-07-17T10:14:25.239-04:00Roland,
I'm sure they are meant for drawing o...Roland,<br /><br />I'm sure they are meant for drawing on paper, and the means of proceeding you suggest is fine. I followed the text to the letter, starting with a plan view of the post.<br /><br />It is true that pencil and compass on paper has a certain feel, however if I had drawn it that way, and not actually laid out on wood and cut the pieces afterward (i.e., trusting completely in the text), I may not have discovered the error in the drawing. Having the ease of converting parts to 3D solids and confirming the 2D is a decided advantage I think, and no wood needs to be wasted. Also, some problems are easier to understand in 3D presentation - like cutting planes and their relationship to the parts on the floor.<br /><br />~CAnonymoushttps://www.blogger.com/profile/14328401081765407624noreply@blogger.comtag:blogger.com,1999:blog-6261993076995357307.post-50170525326299744102016-07-17T09:04:17.651-04:002016-07-17T09:04:17.651-04:00Exercises like these are really meant to be done o...Exercises like these are really meant to be done on a drawing table, I think.<br />Doing them that way would give a much better "feel" for the problem.<br /><br />If I had to to this, I would probably start with the center lines of the beams in side view. Then add the cross-sections of the respective beams on the center lines and proceed from there.Roland Smithhttp://rsmith.home.xs4all.nl/noreply@blogger.com