Chap 3A

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tkat@tkat.com
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Joined: Fri Mar 09, 2007 5:47 pm

Chap 3A

Post by tkat@tkat.com »

There's one feature I left out. That's the top 15° chamfer line. Wouldn' tbe hard except the center of the large arc won't show up on the dwg.My guess right now is that it can be done w/ layers --- as soon as I figure out how to use them. Howzabout bringing up a new layer, drawing a complete 1.849R cir. Constructing a perp line from elevation view to the C/L of the top view. Select Cir->ctr/point and constructing the inner cir.Trim it to the reqd arc and then move it back to the orig layer. That should work but it seems cumbersome.Any old hands out there care to stick in yer 2 cents worth? Particularly w/ instructions on how layers work.Yeah, I know 2.875-1.849=1.026 as the x co-ord ctr [Google calc] but I'd like to know how to do it via drafting only.Ciao, Tkat"Everybody crashes, some get back on, some don't, & some can't."
RowlandCarson
Posts: 2
Joined: Fri Dec 30, 2016 10:56 am

Re: Chap 3A

Post by RowlandCarson »

At 2005-04-26 14:19 -0700 tkat@tkat.com wrote: >There's one feature I left out. That's the top 15° chamfer line. >Wouldn' tbe hard except the center of the large arc won't show up on>the dwg. Tkat - here's my immediate response to the problem.Choose Graphic / Measure tool and measure the arc. As measure wants 2 elements to work on, I clicked first on the horizontal centre line. This gave the following in the floating Information window:Type LinesPen 1Intensity 100%Style DashdotColor 0, 0, 0Width 0.250Group 0Layer 1Scale 1:1x0 -3.441Inchy0 5.650Inchx1 0.521Inchy1 5.650InchLength 3.962InchAngle 0.000°-Type ArcPen 2Intensity 100%Style SolidlineColor 0, 0, 0Width 0.350Group 0Layer 1Scale 1:1xm -1.026Inchym 5.650Inchr 1.849InchStart angle 116.804°End angle 243.196°Contour 4.078Inch-Intersection Pointsxs1 0.822Inchys1 5.650Inchxs2 -2.875Inchys2 5.650InchDistance 0.000Inch------------------------------This is after I moved the plan up 4", of course, so all the y co-ordinates are offset by that amount.So, the centre of the arc is x = -1.026 & y = 5.650.Pick line type 3 (dash-dot) & draw a line at an angle, starting at -1.026, 5.65 with angle 90 and length 1.Trim it in freehand selection mode to look a nice length above & below the centre line.Switch to auto selection mode & draw a construction line from the top edge of the chamfer in the elevation, angle 90, length 5.Switch back to line type 1 (solid) & choose Arc defined by centre & radius.Click the centre point as drawn above.Click the intersection of the horizontal centre line and the construction line from the elevation drawn above, for the radius.Click the intersection of the vertical centre line and the upper and lower edges respectively for the start and end angles.Choose Trim / Split and split the arc at both top & bottom edge lines.Choose Delete / Delete Object and get rid of the end whiskers of the arc.Delete the 5" construction line between plan & elevation. >My guess right now is that it can be done w/ layers --- as soon as I>figure out how to use them. Howzabout bringing up a new layer, drawing>a complete 1.849R cir. Constructing a perp line from elevation view to>the C/L of the top view. Select Cir->ctr/point and constructing the>inner cir.>>Trim it to the reqd arc and then move it back to the orig layer. That>should work but it seems cumbersome.>>Any old hands out there care to stick in yer 2 cents worth? >Particularly w/ instructions on how layers work. I'm not really clear why you needed to go to another layer to do this; without actually trying this (agreed cumbersome!) procedure I don't see why it shouldn't work OK in the working layer. All you'd need to do would be delete the construction circle when you're finished with it. >Yeah, I know 2.875-1.849=1.026 as the x co-ord ctr [Google calc] but>I'd like to know how to do it via drafting only. In CADintosh, it's often much handier to use the calculating ability of the text entry line than to figure out an elegant geometrical way to do things! But stuff like an arc through 3 points is much easier to do with the CADintosh tool than it ever would be with pencil & paper.Having written that, here's a completely different way to skin this particular cat which is mostly "drafting".In the first place, instead of drawing an arc through 3 points, draw a complete circle thorugh 3 points instead. Draw the vertical line through the circle's centre using the auto select mode (hover near the circumference of the circle, not the centre) to place it. Now the centre of the circle is marked, you can convert it to an arc. Split the circle at the top and bottom edges of the part, then throw away the scrap t leave the arc. Draw the second arc, using the centre just produced and the construction line from the elevation as described above.I think on reflection this is a simpler and more elegant way to achieve the same result - but maybe all the natter above may answer other questions even if it isn't the right answer for this one!regardsRowland-- : Wilma & Rowland Carson <http://home.clara.net/rowil/>: <rowil@clara.net> ... that's Rowland with a 'w' ...
tkat@tkat.com
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Joined: Fri Mar 09, 2007 5:47 pm

Re: Chap 3A

Post by tkat@tkat.com »

Thank for the review.I was wondering what use the measure tool was. Several of your methods are more elegant than a layers approach.But remember how this all started. I'm a interested rookie. I'm "going to school" on you. ;^)TkatArtificial intelligence is no match for natural stupidity.
RowlandCarson
Posts: 2
Joined: Fri Dec 30, 2016 10:56 am

Re: Chap 3A

Post by RowlandCarson »

At 2005-04-26 14:19 -0700 tkat@tkat.com wrote: >Any old hands out there care to stick in yer 2 cents worth? >Particularly w/ instructions on how layers work. Tkat - I will upload a drawing with some layer stuff on it. It was made to check the geometry needed to add gas springs to a drop-down trailer ramp, so I wouldn't strain my back so much every time I closed it.It's got various views on different layers, accessible by the layer filter palette. You can also use the layer pop-up menu found among the items at bottom left to switch between layers. Note that (if I remember right) the active layer is always visible irrespective of the layer filter chosen, which can be confusing at times.Note that this was not really designed for others to understand - I can hardly remember myself all that I did as it grew like Topsy, but it provides a good playground for exploring layer effects.The drawing started out as a feasibility study, then helped to choose the strength of gas spring with the aid of an Excel file (not shown!) and finally provided drawings for the welder to construct the required fittings, which were slightly different from my original conception.regardsRowland-- : Wilma & Rowland Carson <http://home.clara.net/rowil/>: <rowil@clara.net> ... that's Rowland with a 'w' ...
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