Auggy512 Posted February 14, 2013 Posted February 14, 2013 Having trouble helping students create this... If anyone has pointers on how to complete the drawing please give me some inside info. I can get the slots and circles and think I have done the bottom arcs correctly but cannot figure out the proper way to solve the top fillets and arcs... Thanks in advance Quote
ReMark Posted February 14, 2013 Posted February 14, 2013 Try the CIRCLE command with the TTR (tan-tan-radius) option. You know the radius is 6.00. Make the circle tangent to the half circle on the left (r 0.75) and the full circle on the right (dia. 1.50). Quote
Auggy512 Posted February 14, 2013 Author Posted February 14, 2013 I have tried but what happens is that the circle ends up on the wrong side meaning the arc is going in opposite direction Quote
ReMark Posted February 14, 2013 Posted February 14, 2013 Maybe it has something to do with where you made your picks when asked to specify a point on the object for your tangent. It does make a difference. Try again. I know you can do it. Quote
Auggy512 Posted February 14, 2013 Author Posted February 14, 2013 Do you mean close to where it is tangent in the drawing cause I have tried every option but yet it still draws it like this Quote
dbroada Posted February 14, 2013 Posted February 14, 2013 I think you are selecting the tangent points incorrectly. Select them close to where you want the arc circle to pass. Quote
Auggy512 Posted February 14, 2013 Author Posted February 14, 2013 Maybe its the school version of cad (A+CAD software) that I am using that won't let me do it that way... is there another way without using ttr Quote
ReMark Posted February 14, 2013 Posted February 14, 2013 It has nothing to do with the version of the software you are using. Both Dave and I have said the same thing. It is where you are making your picks on the two pieces of geometry. I can use the exact same geometry but if I make my picks somewhere else along the arc and circle I can get my 6.00 diameter circle to land completely opposite of where it should be. Quote
Auggy512 Posted February 14, 2013 Author Posted February 14, 2013 Where Dave has his points circled in yellow I have selected, tried left side first then right side second, vice versa and everything else in between. Even tried lower portions of the slot to no avail... Now I have tried it on a machine that uses Autocad 2009 and it works where I have tried it on this other software... Quote
ReMark Posted February 14, 2013 Posted February 14, 2013 Draw a circle with a radius of 5.25 from each of the two points circled in red. Where they intersect (red cloud) draw a circle with a radius of 6.00. Does that work for you? Quote
nukecad Posted February 14, 2013 Posted February 14, 2013 You could always go "back to the drawing board". Think of how you would do it on paper with a pair of compasses. You have the centers of the circles you need to blend tangent to, you have the radii of these circles and you have the radius of the arc to blend with. Subtract one of the circle radii (0.75) from theblend radius (6.00) and use this to draw temporary circles (5.25) from the circle centres. Where these two large circles cross is the centre needed for the 6.00 blending radius. To find the tangent points join the circle centres and extend through to the circle circumferences. Join these tangent points with a R6.00 arc. Quote
eldon Posted February 14, 2013 Posted February 14, 2013 As AutoCAD prefers to draw its circles anti-clockwise, I tried it by picking the higher circle on the right first, and got the correct circle first time. Quote
Auggy512 Posted February 14, 2013 Author Posted February 14, 2013 See the problem is that I cannot give the students the autocad 2009 to take home because we have a license here but the A+CAD we can let the students take it home... So I am trying to figure out another way to draw this without the TTR.... Disregard I just saw the two replies and that will definitely work... Thank you all so much... I might have another problem tomorrow that will need your help if you all don't mind Quote
dbroada Posted February 14, 2013 Posted February 14, 2013 have you tried nukecad's method? I had to do that for the R1 blend on my drawing as no centre is given. Quote
ReMark Posted February 14, 2013 Posted February 14, 2013 Both eldon and I gave you a way to create the circle without using the TTR option. Did you skip over those posts? What is this A+CAD you speak of? ***NOTICE*** Students and teachers can download the latest versions of many AutoDesk programs, including AutoCAD 2013, for FREE at the Educational Community found on the AutoDesk website. Quote
ReMark Posted February 14, 2013 Posted February 14, 2013 I guess there is such a thing as A+CAD. I found a link to download the program (almost 92MB! LoL) along with a Quick Start, Fundamentals and Command List PDF's. Who knew! Still, if teachers and students can download the real deal (AutoCAD) why bother with a clone? What is the advantage? Quote
Auggy512 Posted February 14, 2013 Author Posted February 14, 2013 Well the school purchased a 3d printer, solidworks, A+CAD, Google Sketch Up Pro, PowerCivil, ArchiCAD and Blender with curriculum. But I found that the curriculum wasn't challenging high school students so I wen't and found some drawings and have changed the entire curriculum... Quote
ReMark Posted February 14, 2013 Posted February 14, 2013 Well you might want to point someone at admin to the AutoDesk website so they can see what they are missing (besides the money they have already shelled out). As far as challenging drawings go any good technical drafting book, and we could name a handful here, will give you and your students all the challenges they can handle and then some. If you don't mind me asking, what are you using as a textbook for teaching CAD in general? Quote
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