AerospaceDesk Posted April 4, 2015 Posted April 4, 2015 (edited) Here I have a flanged Alclad Plate I developed in AutoCAD2015 Trial, I since ran it through CorelCAD 2015 because I ran out of trial time. I have to sort it out to get more time. The problem is that I tried to put a third flange on the plate (a 90 deg one) after I had successfully extruded all the holes you can see. The 3rd flange was created by extruding concentric cylinders and subtracting a rectangular block from that. I found out I was having trouble when I tried to put a relief hole in the corner where the end of the 3rd flange meets the plate at a perpendicular intersection. That did not work; but sheetmetal workers do this before they bend the metal. I found that in the 2D views, the third flange separates form the plate. In the 3D model space, AutoCAD and CorelCAD both report the "assembly" as a 3D Solid. I would like to learn what is causing this to happen; stopping me making more holes.. Thank you for your help. CorelCad Alclad Flange 02042015 Stiffening Flanges A Relief Hole.dwg Edited April 4, 2015 by AerospaceDesk syntax error Quote
Dadgad Posted April 4, 2015 Posted April 4, 2015 (edited) Welcome to CADTutor. Since you now understand that the flange (which appears to have already been UNIONED to the original plate) doesn't actually touch it, might that explain why you are unable to place a new hole, where they DON'T in fact meet? You need to UN-UNION (using the separate tool from the Solid Editing toolbar) them, which can be done, and I have done in your drawing, and attached it to this post. The new flange which you created seems to have a few problems, as follows... 1. it is thicker than the base plate to which you are trying to UNION it 2. it protrudes past the quadrants of the curved surface to which it is meant to mate 3. When you Subtracted the other solid from it, it was out of position, so it has an odd little radial tail extending off it. I have put the parts close together, but they aren't really correct, nor have they been UNIONED, as I thought you might want to fix the flange first. Do you mean to be working in Inches? If so, you should have started on an Imperial template. This appears to have been started on a Metric template, as evidenced by the system variable MEASUREMENT which is set to , which is for a Metric drawing. I hope that helps you. CorelCad Alclad Flange 02042015 Stiffening Flanges A Relief Hole.dwg Edited April 5, 2015 by Dadgad Quote
Dadgad Posted April 4, 2015 Posted April 4, 2015 (edited) Idle VIRTUAL hands are the tools of the Devil, as evidenced by my having taken a few minutes out of this beautiful Saturday afternoon to redo the problematic flange in your drawing. I noticed that one of the existing holes in a side flange did not pierce the plate, so I fixed that too. I have not UNIONED it to the plate of which it is meant to be an extension, figured I should leave you something to do. I did it how I figured it was meant to be done, slightly different, but I believe correctly. Now all YOU need to do is to UNION the flange to the baseplate, and SUBTRACT the two drill bits which I have placed in what I believe are their intended destinations. CorelCad Alclad Flange 02042015 Stiffening Flanges A Relief Hole fixed with drill bits in place .dwg Edited April 11, 2015 by Dadgad Quote
AerospaceDesk Posted April 4, 2015 Author Posted April 4, 2015 Hi Dadgad, That's been a useful exercise for me to do. I ended up completely redoing the third flange a different way using two concentric quadrant arcs then creating a closed polyline from that and extruding to the right length. Well, that seemed a lot quicker than before. The problem then was to connect it to the base plate and see if I could extrude a hole through where they originally met. But it didn't work. It could only extrude a hole through the 3rd flange, the other "half" of the hole just disappeared. Back to the drawing board. Quote
AerospaceDesk Posted April 4, 2015 Author Posted April 4, 2015 Okay, thanks Dadgad, I will have a look at that also because, this Union thing is puzzling me. I understood if you union something you overlap it slightly and then invoke the Union function and it supposedly snaps to the surfaces being Unioned. Do I need to concentrate on the union being exact then? Quote
Cad64 Posted April 4, 2015 Posted April 4, 2015 The objects do not need to overlap in order to Union, but they do need to align with each other so there are no gaps along the seam where the Union is to take place. Also, the objects will not snap together during the Union process. They stay where they are in space and just become one object. You can actually Union two objects that are separated and not touching at all. So yes, you need to be precise when locating objects in relation to each other before running the Union command. Quote
AerospaceDesk Posted April 4, 2015 Author Posted April 4, 2015 Thanks Cad64. That answer gives me some good insight. Do you think alignment is the problem here? I have attached the file with my better 3rd flange in position but under really high zoom there is still a little offset from the 3rd flange's extra thickness. I am not sure how to get the z-dimension of the flange at the union with the base plate to contract to meet the base plate edge to edge. In this file, I have left my 5/64" diam extruded cylinder in place. If you subtract that from the Unionised solid, you can see it subtracts from the flange and not the plate. CorelCad Alclad Flange 04042015 Stiffening Flanges - Cleaned Up 3rd Flange.dwg Quote
Cad64 Posted April 4, 2015 Posted April 4, 2015 I opened your file, but as soon as I tried to Orbit around the parts, the plate disappeared. So I did a Zoom Extents and found that your plate is floating out in space. It is nowhere near the other objects. In the screenshot below you can see how the objects are separated by a great distance. Quote
Cad64 Posted April 4, 2015 Posted April 4, 2015 In the screenshot below, you can see that after I moved the plate into the correct position I was able to subtract the cylinder and create the hole. Quote
Dadgad Posted April 5, 2015 Posted April 5, 2015 (edited) As Cad64 has kindly pointed out, clearly you still have a huge alignment problem. Take a look at this screenshot, which displays four different perspectives simultaneously of your model? Look good? Not exactly what you had in mind, methinks. It is always a good idea to confirm from another perspective that things are as they seem. The difference between the two isometric perspectives speaks volumes to the cause of your difficulty. When aligning the 3D Solids, use your snaps, and if you really just can't seem to do it, there is the 3DALIGN command, which I don't really see you needing in this instance, as things are not off axis, just off in space. You shouldn't be winging it, close is not good enough. Edited April 5, 2015 by Dadgad Quote
AerospaceDesk Posted April 8, 2015 Author Posted April 8, 2015 Yes Dadgad and Cad64 that looks terrible. Thanks for giving your valuable time to help me out. I see what you are both saying. I redid the flange yet again and used a 3D Align to get things lined up. But in this 3D solid (see attached DWG file) I cannot put any more holes into the flange or plate. Yet, someone else managed to get holes into the plate from opening this drawing. But it doesn't do it on my computer. Alclad Base Plate with 3rd Flange 07042015.dwg Quote
ReMark Posted April 8, 2015 Posted April 8, 2015 (edited) I was able to create a new hole in your plate and in one of the flanges. By any chance are you working in either a conceptual or realistic visual style? You failed to correct the problem of the third flange (as per Dadgad & Cad64 instructions) in the drawing attached in post #11. Edited April 8, 2015 by ReMark Quote
ReMark Posted April 8, 2015 Posted April 8, 2015 Download the attached. I repositioned and unioned the third flange for you. File saved in 2010 file format so you should have no trouble opening it. Base Plate with 3rd Flange.dwg Quote
Cad64 Posted April 8, 2015 Posted April 8, 2015 Yes Dadgad and Cad64 that looks terrible. Thanks for giving your valuable time to help me out. I see what you are both saying. I redid the flange yet again and used a 3D Align to get things lined up. But in this 3D solid (see attached DWG file) I cannot put any more holes into the flange or plate. Yet, someone else managed to get holes into the plate from opening this drawing. But it doesn't do it on my computer. When working in 3D, you should routinely orbit around your model and look at it from different angles to make sure things are lining up the way you expect them to. If you always stay in just one view, looking at your model from just one angle, problems like this can happen. And make sure you have your object snaps enabled. I'm not sure how you were attempting to align those objects, but they obviously were not snapped together because that plate was way out in left field. Quote
JD Mather Posted April 8, 2015 Posted April 8, 2015 I redid the flange yet again .... Use the Solidedit Separate to separate the disjointed solid body you have at the origin. Then delete that floater. I recommend that you move your main body to the origin. Although it is less of a problem now - CAD programs can start to mess up the math when you are a long distance from the origin. I always use symmetry about the origin when possible. Quote
ReMark Posted April 9, 2015 Posted April 9, 2015 I've been informed you posted the exact same question over at the CAD Everything website. Included in your post was the latest copy of your drawing. The drawing is still incorrect. The top and bottom (curved) flanges are NOT actually unioned to the plate. I previously asked you if you were editing the drawing using either the Conceptual or Realistic visual style. You never answered my question but I suspect it is so. If you are not well acquainted with working in those visual styles it is possible to incorrectly position parts of a 3D model then union them. From certain viewpoints the finished model looks totally correct when in reality the "unioned" parts are nowhere near each other. The Union command does not care if the parts are correctly or incorrectly aligned (touching) and will in fact appear to function as expected. It is only after using the 3DORBIT command or switching to a different view (front or side) that one sees their mistake. For you to continue with this project the flanges have to be separated first, moved to their correct position and then unioned. Quote
Cad64 Posted April 9, 2015 Posted April 9, 2015 I think this is a case of leading a horse to water but not being able to make him drink. Quote
ReMark Posted April 9, 2015 Posted April 9, 2015 Or the OP was seeking a second opinion like one would about a medical procedure? Quote
Cad64 Posted April 9, 2015 Posted April 9, 2015 Second opinion? There have already been 4 of us weighing in on this issue and the solution has been stated and restated several times by all of us. Move the objects and snap them together. Then Union the parts and subtract the cylinder to create the hole. It's all very simple. Was the advice on the other forum any different? Quote
ReMark Posted April 9, 2015 Posted April 9, 2015 The advice at the other forum was virtually identical. The OP was under the assumption that there is something wrong with AutoCAD's user interface. Quote
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