ChrisWatkins Posted September 14, 2007 Share Posted September 14, 2007 Hi Everyone, I cannot figure out how to put threaded holes in the outer edge of this part. I need the holes to go where the circles are drawn around the radius, with the direction pointing to the center of the radius. This is driving me nuts, but it's a short trip already. I am using Mechanical 2004. I can email the file to someone who wants to help me out. Thanks Quote Link to comment Share on other sites More sharing options...
Hedgehog Posted September 14, 2007 Share Posted September 14, 2007 I'd extrude the circles into the object & then subtract 'em from the object (if the extrude goes the wrong way use a -ve value) Quote Link to comment Share on other sites More sharing options...
ChrisWatkins Posted September 14, 2007 Author Share Posted September 14, 2007 Thanks Hedgehog, I was able to extrude through the part, but now I do not know how to join the extruded hole to the main part. If I try awhile I imagine I will figure out how. However, I'm not sure if this is really what I want. I sure would like to place a threaded hole instead. Quote Link to comment Share on other sites More sharing options...
SLW210 Posted September 14, 2007 Share Posted September 14, 2007 I usually get a long 3D bolt .sat from McMaster and then locate and subtract. Quote Link to comment Share on other sites More sharing options...
Mr T Posted September 14, 2007 Share Posted September 14, 2007 Thanks Hedgehog,I was able to extrude through the part, but now I do not know how to join the extruded hole to the main part. If I try awhile I imagine I will figure out how. However, I'm not sure if this is really what I want. I sure would like to place a threaded hole instead. So if the existing holes need to be threaded - Delete the existing holes and Circ pattern (array) a threaded hole dropped in and job done ?? Nick Quote Link to comment Share on other sites More sharing options...
figure1a Posted March 4, 2012 Share Posted March 4, 2012 I usually get a long 3D bolt .sat from McMaster and then locate and subtract. I think this is a brilliant idea. I just did it and it works great. But then I thought if those are the threads of the screws shouldn't the threads of the tap be slightly bigger? I am new to all this but if the threads of the screw and the tap are the same size then the fit would be so tight the screw would not go in? Let me know if my logic is right or wrong. thanks! Quote Link to comment Share on other sites More sharing options...
Dadgad Posted March 4, 2012 Share Posted March 4, 2012 I am guessing that the threaded hole will serve as a representation of whatever specification is attributed to it, and that it will be machined to the specified attribute, rather than the 3D model. I guess if you are using CNC, then that might not be the case. You could scale along the appropriate axis to gain your thread relief when you are inserting the block, so that when subtracted you get that extra margin of comfort. Quote Link to comment Share on other sites More sharing options...
SuperCAD Posted March 4, 2012 Share Posted March 4, 2012 The problem with downloading a threaded part of McMaster is that more often than not the threads are inaccurate. The angle of the thread is usually wrong and it looks like they mirrored one side to the other. On occasion they do it correctly, but the files sizes are way up there. But if that's the way you want to go, here's what you do. Find a hex nut that matches the thread you want to create. Now make a solid rod that is larger than the internal major thread diameter, but not so large that it is bigger than the nut itself. Subtract the hex nut from the rod to make a negative of the internal thread shape. Now subtract the negative from the holes in your part. Quote Link to comment Share on other sites More sharing options...
figure1a Posted March 5, 2012 Share Posted March 5, 2012 The problem with downloading a threaded part of McMaster is that more often than not the threads are inaccurate. The angle of the thread is usually wrong and it looks like they mirrored one side to the other. On occasion they do it correctly, but the files sizes are way up there. But if that's the way you want to go, here's what you do. Find a hex nut that matches the thread you want to create. Now make a solid rod that is larger than the internal major thread diameter, but not so large that it is bigger than the nut itself. Subtract the hex nut from the rod to make a negative of the internal thread shape. Now subtract the negative from the holes in your part. Thanks! Followed your directions and it seemed to work great. Hopefully will CNC this later this week and see if works out. Quote Link to comment Share on other sites More sharing options...
Dadgad Posted March 5, 2012 Share Posted March 5, 2012 The problem with downloading a threaded part of McMaster is that more often than not the threads are inaccurate. The angle of the thread is usually wrong and it looks like they mirrored one side to the other. On occasion they do it correctly, but the files sizes are way up there. But if that's the way you want to go, here's what you do. Find a hex nut that matches the thread you want to create. Now make a solid rod that is larger than the internal major thread diameter, but not so large that it is bigger than the nut itself. Subtract the hex nut from the rod to make a negative of the internal thread shape. Now subtract the negative from the holes in your part. If it is done correctly then the file sizes will be way up there. Much as I enjoy modeling threads in 3D, I do it mostly representationally, sort of as eye candy, without needing to worry about actually passing my model to a CNC machine. Easy enough to get all the thread pitch information, just glad I don't need to. I would be very wary of any models which you have not done yourself. Quote Link to comment Share on other sites More sharing options...
SuperCAD Posted March 5, 2012 Share Posted March 5, 2012 When I make a threaded part in AutoCAD, I save the part as a separate file, and then XREF it into my working drawing file. It helps keep the file sizes down while still giving our customers the eye candy. They love pretty pictures. Quote Link to comment Share on other sites More sharing options...
Dadgad Posted March 5, 2012 Share Posted March 5, 2012 Me too, but rarely get to use them as our files are huge and we can't afford to have thousands of eye candy tapped holes bulking them up. Don't we all? Quote Link to comment Share on other sites More sharing options...
JD Mather Posted March 5, 2012 Share Posted March 5, 2012 If this is going to CNC g-code then you SHOULD NOT model threads - use tap drill size. If it is going to Rapid Prototyping machine the you can add threads - but keep in mind that RP tolerances aren't particularly tight so allow extra clearance. Quote Link to comment Share on other sites More sharing options...
SuperCAD Posted March 5, 2012 Share Posted March 5, 2012 we can't afford to have thousands of eye candy tapped holes bulking them up. Typically, I'll only use the tap hole details for, well, details. I won't put them in the actual model. For all of the other views, I've made dynamic blocks that allow you to select a fastener size and resize the thru hole and the major diameter according to standards. There are other holes included in the file too, such as CSK holes and Thru holes, both for raw material and powdercoated material. Tapped Screw Hole.dwg Quote Link to comment Share on other sites More sharing options...
SLW210 Posted March 5, 2012 Share Posted March 5, 2012 If this is going to CNC g-code then you SHOULD NOT model threads - use tap drill size. If it is going to Rapid Prototyping machine the you can add threads - but keep in mind that RP tolerances aren't particularly tight so allow extra clearance. Correct. You need to use the specs for the TAP if this is for CNC. Information given is just for "eye candy". Quote Link to comment Share on other sites More sharing options...
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