gazza_au Posted June 3, 2014 Share Posted June 3, 2014 Im strugling to constrain the bobbin to the float arm so that it slides when the float is moved, I will attache 2-folders as they are large parts and i do not want to move the end of part tree up as this will lose me constraints. Float-1.zip Quote Link to comment Share on other sites More sharing options...
gazza_au Posted June 3, 2014 Author Share Posted June 3, 2014 Thanks in advanced if anyone has the time to look at this. rgds Gazza Float-2.zip Quote Link to comment Share on other sites More sharing options...
JD Mather Posted June 3, 2014 Share Posted June 3, 2014 These 4 dimensions are not needed and there is an extra line overtop of a line. I would never ever use a zero dimension. I did not investigate any further. I recommend you start here http://www.cadtutor.net/forum/showthread.php?85808-Inventor-101 Quote Link to comment Share on other sites More sharing options...
gazza_au Posted June 3, 2014 Author Share Posted June 3, 2014 (edited) Sorry for my outburst. Edited June 4, 2014 by gazza_au Quote Link to comment Share on other sites More sharing options...
ecshclark Posted June 3, 2014 Share Posted June 3, 2014 One quick way is to create an axis thru the the bobbin cone where it would be tangent to the slot edge. Then mate the axis to the surface of the arm. With this method you will have to create another axis on the other conical surface, and apply a mating constaint to the bottom face of the arm. This will over-constrain the assembly, but you can make two position representations, one for pushing, one for pulling. Suppress the constraint not required for the action. May not be the most elegant, but it works. Quote Link to comment Share on other sites More sharing options...
JD Mather Posted June 3, 2014 Share Posted June 3, 2014 There are a plethora of other problems as well, critical problems. Not the least of which are wrong size holes for threaded holes. Tap drill size is usually covered in first semester design class. But you don't even have to know this if you use the Hole feature to create threaded holes rather than extruded circles. Quote Link to comment Share on other sites More sharing options...
ecshclark Posted June 3, 2014 Share Posted June 3, 2014 Yes, I saw they have many issues in technique, dimensioning and fits, etc... I assume the design isn't completely fleshed out. But the question is an interesting problem to me. How to constrain the thing-a-ma-bob to the thing-a-ma-jig so it all slides up and down was new to me. I hadn't ever had to work with any assembly with these kinds of features and motion. After looking at it for about two minutes, I think it took about three minutes to add the axis and constrain. May not be the best, but seems to work well enough. Maybe making a control sketch to derive parts and controlling motion would be the way to go here. Due to the previous rude comment, there must be a deadline that has come and gone to get this design out the door, and the boss is breathing down their neck. That... or since the assembly looks like something you'd put in a toilet, they are just tired of being up to their ears in you-know-what:D Quote Link to comment Share on other sites More sharing options...
JD Mather Posted June 3, 2014 Share Posted June 3, 2014 ... I hadn't ever had to work with any assembly with these kinds of features and motion. .... there must be a deadline that has come and gone to get this design out the door, and the boss is breathing down their neck. I will try to post a better kinematic solution later tonight or tomorrow, but first I will have to rebuild all of the parts. In my experience it is faster to model correctly than to model incorrectly even for a quick "mock-up". Most of the problems I saw - Inventor will actually do the work correctly for you - so it to more work, more time on the part of the designer to do it incorrectly. Quote Link to comment Share on other sites More sharing options...
JD Mather Posted June 3, 2014 Share Posted June 3, 2014 ....i do not want to move the end of part tree up as this will lose me constraints. Rolling up the EOP does not cause loss of assembly constraints. Quote Link to comment Share on other sites More sharing options...
JD Mather Posted June 3, 2014 Share Posted June 3, 2014 I just ran across this - maybe it will help. http://inventortrenches.blogspot.com/2011/03/inventor-101-simple-fully-constrained.html Particularly the Be lazy tip. Quote Link to comment Share on other sites More sharing options...
gazza_au Posted June 3, 2014 Author Share Posted June 3, 2014 One quick way is to create an axis thru the the bobbin cone where it would be tangent to the slot edge. Then mate the axis to the surface of the arm. With this method you will have to create another axis on the other conical surface, and apply a mating constaint to the bottom face of the arm. This will over-constrain the assembly, but you can make two position representations, one for pushing, one for pulling. Suppress the constraint not required for the action. May not be the most elegant, but it works. [ATTACH=CONFIG]49279[/ATTACH] ecshclark Thanks for taking the time to look at this, Im profitient with AutoCAD but new to inventor and once this design has more time to spare, my own! Then i will fully constrain/dimension and do everything else corectlly that i should have done... I apolige for my outburst as i only asked a question about motion constraints. Most of the valves i make are for auto-venting and coal seem gas applications and my company do not see the benifits like i do for modeling the parts so im using my own time to try and learn Inventor. Quote Link to comment Share on other sites More sharing options...
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