collision detection in Alibre?
- Thread starter Howie17
- Start date
Re:
heh heh heh . . . I guess that's one of those "not easily possible" things that I mentioned above . . . :wink: . . . there are some real wizards in this forum, so hopefully someone will have some ideas for you (I, unfortunately, have not yet earned the "wizard" title) . . .
I recall reading in another thread that someone was considering creating a set of "linkages" that would limit the motion appropriately, and then hiding those components in the assembly. Seems like a lot of work, but I could see where someone might need to do that once in a great while and not want to spend the money for AD Expert . . .
Regards,
Greg
Howie17 said:
heh heh heh . . . I guess that's one of those "not easily possible" things that I mentioned above . . . :wink: . . . there are some real wizards in this forum, so hopefully someone will have some ideas for you (I, unfortunately, have not yet earned the "wizard" title) . . .
I recall reading in another thread that someone was considering creating a set of "linkages" that would limit the motion appropriately, and then hiding those components in the assembly. Seems like a lot of work, but I could see where someone might need to do that once in a great while and not want to spend the money for AD Expert . . .
Regards,
Greg
swertel
Alibre Super User
The closest thing on the market I know of that is close to "limit constraints" is in Solid Edge. They have "sensors" which are just values you put on onto a variable (dimension). Once the dimension goes outside the values set up in the sensor, a warning goes off. IT DOES NOT PREVENT THE USER FROM EXCEEDING THE LIMIT, though. If Alibre came out with limits constraints, it would be first on the market to accomplish such a thing.
<As Scott steps up on his soapbox>
There are actually 2 things that the MCAD market in general has to develop in the near future in terms of limits: dimensional tolerances and assembly constraints.
In terms of dimensional tolerances, the application needs an easy way to apply standard and specific tolerances to every dimension on the model so MMC and LMC and mean conditions can be checked for form fit and function (tolerance stackups). I would hate to see an upper and lower limit show up in my equation editor/variable table for each dimension I place. Nothing like having 9 variables listed to define a cube.
In terms of assembly constraints, the application needs an easy way to allow for the tolerance stackup from the above. Yes, I want to align these two holes, yes I know they are .005 inches off, but a bolt will still fit through so do it. Tell me, but do it. If a bolt wouldn't fit through, then don't apply the constraint. Movement also applies to this area. In the example in earlier posts, I have a part that can clock X number of degrees, I want to give it that freedom to rotate, not lock it into just one position.
Maybe v10.
<As he steps down from his soapbox with head held low.>
Linkage Limiting Angles Idea
Hi Greg, Howie - not sure If I suggested it first - but in any case my thoughts on this idea - see my Alibre pages and see some of the linkage animations there for a general look. http://www.aircraft-computational.com/alibre/animations-1.html.
More specifically - the linkages can be set so that something about them is allowed to constrain with an offset of - say 0 - at the one limit - and an offset of - say 5 - at the other limit. this can be a Mate or Align Base Constraint - I would use mate, myself, something like a slider (Square extrusion in a parallel sided cutout <track> that has a round pin extruded on top of it - connecting to an arm - that connects to your 'gear' - or 'wheel' with an align constaint using two 'holes' <they can be really small - but need to be round - ie: .001"> one hole in the arm <usually centered in the width of the arm> and one on hole in the 'wheel' or whatever.
Then - you control the rotation of the wheel simply by editing the offset in the constraint! (Think - Steam engines on old trains.) These parts in the assembly - can be given transparent color properties when you need to take images of your idea to show, or left visible while working with the idea! Parts needed: 1-slider track, 1-slider pin, 1-arm. Constraints needed: 1-mate, 2-aligns. Robert
Hi Greg, Howie - not sure If I suggested it first - but in any case my thoughts on this idea - see my Alibre pages and see some of the linkage animations there for a general look. http://www.aircraft-computational.com/alibre/animations-1.html.
More specifically - the linkages can be set so that something about them is allowed to constrain with an offset of - say 0 - at the one limit - and an offset of - say 5 - at the other limit. this can be a Mate or Align Base Constraint - I would use mate, myself, something like a slider (Square extrusion in a parallel sided cutout <track> that has a round pin extruded on top of it - connecting to an arm - that connects to your 'gear' - or 'wheel' with an align constaint using two 'holes' <they can be really small - but need to be round - ie: .001"> one hole in the arm <usually centered in the width of the arm> and one on hole in the 'wheel' or whatever.
Then - you control the rotation of the wheel simply by editing the offset in the constraint! (Think - Steam engines on old trains.) These parts in the assembly - can be given transparent color properties when you need to take images of your idea to show, or left visible while working with the idea! Parts needed: 1-slider track, 1-slider pin, 1-arm. Constraints needed: 1-mate, 2-aligns. Robert
