screw mate with limit distance?

[DerrickM]

ok, im attempting to add a limit distance mate to a part that is also using a screw mate. everything works just fine but is says that the assm. is over defined. but i need both the limit distance mate (to keep it from moving past the bounds in my assembly) and the screw mate to move the part verticaly with a hand crank.

so i was wondering if there is a way to make these two mates get along. any ideas?

 

[NL8]

Typically these mates play very well together, I've used them several times. Can you post the assembly in question?

Joe Hasik,
CSWP/SMTL/MTLS
SW 09 x64, SP 4.1
Dell T3400
Intel Core2 Quad
Q6700 2.66 GHz
3.93 GB RAM
NVIDIA Quadro FX 4600

 

[DerrickM]

well, i might be able to post a picture, but i cant post the assembly. let me check with the boss and see what he says.

 

[NL8]

A generic example would work too, just a cylinder and a couple of plates mated the same was as your assembly. That would at least give us something to chew on.

Joe Hasik,
CSWP/SMTL/MTLS
SW 09 x64, SP 4.1
Dell T3400
Intel Core2 Quad
Q6700 2.66 GHz
3.93 GB RAM
NVIDIA Quadro FX 4600

 

[SincoTC]

I've used that combination without problems too. Did you first locate the screw into its mating part with a concentric mate and then add the screw mate? Because when you select the axes of rotation for the Screw Mate, they make the previous Concentric mate redundant. It doesn't seem to matter and works OK whether it's suppressed or not, but it is technically over defined if it suddenly decides to start getting "picky" during a rebuild!

Trevor Clarke. (R & D) Scientific Instruments.Somerset. UK

SW2009x64 SP4.0 Intel Core i7 2.94Ghz, 12Gb Ram, NVIDIA Quadro FX3700 Driver: 6.14.11.8246
SW2009x64 SP4.0 Intel Core 2 Duo 3.17Ghz, 8Gb Ram NVIDIA Quadro FX3700 Driver: 6.14.11.8246

 

[DerrickM]

its not the screw mate that has the problem, its my limit distance. as soon as i suppress that mate everything is just fine most of the time, its a large assembly and sometimes it just falls apart for no reason. just have to close it and reopen it to work again, with no changes before or after. im willing to bet its my computer though.

is it important to have the limit distance mate on the two parts being use for the screw and not on other parts that are mated to them?

 

[SincoTC]

DerrickM,

With regard to your question, I usually do try to apply the mates as directly as possible to their relevant parts, with the hope that it makes it simpler for the software to evaluate if the move will be within limits, without having to check first if the mates on some intermediate parts are valid.

I've found all forms of "Limit Mates" and flexible sub-assemblies to be rather fragile, especially when used in large assemblies and where there are multiple configurations, where very often a mate may have been "flipped" to make it work as desired, but this action will have "broken" lots of mates in another config. I believe that Design Tables can make managing these different configurations more robust.