Minimum Mate Limit Should be Smaller than Maximum Limit

famadorian

What is the reason that it has to be smaller?

I could turn this around to make it not display that message, but why?

john_mcclary

Consider the following:

min = 0
max = -600
if ( x >= min && x <= max)   // this says x can only be a value between min and max

lets set x = -10 for example and re-write the equation
keep in mind, both sides of the && symbol must be true for the IF statement to be valid
if ( -10 >= 0 && -10 <= -600) 
-10 >= 0  (false)
-10 <= -600 (false)

---
try x = 10
10 >= 0 (true)
10 <= -600 (false)

--
try x = -700
-700 >= 0 (false)
-700 <= -600 (true)

so the if statement has no possible value and fails 100% of the time.

owen_sparks

I'd read the original question slightly differently. (Similar to the no wrong answers philosophy in another thread)
Why do we need Min and Max? How about we simply say "Between" instead?
Between -20 and -10
Between -10 and -20
Both valid, no need to do the mental gymnastics as to which negative number is bigger and is the max.

Cheers, Owen.

john_mcclary

@owen_sparks I realize your point, and almost elaborated about that in the original post.

But, if you give a user the option to input values willy-nilly in multiple input blocks and then try to interrupt what they "meant" to do, then you are asking for trouble down the line.

This could also cause conflicts with configurations if you configure an input, but half the time the user was able to put the smaller value in the top cell, etc... 

When it comes to computers, it is always: "Garbage in, Garbage Out"
It isn't too much of a stretch to realize which number is smaller while inputting.

billy2

@famadorian

There is only 1 way to set limit mates in OS, from what I've discovered.

While defining the limits, grab the part and move it, a dimension will appear and use it. From this dimension, you can enter in the minimum which is usually negative and maximum which is mostly positive. Looking at the mate connector's "Z" orientation and trying to figure it out is impossible at least for me.

Moving the part while defining the limits is the best way I've found to define them correctly the 1st time.

Also, since higher assemblies inherit lower assembly constraints. Please define limits in your assemblies. The ultimate goal is to have a library of assemblies that function properly when building your top. For automated equipment, this workflow in OS is going to totally change the way we design automated equipment.

john_mcclary

billy2 said:

Also, since higher assemblies inherit lower assembly constraints. Please define limits in your assemblies. The ultimate goal is to have a library of assemblies that function properly when building your top. For automated equipment, this workflow in OS is going to totally change the way we design automated equipment.

For sure, in SW all sub assemblies are rigid. You can set them to flexible (at your own peril & major performance loss & constant mate breaking).
But it all just works so smooth and fast in Onshape it feels so natural. When you go back to SW it feels like a tinker toy. No more defining 100 configurations for a cylinder's stroke, just set its limits in OS and constrain the part itself.