This is a YouTube video. To mate two gears parallel mate was selected. Why not Coincident Mate? Folder is attached.
https://www.youtube.com/watch?v=F2sKs0YmM_w
Time 26.01
This is a YouTube video. To mate two gears parallel mate was selected. Why not Coincident Mate? Folder is attached.
https://www.youtube.com/watch?v=F2sKs0YmM_w
Time 26.01
I guess concentric mate already applied, then no need for incident mate (lock them together) but parallel is more open for part rotating together
The coincident mate would lock the two faces/points together not let it rotate.
in the video the planes are being used to align the teeth of the gears.
Coincident mates would require them to be precisely in line (X Y & Z) with each other where parallel only requires them to be in line in the X and Z direction. If the gears were not exactly in line in the Y direction the mate could not be successfully made.
The RED gears are constrained into the mounting brackets on top and bottom and the gray gears are constrained to the center of the hole in the large blue gear. If these features were off in the slightest amount the mates will fail.
These mates are also just being used to align the teeth so there is no need to be precisely aligned in all 3 axis.
The parallel leaves more freedom.
I experiment with simple parts with having Coincident Mate and Parallel Mate separately but I couldn’t see any differences.
Parallel = inline
Coincident = faces stuck in same plane
This parallel mate later has been suppressed. I don't know the reason.
If a mate is greyed out then it is suppressed and not used. Personally, I consider this poor modeling practice. It might have been initially used just to get things to line up.
In this case do you see anything to get things to line up?
IMHO, I would have aligned/mated/fixed the two idler gear mounts on the big ring gear first. 2nd, put the idlers 'on' the mount but don't fix the rotation. 3rd, position the axle gears, again, w/o fixed rotation initially. Then I'd try to set tangent mate between appropriate gear teeth surfaces from one to the next.
That was the way it was done in the video - the mate was used to initially align the teeth in the gears and then suppressed to allow them to rotate.
Maha,
In the video the parallel mates are just used to ensure the teeth of the gears line up correctly. In one part of the video he has to add a rotation offset to the parallel mate to get the teeth to line up. Then a mechanical gear mates are added & the tutorial says it will over define the assembly but not to worry. Then I'm guessing that at a later stage in the tutorial the parallel mates are supressed leaving the assembly to move freely with the teeth meshed perfectly.
Thanks
Maha,
Since there are numerous answers to this question I will add what I "Teach" my new designers in respect to this very question.
Mate a round part concentric, in this form "Z" axis is controlled. Mate to a surface "Y" or "X" axis is controlled.
If rotation is not desired plane to plane parallel is the preferred mate.
This is done for various reasons the most simple being overdefining an assembly. If you make those planes coincident and have a few gears and shafts it will probably never be a problem.
If however you are assembling a gearbox, that goes into a drive motor assembly that lines up with an output shaft which eventually goes into an auger machine(10,000 + parts) it becomes inherent to control your design.
So in the case of the above gearbox if you mated the planes coincident on every cylindrical part and you happen to be the lucky guy who has to finalize design on the auger you are going to encounter over defined parts(ALOT). SWX can update a model fairly quickly with base mates of concentric and parallel over various parts, start putting coincident conditions to lock rotation of said round parts and it will start generating issues down the assembly.
This has come from years of working in automaton and machine build designs, I am not going to say it is the gospel just my experience in working with power transfer design most of my career.
To recap in a small assembly for your theoretical project the coincident mate is not going to hurt anything, John's suggestion of tangent mates to align(clock) the gears is viable as well. Myself if I have to show clocked gears I make relevant planes between the gears to clock them properly.
I would definitely avoid coincident mates "If" you need to make things move and I would also definitely avoid using the gear mates as well "If" you can use parallel mates.
Sometimes it's hard to simplify the mating process and which mates to use, however the longer your Mate Feature is the longer it takes to rebuild, most times you can use two mates and that's it..
Maha,
In the video the parallel mates are just used to ensure the teeth of the gears line up correctly. In one part of the video he has to add a rotation offset to the parallel mate to get the teeth to line up. Then a mechanical gear mates are added & the tutorial says it will over define the assembly but not to worry. Then I'm guessing that at a later stage in the tutorial the parallel mates are supressed leaving the assembly to move freely with the teeth meshed perfectly.