BOLT AND SLOT MATE

Logan_5 · March 2018

I am needing help mating parts in an assembly I am working on that uses a diamond u-bolt and a bracket that has two slots. I am wanting to know the best way to mate the u-bolt into the bracket. I have only spent a small amount of time working on mates in Onshape, so this is difficult for me. I am also a new Onshape user coming from a SolidWorks background of 10 years. I would have designed the bracket differently to make the slot concentric of the u-bolt, but the customer already had this designed.

Here is a link to my assembly that I am trying to mate.

https://cad.onshape.com/documents/ae472d6c4b26fb566658f21d/w/4f39a9d925509bd51b030b41/e/719062bb0280b59b9119dbc8

Thanks,
Logan

john_mcclary · March 2018

I find when you have odd things like this, it is best to create a mate connector in the part studio.

Then set the mate connector to the center of one of the slot radius.
Then set the owner part to the bolt.

Now when you go into your assembly, all you need to do is mate the connector that is attached to the bolt, to the same radius in every slot you come across.

If this is a one time only thing and both parts are drawn together (as in your example) then the best way would be to insert them together, then use a group mate

Image: https://us.v-cdn.net/5022071/uploads/editor/vf/fuvymed2wquu.jpg

john_mcclary · March 2018

Also consider adding your vote to slot mate improvement request:

https://forum.onshape.com/discussion/7863/new-mate-slot-mate#latest

brucebartlett · March 2018

Yes please vote on this improvement, I regularly have slotted holes I want to mate a bolt into the center of and find it frustrating having to do the extra mate connector step.

Normally I mate to one end of the slot then edit the mate connector related to the slot to with a move on the x -(slot length/2). However, I don't like having a non-para-metric slot length in the move, if it was really important I'd add a mate connector in the part studio.

Image: https://us.v-cdn.net/5022071/uploads/editor/oe/n2u6rlacbzyp.png

Image: https://us.v-cdn.net/5022071/uploads/editor/8m/4dwxr5o9i0fm.png

john_mcclary · March 2018

@brucebartlett
Yea I try to avoid editing and creating offsets within a mate like the plague.

Although it is fine for very small assemblies where there are only a hand full of mates. It is just not parametric enough for me.
Hell I don't even use distance mates in Solidworks for the same reason.
If I grow that slot I will still be in the part studio and can make the adjustment at the part level once. Whereas if i change the slot and need to re-center the bolt in the assembly through edits. I would need to go through every mate that I can "visually" notice is off and edit them all one at a time. (I get chills thinking about it)

Gee I'd sure love a slot mate

brucebartlett · March 2018

@malay_kumar are there any plans for a slot mate? as you can see from this post the issues @john_mcclary, the OP and I are having but with more thought it goes beyond just slots to sort of parts that need to be mated into the centre of a pocket maybe the best solution is a way to hover on any pocket on in a flat face and have an auto-creating a mate connector at the centroid the same as we would get with a face.

john_mcclary · March 2018

If you do it like Solidworks, then it can free float inside the slot, or be locked to center.
Huge advantage when they came out with that. although theirs is buggy and will break often (such is the life of a solidworks user though)

brucebartlett · March 2018

@john_mcclary the more I think about it what I really want is just to hover in a pocket and get an auto MC in the center, then I can use a slider mate to create float if need be but 95% of the time it will not be needed. This would also help with those come to Onshape from other CAD and having to learn the whole Mate Connector method.

john_mcclary · March 2018

problem I have with slide mates is it will still require distance and direction hand edited at the assembly level.

almost all of my parts usually have double slots, so there is almost never a good place to mate a bolt without creating secondary mate connectors in the studio.

multiply this by 1000 per job, and you see why fewer inputs are better.

I would use pin-slot mate but it never seems to be in the direction I need, and it still requires maintenance and setup time.

With Solidworks slot mate it is just click the inside face of slot 1, click the inside face of slot 2. and you can leave it at that, or go in and say center in slot (I wish center in slot was default...)

Most of what we do is double slotted sheet-metal, because we own a laser table, and we outsource crappy benders.
so slots are free to make, and they take up the +/- .125" that we get from our benders.

With the current system I really don't bother with fasteners much, because of the mating issue mostly. So I've been doing it the old fashioned way on pen and paper, then entering it all in the BOM. Still have to measure every depth throughout the model anyways. It would be faster to just add the fastener there..

Logan_5 · March 2018

Thanks for the replies, everyone. I seem to have stumbled on a necessary update to the mate connector arsenal. I have really enjoyed Onshape and its usability so far, but need to spend more time in assemblies to really fine tune my mate connector skills. I will be upvoting the slot mate.

malay_kumar · March 2018

brucebartlett said:

@malay_kumar are there any plans for a slot mate? as you can see from this post the issues @john_mcclary, the OP and I are having but with more thought it goes beyond just slots to sort of parts that need to be mated into the centre of a pocket maybe the best solution is a way to hover on any pocket on in a flat face and have an auto-creating a mate connector at the centroid the same as we would get with a face.

Adding more kinds of mate connector definition and mates are in plans. Adding an auto mate connector at the center of slot should be easy and will allow to lock at the center. For defining degree of freedom along slot, Pin slot should work in single slot case. But to really constrain correctly with correct limits we would need to be recognizing slots and and have special slot mates. Limits are expensive though. How often do you guys need to just lock at the center vs have motion along slots vs have motion along slots with limits? Do you guys mostly use sketch slot tool to create slots?

For now creating a mate connector in part studio is the best.

john_mcclary · March 2018

98% of the time I'm designing to the center of a slot

50% of that is the center of cross slots

Because I don't "need" limits in slots very often, I can be happy with center only.

Now you would be my hero, and I'll buy you a beer if you can make it work tangent to a cylinder ;p
But we all know that isn't feasible

Image: https://us.v-cdn.net/5022071/uploads/editor/ld/pqivp1rrqv6l.png

brucebartlett · March 2018

@malay_kumar 95% of the time I'd want to mate to the center of the slot.

malay_kumar · March 2018

Thanks @brucebartlett and @john_mcclary for confirming this.

dan_aberle · May 2021

It would really be nice if the Pin-Slot mate limits were parametric based on the length of the slot, rather than a manual input. If the limit were instead tangent to the end of the slot, any update to the slot length at the part studio level would update in the assembly. A pie-in-the sky Pin-Slot mate would allow the pin to mate tangentially to both edges of the slot, representing real-world pin travel, as good design practice sizes the pin diameter smaller than the slot width. The current Pin-Slot mate is concentric on one end of the slot, which introduces a small error of half of the clearance distance.

BOLT AND SLOT MATE

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