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Mating axis' between bolts and holes
3

Mating axis' between bolts and holes

Mating axis' between bolts and holes

(OP)
Hello all,
I am coming across many different things I have not seen done before while working this contract job.  I noticed that all of the nuts and bolts have been created from scratch (not from TB) and they all hace an axis included.  On the assemblies, they mate the axis of the bolts with the axis of the hole they are being used with rather than concentric mates.  Why would this be the preferred method or am I missing something here?  When I asked why they were creating bolts from scratch and not pulling them from TB, they said "what's toolbox?".........surprise

RE: Mating axis' between bolts and holes

I can't think of a benefit for mating Axis-Axis.

"Art without engineering is dreaming; Engineering without art is calculating."

Have you read FAQ731-376: Eng-Tips.com Forum Policies to make the best use of these Forums?

RE: Mating axis' between bolts and holes

I can think of two reasons to use axes instead of faces.

1) Planes and axes (not temp axes) created from planes are more stable than faces and geometry. Faces and geometry ID's can change if they are modified in some way.

2) Created axes can be selected from the FM, which is much easier than zooming in to select individual faces.


My company only has the Standard package plus the PhotoWorks/PV360 and FeatureWorks modules (no Toolbox).
I did have the opportunity to try Toolbox for a while, but didn't like it. I created my library from a utility called SolidMech (sadly no longer available). Any new items are either modified from existing or created from scratch ... and where applicable, always with axes.  

RE: Mating axis' between bolts and holes

I tend to mate the axes.  My impression is that they are more stable / persistent than the surfaces / edges that are used in concentric mates.  Additionally a concentric mate means align the axis of these two cylindrical objects.  Using the axis directly conceptually cuts out the middle man.  I am also not sure when concentric mates became available.  It might be that axis to axis was the only option when I started on ProE way back when and I just stuck with what I knew.

Eric
 

RE: Mating axis' between bolts and holes

2
BodyBagger,

   On my first enounter with toolbox, I worked out that it did not meet our requirements.  It did not work well with mulitple users, and the BOM entries were too cryptic. I want to copy and paste from the BOM, to our purchase requisitions and I want to check fasteners into PDM.  I designed my own fasteners, admittedly, without centre axes.

   Ask, tactfully.

   I set all sorts of stuff up shortly after we installed SolidWorks.  I would do a lot of it differently now if I had to start from scratch, again.

               JHG

RE: Mating axis' between bolts and holes

My only argument against using axes is the they have to be turned on.  In a complex assy having all of those crappy little blue lines all over Hell's creation is a bit of a mess visually.

Dan

www.eltronresearch.com
Dan's Blog

RE: Mating axis' between bolts and holes

Eltron,

That's mainly for the Temp Axes. If you create and use reference axes, you don't need to have the View > Axes active, because they are selectable from the FM.

RE: Mating axis' between bolts and holes

Eltron,

   Turn the axes on when you need them, then turn them off when you are done.  I hate having to switch stuff off from the view menu.

   I can make a good case for using the hole wizard sketch points for centreing fasteners.  If you do it this way, you can change the holes without losing your assembly constraint.  Now if only I had done it that way...

   You can centre on the fastener body.  There is no need to use axes.  

               JHG

RE: Mating axis' between bolts and holes

And some days you just want to put a square peg in a round hole.

RE: Mating axis' between bolts and holes

drawoh,

The visibility of Axes and Temporary Axes can be toggled with keyboard shortcuts.

"You can centre on the fastener body"
Do you mean by selecting the cylindrical face?

I agree, there is no need to use axes ... it's just personal preference.

RE: Mating axis' between bolts and holes

A face is about the least likely bit of geometry to be lost.  Especially true for hardware, which isn't subject to design changes.

Using axes precludes use of concentric mates.  This is a bit of an annoyance when trying to decipher and correct mate conditions.

RE: Mating axis' between bolts and holes

CorBlimeyLimey,

   Yes, I meant the cylindrical face.  I have used axes for mating on occasion.  Adding an axis to a slot makes slots easier to centre on.

TheTick,

   You do not lose faces on your standard parts.  You do lose faces when you mess with the hole wizard, and I believe firmly in messing with the hole wizard.

               JHG

RE: Mating axis' between bolts and holes

About the only time I lose a face using hole wizard is if I switch from a c-sink hole to a regular hole etc.  In this case a concentric mate will lose its face.  This doesn't bother me, I still mate concentric.  If mating to an axis (not a temp axis)... you would have to create an axis for each hole... right?  That seems like a royal waste of time.  Though just one axis for the seed hole of a pattern is all that is necessary... but this still seems like it is not the best solution.

-Dustin
Professional Engineer
Certified SolidWorks Professional
Certified COSMOSWorks Designer Specialist
Certified SolidWorks Advanced Sheet Metal Specialist
 

RE: Mating axis' between bolts and holes

I agree with Drawoh regarding creating an axis in a slot for mating.  This is the only time I mate a fastener to an axis.

-Dustin
Professional Engineer
Certified SolidWorks Professional
Certified COSMOSWorks Designer Specialist
Certified SolidWorks Advanced Sheet Metal Specialist
 

RE: Mating axis' between bolts and holes

In terms of using the Toolbox, discussions on this Forum and the Solidworks Forum would suggest that less and less people use the Toolbox, especially so in multi-user enviroments.

Setting up a good fastener library seems to be the way a lot of people have gone (my last 3 jobs included).  Quite often people use Toolbox to generate the part, then saveas to put it in the library.

Have a look into the overheads of having all the configurations that Toolbox creates for parts.

Also look into the issues created when sending designs to outside customers.  If they don't run off the same Toolbox Database, then all hell breaks loose.

Both of these issues have been identified as major headaches with Toolbox in the past.  They have been fixed in later editions, but are likely why long time users of Solidworks stay well clear of them.  Once you have your library setup, then it is not a problem.

In terms of the axes, check that they are not using something tricky like auto-mates.  This could explain the reason for using the axes.

Craig Pretty
Tru-Design Plastics

RE: Mating axis' between bolts and holes

Thanks for the vote of confidence, guys.  I know how to toggle the temp and ref axes.  It's just usually an unnecessary hassle for fasteners.  I think I'm going to switch the toggle to a Mouse Gesture in 2010...when I get around to it.

Dan

www.eltronresearch.com
Dan's Blog

RE: Mating axis' between bolts and holes

To mate bolts/capscrews in a slot it is very effective to use the width mate....

RE: Mating axis' between bolts and holes

Question - do you fully define capscrews in your assemblies, that is; stop them from spinning in the hole?  Some of our modelers don't bother, but I believe it is better for drawings (balloons), and so that you can keep your assemblies fully defined (good practice IMHO)

RE: Mating axis' between bolts and holes

It's not really necessary to fully define fasteners, o-rings, etc, to prevent rotation.

Some upsides;
Keeps the FM 'cleaner' looking.
Easier to find under-defined mating of other parts (because the (-) stands out).
Keeps the OCD sufferers calmer.

Some downsides;
More mates = more time to rebuild.
More mates = potential for more to go wrong (arguable).
The assy becomes easier to over-define.

RE: Mating axis' between bolts and holes

CBL- do you balloon fasteners?  I find that there are enough little things that change when you open a drawing without needing to align balloons and leaders to bolt heads &etc.  We reuse most of our assemblies, so the odds of an under defined part getting a little drag are quite good.  I agree though that more mates are not a good thing from a rebuild point of view.

RE: Mating axis' between bolts and holes

gwubs,

   I fully define and balloon all fasteners.

   In the assembly model, I want to scan down through the assembly tree and see that everything is fully constrained.  There is no absolutely easy way to distinguish between components that are allowed to float and components that must be retained.

   Designers should pay attention to fasteners.  If a worker needs 43 different screws to assemble a widget, the stock room has to locate and kit the correct quantity of each fastener.  The workers must carefully examine the drawing and select the correct fastener, correct torque wrench and screw bit.  Unless you are trying to minimize weight and size, this all is a non-value-added cost.

   If the designer can ignore fasteners at modeling and documentation time, the stock room and workers have even more of a mess on their hands.  If you scan through your complete assembly drawing with all its fasteners, you can see opportunities to standardize stuff.  You can also see assembly problems that you as the designer can correct.  

   SolidWorks does an excellent job of modelling idiocy.  If the modeling and documentation of an assembly process is difficult, the assembly of the actual system is also probably difficult.  And expensive.  And unreliable.

               JHG

RE: Mating axis' between bolts and holes

"CBL- do you balloon fasteners?"
Usually, yes, but more often than not I use the Auto-balloon function which requires very little tweaking, and therefor little risk of moving any parts. If a fastener does get rotated, it's no big deal. If it's rotational position was critical it would have been mated.

RE: Mating axis' between bolts and holes

A star for you drawoh. Very well put.

-Dustin
Professional Engineer
Certified SolidWorks Professional
Certified COSMOSWorks Designer Specialist
Certified SolidWorks Advanced Sheet Metal Specialist
 

RE: Mating axis' between bolts and holes

Someday, drawoh, your employer might learn about work instructions.

RE: Mating axis' between bolts and holes

The best reason for using mate geometry in standard components is interchangeability. If all nut, bolts and washers are based on the same model using mating geometry created before geometry creation these fasteners can be interchanged without fixing mates.

Example: Model 1 is designed for as a small version so several different size and length of fasteners are used, small bearings are used as well as small plumbing and wiring. This product is a winner so a medium, large and extra large are to be built. If you do a file save as for the drawings, parts and assemblies and you have a smart library of parts the parts that need to be changed can be replaced with a few mouse clicks and no mates will need repaired. The assemblies and drawing pages will update and in many cases the manual pages will require only minimal work to finish. This can save many hours on assemblies with a few hundred parts or several days on large assemblies.

Sad part of this story is I tried to convince SolidWorks to provide a smart library of parts with every seat back in 1997-1999. May position was it costs about $10.00 per part to create this smart library once and providing it would save every user at least $50,000.00 in the first 5 years of ownership.

Ed Danzer
www.danzcoinc.com
www.dehyds.com

RE: Mating axis' between bolts and holes

I failed to mention that you do not have to see the mating geometry to use it in the feature manager. If you have large parts relative to the fasteners, assembling the parts by clicking on reference geometry in the feature manager is faster than zooming around trying to find the correct faces.

Ed Danzer
www.danzcoinc.com
www.dehyds.com

RE: Mating axis' between bolts and holes

EdDanzer - you should get a Spaceball!  Zoom, Pan & Rotate quickly without any conscious thought.

RE: Mating axis' between bolts and holes

You can speed up the addition of adding fasteners to an assembly by using smart mates. The concentric and coincident mates are added automatically.

Also, use those filters! If you are adding axis's for coincident mates, select those filters and you will eliminate accidently selecting edges, faces, vertex's, etc...

In my eight years of using Solidworks, I have found no advantage, nor disadvantage to using axis mates versus concentric mates. It is entirely user preference.

Mad Dog

RE: Mating axis' between bolts and holes

Gwubs,
I have some physical/mental limitations and can't make a space ball work even typing is a challenge some times. I bought a space ball several years ago and ended up giving it away after receiving much heckling from my coworkers for my limitations, not that I didn't deserve the heckling.

Ed Danzer
www.danzcoinc.com
www.dehyds.com

RE: Mating axis' between bolts and holes

You don't have to turn the axis on to use it, just find it in the Feature Tree of the parts and select it that way.  It will still work.

RE: Mating axis' between bolts and holes

You still have to create an axis in the mating part... that seems like the limitation to this method.  Unless you plan to use a temporary axis... but that just seems well... um... temporary.

-Dustin
Professional Engineer
Certified SolidWorks Professional
Certified COSMOSWorks Designer Specialist
Certified SolidWorks Advanced Sheet Metal Specialist
 

RE: Mating axis' between bolts and holes

You can mate an axis concentric to a revolved face.

RE: Mating axis' between bolts and holes

ShaggyPE,

   If you are assembling parts modeled by someone else, then you are stuck with whatever features they provided you.  If you are modeling something, you can anticipate assembly requirements, and add points, axes and planes accordingly.   

               JHG

RE: Mating axis' between bolts and holes

drawoh,
Absolutely, but why would you add an axis to a hole specifically for mating a fastener to it.  Seems like wasted effort for really no additional robustness.

Now a fastener to a slot... that is a reason to add an axis.

-Dustin
Professional Engineer
Certified SolidWorks Professional
Certified COSMOSWorks Designer Specialist
Certified SolidWorks Advanced Sheet Metal Specialist
 

RE: Mating axis' between bolts and holes

ShaggyPE,

   In the case of a wizard hole, You could do a centreing mate of the cylindrical face of your fastener with the point that defines the centre of your hole.  The point is an integral part of the wizard sketch.  Combined with the face to face mount below a screw head, the assembly is even more robust because there is no need for the fastener face to be perpendicular to the round part.  Admittedly, this is an unlikely screw-up.  In reality, I usually mate the cylindrical faces.  

   I do try to use as few mates as possible, as this makes for a more robust model.

   I don't add axes unless I need them.  In the case of round fasteners in round holes, I don't.  

               JHG

RE: Mating axis' between bolts and holes

Yeah... I am in your same boat.  This method just seems like a waste of effort.

-Dustin
Professional Engineer
Certified SolidWorks Professional
Certified COSMOSWorks Designer Specialist
Certified SolidWorks Advanced Sheet Metal Specialist
 

RE: Mating axis' between bolts and holes

EdDanzer - sorry to hear that you have difficulty with things that many of us take for granted, there was no disrespect intended.  My typing skills (or lack of) are nothing to write home about....

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