Mating axis' between bolts and holes 3

[BodyBagger]

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?".........

 

[drawoh]

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

 

[CorBlimeyLimey]

"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.

 

[ShaggyPE]

A star for you drawoh. Very well put.

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

 

[TheTick]

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

 

[EdDanzer]

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

http://www.danzcoinc.com

http://www.dehyds.com

 

[EdDanzer]

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

http://www.danzcoinc.com

http://www.dehyds.com

 

[gwubs]

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

 

[MadDogMcDurmott]

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

 

[EdDanzer]

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

http://www.danzcoinc.com

http://www.dehyds.com

 

[NomLaser]

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.

 

[ShaggyPE]

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

 

[TheTick]

You can mate an axis concentric to a revolved face.

 

[drawoh]

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

 

[ShaggyPE]

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

 

[drawoh]

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

 

[ShaggyPE]

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

 

[gwubs]

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....