How do I follow workshop practice in welding?

[rickduley]

Stitch welding is a common practice in a welding workshop, and the general idea is to alternate welds side to side like this

but it is also standard practice to "wrap" around the ends

completing the weld run round the end of the stiffener at (1) and, say, 10mm around the corner at (2).

How do I duplicate this in Inventor 2015?

[blair · Accepted solution]

You will need to create another weld with lenth only and start from the end, or trick it and do a Split-Face on the verticle at the ends to get a weld bead of the length required.

Sometime Welding in Inventor is more stuborn than the welders on the production floor.

[rickduley]

Hi Blair

What you are saying is that Inventor cannot do this (yet) and I will have to wait until the draftsman brings the job to me and solve it as I always do (as one of those "welders on the shop floor". 

[blair]

Changing the selection criteria and direction may allow you to create a short weld from the end to the first staggered weld. Sometimes it works easly with the first selection, other times it feels like herding cats.

Between selection and direction and then selecting the end of the weld across each end should get the results you require.

[jyager]

Modeling the welds seems like a giant waste of time anyway. Faster just to annotate them on the drawing.

Out of curiosity...does anyone find it's actually useful to spend the time toying with the weld function?

[rickduley]

Hi Jason

>> Modeling the welds seems like a giant waste of time anyway. Faster just to annotate them on the drawing.

Sure it is - if you are prepared to leave the actual practice up to the welders on the shop floor

>> Out of curiosity...does anyone find it's actually useful to spend the time toying with the weld function?

I guess I would if I was building (virtual) a device which involved a lot of welding and I wanted to run tests on stress and weight distribution etc.

[jyager]

Not following how annotating the welds is leaving the practice up to welded in the shop? Maybe I'm misunderstanding the statement.

Sent from my iPhone

[rickduley]

Show me how you annotate the weld we have been discussing so that you are INSTRUCTING the welder to weld round the end of the rib as I depicted.  This discussion has not revealed a means, and I do not believe that Inventor 2015 has a means (yet).  In that case, you insert a weld symbol which is a generic REQUEST for a stitch weld - and leave the actual implementation up to the welder.

Just another case of the tradesman making real what the engineer dreamed about.    Happens all the time!

[jyager · Accepted solution]

What doe's a "generic request for a stitch weld" mean? Weld symbols are instructions on how to weld something. The weld symbol either relays the information or it doesn't. Our shop floor wouldn't be welding anything without it being clear exactly what the weld is, to be tracked, or our QA would have them strung up.

How would you have done this if you were just in regular autoCAD or on paper?

I see this type of weld all the time at power plants, from coast to coast, and these utilities have some of the most stringently regulated weld programs through their QA/QC depts you're likely to see. They often weld structural supports or anchor plates like this.

A couple examples attached.

Not sure what the tradesman (I've been a union sheet metal worker for 18 years) even needs to interpret at this point. Seems like you're just looking to make passive agressive jabs about tradesman vs engineers w/ each reply.

My issue is modeling the welds. I frequently have assemblies with 50+ welds. I can go through and tag all 50 in a couple hours or spend a day chasing my tail trying to model them. Unless you're really concerned about the filler metals weight it seems like a lot of effort for little reward.

Should Inventor be able to do this more easily? Maybe...but it also should probably have a native spellcheck, etc etc. Nothing is perfect.

[swalton]

99% of our welds are not modeled in the assembly.  They are just called out on the 2d print.

Here are the main reasons:

Time to model

Overhead on large assemblies (the machine I have open right now has 4546 components, 598 unique)

We will model welds when a post weld machining process is required.  We will also do it if necessary for a FEA.

[LT.Rusty]

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@Blair wrote:

You will need to create another weld with lenth only and start from the end, or trick it and do a Split-Face on the verticle at the ends to get a weld bead of the length required.

Sometime Welding in Inventor is more stuborn than the welders on the production floor.

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Nothing - NOTHING - is more stubborn than the welders on the production floor.

They absolutely HATE that I know how to weld, so I know perfectly well what they can and can't do, and can tell the difference between a valid complaint and a lazy complaint.

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@jyager wrote:

Modeling the welds seems like a giant waste of time anyway. Faster just to annotate them on the drawing.

Out of curiosity...does anyone find it's actually useful to spend the time toying with the weld function?

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If you're modeling the welds, then yeah - huge waste of time.  If you're using the built in welding function, not a waste of time.

As was mentioned earlier, stress analysis is a very handy thing to be able to do on your welds.  

[jyager]

Our stuff (maybe fortunately for me) is required to be run through structural ANSYS, so that probably wouldn't help me then.

It might be handy to make sure I'm in the right ballpark in the early design, but usually we're so overboard to compensate for seismic loads it probably wouldn't make a noticeable difference in the design workflow.

[rickduley]

>> Unless you're really concerned about the filler metals weight it seems like a lot of effort for little reward.

Couldn't agree more.

[Paul-Mason]

Two ways I used to do this, when I was a welder.

1) The two end/tack runs, check for squareness or the correct angle

2) A HALF length intermittent weld on one side with a full length on the other side (ie 20mm weld with 20mm space) 10mm on one side and 20mm other side

3) Mirror actions at other end

4) Carry on & complete the weld runs

other way

 1) The two end/tack runs, check for squareness or the correct angle

2) A HALF length intermittent weld on one side at each end and a full length on the other side at each end

3) Carry on & complete the weld runs

with either of these the weld should look something like a chamfer

[rickduley]

That's how the welder does it!

Problem is, how does the draftsman indicate that that is what is requested?  What does the wleding symbol look like?  How do you do this in Inventor? 

These questions remain unanswered.

[jyager]

Posted two possible options actually. Seems like we're making a mountain out of a mole hill, this isn't some revolutionary new weld arrangement that's never been done before.

Again. Forget Inventor. How would you show this weld in vanilla AutoCAD, or in paper? It's the same thing.

[rickduley]

Sorry about that

Missed your JPEG.

Do I have this right - you simply add a note at the end of the symbol saying to weld round the end.

Cheers

[jyager]

I have seen it done that way at multiple unrelated utilities over the years, yes.

Sent from my iPad