2 Column Assembly Stack calculations - can anyone help?

[Tetragrammaton]

Hi All,

I have been working my way through 2 Column Assembly stacks and am a little puzzled over a problem.

Does anyone out there have any experience in doing 2 Column Assembly Stack calculations?

Or alternatively know where I could find a forum or other material that would be helpful.

Thanks in advance

Best Regards

Dave

 

[Heckler]

Dave,

I have never heard of "2 Column Assembly Stack" is that a method similiar to Direct Linearization Method (DLM), and Monte Carlo simulation?

Best Regards,

Heckler
Sr. Mechanical Engineer
SW2005 SP 5.0 & Pro/E 2001
Dell Precision 370
P4 3.6 GHz, 1GB RAM
XP Pro SP2.0
NVIDIA Quadro FX 1400
o
_`\(,_
(_)/ (_)

Never argue with an idiot. They'll bring you down to their level and beat you with experience every time.

 

[KENAT]

I'm with Heckler, what do you mean by 2 column.

Do you just mean +-, ie finding the minimum and maximum values?

Ken

 

[Tetragrammaton]

Hi and thanks for the quick replies.

Sorry I should have been more specific, I am referring to to the Advanced Assembly Stack Calculations taught in a course by Alex Krulikowski.

BTW I have no idea about DLM and the Monte Carlo Simulation.

No offence intended but at first I thought you were pulling my leg until I did a quick search on the net and found both of them. From the looks of both you mentioned they very heavily based in mathemetics although the 2 Column method is mathematics to the extent where you add up the min/max columns that's it to give a desired solution. It is also ideal in the respect that you can then optimise you tolearance if you wish it to be looser or tighter.

Esentially in the 2 Column Stack method is summarised as follows:
1. You identify the problem (make a note of conditons affectiong the stack to be considered, label the start/end point and direction of your stack),
2. Choose a desired answer (IE identify what you are seeking, min/max dist or both),
3. Identify the stack path (ie where all the repsective components contact each other and and form the shortest path, label the path, write the details in the respective columns.
4. Do the math

Please bear in mind i have put in 4 very short points the essesnce of what the course teaches. It is hard to convey a whole course in a few short lines but I hope this may give some of you a rough idea.

Regards for now, thanks in advance and hoping for some really interesting feedback. I'd really hope to find someone else who has done the course as well. Surely I can't be the only mortal who has done this specific course....pls

Best Regards

Dave

 

[Heckler]

Here is his website:

http://www.etinews.com/services_onsite_statistical_stacks.html

Are you taking the online class? You should be covering the two methods I listed above along with RSS and other stastical methods.

Best Regards,

Heckler
Sr. Mechanical Engineer
SW2005 SP 5.0 & Pro/E 2001
Dell Precision 370
P4 3.6 GHz, 1GB RAM
XP Pro SP2.0
NVIDIA Quadro FX 1400
o
_`\(,_
(_)/ (_)

Never argue with an idiot. They'll bring you down to their level and beat you with experience every time.

 

[KENAT]

If I've understood what you're saying then yes I've done it quite a few times, wouldn't claim I was an expert though. To me it's about the most basic tolerance analyis you can do, I didn't even realise there'd be a course on it, I just got told to get on and do it.

It gets more fun for something like a strap wrapped around something of which the diameter can vary but the basic process is fairly straight forward.

Following the steps you've put should cover it. The big thing is to make sure you have whether the dimension has a positive or negative effect, and hence whether you actually put the min or max value in that column.

When I find it more challenging is when as well as the hard dimensions you also have components that can float to some degree. Now that gets fun.

Did you have a specific question?

 

[TomGDandT]

Tolerance stack can be done fom 1D to 3D depending on your requirements, methods, and tools.
Software analysis programs that work with CAD data can be simple to use.

Tom Rhodes, GDTP-S
QMC LLC;

http://www.qmc.com

Senior Dimensional Management Engineer.
CeTOL 6 Sigma