Tab and Slot Joints in honeycomb panel

[RicN]

Hi,
I am new here as I just found out about the site. I just got a job at Boeing in the Payloads group as a designer working on cabinets, closets.. I got a design assignment making a plenum. It basically a rectangular box made up of honeycomb panels, and my lead said to use the tab and slot joints. I did a quick search on Boeing documents about the subject, and found some about Mortise and Tenon joint, and Rabbett joint. However I haven't found any document that says how loose/tight should the tab/slot be, spacing between the adjacent tab/slot. Before I went to my lead and ask for more specific infos, I wonder if anybody here know anything about it and can offer me some kn

 

[RicN]

oops..the end of the previous meesage was cut off for some reason.
I wonder if anybody here know anything about it and can offer me some knowledges on the tab and slot joints subject
Thanks a lot

 

[der8110]

Ah, the Boeing scavenger hunt. Bet you had to sit and listen for hours about how great your lead is, then sent out to find a safety pin, a length of twine, and a bottle of propwash.

Tolerances are going to be driven by the bond line thickness of the adhesive used. Often times a round bit (they tend to be) is used to cut a slot and the ends are left radiused. Where glue does not stick is filled with a compound like ATR1000 or EC3524. The bit diameter is slightly more than the nominal panel thickness, or the same diameter and a hand file is used to open it up a small amount.

Of course you did not find information on how tight/how loose, or spacing (pitch), since those would be separate documents! A roundabout way to find this is to get the joint strength allowables, which will tell you the configurations and conditions of test. You are going to need this eventually; sooner or later you will have to pay homage to the tin gods known as DER's, and no new engineer can be allowed to pass without knowing the strength of the most trivial piece of interior trim. Your design better be one of those already tested. And once you are brought into the inner sanctum, don't try to know answers to every question - you will be labeled as a smart aleck and sent off to find something else.

 

[wes616]

I believe that there is an SAE paper on this subject.

Wes C.
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[RicN]

Thanks for the tip DER8110.