Challenging Mechanical Joint...Ideas?

[AlexLPD]

So I need to build the frame in the pictures, it is from withe aluminum comercial profile 2x 3/4" or so...
In one side of it, I planed to put acrylic and in the other side a metal sheet. Inside in the bottom (the narrow end)
put a neon ligth and voila... we get some decent ilumination for a small private pub.


So the question is, how to joint the C channel and the square tube...

I cant weld, because it will damage the withe paint.
I cant rivet, because as you can see, it isn fully backed in the c channel (space to slip the acrylic)
I cant use some long screw because I need the C channels as flat as possible. (see the picture)

I remeber saw some time, a sort of "expansion nut" If this will aviable I can put one in the inside of
the squere pipe and drill the C chanell, and use a chammfer screw for joint stuff together.

Any body know the rigth name for this? or maybe has do something like this?
I allready try to find this on the web but I cant find nothing like I need.

Kind Regards. Alejandro.




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[rake60]

Hello Alejandro

The focus of HMEM is on building running model engines.
I have no experience in the venue of building fixtures to light a pub.

If you get no other replies here please don't take it personally.
Your question just doesn't fit into the target interest of this forum.

However, I'm sure that if any of our members can answer your question
they will!

Rick

 

[RICHARDDV]

I make signs and other displays of a similar nature here at the casino that I work at and this is what I do when I need to join tubing to any other shape where welding wont work. I make a hardwood (brown stuff) plug that is a close slip fit inside the tube and secure it in the tube with Loctite pro-bond 420 ( industrial super glue). I then drill a pilot hole and use an approriate screw or other fastener to make the connection. This results in a strong and reusable connection --- Richard

 

[bearcar1]

Hello Al'. If I am understanding you correctly, you are wanting to build a type of frame arrangement from some C channel, with a solid sheet metal panel as a bottom (or top) plate and an acrylic sheet as the opposite side. Your problem of not being able to attach the small square stringers to the channels is creating the roadblocks, is that correct? If this is so, why not utilize the sheet metal portion of the assembly as a structural component much like the monocoupe shells used in the auto industry. A flange could easily be bent along the outer edge of the panel to fit inside the side rails and if mechanical fasteners aren't in the design criteria, then there are industrial metal bonding adhesives available that if applied properly, would be up to the task of holding everything in its place. Of course if the cross pieces were still needed for visual effects, they to could be secured in place using the same method but would not be integral to the frames overall strength. I do hope this makes some kind of sense and wish you the best of luck in your attempts at tackling the problem that has been presented to you.

regards
BC1
Jim

 

[Mainer]

You might try http://bbs.homeshopmachinist.net/

I'd probably make some square aluminum plugs that just fit the inside of the square tube, drill/tap the ends, slip them in, and put a screw through the side to hold them. Then drill through the C-channel and put a screw into the tapped end of the plug.

 

[Lew_Merrick_PE]

I remeber saw some time, a sort of "expansion nut" If this will aviable I can put one in the inside of
the squere pipe and drill the C chanell, and use a chammfer screw for joint stuff together.

Any body know the rigth name for this? or maybe has do something like this?

Alejandro,

What you are looking for has a brandname "RivNut" and is available generically as a "nut rivet." http://www.atlantictools.com/ has a fair selection without getting too pricey.

 

[AlexLPD]

Hello Alejandro

The focus of HMEM is on building running model engines.
I have no experience in the venue of building fixtures to light a pub.

If you get no other replies here please don't take it personally.
Your question just doesn't fit into the target interest of this forum.

However, I'm sure that if any of our members can answer your question
they will!

Rick

I dont take personal, It is just I don know how else to ask, and thinking there are plenty of
-mechanical related crafters- in here will be some one who knows anything. And for the replys
I can see, there is some good nice Ideas.
Thanks for reply, I hope keep learning in this forum.

Kind regards.

 

[AlexLPD]

Hello Al'. If I am understanding you correctly, you are wanting to build a type of frame arrangement from some C channel, with a solid sheet metal panel as a bottom (or top) plate and an acrylic sheet as the opposite side. Your problem of not being able to attach the small square stringers to the channels is creating the roadblocks, is that correct? If this is so, why not utilize the sheet metal portion of the assembly as a structural component much like the monocoupe shells used in the auto industry. A flange could easily be bent along the outer edge of the panel to fit inside the side rails and if mechanical fasteners aren't in the design criteria, then there are industrial metal bonding adhesives available that if applied properly, would be up to the task of holding everything in its place. Of course if the cross pieces were still needed for visual effects, they to could be secured in place using the same method but would not be integral to the frames overall strength. I do hope this makes some kind of sense and wish you the best of luck in your attempts at tackling the problem that has been presented to you.

regards

BC1
Jim

Thank you for the idea... if I pick up correct, look some like the pics, In did, its a very simple and elegant solution,
it just need to be test on the field, to see if there is enougth structural ridgity. The panels always will be in a small
pub, so there is strong vibration of the speakers hiting everyting in the place. And maybe if the panels arent enoug
ridgid the will vibrate therefore mess the acoustic. I say this for the acrylic part, I dont thing the metal sheet vibrate once it is complete glued.

KInd Regards.
Alejandro.

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[AlexLPD]

I make signs and other displays of a similar nature here at the casino that I work at and this is what I do when I need to join tubing to any other shape where welding wont work. I make a hardwood (brown stuff) plug that is a close slip fit inside the tube and secure it in the tube with Loctite pro-bond 420 ( industrial super glue). I then drill a pilot hole and use an approriate screw or other fastener to make the connection. This results in a strong and reusable connection --- Richard

Hello and thanks for the respose, in did there was something like this the most aproximated thing
I had in mind. I firs think in desing and cut some wood to achive the bewel efect, expansive inside the
square tube... But I will be much more complicated an much more expensive for achive the same effect
thath you accurratly describes some lines up.

I like this Idea because its easy, and can achive a decent tension, and even if there is neccesary use some
of the wood on the plug to make the chammfer of the screw allowing the perfect flat profile necessary.

And in case I accidentally cut some longer, I can put back in the mitter saw and cut througth the good and the Al.

Thnaks for the reply.
Kind regards.
Alejandro

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