I've been trying to figure out the best way to do this for a few weeks
now, and I haven't come up with anything I like yet. I'm working on a
product where 4 pieces of 1/4" round aluminum need to be able to screw
onto four sides of both 1 1/2" OD aluminum tube and 2" OD tube. Both
tubes are .065. Picture a hat rack with the large tube being the
center, but that's not what it is. These parts will be assembled by
the buyer, so it has to be simple, and yes, it does have to be in
separate parts... it can't be welded. Having nuts welded onto the
inside of the tube would probably be best, but the tube is too long to
do that. The best I can come up with is to just send a 4-40 machine
screw all the way through the tube and two pieces of 1/4" at a time,
and put a nut on the opposite side, but the proper lengths for the
screws to do that don't seem to be standard in 4-40 size. It would be
great to figure out a way to screw the rounds directly to each four
sides of the center tube, but I can't think of a way to do it.

Any mechanical geniuses have a good idea?

Dave99 wrote:

I've been trying to figure out the best way to do this for a few weeks
now, and I haven't come up with anything I like yet. I'm working on a
product where 4 pieces of 1/4" round aluminum need to be able to screw
onto four sides of both 1 1/2" OD aluminum tube and 2" OD tube. Both
tubes are .065. Picture a hat rack with the large tube being the
center, but that's not what it is. These parts will be assembled by
the buyer, so it has to be simple, and yes, it does have to be in
separate parts... it can't be welded. Having nuts welded onto the
inside of the tube would probably be best, but the tube is too long to
do that. The best I can come up with is to just send a 4-40 machine
screw all the way through the tube and two pieces of 1/4" at a time,
and put a nut on the opposite side, but the proper lengths for the
screws to do that don't seem to be standard in 4-40 size. It would be
great to figure out a way to screw the rounds directly to each four
sides of the center tube, but I can't think of a way to do it.

Any mechanical geniuses have a good idea?

You're talking about square tubing, right?

http://www.cardinalcomponents.com/fasteners.htm

Either screw your 1/4" Al to suit or drill for a screw fastener and use the
appropriate Rivnuts.

Tom

On Tue, 22 Apr 2008 21:44:21 -0700 (PDT), Dave99
wrote:

I've been trying to figure out the best way to do this for a few weeks
now, and I haven't come up with anything I like yet. I'm working on a
product where 4 pieces of 1/4" round aluminum need to be able to screw
onto four sides of both 1 1/2" OD aluminum tube and 2" OD tube. Both
tubes are .065. Picture a hat rack with the large tube being the
center, but that's not what it is. These parts will be assembled by
the buyer, so it has to be simple, and yes, it does have to be in
separate parts... it can't be welded. Having nuts welded onto the
inside of the tube would probably be best, but the tube is too long to
do that. The best I can come up with is to just send a 4-40 machine
screw all the way through the tube and two pieces of 1/4" at a time,
and put a nut on the opposite side, but the proper lengths for the
screws to do that don't seem to be standard in 4-40 size. It would be
great to figure out a way to screw the rounds directly to each four
sides of the center tube, but I can't think of a way to do it.

Any mechanical geniuses have a good idea?

This is a product that you intend to sell for profit, right? I
missed the part where you mention how you'd compensate one or those
who provides you with the idea(s) you profitably use.

Dave99 wrote:
I've been trying to figure out the best way to do this for a few weeks
now, and I haven't come up with anything I like yet. I'm working on a
product where 4 pieces of 1/4" round aluminum need to be able to screw
onto four sides of both 1 1/2" OD aluminum tube and 2" OD tube. Both
tubes are .065. Picture a hat rack with the large tube being the
center, but that's not what it is. These parts will be assembled by
the buyer, so it has to be simple, and yes, it does have to be in
separate parts... it can't be welded. Having nuts welded onto the
inside of the tube would probably be best, but the tube is too long to
do that. The best I can come up with is to just send a 4-40 machine
screw all the way through the tube and two pieces of 1/4" at a time,
and put a nut on the opposite side, but the proper lengths for the
screws to do that don't seem to be standard in 4-40 size. It would be
great to figure out a way to screw the rounds directly to each four
sides of the center tube, but I can't think of a way to do it.

Any mechanical geniuses have a good idea?

Countersunk Rivnuts?

--
Steve W.

"Dave99" wrote in message
...
I've been trying to figure out the best way to do this for a few weeks
now, and I haven't come up with anything I like yet. I'm working on a
product where 4 pieces of 1/4" round aluminum need to be able to screw
onto four sides of both 1 1/2" OD aluminum tube and 2" OD tube. Both
tubes are .065. Picture a hat rack with the large tube being the
center, but that's not what it is. These parts will be assembled by
the buyer, so it has to be simple, and yes, it does have to be in
separate parts... it can't be welded. Having nuts welded onto the
inside of the tube would probably be best, but the tube is too long to
do that. The best I can come up with is to just send a 4-40 machine
screw all the way through the tube and two pieces of 1/4" at a time,
and put a nut on the opposite side, but the proper lengths for the
screws to do that don't seem to be standard in 4-40 size. It would be
great to figure out a way to screw the rounds directly to each four
sides of the center tube, but I can't think of a way to do it.

Any mechanical geniuses have a good idea?

rubber Wellnuts (TM)?

On Tue, 22 Apr 2008 21:44:21 -0700 (PDT), with neither quill nor
qualm, Dave99 quickly quoth:

I've been trying to figure out the best way to do this for a few weeks
now, and I haven't come up with anything I like yet. I'm working on a
product where 4 pieces of 1/4" round aluminum need to be able to screw
onto four sides of both 1 1/2" OD aluminum tube and 2" OD tube. Both
tubes are .065. Picture a hat rack with the large tube being the
center, but that's not what it is. These parts will be assembled by
the buyer, so it has to be simple, and yes, it does have to be in
separate parts... it can't be welded. Having nuts welded onto the
inside of the tube would probably be best, but the tube is too long to
do that. The best I can come up with is to just send a 4-40 machine
screw all the way through the tube and two pieces of 1/4" at a time,
and put a nut on the opposite side, but the proper lengths for the
screws to do that don't seem to be standard in 4-40 size. It would be
great to figure out a way to screw the rounds directly to each four
sides of the center tube, but I can't think of a way to do it.

Any mechanical geniuses have a good idea?

Pemnuts should do the trick for you, Dave.
http://www.psminternational.com/html...ING-BUSHES.pdf
or
www.mcmaster.com catalog page 3150

--
Happiness in marriage is entirely a matter of chance. If the dispositions
of the parties are ever so well known to each other or ever so similar
beforehand, it does not advance their felicity in the least. They always
continue to grow sufficiently unlike afterwards to have their share of
vexation; and it is better to know as little as possible of the defects of
the person with whom you are to pass your life.
-- Jane Austen, Pride and Prejudice, 1811

On Tue, 22 Apr 2008 21:44:21 -0700 (PDT), with neither quill nor
qualm, Dave99 quickly quoth:

I've been trying to figure out the best way to do this for a few weeks
now, and I haven't come up with anything I like yet. I'm working on a
product where 4 pieces of 1/4" round aluminum need to be able to screw
onto four sides of both 1 1/2" OD aluminum tube and 2" OD tube. Both
tubes are .065. Picture a hat rack with the large tube being the
center, but that's not what it is. These parts will be assembled by
the buyer, so it has to be simple, and yes, it does have to be in
separate parts... it can't be welded. Having nuts welded onto the
inside of the tube would probably be best, but the tube is too long to
do that. The best I can come up with is to just send a 4-40 machine
screw all the way through the tube and two pieces of 1/4" at a time,
and put a nut on the opposite side, but the proper lengths for the
screws to do that don't seem to be standard in 4-40 size. It would be
great to figure out a way to screw the rounds directly to each four
sides of the center tube, but I can't think of a way to do it.

Any mechanical geniuses have a good idea?

Oops, I forgot one. I used to use one of these to put nuts in truck
doors for permanent mounting of large trailer mirrors.
http://www.harborfreight.com/cpi/cta...temnumber=1210

--
Happiness in marriage is entirely a matter of chance. If the dispositions
of the parties are ever so well known to each other or ever so similar
beforehand, it does not advance their felicity in the least. They always
continue to grow sufficiently unlike afterwards to have their share of
vexation; and it is better to know as little as possible of the defects of
the person with whom you are to pass your life.
-- Jane Austen, Pride and Prejudice, 1811

Those are all great ideas guys, thanks a lot. I knew there had to be
something like that, but I couldn't find it. Sorry, I forgot to
mention that this is round tube for the center, not square. But I
would think one of these would still work though, right? Since it's
just a 4-40 size, the heads won't be that big on the round tube.

Dave

On 2008-04-23, Steve W. wrote:
Dave99 wrote:
I've been trying to figure out the best way to do this for a few weeks
now, and I haven't come up with anything I like yet. I'm working on a
product where 4 pieces of 1/4" round aluminum need to be able to screw
onto four sides of both 1 1/2" OD aluminum tube and 2" OD tube. Both
tubes are .065. Picture a hat rack with the large tube being the
center, but that's not what it is. These parts will be assembled by
the buyer, so it has to be simple, and yes, it does have to be in

[ ... ]

Any mechanical geniuses have a good idea?

Countersunk Rivnuts?

That is what I would suggest, too. It helps to have the right
tooling, of course. The larger steel ones want hydraulic pullers, but
for aluminum ones (the most common), try ebay for the tooling:

320242645479 10-32 puller. (Called a "speed tool")
290223988051 100 10-32 Rivnuts.
Grip range .010 to .075 inch.

Scroll down to see what an un-set Rivnut looks
like. It expands in the middle to grip the
sheet metal from the inside, and leaves a
threaded section beyond that.

320242645759 8-32 puller. (Called a "speed tool")

190216705352 Three sizes -- but they don't say which sizes. :-(
Also called a "speed tool"

300218570212 Pneumatic powered -- expensive, but if you're
doing serious production it might be worth
while. This one is 6-32.

310043802502 Same, but 10-32.

(there are also 4mm and 6mm ones)

190217110740 Cheap, but you don't want this style if you have a
choice These are slow and clumsy.

My ebay search string is designed to skip a bunch of things
which I did not want when I was looking for these, and it seems to turn
up a pretty clean search still:

rivnut* -damper -"reference cd" -cessna -helmet -"belly pan" -ford
-raover -"cad plated aircraft grade bolts"

Note that for some Rivnuts there is a key on the underside of the
flange, and there is a separate tool for notching the hole for the key
to keep it from spinning inside the hole. It also has an angled handle
like the speed tool, but does not have the mushroom shaped handle to
pull out and in to spin the threaded arbor for the Rivnuts. This part
is where the "speed" come from. The tool has to be adjusted to a
specific set of Rivnuts and thickness of metal, but after that it is
every easy to use. Don't adjust it, and you can strip the threads out
of the Rivnuts.

Good Luck,
DoN.

--
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