Connectors

with out knowing all of the factors it is tough to imagine the exact situation. what comes to mind is a dresser coupling or another type of compression fitting. many have differant sizes of inserts to adapt from proposed to existing. offten the sizes of the pipe are not exact to one another. with square stock nothing comes to mind.

Just so I (we all?) understand, I'm guessing the tubing will be in a horizontal (or, at least, a non-vertical) orientation, and supporting the load cantilever fashion?

(Supporting 5 lbs as a vertical column with 1" square tubing would seem to be child's play / overkill.)

Yes correct. My thinking is if I use the nylon square tubing connectors in the tubing and drill through and place a screw or bolt there should be little or no play. The nylon connectors must be hammered in as they are an interference fit. Unless someone physically misuses this the weight on the end would be at most 16 inches, possibly 20 but I doubt it will be that long. basically we would have the possibility of one 4 inch tubing, or an 8 nch, or two 8 or an 8 and a 4. This is to allow a reach based upon the users need. It will hold the load, but it will be a stationary load.

1 1/4" 11 gauge sq tube will make a connector for the 1" tube to side in. Doing it this way aluminum may be better. As steel will have some distortion at the seam where it was welded which would have to be cleaned. 11 gauge spec is .125 most sq tube 11 gauge is .120 so you will have some clearance to slide it in.

Have you thought about using extruded aluminum? Many companies specialize in this stuff, such as Bosch Rexroth, 80/20, and many many more. They can provide you a complete kit including all connectors, screws, fixtures etc... it's a very nice way to simply, and easily construct many different things.

thanks, aluminum is a possibility but my client is more preferable to steel, as am I, though I have and still am considering it.

actually that was exactly what I was thinking and I ordered one to try. My client is not convinced that there would be no play however. I do not think there would be an issue but will try it to make sure.

I think if there is any play, it could be easily eliminated with some sort of thin plastic shim. Although if your going to follow up with screws I can't imagine much, if any play.

GA.

These are great. We've used them to build custom racks for equipment operators in aircraft installations. We usually use the connectors with 4130 square tubing and find them very stiff and stable for potentially turbulent flight conditions.

Hooker

Just had another idea. I wonder if you could make a square compression fitting out of wood with a narrow slit in the ends. Remember Tinker Toys. Might not even need screws.

For production though I am looking for quick and simple and I do not see where these nylon connectors, with a hole drilled and a screw into them wouldnt work, but of course the proof is in the testin so guess I have to wait til the one comes and I can try it. this is for a mounting system which would attach to the back of another device and hold a box basically. I think the design will work wonderfully but I also want to make sure before investing too much time and effort on it. The outer sleeve idea crossed my mind as well using 1.25" tube and tapping it and using set screws to tighhen it. These are all possibilities and definitely some very good suggestions. The main part of the unit is to be made from steel due to the thickness and strength needs. the main accepting slot for the arm is to be steel welded to the plate, so in keeping with this I think sticking with steel is the best choice to keep things simple. if then on the end I have to go back to steel or switch to aluminum then there will be likely the need for welding that as well. I wish to simplify the manufacturing process and the total number of parts and processed. thank you all very much your suggestions are helpful.

I have designed many things using extruded aluminum profiles. You won't need to weld ANYTHING, and I can guarantee it is plenty strong enough to do the job. You might think it's extremely expensive, but it's really not that bad. The end product looks very slick and professional, and is strong as heck. It's so easy a one armed monkey could assemble the structure with only a couple simple hand tools.

Good luck with your project & don't forget all your extra labor costs if you are mucking around with trial and error, welding, cutting, drilling, tapping, fitting, and assembling while trying to reinvent the wheel it can get expensive. The extruded aluminum kits require no cutting, no welding, no drilling, no tapping, no fitting, etc... Just pull the pre-labeled pieces out of the box, pre-cut to your specifications/drawings, with all pre-labeled fasteners/fittings etc... I just know a lot of guys don't compare the cost of labor to the cost of increased materials needing less labor.. oftentimes the more expensive product can reduce a lot of labor time thus increasing your profit margins. Just a thought... I use the stuff and love it. (in many cases it comes out to be way cheaper than welded steel structures).

More links:

http://www.8020.net/

http://en.wikipedia.org/wiki/Extrusion

PS - I should also mention that they will help you with your design, and in most cases, their Engineering is Free.

thank you, I am aware of the strength of aluminum but the overall product is to be sleek and look good with powder coat finish and easy to assemble. I have given much thought to aluminum. there would be the need for a weld because of the nature of the part this will attach to it must be steel and there is no room for bolt heads or anything on the other side, and it is not thick enough for recessed bolt heads so the reciever must be welded to the plate. I could go with aluminum and it is not out of the question but for aesthetics I feel steel would be the way to go.

Only you know the true limitations of your design.

I have simply found that in many cases where people will traditionally cut/weld/fabricate a custom framework for relatively low stress applications out of steel, the same end product can be achieved quicker, easier, at a lesser cost, and in most cases much much better looking, and completely adjustable using extruded aluminum... Most people either don't know about it, or don't think about it.

A couple years ago I designed a automated shoe box folding/gluing machine. The customer wanted a fancy welded steel framework. I proposed using aluminum extrusion...

One of the sell points I used, was the fact that at any time in the future, any of the fixtures, tooling, framework etc can be modified/adjusted/tuned in a matter of minutes, with a single tool.

They were concerned with the structural capacity of the extrusion... Until I showed them the numbers which spoke for themselves. Many of the extruded shapes are stronger than the equivalent size standard steel shapes available.

In the end, they went with the Aluminum which saved them a truckload of money. These machines were to be placed all over the world in many third world countries. If we had made them out of welded steel the shipping and assembly would have cost an arm and a leg, and been a huge headache.

They received each machine as a "Kit" which they were able to assemble using only a couple hand tools. Each kit came with a set of instructions which a 4th grader could follow, and the machines were assembled on site with no issues.

The customer was extremely happy with the decision.

This happens time and time again.

(yes, depending on the job I build plenty of welded steel structures too, but your project seemed like the perfect opportunity for this stuff.)

Hope you find the perfect solution to your problem!

Yes I have seen and had use for that as well in a plant I used to work at. no doubt it is wonderful. weight is really not an issue as overall we would be dealing with a difference of maybe half pound overall for my project. This is more a home appliance than anything and appearance for the customer is one issue. a polished black, solid tube would be preferable. I just thought someone here would know of a metal connector available for this. No doubt the nylon ones will do great but seems to me there would be a metal insert connector similar to the nylon ones. Perhaps I can locate one in this country. I have a source overseas but usually one has to order large quantities for that to be worth the cost.

So then this is not a production scenario...

Have you looked at These?

Also... not sure if it would work, but these guys?

Good luck with the project!