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Advice on riveting moving joints Answered

Hi guys.

I've been prototyping some very basic steampunk mechanisms that I'm preparing an Instructable for, and I'm looking for a bit of advice on how to make the moving joints.

The mechanisms are simple, with parts I'm cutting from brass sheet myself. They'll be using joints that I'd like to make reasonably permanent and low profile, yet able to move (elbow joints, for want of a better description). I've not tested it yet, but I've read that putting a piece of paper between the two arms before riveting them (blind/pop rivets) will allow the joint to move once it's fastened together.

I was also considering whether it might be advantageous to put a nylon of teflon washer between them before riveting, instead.

Any advice on whether this type of moving joint would be any good, if it would last with moderate use, whether it would work at all, and what some possible alternatives might be would be very much appreciated. Thanks in advance!

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You can use a Pivot-Nose to make a get clearance between rivet head and sheet. Check Stanley website..Hope this helps.

I have used regular pop rivets for hinges in sheet metal for many products I have designed. We even instruct the factories to use this setup for production...

Get some very thin shim material, like 0.020" (depends on thickness of parts to be joined). Cut a slot in one end of the shim, slot width should just fit around the rivet body, and this shim will be re-usable for all of you rivet-hinges. put your rivet thru the holes in the pieces to be 'hinged', and put your shim in between the 2 parts. Then place a small washer over the end of the rivet that sticks out through the other side of your parts. Crush the rivet as normal. Remove the shim, and your done. The rivet head and washer should be sandwiching the parts, with a tiny bit of clearance from using the shim, and should hinge quite nicely. We use this as a permanent solution on a lot of sheetmetal products we make, so should hold up well.

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nerd12

5 years ago

well, I think putting a piece of paper would be fine, a washer would make a noticeable gap. I need to make a pantograph mechanism, but i don't have rivets. Is there a substitute? It can be a little weak, due to low stress on the pantograph, but can someone suggest a cheap and easily available substitute for rivets? I am going to use thin metal or plastic for the pantograph, and i don't have an anvil or blowtorch.

Nuts and bolts do the same thing as the rivets. You can cut off the excess bolt but it will protude or have a bump on one side. The nut will need to be fastened with a locknut or thread adhesive. If you are really stuck, use those paper fasteners - gold tacks with the leg that splits and folds out.

I tried to find nuts and bolts, but all the hardware store here have minimum 3-4 mm thickness, and i need 2mm, preferably 1mm. Getting nuts and bolts in such a tiny size is tough, if even possible.

Pop rivet guns/tools are fairly inexpensive $10-20 for the installation tool and rivets. All you need to do is drill a hole to fit the pop rivet.

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ojimon

6 years ago

Hi ... I have a similar question, though I'm not specifically trying to join bits of metal at the moment. I've been searching the Web for advice on how to set a "loose rivet" such that rotation movement could be achieved ... imagine using such rivets as the joints for an articulated paper (or wood) doll, or in a piece of jewelry where you want to join two pieces and let them "spin" independently, for example. I did see the suggestion somewhere of using a piece of paper between the pieces to be riveted, but I admit to still being confused ... is one supposed to tear the paper away after the rivet has been set, so that it fundamentally serves as a temporary "spacer"? If not, does the paper only "ease" movement by reducing friction ... and if so, how does one keep from setting the rivet too tightly to permit movement in the first place? I feel stupid asking this, but everything I've seen explaining how to set rivets seems to assume I want a very tight connection. I actually need a connection that permits easy, unobstructed rotational movement. In the case of an articulated paper figure, I'd prefer a rivet to a brad, because I don't want to have to accommodate the horizontal bits of metal in a brad. Any pointers? Thanks for any help anyone can provide ...

I'm no expert but wouldn't it be simpler to use some form of hinge and only rivet the ends of the hinge to the parts? This way the rivets would be fixed and the movement happens only in a part specifically produced for it.

For certain parts that is indeed a good option -- good thinking. But I'm not sure if it'd work for other parts. Some of the arms are joining together in a kind of scissor link, or crank slider fashion (apologies that I don't know the proper mechanical terms, which would undoubtedly make this easier to explain), so a hinge wouldn't really work in those situations.

Without knowing the exact mechanism you are going for it is hard to suggest a possible alternative but there are all kinds of hinges and joints out there. From your description something like this would seem to work but I don't know the proper name for this either (found it by googling scissor hinge).

DIY stores can carry a nice selection and specialised suppliers will have some more exotic varieties that the DIY stores don't keep in stock.

Sorry I can't really help with making your own joint..

That "piece of paper" advice is exactly what I would have suggested - experiment with scraps, though, to determine exactly how many thickness of paper are required to achieve the freedom you desire.

A Teflon washer would ease movement, but I'm not sure by how much. Again, experiment on scraps, because this option may give the brass less room to move out of the plane of the joint and split.

Thirdly, you may want to extend the joint - if you replace the single rivet with a flat strip, riveted at each end, then each joint will turn half as much, lasting (I hope) twice as long.