[How do I?] Best Way To Design/fab This Hinge?

leeko

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Hi all,

I'd like to make something along the lines of a clothes peg, only in stainless steel and with a tight/ smooth joint. I've attached a picture of what i envision. The problem I'm having is how to make the hinge?

Originally, I'd planned to make the 2 halves first, then clamp them together and run an endmill through the hinge point. Then, braze a hinge into the hole (middle portion brazed to one half, outer portions to the other half, then pinned together). But, I'm now thinking that the braze may get messy around what should be 2 sliding fit pieces. Is there a better way to do this? I have a lathe, mill and rotary table available.

Thanks in advance,

Lee

clothes peg.png

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Make each hinge half then use a ball end mill to cut the groove for the pivot pin. Instead of brazing how about silver solder? Or you could pin the pivot pin to one hinge half. Hope this gives you some ideas.

Tom S.
 
Clamp and bore as you proposed. Counter-bore each end for a bushing. Silver solder the pin to one of the halves. Assemble and silver solder the bushings to the other half with lower temperature solder. Tricky soldering ,and not to be disassembled.


Alternative: counter-bore each end for two bushings. Solder two bushings into each half. Assemble. The pin should be a running fit to the bushings soldered to one half and a light press fit to the others.

Rather than solder you could run screws through from the flat sides of the halves into the shafts and/or bushings.
 
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Lee---after thinking about it ------to give you a better idea, I would need to know approx. the size of the part ---here is how I can picture doing it-----drill your hinge pin holes just big enough so a hardened dowel pin will slip in without any slop----then somewhere on the dowel pin--( in the middle would work for you to picture the method ) grind a groove like an O ring could fit in ---grind it deep enough just leaving the center portion about 1/4 of the diameter------now drill a small hole in the middle section of the hinge that will line up so when you press a small spring pin(roll pin) in it will go through the slot area on the Dowel----now slip the dowel pin in and press the spring pin in so this will keep your dowel from sliding out----you can now understand that the groove can be in any of the three hinge sections as long as you drill your spring pin hole to align to the groove---remember that your groove needs to be a little wider than your spring pin---drill your spring pin hole through the hinge section so you can remove the spring pin easily for disassembly -----Dave *note that if this is a larger part--- a special ground set screw could be used instead of the spring pin
 
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Hi, i just came back to the forum and realized i never rechecked this thread. Thank you all for the excellent ideas, which pretty much all sound like they will do the job. Dave, I'm having a bit of a hard time visualizing yours though. Are you aware of any examples by any chance? My part will be about 10" in length overall.

Just a minor question, though - is there a benefit to silver solder over braze?

Thanks again!

Lee

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Some silver solder can be done with a propane torch. Witch is good if you don't have an OA set.
 
Ideally a 2 axis CNC mill.
Manually a rotary table would do nicely, first bore the pivot hole in the over sized stock as a reference surface which will be X0, Y0.
Calculate the positions and angle where the tool should begin and end cutting plus the tool radius offset, if done correctly the tool will be in position to rotate about the center of the hole and begin the next angle until finished. Keep in mind that stopping the tool will leave a mark that many hobbyists find undesirable.

I drew this because I'm bored and it may help someone, used whole fractions for simplicity.
The white lines are the part, the cyan lines are the tool and tool path.
The upper drawing describes the part dimensions, the lower drawing defines the tool position in cartesian coordinates (1/4 diameter tool), these are positions relative to X0, Y0, software may call this ordinate or absolute position
hinge_zpsfs5eogly.jpg
 
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lee---I'm not one that can draw things out----think of it as a regular hinge with a pin that goes through the three to hold it together and allow it to rotate--on a door hinge the pin has a top on it to keep it from sliding down----on your part you use a nice hardened dowel pin to fit flush on each end---on the middle section of the dowel grind a slot like an O ring could fit in---now drill your roll or spring pin hole through the middle section to line up with the groove on the dowel pin so when you rotate your hinge your dowel pin is able to rotate but not slide out either direction ---your groove on the dowel can be ground deeper than the spring pin diameter but not much wider so it can't move side to side---just needs to rotate---hope this helps you ---I'm not real good at explaining my ideas----Dave
 
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Make each hinge half then use a ball end mill to cut the groove for the pivot pin. Instead of brazing how about silver solder? Or you could pin the pivot pin to one hinge half. Hope this gives you some ideas.

Tom S.
The silver solder is best over brazing; a very strong, THIN, joint.
 
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