What kind of hinges are these?

I don’t think they make those anymore, but it is very similar to flange hinges, soss hinges, and knife hinges. Most utilize a stacked setup now, instead of a slotted one like the picture above.

Scissor hinge – rockler has ‘em.

M

Scissor hinge – rockler has em.

M

- Madmark2

No, Rockler does not have them. They have knife hinges, but that’s not exactly the same thing. I had already looked at the usual places on line — Rockler, Garrett Wade, Lee Valley, no luck. Even the images that web searches returned never showed a hinge, always a folding rule with the hinge.

I’ll probably just buy a folding rule and take the hinge from it.

-- Half of what we read or hear about finishing is right. We just don’t know which half! — Bob Flexner

It looks like a rule joint. Thats used on tables sometimes. So maybe a rule joint hinge

-- Aj

http://www.whitechapel-ltd.com/product/202FS2A.html
Saw these, not cheap, maybe some more searching will turn up cheaper one’s

That’s what it is Aj. Good find. I still don’t see hinges for sale, but I’ll keep looking. Like I said, it might just be easier to buy a folding rule. I’m not ready to give up like that though :)

-- Half of what we read or hear about finishing is right. We just don’t know which half! — Bob Flexner

http://www.whitechapel-ltd.com/product/202FS2A.html
Saw these, not cheap, maybe some more searching will turn up cheaper one s

- cutmantom

I saw that. I could definitely adapt it for my needs, but I can buy a folding rule and steal the hinge for less. Thanks for looking though.

-- Half of what we read or hear about finishing is right. We just don’t know which half! — Bob Flexner

You need the hinge to build a sector correct? I am looking for the same thing you are, and I am having trouble as well. You might have better luck searching for a “Pivot” or “Pivot Hinge”. Using those keywords, I have come very close to finding what I need, but have not hit the jackpot yet. I’m not giving up, and if I find the right pivot I will post the source here 4 U.

Also, as you may know, you can use a folding ruler as a sector. I do it all the time and it works quite well. The problem is you don’t have all three lines (line of lines, line of polygons, and line of circles) that are on a “real” sector. But, as woodworkers, we most commonly use a sector for finding proportions without using a measuring tape and doing the math (nice!). That can be done just using the “line of lines”, or more simply put, just using marks on the edge of the sector.

Good Luck!
Bill

Probably your best bet is going to be to cannibalize and old Stanley folding rule, they are running about $15 on ebay. That is probably less than what you would pay if you could find the hinge.

-- Bondo Gaposis

i’ve seen some pivot hinges that look somewhat similar. if you don’t need many, perhaps you can make some

-- “Facts don't care about your feelings.” ..., Ben Shapiro

Since Rich was originally looking for these in April of 2017, I’m going to go out on a limb here and say he has either already found them or has stopped trying…Rich?

-- The optimist says "the glass is half full". The pessimist says "the glass is half empty". The engineer says "the glass is twice as big as it needs to be"

Well, the hinge that is in the bottom picture of the original post was designed and manufactured by the same guy who built the sector it is in. I can’t remember his name, but he teaches a class on building sectors. Bottom line is there is no commercial source for that hinge.

The idea of scavenging a pivot hinge from an old folding ruler may be doable, but I don’t think it is a practical solution. the part of the hinge that gets embedded into the wood is quite thin, and I don’t know how you would accurately cut groves for them in the new project.

I just finished a prototype of a simple sector that is working very well for me. I just used a 10 X 32 machine screw at the “pin” so the two wooden legs of the sector pivot around it. I put a knurled nut on the top of the screw so I can tighten it as required.

Tung’s right. This is an old thread and I’ve found a hinge that works. For the record, the designer of the sector shown above is Brendan Gafney. I corresponded with him regarding obtaining a hinge, but he had only made enough for that run of sectors that sold out.

Scavenging an old hinge is very doable. Not all folding rules have the same style of hinge. Among Stanleys for instance, there are round, square and arched. They all connect to the legs in a different fashion and some are more suitable for repurposing than others. Not to take anything away from Brendan’s fine work, but the round hinge is the weakest and was only used on low-end rules back in the day.

Also, proper use of a sector does not require locking the legs with a nut. All transfers are done to and from the sector with dividers. You never place the sector itself against the workpiece. I know articles have been written that show that technique, but they are dumbed-down to make them more approachable to someone just wanting to use a couple of sticks as a rough approximation. That will get you most of the way there but is very inaccurate.

-- Half of what we read or hear about finishing is right. We just don’t know which half! — Bob Flexner

I took Brendan’s sector making class at Lost Art Press this year. It was great a great class and all six of us made beautiful sectors.

By his own admission, Brendan sacrificed many old rules to understand the hinge. He designed the sector hinge and found a machinist with a water jet to cut the pieces. The hinge was actually 5 pieces of brass (not counting the 5 pins). There are 2 disks and 3 shaped pieces that are inserted into the wood arms. Once the pieces were inserted into slots in the wood and the 4 pins inserted to hold them, the pivot pin was inserted and peened. The holes in the top and bottom disks were slightly “countersunk drilled” to provide space for the peen to hold everything in place.

TonyC

Brendan is holding another class in Sept. of 2019. I would love to go, but not sure I can given it is 1,700 miles North West of me. That adds a lot to the cost of the class. So, I have opted to work with a simpler version that only has the “line of lines” on it. The prototype I made works quite well but, there is one thing I don’t like about it. The line is just the inside edge of the sector with marks like a ruler to show the increments.

@Tony Could you describe the method used to mark the line of lines on your sector? I assume the angle is somewhat arbitrary as long as each line is exactly the same angle from the center of the hinge. I would like to figure that out before making another sector.

Bill