Bracer radius

[ETW Grumpy]

Does anyone know how to figure the top and bottom radius for a wrist bracer? Also, is the radius different for different lengths?

[MikeCahill]

Does anyone know how to figure the top and bottom radius for a wrist bracer? Also, is the radius different for different lengths?

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get an old piece of wall paper left over from when you last decorated, about 3 ft. long at the left hand end draw a line from the middle of the paper to the edge at the other end, you now have a line that runs the length of the paper diagonally from the middle at the left end, to the edge at the right hand end. now lay your arm along side the line at the right hand end and mark a point on that line at your wrist, and another up where you want the bracer to end, near your elbow. Now with a pencil held vertically draw a line along the other side of your fore arm use a straight edge to continue that line until it intersects the first line this is where you get the arc from. Use a pencil and piece of string to strike two arc's one at your wrist point, and the other at the elbow point . measure around your wrist, transfer this measurement to the wrist arc, strike a line from where you started the arc's through the wrist arc, to the elbow arc. You now have "A development of a Truncated Cone" as my tech. drawing teacher would have called it, cut it out, wrap it around your fore arm, and play about with the shape until you are happy with it, thats your pattern. you can now make them any size

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[NoahL]

For wrist cuffs, which are just short bracers, I just take too measurements--one around the wrist, and one around the forearm where I want the cuff to end (or start, depending on how you look at it). Then, I lay those measurements out on a large piece of paper, connect the ends with straight lines, and viola, a pattern. If you are referring to getting the curve for the ends...I just eyeball that, to be perfectly honest

~Noah

[ETW Grumpy]

Mike, I'm a little slow, so bear with me. I'm drawing a line from the mid point on the left edge to the lower right hand corner to get a diagonal line?

[MikeCahill]

Mike, I'm a little slow, so bear with me. I'm drawing a line from the mid point on the left edge to the lower right hand corner to get a diagonal line?

Drawing the first line like that was just so you wouldn't run out of paper when you started constructing your drawing. your wrist is narrower than the flesh of your arm near your elbow, line up the outside of your fore arm with the first line with your hand pointing to the start of the line. Now mark how wide your wrist is on the paper at the inside of your wrist, and mark how wide your forearm is at the point where the bracer will end. Move your arm, and you have two marks on the paper. use a long straight edge, and draw through the forearm mark, through the wrist mark, and keep going until the line crosses the first line you drew.

Still with me? Now using a big pair of compasses, or a piece of string, pencil and nail, so you can draw curves fasten the nail, (or put the point of the compasses) where your second line crosses the first, and use the pencil and string to scribe two lines from the first line, one at the wrist mark and one at the fore arm (elbow mark). measure around the wrist and mark that length on the wrist arc from the first line. put one end of the straight edge against the nail, and draw a line through the wrist marks, and on through the forearm arc. The shape you have just drawn is like a paper cone with the top cut off and then cut along its length and opened up.

It's not an easy thing to explain, hope you understand, pm me if you want me to send some pictures, can do that tomorrow

[Storm]

I just got through making one from scratch so here was my approach. I used some heavy brown craft paper from Walmart.  I also got a reasonably priced adjustable curve from Staples a Staedtler 971 60-18. First I measured the wrist diameter second I used a ruler to see hoe far up the arm I would go and at the top I took anther measurement around my forearm. I also added another inch and a half for an overlap. On the craft paper draw a center line that is the length from wrist up the forearm

and using that as your center measure half the distance to the right and half the distance of the wrist to the left. Repeat at the top. Use the large flexible curve by using its center on the center line and draw connesting the right and left sides at the top and bottom.  You may have to do it a couple of times but from the paper pattern you can generate a pattern  on matte board or plastic. Then cookie cutter both the left and right sides using one pattern.

Hope that this help a bit. 

Storm

[MikeCahill]

I just got through making one from scratch so here was my approach. I used some heavy brown craft paper from Walmart. I also got a reasonably priced adjustable curve from Staples a Staedtler 971 60-18. First I measured the wrist diameter second I used a ruler to see hoe far up the arm I would go and at the top I took anther measurement around my forearm. I also added another inch and a half for an overlap. On the craft paper draw a center line that is the length from wrist up the forearm

and using that as your center measure half the distance to the right and half the distance of the wrist to the left. Repeat at the top. Use the large flexible curve by using its center on the center line and draw connesting the right and left sides at the top and bottom. You may have to do it a couple of times but from the paper pattern you can generate a pattern on matte board or plastic. Then cookie cutter both the left and right sides using one pattern.

Hope that this help a bit.

Storm

Building on Storm's solution, continue the line from the elbow mark, through the wrist mark, through to where it crosses the centre line, that is the centre of the radius, pencil and string from that point and you have perfect arc's

Cheers

Mike

[UKRay]

I thoroughly enjoyed this thread despite not understanding a word! I'll thank you for a lesson over a pint sometime, Mike.

Ray

[MikeCahill]

I thoroughly enjoyed this thread despite not understanding a word! I'll thank you for a lesson over a pint sometime, Mike.

Ray

It's not rocket science, I did this for my 11+ exam, the other one was calculating the volume of a cylinder, I can't remember that one probably because I've never had to use it, perhaps the problem is the quality of my explanation. I can see a mental image of it as I write this. by the way, the answer to your PM is sure, any time, give me a bit of warning, and I'll spend a couple of days digging some of the rubbish out of my workshop so you will be able to get into it

[Storm]

Good one Mike! I was thinking about saying that one could use a beam compass but I was not sure if many would know what this old arhitectural designer was talking about. I have found a nice one on Amazon.com with extension for US$37.42. Granted a compass and a string is fine but these work great for making large arcs and circles.

Storm

[Storm]

Before anyone has to shovel out their shop or warm up their ale.... I have come up with a visual aid which might do the trick. This does not preclude the idea Mike can stand a pint or two at the pub or Ray can fill us in on the Shropshire Slasher. Gin and lime for me thanks! LOL! All kidding aside I thought this might help. Hope its self explanitory enough.

Cheers,

Storm

PS: If anyone has a problem downloading this the PM me with your private Email and we will do it that way.

Edited February 2, 2010 by Storm

[MikeCahill]

Before anyone has to shovel out their shop or warm up their ale.... I have come up with a visual aid which might do the trick. This does not preclude the idea Mike can stand a pint or two at the pub or Ray can fill us in on the Shropshire Slasher. Gin and lime for me thanks! LOL! All kidding aside I thought this might help. Hope its self explanitory enough.

Cheers,

Storm

PS: If anyone has a problem downloading this the PM me with your private Email and we will do it that way.

spot on storm, by the way I was brought up to call the beam compass a trammel bar (Two peoples divided by a common language and all that)

[556guy]

I've used this method to layout bracers and cuffs in the past. It works well and gives a nice flat circle on each end. A beam compass like the one Storm showed helps a lot when laying these out. Remember to add any overlap you need for snaps.

Follow the instructions for Radial Line Development..

http://www.tpub.com/...ss/14251_62.htm

http://www.tpub.com/...ss/14251_63.htm

Hope this helps...

[Storm]

spot on storm, by the way I was brought up to call the beam compass a trammel bar (Two peoples divided by a common language and all that)

Beam or trammel, Potatoe or potahtoe, tomatoe or tomahtoe....HA! Although a length of string, a sharp lead pencil and a push pin or thumb tack(English translation inserted here  please) should work quite well as a field expeient. Oh lord how luddite of me. LOL!!! I will PM you a funny true story.

Storm

[MikeCahill]

spot on storm, by the way I was brought up to call the beam compass a trammel bar (Two peoples divided by a common language and all that)

Beam or trammel, Potatoe or potahtoe, tomatoe or tomahtoe....HA! Although a length of string, a sharp lead pencil and a push pin or thumb tack(English translation inserted here please) should work quite well as a field expeient. Oh lord how luddite of me. LOL!!! I will PM you a funny true story.

Storm

Drawing Pin!!

[ETW Grumpy]

Thanks to all of you. I believe I can get it right this time.

Storm: nothing wrong with low tech sometimes.

I'll post pics when I get it done.

Levi

[Storm]

Drawing Pin!!

I am going back a bit but I remember guys using a version of a thumb tack with two small holes which they called a Drawing Pin. They came with this little two pronged tool to pull up the pins. We used to use them mainly on maps created  with india ink and starched linen. I am feelingso old! HA! Here is a quick illustration of what some would call a push pin.

Storm