Metal layout

Re: Metal layout

L. Hanson

>There's a DOS program for it here:

http://www.geocities.com/mklotz.geo/

and the calculations are listed here:

http://www.webcalc.net/calc/0041_help.php

HTH

Leif

NorseWoodsmith.com

Re: Metal layout

Roger in Texas

>If you have access to Autocad or Turbocad I can send you layout diagrams. If not Ican probably walk you through it. It's a simple layout for a truncated cone.(2 actually: the neck and the "big part")

Re: Metal layout

Roger in Texas

>Lief,

Thanks for the geocities site. That looks like it will keep me busy for awhile.

Re: Metal layout

Todd O. Cronkhite Maine Native in FL. Exile :~(

>Ok Roger, see if you can walk me thru this. A fellow here at school is building a rescue bouy for a local Life Guard out of aluminum that has a cone on each end. Basically a cylinder with a cone on each end. He simply has forgotten how to lay out a cone/funnel. Old age I think, and just needs a kick in his memory.

Todd O.

Re: Metal layout

Ed Thomas, Leaside (Toronto) Ontario

>A cone is made with a pie shaped section of a circle. Bigger piece of pie gives a flatter cone. Maybe this will be enough to jog his memory.

The radius of the circle can be calculated from: the radius of the main cylinder he's attaching it to and the length of the cone required (Pythagorus(sp)). The circumference of the main cylinder can be used to calculate the arc required as a percentage of the circumference of the circle. Tools required: ruler/straightedge, compass and protractor.

Re: Metal layout LONG!

Roger in Texas

>Draw a 90 degree angle

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Decide how tall the cone will be (overall, not up the face othe cone at whatever angle)

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and draw another line across. The distance from the bottom line to the top line is equal to the the heighth of your finished cone.

From the vertical line measure horizontally , on the bottom line,(to the right in this crude ascii art)the radius of the cylinder you are trying to match.

Next,I'm going to ASSUME ( yes I know what that does) that you aren't actually going to truncate the cone, but want a "point". If this is the case,

then take a pair of dividers and set the distance

on the dividers to the point at the intersection of the top horizontal line and vertical line to the point on the bottom horizontal that you measured above.(the radius of the cylinder).

Now you can transfer this length to your sheetmetal and scribe an arc. The length of this scribed line needs to be slightly longer than the circumference of the cylinder you are trying to match. Take a straightedge and start at the center point of your arc and draw a straight line to one end of the arc. Now start at the intersection of this line and the arc and measure along the arc the circumferance of the cylinder and make a point. From this point draw a straight line back to the center point of the arc. this should now look like a triangle with one of the sides being an arc. From here add whatever you need for laps( to attach the sides of the cone to itself and the cylinder) and cut to these lines. Roll to cone shape and fasten. If you actually want a cone that has it's top cut off, then we need to go farther, otherwise I think this is long enough. Possibly, further discussion should happen by email being as this doesn't have a whole lot to do with wood. I would be more than happy to continue either here or email, just don't want to upset anyone by hogging bandwidth.

Thanks Roger !

Todd O. Cronkhite Maine Native in FL. Exile :~(

>I dunno what you said, but he read it and now is as happy as a clam! You said something that tripped his 70 year old memory.

Also thanks To everybody who responded, it made my day that you guys helped me make his day. :~)

Todd O.

Re: Thanks Roger !

Roger in Texas

>Any time I can Help.

It's nice to finally be able to answer a question on this forum, obiviously not woodworking because I have way to much to learn.

you had me worried....

Steve Kubien

>I thought you were going to make one of them cyclone dust collectors or something! Can't for the life of me figure what you'd do with such a thing in an neander shop.

Steve Kubien

Re: Metal layout

paul womack

>There are whole books on sheet metal layout, and it used to be a specific trade.

BugBear

Yep,"Tinknocker".

Bob Hackett

>

Still is

Bill Houghton, Sebastopol, CA

>Tinbender is the slang term in common use here on the Left Coast, or was during my brief sojourn in the trade.

The apprenticeship test used to use the Air Force shape recognition tests, and you have to be able to visualize a three-dimensional object and then imagine what lines and points will be necessary to lay out on a two-dimensional object to get there. It's kind of neat learning how to do that. The trade used to use a term that now escapes me (ah, god! middle age!) that was similar to the way boatbuilders talk about lofting, and, in fact, boatbuilding may be the best wooden analogue.

I still have the hand tools, but it's hard to do much without a good brake. If I ever get a decent-sized shop and stumble over a brake for cheap, I'll be really tempted...

Re: Still is

Roger in Texas

>If you stumble across two, I'll take one