Converting a 3D object to a flat layout

[richmond0001]

I am wondering if I can convert or extract a flat sheet layout from a 3D cylinder. I would like to provide a 3rd. party Laser Cutting shop with a flat layout to cut my cylinder walls from.

[steve216586 · Accepted solution]

Start REC command. Click on start point. Input in (x,y) format ([2xPIx{radius of cylinder}], [height of cylinder]). 

If it is the same cylinder you asked your other question about which has a 10 degree slope for a bottom you will have to select the max height of the cylinder as the "Y" value length. Then draw two lines starting from the midpoint of the edge which represents the bottom circumference at 10 degrees to the edges. The top (lid) if needed, will be a circle with the circumference of the cylinder OD + any overhang. The bottom will be an elipse which you can draw on your 3D model OD to find the radii of the arcs required + any overhang.

[JDMather]

You left out Bend Allowance calculation.

Material stretches on the outside of a bend and compresses on the inside.

Then neutral plane (neither stretch nor compress) is usually not midway in the material.

Bend Allowance dependant on
Material

Thickness
Bend Radius

Bend Angle

Machinery's Handbook covers this and modern CAD programs like Autodesk Inventor calculate Bend Allowance or use of Bend Tables generated from machine specific data.

[steve216586]

JD

That's all well and fine if you are designing >14" thick ship hulls I guess but here (http://www.jazdwater.com/waterwastewaterdirect/company/Burt-Process-Equipment.htm?categoryPath=Tanks...) we make 1/2"-3/4" Polyethylene, Polypropylene & Stainless Steel tanks, similar to what was drawn in the other question, and don't calculate for bend allowances. Machines are pretty advanced for this type of operation and our tolerances are in the 1/8" area. Your comment is very well based in theory but just not necessary in real world applications of this sort. Classroom FYI, IMHO.

[JDMather]

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@steve216586 wrote:
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 Classroom FYI, IMHO.

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Most sheet metal isn't particularly close tolerance - but I recommend you post your observations over in the Inventor forum where there are a lot of sheet metal users.  I think they might have some observations that go beyond the classroom.  (an 1/8 tolerance would be rather extreem for them) There is a reason the Machinery's Handbook has a section on this.  I haven't checked - but I rather doubt the tables in the Handbook go anywhere near 14" thickness.

[steve216586]

Again JD,

I checked out my copy of the Machinery's Handbook pgs 1304-1311. You are way off if you think these tables refer to storage tanks or large diameter bends. Those tables and formulas are for "drawing" metals and bending metals @ 90degree bends with a dedicated section with formulas for calculating angles other than 90degrees with simple tools or on a bench, seen on pg 1307. Sheet metal as in presswork or duct work. Not cylinder fabrication of large diameter storage tanks of any material, especially stainless, PP or PE. Did you even look at the link in my previous post? D-

When I referenced a 1/8" tolerance It is understood in my area of expertise to mean total diameter. Our tanks can be specified at 60" but 59 7/8 to 60 1/8" is perfectly acceptable. We aren't fabricating anything with an FN interference fit.

[Bob_Zurunkle]

My understanding is that different shops have their own bend tables based upon experience with their particular equipment -- so whatever comes with Inventor or Solidworks is just a starting point, that can then be tweaked for a particular shop's standards.

[JDMather]

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@Bob_Zurunkle wrote:

My understanding is that different shops have their own bend tables based upon experience with their particular equipment -- so whatever comes with Inventor or Solidworks is just a starting point, that can then be tweaked for a particular shop's standards.

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SWx and Inventor both allow either a k-factor calculation or experienced based Bend Tables.
I think the OP is long gone.  Who knows what their real need is?