sheet metal cylinder

[scoopthepoop2000]

I am using IV 2009. I have made a sheet metal cylinder and it unfolds just fine. However now I would like to put some holes through it. The way that I would like to do this is by using the project flatten pattern tool, draw some circles for the holes then use the cut across bend to make the actual hole. Is this possible to do? I know that I can do it in the flat pattern model but this does not reflect back when it is folded and I can put holes in it folded but when it lays flat the holes are eliptical.

[Anonymous]

All "features" done in the "flat pattern" context,
stay in the flat pattern only. It might be easier for this to start with a flat
sheet and fold each side to get your cylinder. Any features placed on the flat
sheet before the fold will be processed as a straight through hole and will show
the distortion as folded, but will be correct when flat.

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<scoopthepoop2000> wrote in message
href="news:6139363@discussion.autodesk.com">news:6139363@discussion.autodesk.com...

I
am using IV 2009. I have made a sheet metal cylinder and it unfolds just fine.
However now I would like to put some holes through it. The way that I would
like to do this is by using the project flatten pattern tool, draw some
circles for the holes then use the cut across bend to make the actual hole. Is
this possible to do? I know that I can do it in the flat pattern model but
this does not reflect back when it is folded and I can put holes in it folded
but when it lays flat the holes are eliptical.

[JDMather]

There is an easy method. Sketch your holes (anywhere, on flat is fine). Roll up the EOP, zip and attach here and I'll demonstrate.

[scoopthepoop2000]

Here it is with cut holes through the flat pattern.

[JDMather]

Here it is with the Cut Across Bend.
Drag down the EOF marker.
This was done in edu version so of course you will have to do it over after examining the technique.

[scoopthepoop2000]

That works really well. See if you can help me with one other problem regarding this cylinder. I have reattached the cylinder only now I made it into an ipart. The only difference between both parts is the width. The only problem that I have is the sheet metal extents do not update. How do I get them to update? It would appear I can over type the cell with the correct value but that does away with the parts list and the part being associative. As it is now when the parts list references this part the length and width read the same for both parts.

[Yijiang.Cai]

Hello,

If you would like to get the desired sheet metal flat pattern length and width associated with each iPart member, please see this thread located at http://discussion.autodesk.com/forums/thread.jspa?threadID=719055&tstart=0

Thanks,
River

[RANDYWINDERS]

I have a question concerning the cut across bend on the cylinder. I have a very similar problem. I am making a liner for a cyclone, cylinder on top of a cone. six pieces, each rolled. Will be subsequently bolted to inside of the cyclone. When JD made the sketch for the holes what plane was the sketch drawn on? I can't see it. I want to be able to do the same on each of my liner pieces.

[JDMather]

>When JD made the sketch for the holes what plane was the sketch drawn on?

Look very very closely. Of course the sketch must be made on a planar face of the part. Size of that planar face can be microscopic. I removed the sacrificial face as part of the Cut.

Might be easier in v2010 if you have it.

[RANDYWINDERS]

don't have 2010, working with 2009. did you make the sketch on the flat pattern? if not how did you get a planar face on the cylinder?

[JDMather]

>how did you get a planar face on the cylinder?

Your not looking close enough.
Examine the gap in Sketch1.
Very small line connected to arc at gap.

[JDMather]

Maybe this will help - very same file with the gap dimension increased a bit.
(do not pull down the End of Part marker below the Cut1 feature - only below the Contour Flange feature)

[RANDYWINDERS]

thanks JD. I had to change my sketch to make the planar face tangent to the arc rather than just the endpoints coincident. It worked. thanks a bunch.

[RANDYWINDERS]

OK, now I need to do the same thing with a cone segment. I built the cone segment with a surface loft with a short tangent line on one end. without the tangent I can flatten it. with it I cant. I would like to use the same concept of putting holes in it as the cylinder but can't figure out how to get the flat pattern to project and layout the holes. Please help.

Inv 2009

[JDMather]

>built the cone segment with a surface loft

Did you do a search on this? This has been covered many many times here with examples.

Can't use Loft for this in r2009 or earlier - must use Thicken.

[RANDYWINDERS]

yes, I did a search. Thats how I learned to make a cone that would flatten. I used a surface loft and then thicken. Getting the cone segment to flatten is not a problem. Its getting the flat to project to lay out holes. did you look at the attached file?

[JDMather]

I haven't had a chance to look at the file, but I would use a Revolve surface rather than a loft.

[RANDYWINDERS]

the problem with the revolve is that I still need a planar surface to sketch on to layout mounting holes.

[JDMather]

See attached. Pull down the red EOF marker. Zoom all.

[RANDYWINDERS]

OK, I did the revolve, extruded a .1875 planar face to one edge tangent to the cone, was able to project the flat pattern onto the sketch plane and layout a series of holes, but when I "cut across bend" I not only get flat pattern error but the holes don't go through the part. I have attached the latest attempt.