1-Visitor

Question

"rolling" a sheet in Creo

Forum|Forum|14 years ago
January 10, 2012
59 replies
34752 views

Hi there,

I've been a Creo Parametric user for around a year now and I've run into a problem that's stumped everyone around me...

I'm designing a sheet that will be rolled up into a cylinder. This sheet has irregular markings on the top and bottom edges, and I need to see how they line up when this sheet is rolled up into a cylinder. I have the sheet ready, but I cannot figure out how to "roll" it up virtually. Is this even possible?

Thanks in advance!

Patriot_1776

22-Sapphire II

Toroidial bend is probably your best option.

P

ptc-4401544

Author

1-Visitor

I was thinking about that, but I'm not too familiar with toroidial bends. Is it even possible to bend it over itself multiple times? Basically, the sheet will form a thick cylinder with multiple layers after being rolled up. How would I go about doing this?

B

BrianMartin

13-Aquamarine

Hi Pum (or Pum Sang)...

I encountered this exact same problem when working for a battery company. They had very long, thin sheets of metal that needed to be rolled into a tight coil. There are some methods you can use to "roll" your sheet, but all of them have some problems you'll need to be aware of.

For this kind of thing, I think a spinal bend is a better choice than a toroidal bend. A toroidal bend will do a nice job of rolling the sheet but it won't keep rolling it back on itself like a spinal bend can. I think you're going to be stuck though when the solid geometry begins to self-intersect. I'll do a quick example and upload it for you to take a look at. If all else fails, you can make your object as a surface and see if that gives you the information you're looking for.

Fair warning... the tighter you try to wrap the sheet, the more difficult it's going to be to get what you want. I'll try to explain that in the next email. For the time being, play with spinal bend. I'll make the object and try to take some screen shots for you.

take care..

-Brian

Patriot_1776

22-Sapphire II

Pum: Are you rolling it into a cylinder, or into a spiral of Archimedes?

P

ptc-4401544

Author

1-Visitor

Hi, I am rolling it into a cylinder.

Patriot_1776

22-Sapphire II

Is this something like what you want? I whipped this up in about 10min. It doesn't have notches, but you can see in it's developed length, it has a smooth taper from the tabs to a full radius.

1_jelly_roll-01-prt-1.zip

P

ptc-4401544

Author

1-Visitor

It is quite similar. However, I'm wondering what that helical tab in the middle is for. What I need is basically a piece of paper laid down, then rolled up along one of the edges. It needs to be done quite tightly with minimal clearance. But yes, the shape is most certainly there and looks like a good start.

Patriot_1776

22-Sapphire II

I did that just for fun to see what can be done with a particular technique I have. If you need both a flat and a coiled version, you can do one part as an instance of the other, in your case it sounds like the coiled version would be the instance of the flat version. That part took a total of 7 features excluding the initial datum planes and CS. So, it's actually a pretty simple technique.

P

ptc-4401544

Author

1-Visitor

Wow quite a lively discussion you have going on there.

Just a quick question, since you both seem to know a lot about this.... Do you have any idea how I could make a model bendable? In this case, I'm trying to "bend" a tab on the jelly roll around some features, but I can't think of an easy way to do this. Since this tab is so thin, it will be bent in many different ways so I would very much like a dynamic way of just dragging and bending with a mouse. Does such a feature exist?

B

BrianMartin

13-Aquamarine

Whoops! I answered this in your other thread. If you want to bend and twist sort of "on the fly", you're definitely talking about a Warp feature. This feature has several subfeatures that allow you to play with the model as if it were virtual putty.

The problem is that it doesn't necessarily bend in a real-world manner. The model doesn't behave with real world physics or anything... it just moves and twists with the mouse. You'll have to be careful to apply the bends and keep the tab geometry realistic.

If we can see what you're doing, it's easier to help. There's also some rarely used features in sheet metal and a practically UNKNOWN feature in regular Pro/E that can help with bended tabs. One of my all-time favorite forgotten Pro/E features is the EAR. The Ear can do some pretty cool things with tabs.

Once we see a picture I'm sure we can help more.

Thanks!

-Brian

P

ptc-4401544

Author

1-Visitor

Sorry, I should have been more precise in my question. I have two problems. This is my first.

I need to "fold" the circular ridge onto the rounded cap (basically crimp the cap into place with the circular ridge). I could do this manually, but I'm sure there must be an easier way.

B

buddyer

1-Visitor

英语不太好不是很懂什么意思，惭愧。。

B

BrianMartin

13-Aquamarine

Pum/Everyone else...

Okay so FINALLY we're going to dig into this entire battery project and try to make some headway on documentation.

This thread jumps around so much I didn't know where to put this. I'm just going to drop it here and then, hopefully, pull everything together into one document.

FYI... I'm going to take all of the slides I've done for all the questions I've answered on Planet PTC and post them as documents. I'm also going to link them to my own private website which is launching in the next few weeks. But more on that later...

Pum's original question was:

Pum Sang Cho wrote:
I'm designing a sheet that will be rolled up into a cylinder. This sheet has irregular markings on the top and bottom edges, and I need to see how they line up when this sheet is rolled up into a cylinder. I have the sheet ready, but I cannot figure out how to "roll" it up virtually. Is this even possible?

The short answer here is: Yes, well, sort of... it depends! I have gotten as far as I can go... with is 98% of the way to a solution. Hopefully once I post this, the community at large can come together and get us the last 2% of the way there.

The longer and thinner your sheet is, the harder it will be to roll it up into a cylinder. You're going to eventually hit an accuracy wall where Pro/E just can't go any further. Therefore, the first step is to perform a maneuver I've never had to do in almost 25 years of practical Pro/ENGINEER experience... RESET the lower accuracy boundary.

I'd love to get a show of hands to see how many people even knew that was possible!

In fact, in addition to resetting the lower accuracy boundary, we need to set several other rarely used switches before I can even begin this tutorial. We're going to be making something that looks like the image below... and it's pretty intensive and nasty although it looks deceptively simple.

... <More steps on the way... I'll edit to add more to this message>

P

ptc-4401544

Author

1-Visitor

Thanks Brian!

I look forward to the rest of your writeup. You seem like a very detailed and meticulous person.

B

BrianMartin

13-Aquamarine

Hi Pum...

I'm totally agonizing over this thing... it feels like I'm giving birth or something. It'll either be great... or totally useless. Sometimes I'm not sure which it's going to be until it's done.

I'm still working. I'm anxious to unveil this presentation because it represents much more than just an answer to your question. It's a bit of a glimpse into my future. Hopefully it isn't junk!

And I really apologize for the long delay. Maybe if I wasn't taking excruciating detours to worry about fonts, templates, graphics quality, writing 'tone', instructional clarity, and other nonsense... I'd be able to finish faster!

I should be able to post the first of the three tutorial objectives tomorrow morning. I'm going to sleep and get back to it early in the a.m. I'm not answering any more questions on Planet PTC until I clear out the backlog of responses, models, and tutorials I've already promised people. And you're up first!

Take care...

-Brian

P

ptc-3068803

1-Visitor

Brian - I'm extremely lucky to come across this thread as I am trying to acheive something simular to this. Although I keep getting stuck at step #4 because my geometries intersect

Anyhow I have manage to create a simple method to create a tightly rolled cylinder.....

1 - Simply create a datum curve with a cylindical equation. set the IR to something like 5mm and OR to 50mm, and set number of layers to 20. This will give you a tight spiral......

2 - Next select INSERT > SWEEP > PROTRUSION

3 - Now sketch a long thin rectangle i.e. 100mm x 0.5mm....now tick 'finish and there you go!!

SEE IMAGE ATTACHED

The only addtion to this which I cannot achieve is the zig-zag pattern I am trying to create which will follow the datum curve all the way to the centre. It can be done with thousands of Datum Points, but there must be an easier WAY?!! This is why I started searching for Spinal bend methods as I though it might be do able If i started with a flat sheet with a zig-zag surface already in place....?

B

BrianMartin

13-Aquamarine

Thanks Alistair...

At the time I wrote it I was making several of these a week for users on PTC Community with plans to save them all on my personal website. But... I got overwhelmed with work and personal issues so I had to scale back my efforts. I'm glad you were able to make use of the information.

I've seen your screenshot and I see what you're trying to do. I agree that an equation to create the spiral is the best way to go. The tutorial used something more complex because the user needed a spiral with all these crazy cuts patterned along the length. In your case, a simple spiral equation works well.

To create the zig-zag, there are several things I would try. First, try patterning along a curve. Use the curve created from the equation to replicate the zig-zag geometry along the entire spiral. You can choose the number of zig-zags or the spacing between them (and let Creo make as many as it can at the given spacing).

If this doesn't work... you might try patterning the zig-zags as enclosed SURFACE features. You will not get any self-intersection errors this way. Once the pattern is created, SOLIDIFY the surfaces to make them solid. This could be dicey and you may need to crank the accuracy down to a smaller value to make it work- but there's a chance this technique will work as long as your spiral isn't really, really tight (like the one in my tutorial).

The last thing you might try would be to make a surface from your spiral equation. Instead of making a solid, make it a surface (like I did in the tutorial). Drop a point on the surface at the very edge... it has to be an "on surface" point but it can lie on the edge. Then, use Flatten Quit to make a flat surface. Next, create your zig-zags using the flat quilt as a reference. Make these solid extrusions. Allow them to extrude down the length of the quilt. Once you've patterned your zig-zag down the length of the surface, use Thicken to give the original surface a thickness and turn it into a solid. Now you'll have a long, thin solid with the zig-zags running down the length of them. Finally, use Solid Bend (renamed Flatten Quilt Deformation in Creo 2) to bend the solid back into it's coiled shape.

This last technique definitely works. I've tried it (at least in Creo 2)... here's what it looks like:

I realize I put the zig-zags on the wrong side but that should be easy to fix. I've included a model for you to examine. It's been done using Creo 2. I didn't catch which version of Pro/E or Creo you were using. If it's something earlier than 5, let me know.

Thanks!

-Brian

Just for the heck of it... here's an example of something else you can do...

You can use your imagination... it's possible to make some crazy shapes with Creo.

1_coil_demo2-prt-3.zip

P

ptc-3068803

1-Visitor

Hi Brain,

Thanks for taking the time out to answer my question and answer it in such detail. Very Helpful!

I am using Wildfire 2 at work and 4 at home currently, so I dont know how that does effect the methods you have suggested above.

When I get a chance to I will work my way through you advised methods and see if I can get this to work! The examples you have produced look great!

Thanks

Alistair.

A

AmitDeshpande

18-Opal

Hi,

If one of the responses helped resolve your issue, would you please mark it as the Correct Answer? That way other users visiting the discussion will know; as the correct answer gets copied right below the question.

Thanks,

Amit

Sign up

Please use your PTC eSupport account.

Welcome to the PTC Community

Please use your PTC eSupport account.