Punching Sheet for C-Section


I am trying to produce a 2d View of a Csection from my model that will flow to Layout and be able to see flange and web holes that can be used to dimensioned.

The issue I am having is that you cannot see the flange holes to dimension to as our supplier views from the Web side of the C-Section (wouldn’t see them from the lip side either, as the section is normally only 1.5-2.4mm thick)

Has anyone done C-section / Z-Section punchings in layout and have advise how I can set this up. I am loving the modelling part of Sketchup but find setting up workshop and rollformer paperwork very clunky in Layout.

Thanks in advance for any help.

Share the LO file so we can see what you’ve got.

Thanks Dave
Punching.layout (2.6 MB)
21-00257 Greg Priebe.skp (2.6 MB)

Hi Steven,

So for something like this I would set up a 3-view of the part. Personally I would do this in SketchUp instead of in LayOut because I think it’s easier to manage. In your SketchUp model I set up the 3-view of the part shown on the first page of your LO doc. In Perspective those parts are arranged like this.

I’m guessing that in your part of the world 1st Angle projection is the norm so that’s how I set up the copies of the part. Here in the US it would typically be 3rd Angle projection.

The Parallel Projection view in LO looks like this.

Due to the size of the part and the size of the paper I used a non-standard 1:15 scale for the viewport. I think I would really choose to show the part at a larger scale and break the part across two viewports. Then note the number of holes at the 450 spacing. That would also make it easier to show details like the two intersecting holes at the end. I didn’t add hole diameter here but that could be in a note anyway.

Just a note regarding your SketchUp model: I would use a component instead of group for the part since there are multiple copies of it, using a component makes edits later much easier.

I’ll make an example with the split viewport thing.

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That’s great thanks. Yes if you could do the split viewport would be great.

How do you do a running dimension in layout eg 25,150,290 etc.
Also did you use the hover over centre of holes or is there a better way.

Thanks for your help

I wouldn’t like to add those extra components - as I am looking to use the model for a list of items. Also I would worry of not having them turned off and grabbing them when modelling or dimensioning - or is this my novice to Sketchup talking.

Have I interpreted your first drawing in model correctly. You are creating 2 x copies of that component.


Here’s a sample of the split. Due to the distance of the last hole on the right end I made two splits so three viewports. I’d actually probably add a smaller ISO view of one copy of the part to show the holes all the way through. I didn’t add dimensions for everything that should be dimensioned but of the ones I did place I avoided creating conflicting dimensions.

First, I did hover over the circles to find their centers. In a run like you have here, after the first dimension is placed you can go to the center of the next hole and double click to create the next dimension. Repeat for each dimensions in the run.

The 25 was done separately. Depending on how the holes are to be drilled, it might make more sense to dimension all of the holes from a common datum such as the lower left corner of the part. This would make more sense for CNC drilling since the end can be set up as a zero. Of course it also depends on whether it’s the distances from the end to each hole that are important or is it the distance between holes. If you had a position tolerance of ±0.01mm and each hole was +0.01 the end one could be quite a ways out of spec.

I’m not sure how adding labels or comments would cause a problem with that.

Might be the novice talking. Put the model viewports on a layer or two. I used stacked viewports for the split view so I cold add the hidden lines. (I didn’t use Back Edges for that.) Another layer for break lines, and still another for dimensions. Those layers can be locked if needed. Their visibility can also be turned off but that’s just one of the ducks you need to keep in a row when you are working.

By the way, it would be a good idea to get to grips with correct tag usage. I found a few faces that were tagged in your SketchUp model which I fixed. (ALL edges and faces should be created and remain untagged.) Also get in the habit of purging your files once in awhile. this reduced the SketchUp file size by about 85%.
Screenshot - 9_20_2021 , 10_01_33 PM

FWIW, here are the two files to give you an idea.
21-00257 Greg Priebe.skp (401.6 KB)
Punching.layout (505.9 KB)

I did create two additional copies of the part although I didn’t convert the group to a component. I should have done so but I left it because I was thinking more about the LayOut side of things.

As I am not a drafty, Is there a symbol commonly used to indicate 1st vs 3rd angle projection

I love the split view for clarity. For the overall dimension though do you have to manually type the length in

Can you send me the updated layout and model file also would be a great help

Yes. Like these.

Nope. LayOut will dimension across viewports.

I uploaded the most recent version of both files in my post about an hour ago.

FWIW, I did the following illustrations a while back for some high school students I work with. This shows a way to think about the development of 3rd Angle projection.

For 1st Angle consider inverting the bowl.

Yes I will have to find more information on this as I don’t totally understand it yet. Thanks for all your help, you are a legend.


The projection thing is worth getting to grips with. Figure out which one is standard in your area. Machinists and those types will want to see that when they look at your drawings. Also learn about how they would expect to get dimensions so you can give them what they need to see without causing confusion.

I also find it handy to create simple 2d symbols to mark the hole or fitting locations…

bolt-15.skp (26.5 KB)

easier to dimension and you can turn them on / off as needed using tag visibility

eg. this simple bolt component

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Is there a way to easily get the hole locations into a csv or table

great and thanks for that

There’s an extension that will create a CSV of the coordinates of guide points. It’s called TIG: Export Construction Points to CSV. You can place a guidepoint at the center of each hole and then run the exporter. I think for the sort of thing you are doing you would want to copy the component into a separate file and position it so the model origin is at your datum point for the part.

Edit: look at that extension and see if it will do what you need. I haven’t used it in nearly 10 years. there may be other options but I’ll have to look.

Placing some sort of guuide like gsharp suggests can be helpful but remember it has to be moved if the hole has to move. Connecting the dimension to the center of the hole isn’t difficult.

I made a quick example. Exported the Cpoints to a CSV file which I massaged a little in Excel to order the points and separate out the large holes from the small. Then saved as a .xlsx file which I inserted into the LayOut file.