Marking out awkwardly spaced rivets etc.

Jakko

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With things like rivets or bolt heads on models, it’s often difficult to get the spacing right because you simply can’t measure finely enough. For example, on the Sherman ex-Crab I’m building at the moment, the front and rear edges of the engine deck needed fourteen bolt heads over a length of 43 mm. That means one bolt every 43 mm ÷ (14 − 1) = 3.3 mm (not every 43 mm ÷ 14 = 3.1 mm, because that would result in fifteen bolt heads!). Now, I don’t know about you, but I for one can’t accurately measure 3.3 mm with a ruler that is marked in half-millimetre increments and a mechanical pencil with 0.5 mm lead.

However, this kind of thing is very easy to do in a computer graphics program. All you need to do is make a drawing with correctly spaced lines, print it out and hold it up to the model so you can make pencil marks by following those on the paper. For those not used to graphics software, here’s how to make that kind of drawing.

What you need is a vector graphics program, like Adobe Illustrator (which is expensive), Inkscape (which is free), Affinity Designer (which is affordable), CorelDRAW (which is also expensive), or similar. I’ll be using Illustrator here, as it’s what I’ve got available (and because Inkscape is really awkward to use on a Mac), but the basic techniques should work in pretty much any program like this.

In my case, I drew two rectangles to represent the engine deck plates I was scratchbuilding; if you need just a line of rivets, of course, you don’t need to draw more than a simple line. Regardless, make sure these are the same size as you need on your model. Then, put a little line where the first rivet (or whatever) is to go. In my case, I put it at the top left:

Step 1.png

(For reference, the top rectangle here is 45 mm × 23 mm and the little vertical line is 3 mm long, 1 mm in from the left side.)

Draw another little line at the position of the last rivet, here at the top right:

Step 2.png

The positions of these two are important — make sure they are exactly where you need them to be, else everything else will end up off as well. You can try to position them correctly with your mouse, but it’s much easier to position them by typing in the x and y coordinates so the lines are precisely where you want them to be. In Illustrator, you use the Transform panel to do this:

Coordinates.png

Once these two lines are in the right places, just draw some more between them. It doesn’t matter where you put them, as long as they are between the first two:

Step 3.png

Here, I drew twelve more little vertical lines so I had 14 in all. (Actually, I clicked on one, kept the mouse button pressed and then dragged it to the right while keeping the ⌥ Option (Alt on Windows) key pressed. This will make a copy of the line rather than move it, and is much quicker than drawing a whole bunch of little lines individually.)

That done, select all those little lines by clicking and dragging with the mouse:

Step 4.png

Take care here that you don’t accidentally select the baseline. If you do, let go of the mouse, click somewhere outside of everything so that nothing is selected, and try again.

Once all the lines are selected, you can very simply use one of the distribution tools (in the toolbar at the top of the window) to evenly space them. In this case, Horizontal Distribute Center:

Step 5.png

Of course, if you’re putting them on a vertical line, you need the Vertical Distribute Center instead. Anyway, click on the button, and presto:

Step 6.png

Fourteen perfectly spaced lines! The left- and right-most ones stay where they were, and all the others are spaced equally between them.

I then needed to repeat this with the other sides of my engine deck, of course, and ended up with:

Step 7.png

After that, I just printed it out, put my plastic card engine deck on top of the rectangle and made pencil marks corresponding to the printed-out lines:

IMG_6156.JPG

Of course, if you’re doing this to put a line of rivets on a more complicated part, you may need to cut it out from the paper, fold it, or similar to get it to fit, but the basics should work just the same.
 

Dave Ward

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Jakko,
one thing to remember is to remove any scaling effect on your printer, some printers default to 'shrink ( or expand ) to fit the page ' which will make a real nonsense of everything!
Dave
 

Jakko

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Good point that I forgot to mention, yes. Make sure you print out at 100% size, not scaled to fit the paper or anything like that.

Another thing I remembered sometime after posting: in Adobe Illustrator, you can have it calculate offsets for you. For example, if you’ve drawn a rectangle 68.2 mm wide and want the “end” line 1.9 mm from the corner, just draw it on that corner (the “magnetic” effect will make that easy) and in the x field in the Coordinates window, just type -1.9 after the current coordinate (so it reads something like “68.2 mm -1.9”) and press the Return key on your keyboard. The line will move to x = 6.63 mm by itself.

Also, if like me, you need the same lines on opposite sides of a rectangle, don’t bother drawing them all. Instead, just draw them on one side. Then select them all (as I explained above) and click-and-drag them to the other side while keeping the ⌥ Option or Alt key pressed, so that you make a copy. In Illustrator, if you also keep the ⇧ Shift key pressed, you can only move them horizontally or vertically, meaning you won’t end up accidentally moving the copied lines a little to the side if you want to only move them straight up or down, for example.
 
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