Long story but I’ve been playing with this little pattern piece…

…and it has some unique properties that made it easy to use for a little teaching quiz. Are you up for a chance to test yourself how well you understand certain manufacturing concepts? I thought you’d like the chance to show how much you’ve learned. By the way, this is a pattern of the cover of a baseball. A baseball takes two per of these. I describe this kind of pattern as a perfectly symmetrical ouroboros. There are several kinds of ouroboros patterns, each with varying characteristics, this is but one of them. One of these days I will get around to writing about ouroboros pattern making but I’m not finding the words to describe it -but I digress.

There are 5 questions, three about production pattern making, and one each in marker making and grading. If you need a copy of the pattern piece above to illustrate some of your answers, a full size copy is here.Professionals are ineligible for now. These should be easy if you’ve read the book, only the last question is hard. Without further ado:

Assume you are using a much larger version of this pattern to make novelty throw pillows:

- Since these pieces are obviously symmetrical, explain or illustrate with your pattern piece, how you’d ensure these pieces would be lined up when being sewn.
- Assuming you were making the throw pillow in contrasting colors, make a mock up of what your pattern would look like.
- Assuming that your pieces were fused individually (not block fused) make a mock up of what your pattern would look like.
- Draw up a mini marker.
- How do you grade this thing?

I don’t know the answer to number 5 because I don’t know anything about radial grading and I have to think it through. It’s all math. I wish I’d had more math.

Off tangent, I think this little pattern piece would be a good sewing exercise too. If you want to try it out, there is no seam allowance. On a baseball, the seams are abutted so you’ll have to add it.

Radial grading, really? I can see axial grading; but, I’m at a loss to find the location points through which to radiate the grade.

J C,

This is mostly hunch, but I think you will have to switch to spherical geometry for this one, origin point at the sphere’s center. Change radius for sizing, then go to trig functions to translate to rectilinear for shaping the skin. No, I’ve never done that. Arrrrgggg!

Tom Willmon

Recovering Engineer

Mountainair, (mid) New Mexico

Grading: use a grid. Or rather, a series of grids with larger and larger squares. Drawing the pattern in a small grid and redrawing it in a larger grid will make it larger.

If you want to grade it up 1″ in the diameter, you have to increase the circumference by “pie” times the diameter increase, or 3.1415 inches. If you cut the ball though the center, you strike two seams, so each piece gets an additional 3.1415 divided by 4 inches.

Am I missing something here?

For grading, it seems like there would be a way to photoshop the pattern piece, input the x and y measurements and then decrease the picture whatever percentage you wanted…but are you looking for a non-CAD way to do it?

I would fold the piece in half lengnthwise and in half crosswise and grade just the quarter then trace onto a similarly folded pattern paper.

genius!

I don’t know… I still don’t think we’ve addressed the elongation of the arc and the rest of the ellipse.

Perhaps we need a little Algebra review.

[Insert evil laughter]

ok, this was really easy, except for the part about fusing, because I don’t know what that means. Then again, I make bags. hmm.

1) I lack the english word, in turkish it’s “cit”. Anyway, put a slice/cut into the middle of the bottom of one and into the middle of the side of the other. These will line up when sewn properly.

2) In production, there would only be one pattern, and it would be labeled something like, “2 pieces, one Red fabric, one white fabric, top and side”

3) I don’t know what this means.

4) Up-Side-Up-Side…

5) Forget about math, it makes it much harder. Do what normal people do: use a plotter/photocopy machine. Really. If you want to do it with math, I can explain that if you want. It’s not really about geometry…

Grade a pillow?? Why bother? Forget the math and the copy machines. Just make the pillows as large or as small as you like! I like to keep things simple :-)

I can’t answer the first questions, but number 5 I (think) I can.

The end result is a ball, made with 2 pieces one vertical, the other horizontal. (We use them for cricket here in the UK), anyway, the circumference of the ball will be the longest measurement added to the shortest. The longest part is 5.5 times longer than the shortest. So if you know the circumference you want, divide by 6.5. This will give you the width of the shape, the remainder will be the length of the shape. I would then just expand the existing shape roughly on the photocopier and then draw an appropriate bigger or smaller parallel line.

Do you mean notches for lining up?

Marina

I have made several of these in fabrics with different sizes. 1) to stitch together place rounded end of one peice into curve of other rightsides together and stitch your way round. (effectively centred and at right angles to each other)

Fusing ? with two pattern peices only what do you need to fuse ( Maybe i dont get it)

Mini marker sorry no idea what it is.

To resize either scale up using a square paper method like in art , or good old photocopy enlarge or reduce.

Once first ball made measure circumference and length and width of one peice and plot onto a chart the rest can then be worked out in table form so have a variety of sizes.