Constraining spiral shape for resizing

Workshop Modeling Questions
1

My GalPal ( She hates the term “Girlfriend”) sees stuff on Etsy and wants me to print it. In this case it’s for Diamond art canvases. (Like I do not have ENOUGH to do already) :roll_eyes: . The versions I have seen are problematic because they grip the fabric or coil it too tight etc… Why do I think this? When she asks me to help her fix bead rows that have buckled :roll_eyes:.

This is my design thus far. Problem is I need to scale it for different sizes to fit different canvases that vary in size. On the left of the first image, I’m can’t seem to grasp how to constrain the spiral to keep 1/8 thickness for easy resizing. Any hints would be most welcome? I want to scale the the center sketch.

Note: I do intend to add this to Etsy for others for a pittance ($400). :rofl:

Rev 2 (will incorporate table clamp system)

Screenshot 2026-08-28 084342
Screenshot 2026-08-28 084342988×907 113 KB

Rev1

Screenshot 2026-08-28 085546
Screenshot 2026-08-28 0855461920×1117 259 KB

2

So you have the spiral, and you just want to scale it without increasing the amount of spiral, and at the end, you just need constant thickness?

3

Increase/scaling the size of one so that both resize maintaining the .125" between them. Long term, scaling the center sketch maintaining the .125 wall thickness and .5" center hole is the ultimate goal.

4

So, the center size remains fixed, but the outer spiral can be any desired size?

Its a variable spring in a way

5

How did you create spiral?

6

Corel Draw. DXF imported to Shapr.

7

Something like this?

8

Sorry, don’t have anything useful to ad as for the constraints - But is there a reason it needs to be spiral shaped? It’s cool that it is, don’t get me wrong, but wouldn’t it work just as well with a circular outline?

circ
circ1401×1112 87.3 KB

Not a criticism, just curious.

9

image
image1264×1183 98.7 KB

I added the offset. Essentially, I created a spiral in Shapr3D and added variables so you can project it down.

10

I was going for stability while sitting on the canvas + bead height. Reduce friction and wobble by sitting flatter. :man_shrugging:

I suppose playing with the flat’s angles and the opening I could get the same effect using circular shape. Spirals are so pretty though… :sweat_smile:

Thank goodness for outside observation. :folded_hands:

Now, constraining the distance between 2 circles… :thinking: Needs more eye opener :hot_beverage: .

I’ve been up several times this last night tending pork butts on the Pit Boss®. Almost 12 hours in. :yawning_face: 8 more to go.

11

Sorry for the late reply. I’m digesting this… that’s cool. Can you link another spiral concentric to that offset slightly so they maintain a constant distance?

12

Oooh! very nice.

13

Can you share that so I and others can play with it and study it please?

14

I’m using the free version, so I’ll provide more clear instructions.

15

spiral.shapr (796 KB)

Here is the file.

16

Thank you. :grinning_face: