Drawing a stop

Singer 301 tension numerated dial with holes.skp (420.3 KB)
I’m drawing a numerated tension dial for a sewing machine.I’ve drawn it in meters although the final product will be printed in millimeters.
I’ve got the basic shape with a major diameter of 20.12 and a height of 6. There is a series of 14 holes arranged in a circle.
My problem is to draw a triangular shaped stop in the underside of the dial, anchored on the bevel and centered between two holes. The thickness of the stop is .87. The shape is trianglar as shown in this picture. the angle at the top of the stop looks to be in the 90-110 degree range, but it gets flattened before coming to a sharp point.


I’ve been floundering with this for the last hour and I suspect there must be an easy way to do this. Once I know how to draw it I can play with shapes and dimensions to get a good fit.
Any help would be appreciated.

Here’s a picture of the top side of the dial.

Hi Terry. You might find it easier if you turn on Hidden Geometry (View menu) so you can see the actual face where you need to put the stop. Might be that you could simply pull up a single face into a sort of quaked stop and then make the triangular shape from there.

Singer 301 tension numerated dial with holes and stop.skp (463.2 KB)
Turning on Hidden Geometry helped a lot. Not super happy with it but I’ll try printing it tomorrow to see how close I am with my sketch. Thanks

1 Like

Good luck. I’ll look at your .skp file in the morning.

Not sure if this would work? Might help until @DaveR gets back to you.
Done by creating the path and follow me with a semicircle radius 0.435 and then joined the 2 semicircle ends, intersect faces with selection and then cleaned up, removed internal faces and ran solid inspector to confirm it’s a solid.

How much force is there on that stop when it is employed? Does it act in both directions?

There wouldn’t be much force. You turn the dial by hand to get the level of tension you want. The stop is to keep you from rotating the dial more than 360 degrees.

I expect your stop as modeled should work then. I was thinking that it could be modeled with a sort of fillet around the bottom to reduce stress risers. Maybe like this.

looks like this in the slicer.
Screenshot - 12_13_2023 , 10_20_32 AM

basic shape with pin holes.skp (563.4 KB)
On this skp I have circle of 14 holes.
A couple of times I’ve had to go back and change the size of the holes. I’ve been doing it one hole at a time but I think if I’d made proper use of components I could have just changed one hole and the rest would have adjusted automatically. Can I make hole a component?
As it sits right now, nothing has been declared a component, and I’m not sure when to declare a component with the intention of locking down the geometry.

A second issue I’m having, is drawing the “stop” in the underside. It’s been hard to navigate upside down and getting closeups of the area I want to draw, also complicated by drawing on a beveled surface. I often end up inside of a wall. And it’s been hard to get a wall that will react to push/pull because I think what I’m drawing doesn’t have parallel surfaces. And finally, even if I get a basic shape, it’s been hard (impossible) to draw the fillets that Dave did.
Sorry to be so wordy, but brevity was never my strong point. Hopefully there’s an easy answer to my problems.

Good morning Terry.

You can make the hole a component but it won’t really serve your needs because it won’t be solid so you’ll have a bunch of work to do to 3D print the thing that is more than use resizing the holes.

Watch for a PM.