Needs help with helix with bended ends

ZW3D CAD
#1

Hello.
I’m having difficulty drawing a ring with overlapping ends (like a keychain) where the ends are bend outwards (away from each other)
just after they pass each other.
I have tried making a helix spiral. Creating a plane with the wanted angle and then attaching an arc to the end of the helix spiral.
But i can’t create a smooth transition and when i use swept rod it looks awful
Can anyone help me.
ring diameter 45mm
wire diameter 3,5mm
overlap 15mm per end
the ends are bend 4mm outwards (10deg)
bend raduis 3mm

#2

Welcome Kent.
if you can post your model, we have something to work with.
Otherwise it is hard to advise with words alone especially if we mis understand the problem.
If the product is proprietary, just simplify it a bit.
It will be worked on in V2021 so advise what version you are using if not 2021.
Cheers - Paul

#3

Hello Kent,

The attached model is made with a helix and 2 sweeps. Is this what you mean?

Regards, Ton

keychain.Z3 (160.2 KB)

#4

Im using version 2020

#5

I downloaded v2021 and had a look. I got some ideas how to do it.
I made a quick mockup. Is there an easier way to do it.sikkerhedsring.Z3 (82.7 KB)

#6

Hi Kentdam,

That doesn’t look too bad. If you can make all the curves tangent to one another, it will def look even better.

Or do you have any reference image that shows the ideal form?

Best,
Acon

#7

Hi Kent, in the situation Rod struggles a bit.
But there a re many ways to do this. Springs are often challenging.
Here is my attempt in V2021.
Will work in 2020 too.
image
Cheers - Paulsikkerhedsring_Paul.Z3 (163.4 KB)

#8

this is what im trying to draw.
image

#9

Hi Kent,
the method my model shows can be applied for any set of curves. They do not need to be a helix.
If I interpret your drawing, the lower half on flat, then the there is a bend or partial helix then a flat circle offset by the helix.
Do that a sketches.
You might even skip the helix and just do the tow circles offset and use blend curve to join them.
One thing to keep in mind is that the model should always represent reality, so not self intersecting geometry.

Cheers - Paul