reverse engineer ring holder box

[harrybennett]

I'm trying to reverse engineer a half box for displaying/holding some large plastic rings. I have an STL from Thingiverse for the finished product but I want to adjust some of the sizes and also I want to improve my understanding of CAD in the process. I have a couple of ideas of how I might achieve what i'm after but in both cases I feel like I'm making it more difficult than it has to be? I've had a look through youtube tutorials but I couldn't recognise anything similar that would help me. Can anyone point me in the right direction?

This is the STL which I've imported, converted to BRep, and cleaned up to remove the mesh triangles

This is a quick mock-up of what the box is designed to hold. My thinking is that if I just made a simple box then I could use this to cut away the indentations.

My other idea was to sketch the box from above and extrude the shapes as seen in the STL example above.

[davebYYPCU]

On the right track, a few ways to do it, 

Extrude the box, Revolve cut the cavity, and Revolve (360 degrees) solid for the ring, 

add the centre line, and inside wall line of the ring to that sketch.

Might help....

[g-andresen · Accepted solution]

Hi,

try this

günther

[TheCADWhisperer]

---

@harrybennett wrote:

This is the STL which I've imported, converted to BRep, and cleaned up to remove the mesh triangles

---

Can you File>Export your *.f3d file to your local drive and then Attach it here to a Reply?

Looks like one Extrude and one Revolve-Cut to me.  (A second revolve if you also want the ring modeled as indicated by @davebYYPCU .)

[harrybennett]

Thank you @g-andresen

that worked very well and allowed me to use some user parameters to resize for different sized rings.