Help a complete noob to any CAD to draw this

Can anyone help me to draw/craft the shape/object in the pictures. To my mind I would call it a flat topped cone but I suspect it has some strange mathematical name. But , please be aware my knowledge of maths and CAD design is best described as ZERO. Here’s hoping for a kind soul who can assist. The reason for the request is so that I can redraw the item with some tweaks and then print it with a homemade 3D printer. It actually fits on the end of a wood lathe and the redesign is so that I can mount a speed measuring device.

How about some dimensions of the piece. It’s not really a difficult thing to draw once you know a little about Sketchup but to make it usable, we’d need to know how big it is. How thick is the plastic? How big are the mounting holes. the more information you provide, the better the model you’ll get.

Hi there, thanks for your prompt reply,
The thickness is 2 mm overall, and attached are my notes as to size. Hope they are decipherable if not I will re do.
Thanks again Geoff

How tall is it? I don’t see that dimension.

Missed that

Thanks. And the tabs are how wide?

Without the width for the tabs–maybe that doesn’t matter–here it is.

Part for lathe.skp (202.8 KB)
I expect you should check the distance from the center of the piece to the center of the holes. Make sure that will be correct.

Tabs stick out 9 mm and are 12mm wide but that isn’t really critical.
Please direct me to somewhere so I can learn how to do this.
And soooo many thanks for your speedy assistance.

Well, I made the 9mm wide but I can modify them if needed. The location of the holes will be the critical thing, though.

As for how to draw this sort of thing, start with the basic video tutorials under Learn at You need to learn the fundamentals of drawing in SketchUp first.

to make this model I drew a section of it and used Follow Me to create the main portion. I then drew one of the tabs and use Rotate/Copy to make the additional tabs. A little cleanup and it was complete. Note I worked around the origin and the blue axis which makes it easy to keep track of the center of the part since it is used as a reference several times.

The three mount holes are 120 degrees apart. That’s the only critical.

I’ve got them at 120° apart but doesn’t the distance from the center matter? I assume this thing mounts with screws onto a surface that is drilled and tapped?

See your point, 38mm from centre to centre of hole in tab.

OK. Hang on. I’ll fix it.

Quick ? How do I save the file for use in sketchup

Plus is this a file I can play with if I wanted to ?

Is that 38mm to the edge of the hole? Otherwise the hole ends overlapping the flange.

You should be able to download the SKP file and open it in SketchUp. Don’t bother with that one, though. I’ll fix the model to put the holes in the right place.

And yes, you can play with the file if you want.

38mm centre to centre

I would normally start a model like this by taking a scan of the existing parts mating surface…

for clean items I do it direct but often I take a rubbing and scan that…


Hi John.
I had a problem generating the flat top cone. I could make a cylinder but not one with one end smaller than the other. Remember severe noob status here :stuck_out_tongue_winking_eye:

OK. I’ll put the hole in the flange.