How to make a tapered inside cylinder.

[oldraven]

Hi all,

I have been trying to make a tapered hole into a rod.
The design is for a small piston for a steam engine.

I could not figure it out and found nothing on the web.

So, back to BobCAD, Solids.
There I made the piston, inserted a cone, a simple boolean and presto.
Another smaller cylinder and I had the piston ready.

Exported it as Iges file and imported it in Solidworks 2010.

Is there such an easy way to work with booleans as in BobCAD?

[mcphill]

The tapered cylinder is a cinch in SW, sketch the profile, and Boss-Revolve it around an axis. Is the pin hole tapered as well, or straight bored? If tapered, you could use the same method, but you would Cut-Revolve. If not tapered, sketch a circle and Cut-Extrude it through. I can do all these things way faster in SW than BobCAD, but both systems can succeed at making the part.

[oldraven]

Thanks mcphill,

I'll give it a try.
I'm still a novice with SW and haven't used Boss-Revolve yet.
The pin hole is straight, no problems there.

Thanks,

Jos (the Netherlands)

The tapered cylinder is a cinch in SW, sketch the profile, and Boss-Revolve it around an axis. Is the pin hole tapered as well, or straight bored? If tapered, you could use the same method, but you would Cut-Revolve. If not tapered, sketch a circle and Cut-Extrude it through. I can do all these things way faster in SW than BobCAD, but both systems can succeed at making the part.

[DareBee]

You could also do the straight hole first and then do a "chamfer" on the edge
OR
You can extrude the hole with a taper draft in the feature manager Dialog

[oldraven]

success,

I made a drawing as suggested.
Did not work!
After some tinkering I got a result with the Revolved boss/base feature but it was a negative for what I wanted.

Again some more tinkering of the drawing and a lot of fault messages.
So this morning I used the 'normal to' command an saw a center-line at a completely wrong place.
Removed it and 'voila' the piston I wanted.

Thanks guys , it was indeed easy if done right in one go.

Jos