Wrapping a swept profile around a cylinder in Alibre Atom

I've been able to get rid of that now by sketching the helical cut on a different plane

Doing it in Alibre atom makes the smoke trickle from your ears

I would deffo buy Design pro

Well, I've only gone and done it! Or rather, Jason showed me how and I implemented his suggestions.

I can use this part three times and connect them together with suitably sized shafts to make the selector barrel. I merely need to calculate the amount to rotate each consecutive drum to time the gear changes correctly. But not tonight! That's a job for another day.

Thanks to Jason, David, Ady.

John

You need to create an axis along the centre of the cylinder (or centre the cylinder on an existing axis) and revolve your shape around the axis.

Neil

Oops... should have read on...

Neil

Well done you. That was a tough one.

In answer to the question raised by John Hinkley, F360 can also wrap and extrude complex profiles as a single action, as shown by this gearbox camshaft.

Found an easier fast dirty way of doing it because it was really bugging me, this covers 50% of the cylinder

Use the sweep function with a plane on the top surface and cut it DEEP so your full cut depth is achieved at the edges

Then fill it back up inside to your required depth with an extruded cylinder boss and voilla! a perfect depth cut along the entire length

The geometrics of the cut aren't perfect except along the centreline but its a handy workaround

Edited By Ady1 on 27/09/2023 04:34:57

Won't really work ADY as the slots need to be radial otherwise what runs in them will just jam.

I wouldn't use it for Concorde turbine blades but could be used for writing lettering or any less critical apps

The CAD user would need to decide

Just to round this off and put it to bed, this is what the gearing/selector mechanisms looks like inside the case. Still missing are the gear selector forks - still to be drawn, but now that I've got the relative positions laid out, I can start on that.

The gear selector tracks were reasonably easy to set as I'd initially drawn them in 2D and measured the overall length. I then converted that from circumference to a diameter and rounded it up to the nearest convenient size. In this case it was 25mmØ.

Thanks, once again to all who contributed suggestions and especially to Jason for setting me off on a feasible solution.

John