Need advise on aluminium cone/horn design, ideally from a lathe machinist.

[JOGARA]

So I have this cone/horn I need to CAD and potentially get machined and I need advise on designing it so it is practical to machine (and wont cost the earth)...

I am looking at a cone around 75mm long, with a ID of 16mm and 30mm on either side with flat ends of around 3-5mm and 20mm respectively.
What sort of thickness should I look to achieve and is 75mm too long?

This is what I am after doing.

https://s9.postimg.cc/covvyybq7/Capture.png (https://postimg.cc/image/x90pxfrh7/)


Thanks
Jack,

[magicniner]

Material?
If it was Aluminium then that's do-able with a 1mm wall on a manual lathe.
The drawing seems to show two cylinders joined by a cone, not just a cone.

[JohnHaine]

To be clear, you mean two cylinders, one id of 16 the other 30, ~4 mm and 20 mm long, joined by a cone that tapers between these dimensions - correct? The length of the cone being 75 mm. Does the outside have to taper as well as the inside? for example, could you have a tapered bore but the outside being a cylinder of od larger than 30mm but a shoulder on the end where the bore is smallest down to whatever the smallest od of your cylinder is? Would easier is you didn't have to machine the outside to a taper as well. The tapered bore would be a doddle in a CNC lathe.

[JOGARA]

Material?
If it was Aluminium then that's do-able with a 1mm wall on a manual lathe.
The drawing seems to show two cylinders joined by a cone, not just a cone.

Yes Aluminium. Really 1mm?
Yes sorry I should have said 2 cylinders and a cone.


To be clear, you mean two cylinders, one id of 16 the other 30, ~4 mm and 20 mm long, joined by a cone that tapers between these dimensions - correct? The length of the cone being 75 mm. Does the outside have to taper as well as the inside? for example, could you have a tapered bore but the outside being a cylinder of od larger than 30mm but a shoulder on the end where the bore is smallest down to whatever the smallest od of your cylinder is? Would easier is you didn't have to machine the outside to a taper as well. The tapered bore would be a doddle in a CNC lathe.

Yes two cylinders connected with a cone.
The total length being ~75mm

Taper only needs to be OD for looks.
Ideally the larder ID end would also be round over but I guess that is going to be harder/costly?
Would a chamfer be okay?

[m_c]

You could go sub 1mm wall thickness, but 1mm should be thick enough to not have to worry too much about strength while machining.

What do you mean by round over? Just a radius on the end?
On a CNC the difference between square, chamfered, and rounded, is a line or two of code. The only problem would be if you wanted both ends radiused internally and externally, as you're then potentially into a second op.

[JOGARA]

You could go sub 1mm wall thickness, but 1mm should be thick enough to not have to worry too much about strength while machining.

What do you mean by round over? Just a radius on the end?
On a CNC the difference between square, chamfered, and rounded, is a line or two of code. The only problem would be if you wanted both ends radiused internally and externally, as you're then potentially into a second op.

Ah okay.
I probably wont go too thin but 1-2mm sounds good to me. This is going to be one of those things that gets knocked a lot so need some thickness I believe. Though obviously a round tube is stronger than a flat 1-2mm sheet...

Yea just a little radius to take the edge off.
A chamfer will be okay too. Just so the powder coat does not mess up on the ends.
Wont need it on the smaller end, that will get fitted to another part..