Surface finish aluminium

[Screwdriver]

Nah, I am fine with that, don't do a huge amount of aluminium and what I do I get a decent enough finish with standard inserts.

Looks like a spectacular finish from here! It's one of those questions where there are no numbers to aim at or scale to compare so I assume the @fizzy was looking for the ultimate surface finish.

Depending on application, I'd probably be happy with the surface finish from the first post. I have achieved "almost perfect" results when turning Delrin but I suspect that's because it's really easy.

 

[Hood]

Delrin/Acetal is lovely stuff to work with. I use it a lot being as it has a low water absorption in comparison to Nylon and thus is suitable for rudder bushes etc.

 

[henry Kadzielski]

Well my two cents worth, why not polish it if you need a better surface finish. You can get it to mirror in a lathe quite quickly

 

[Kram]

Ahhh! Just seen the tool tip. Ideally you need THESE

www.shop-apt.co.uk/pcd-diamond-turning-inserts/ccmt-060204-pcd-1300-diamond-turning-insert-for-aluminium-alloys-with-less-than-12-si-content.html

www.ebay.co.uk/itm/2pcs-CCMT-CCGT060204-PCD-for-Aluminum-copper-Polycrystalline-diamond-tools/292064462800

This shows the difference

Not that it will last, finger smears dull aluminium very quick if its touched.

 

[Shox Dr]

Delrin/Acetal is lovely stuff to work with. I use it a lot being as it has a low water absorption in comparison to Nylon and thus is suitable for rudder bushes etc.

Worth noting it produces the stringiest swarf know to man, and very very dangerous. KEEP YOUR HANDS WELL AWAY

 

[Hood]

Worth noting it produces the stringiest swarf know to man, and very very dangerous. KEEP YOUR HANDS WELL AWAY

Not Delrin/Acetal, that chips and even if you do get a streamer it will break if you sneeze.
Nylon however is exactly as you describe and can be very strong. I have had a tool pulled out of the CNC's turret with nylon being wrapped round the chuck and the tool.

 

[Screwdriver]

Yeah, still good to get into a habit of using something more disposable than fingers.

 

[Shox Dr]

Not Delrin/Acetal, that chips and even if you do get a streamer it will break if you sneeze.
Nylon however is exactly as you describe and can be very strong. I have had a tool pulled out of the CNC's turret with nylon being wrapped round the chuck and the tool.

It does. However I wouldnt want to try at 1200rpm

 

[Pete.]

Delrin chips nicely if you take a heavy enough cut. Gotta be careful not to pull the part out of the jaws though.