[remotecaptures]

New to using a metal lathe and bought this set of carbidges because I've heard a lot of good things about using carbides and went with this 3/8" indexable Triangle inserts set form Little Machine Shop to turn solid aluminum rods:
https://littlemachineshop.com/produc...ProductID=1669

I also have a set of left/right hand high speed steel tool bits that came with my Taig lathe that cut well but when I try to use the carbide tips I don't seem to be able to cut into the aluminum. There is no bite and some scraping noise which isn't a good sign.

I took pictures of my setups and was hoping someone could spot something obvious. I have read and watched many videos on how to use lathes and it seems like the tip of the carbide that does the cutting isn't that long. I'm turning 1" down to 1/2" in ~1mm increments so pehaps I'm taking off too much at a time for the carbides tips? In the pictures below I did the first cut with a left high speed steel tool and powerfeed which looks great and then tried the carbide tip but the cut looks super rough. Why is is cutting super rough? I was using the AR Tool Bit which is described as:
"The AR-style tool has a 0-degree side cutting angle for general machining applications such as turning, facing, and chamfering. It's suitable for machining to a 90-degree shoulder. The cutting edge is on the left for right-to-left feed".

[metalmayhem]

there are no pictures but first thing that comes to mind is that having the right insert for the job is important . The inserts you have will do for steel and a lot of materials but they won't be too great for aluminum . You need something more like these which are aluminum specific and will have a sharp edge https://www.ebay.com/itm/37487411268...3ABFBMrtXLkc1i

[machinehop5]

...more feed .006-.012 IPR (.2-.3mm) chipload..

[Algirdas]

check what cutting speed for your insert is recommended for that material.
coolant.
check the attack angle of the insert tip.
Is the lathe good alligned? What is the smallest diameter you can cut?
how exactly is the tool tip at the axis of workpiece rotation?

[yelims20]

looks like your cutting tool is above centerline. Are your HHS bit the same size as the carbide tool holder?