Best cutter for this

[GSRocket]

I'm going to be cutting this shape from 90mm aluminium on my lathe.
I've rigged up the cross slide and compound slides with levers and a
profile guide to cut this shape. I want the best possible finish so I don't have to spend to much time
polishing out imperfections.
So would a cutter like this be good?
http://glanze.co.uk/acatalog/PROFILING.jpg

I'm also thinking of this from Eccentricengineering except fitted with a round Crobalt cutting piece (if it will hold it)



http://www.eccentricengineering.com.au/components/com_virtuemart/show_image_in_imgtag.php?filename=resized%2F12mm_Right_Hand__4e7482d40340a_180x180.jpg&newxsize=180&newysize=180&fileout=

http://i1115.photobucket.com/albums/k545/MGRocket/Crush_11-2.jpg

[pipeclay]

The round nose tool should do it.
How many passes were you thinking of doing.
Are you able to get ali tips.

[MuellerNick]

The round nose tool should do it.


I beg to differ.
A round nose tool is good for high feed rates or a high DOC. With shallow cuts, the chip near the tangent of the tool to the part gets too thin for a good cut.
A diamond shaped insert with a tip radius of 0.2 or 0.4 works best. With a tip radius of 0.2, you can reduce the feed rate, but that depends on the lathe. My Chinese lathe doesn't want that, my Haas lathe is fine with it.

Also, a round nose tool has a long engaged cutting edge. That tends to chatter or to squeak unless you have a really rigid lathe. Not good for the surface.


Nick

[GSRocket]

I probably need to give more info....
I want to do the roughing out with the same tool that does the finishing. I'd prefer not to change tools.
Because the slides are controlled by levers, I can alter the feed rate on the run..so to speak.
The idea so far....is to do all the cutting with the profile fixed in one spot then click the profile back 0.5mm
to do a final sweeping cut (right to left?) but I can make the final cut at whatever size I want and also at whatever feed rate I want.
My lathe is old and heavy but difficult to get a good consistence tolerance in the dove tails so you would have to say it's not rigid but
it does have a 2 HP motor.
Pipeclay...When you say 'ali tips', You mean that there a special tips specifically for aluminium turning?

[pipeclay]

You can get tips for the round holder for aluminium.
The depth of cut for the round holder will be limited as there is not a great amount of clearance for the shank of the tool (you could allways grind this to provide more.
The more preffered tool would be a diamond shape ( preferably negative rake ),you can also get these with an ali tip.

[GSRocket]

I'm slowly getting the hang of what's required. So far this is the best I've found. Can someone tell me who the Australian supplier would be for Sandvik Coromant?Here is some advertised on ebay USA Sandvik CCGX 432-AL H10 Carbide Insert | eBay (http://www.ebay.com.au/itm/Sandvik-CCGX-432-AL-H10-Carbide-Insert-/310418310480?pt=LH_DefaultDomain_0&hash=item48465f8550#ht_578wt_924)Or can somebody give me an alternate that's easily available in Aust.?AL CCGX 12 04 08-ALap = 0.5 – 7.0 mmfn = 0.15 – 0.6 mm/r for finish turning in aluminium and other non-ferrous metalsFeed : 0.05 mm/rev; D O C : 0.1 – 7 mmOperations : turning, facing and profiling.Components : aluminium components in generalAdvantages : positive, open geometry giving soft cutting action at high cuttingspeedsLimitations : dedicated to non-ferrous materialsGeneral recommendations : apply highest possible cutting speed (up to 2500m/min) for best productivityPossible optimization : PCD inserts

[pipeclay]

I'm slowly getting the hang of what's required. So far this is the best I've found. Can someone tell me who the Australian supplier would be for Sandvik Coromant?Here is some advertised on ebay USA Sandvik CCGX 432-AL H10 Carbide Insert | eBay (http://www.ebay.com.au/itm/Sandvik-CCGX-432-AL-H10-Carbide-Insert-/310418310480?pt=LH_DefaultDomain_0&hash=item48465f8550#ht_578wt_924)Or can somebody give me an alternate that's easily available in Aust.?AL CCGX 12 04 08-ALap = 0.5 – 7.0 mmfn = 0.15 – 0.6 mm/r for finish turning in aluminium and other non-ferrous metalsFeed : 0.05 mm/rev; D O C : 0.1 – 7 mmOperations : turning, facing and profiling.Components : aluminium components in generalAdvantages : positive, open geometry giving soft cutting action at high cuttingspeedsLimitations : dedicated to non-ferrous materialsGeneral recommendations : apply highest possible cutting speed (up to 2500m/min) for best productivityPossible optimization : PCD inserts

What type of holder are you going to use,if you buy local you may pay a premium price.