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- Jan 20, 2018
- Messages
- 5,654
Sounds like aerospace "excess inventory". Who else can afford to scrap something like that because it costs more to keep it on the books?
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Help/Ideas for turning 2⅛" 303 stainless with low power
- Thread starter OCJohn
- Start date
- Joined
- Jan 20, 2018
- Messages
- 5,654
Wish I had a scrap source like that, just not willing to live in southern California to get one. Maybe something near Boeing.
If I may ask, how much did that chunk set you back?
- Joined
- Dec 6, 2021
- Messages
- 225
I just tried 0.004 DOC and cut only about a half inch before the spindle stopped. (Better finish, though!)
I assume you're cutting 0.005 with more than 250w?
- Joined
- Feb 8, 2014
- Messages
- 11,144
Well a bit more..... OK a lot more . But I'm surprised that your machine stalled at 0.004 DOC. You were in low gear?
- Joined
- Sep 28, 2013
- Messages
- 4,318
DCGT will take less force to cut at the expense of insert life. I used CCGT inserts quite a bit with stainless on my Atlas 618 (similar size lathe) and it worked pretty well. Still slow, but doable.
For HSS, start with the mega thread here on HM.
www.hobby-machinist.com
For smaller machines, a very sharp HSS can help a lot. The ground inserts are great as well. With inserts, try to run a DOC of about 2x the tip radius (should be on the insert package). A good HSS grind can peel off tenths.
For feed rate, with carbide try running faster. I know it's a bit counter intuitive, but sometimes carbide just wants to run hard. And make sure RPM is in the right range for the material. Also try to keep stickout on the tool particularly low. Getting what rigidity you can is only going to help.
Ground "for aluminum" inserts will work well for steel, but they do wear down faster.
Models for grinding HSS Lathe Tools
In a recent thread by @Darkbluesky, http://www.hobby-machinist.com/threads/lathe-accessories-tools-ideas-of-what-to-buy.62043/#post-511618, @ttabbal joked about sending me blanks to be ground into lathe tools ... he was joking! But it got me to thinking ... yeah, I know it's not a good thing...
www.hobby-machinist.com
For smaller machines, a very sharp HSS can help a lot. The ground inserts are great as well. With inserts, try to run a DOC of about 2x the tip radius (should be on the insert package). A good HSS grind can peel off tenths.
For feed rate, with carbide try running faster. I know it's a bit counter intuitive, but sometimes carbide just wants to run hard. And make sure RPM is in the right range for the material. Also try to keep stickout on the tool particularly low. Getting what rigidity you can is only going to help.
Ground "for aluminum" inserts will work well for steel, but they do wear down faster.
- Joined
- Mar 26, 2018
- Messages
- 2,724
I highly recommend "aluminum specific" insert geometry for cutting stainless with low power. These inserts are xxGT ot xxGX (DCGT, CCGT, DCGX, etc.). They have a razor sharp ground edge and make cuts with much less horsepower. The tool life is not great but acceptable. I buy these inserts from AliExpress for about $1 each so the cost isn't bad.
In terms of geometry, the smaller the included angle (DCMT vs CCMT) the lower the cutting forces, but also the weaker the insert and the smaller the depth of cut. VCGT is on the far end of the spectrum and is a great choice for low rigidity machines or poorly supported workpieces.
www.aliexpress.com
www.aliexpress.com
www.aliexpress.com
In terms of geometry, the smaller the included angle (DCMT vs CCMT) the lower the cutting forces, but also the weaker the insert and the smaller the depth of cut. VCGT is on the far end of the spectrum and is a great choice for low rigidity machines or poorly supported workpieces.
7.8US $ 40% OFF|DCGT11T304 AK H01 Aluminum Insert Cutting Tool turning tool carbide wood turning tools CNC lathe tool DCGT 11T304 turning insert|Turning Tool| - AliExpress
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5.88US $ 60% OFF|CCGT060202 CCGT060204 CCMT060208 AK HO1 Carbide Insert CCGT09T304 CCGT09T308 CCGT120402 Aluminum Turning CNC Cutting Tool CCGT|Turning Tool| - AliExpress
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11.5US $ 50% OFF|Vcgt160402 Ak H01 Internal Turning Tool Cnc Lathe Tool Aluminum Alloy Carbide Insert Cutting Tool Vcgt 160402 Turning Insert - Turning Tool - AliExpress
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