[keen]

Hi Folks.

I thought a thread on machining larger steel parts would be useful.

Please share your thoughts and information here.

I'll start the ball rolling with part one of this video series:

Cliff

https://www.youtube.com/watch?v=Pz_12ETmgbQ&t=4s

[jeffrey001]

Touching a drill at the tip on a cnc lathe is great if you do not drill too deep, otherwise, it's better to indicate the center on the holder because if you drill much deeper, you'll get a lot of rubbing on the side of the drill if you are like 0.010 off-center.

Nice video.

[keen]

Touching a drill at the tip on a cnc lathe is great if you do not drill too deep, otherwise, it's better to indicate the center on the holder because if you drill much deeper, you'll get a lot of rubbing on the side of the drill if you are like 0.010 off-center.

Nice video.

I agree - If you are doing critical deep hole work, eg reaming, you actually need to dial in the tool in line with the Z travel in both directions. Having it correct at either end but on an angle will give issues on precision or deep work. Cheers Cliff

[mountaindew]

Your videos are nice. I always pick up a trick or learn something in general.
Do you use conversational programming for most your lathe work?

[keen]

Your videos are nice. I always pick up a trick or learn something in general.
Do you use conversational programming for most your lathe work?

Thanks MD. Yes I use conversational for my lathe work and Bobcadcam for mill. Cliff

[keen]

Hi Folks

Here is part 2. Cheers Cliff

https://www.youtube.com/watch?v=Imd3repqhsk&t=1s

[keen]

Hi again Folks. And here is part 3. Finding the limit in steel.

https://www.youtube.com/watch?v=OxRBgyxbchI&t=3s

[maker of things]

Cliff, thanks for the series of Slant Pro videos. Do you think positive rake holder/inserts such as CCMT would help at all the larger size part?

[keen]

Cliff, thanks for the series of Slant Pro videos. Do you think positive rake holder/inserts such as CCMT would help at all the larger size part?

Hi - The WNMG style I use here is a positive rake insert - but I agree it is not high rake and does take a bit more torque to push that a even higher raked positive insert.

The trouble with going higher rake is the tool is weaker and not so good at rapid stock removal in steel. With a sticky CQ MS high rake tools are more likely to break. Also the 80 deg of the WNMG allows facing and turning with the same tool.

But with a weaker tool with more positive rake, a pronounced chip breaker and lighter cuts, larger diameters can probably be acheived - it will just take more time, and might need more watching.

Cheers Cliff

[mountaindew]

The other day I was watching a tv show of a guy cnc machining lathe parts for high performance engines. He was having same problem and that machine was huge! Was funny because with all the power and precision the guy just made the bird nest faster. .

[keen]

Here is a final summary video. With some repeat video clips to give some background, then on to how SlantPro could be improved.

Cliff

https://www.youtube.com/watch?v=mxQpUNiM_hk&t=11s

[maker of things]

Cliff are you thinking to make a larger pulley for the spindle?

[keen]

Cliff are you thinking to make a larger pulley for the spindle?

I think this developement work should be co-ordinated with changes to the control software and spindle drive system.

This video is partly to raise awareness off this issue. Yes I have sent this video directly to Tormach.

Cliff

[Jim Dawson]

I think this developement work should be co-ordinated with changes to the control software and spindle drive system.

This video is partly to raise awareness off this issue. Yes I have sent this video directly to Tormach.

Cliff

Would it not be more of a question of machine rigidity? How much torque can you throw at the machine before things start becoming unstable? Right now the motor is the weak link and stalls with no damage, but what might give if you double the torque?

[keen]

Would it not be more of a question of machine rigidity? How much torque can you throw at the machine before things start becoming unstable? Right now the motor is the weak link and stalls with no damage, but what might give if you double the torque?

I cover this in the video Jim

[maker of things]

Cliff, if I'm thinking this through correctly, using this chuck would accomplish the same goals as when you modified the jaws? Still would need to bore it out.
https://www.shars.com/products/workh...s-2-piece-jaws

[keen]

Cliff, if I'm thinking this through correctly, using this chuck would accomplish the same goals as when you modified the jaws? Still would need to bore it out.
https://www.shars.com/products/workh...s-2-piece-jaws

Hi Jon - Yes it is similiar, well the 5" is the same size, and the jaw tops can be flipped around. But then I ground off the jaw ends that protrude out etc, you would still need to do that to get the streamline shape.
Or where you thinking of leaving the jaw tops off and shape the underneath portion? I have done that on a 6" and it is very compact, but limited versatility.

Cheers Cliff

[maker of things]

I was thinking that with the reversible jaws, I could hold fairly large stock without sticking out too much. Probably withing the diameter of a 6" chuck. If I have to modify the jaws in the manner you showed, I would probably buy the much cheaper 1 piece jaw chuck.