Mini Lathe - Turning Between Centers?

[D.sebens]

What was your doc? Hss would be better suited. If mild steel you will have a hard time getting a decent finish. I usually polish it with Emery cloth or metal sand paper.

 

[MaverickNH]

What was your doc? Hss would be better suited. If mild steel you will have a hard time getting a decent finish. I usually polish it with Emery cloth or metal sand paper.

“doc”? - not sure what you’re asking, sorry. The material is Al 6061 and the tool was a 3/8” AR indexable carbide. Feed Rate is fixed at 0.004” per revolution (although that can be varied by manually charging gears cogs). Final Cut was 0.003 with cutting fluid.

 

[D.sebens]

Wow. If that’s aluminum something is not right. Doc is depth of cut. I would recommend using hss tools. Also use wd40 for cutting fluid on aluminum it really helps.

 

[MaverickNH]

Wow. If that’s aluminum something is not right. Doc is depth of cut. I would recommend using hss tools. Also use wd40 for cutting fluid on aluminum it really helps.

Thanks - I’ll try HSS & WD40 on a few more passes on this workpiece tomorrow.

 

[verbotenwhisky]

My first attempt turned out OK. A bit rough - I was hesitant to run over 1000rpm with the lathe dog imbalance using a carbide indexable tool, so it's not as smooth as it could be. But it indicates +/-0.0005 across 8 inches

View attachment 466655

I usually run 500 +/- for this material.

 

[MaverickNH]

Much nicer today!

1. Two passes 0.0025" DOC
2. 500rpm 0.004"/rev feed rate
3. HSS T-15 1/64 radius inserts
4. WD-40 cutting fluid

The 1st pass chipped and 2nd pass spun swarf - does this indicate the rough finish on 1st pass?

 

[D.sebens]

The finish looks really nice now. Especially for a mini lathe. How is the taper.

 

[MaverickNH]

The finish looks really nice now. Especially for a mini lathe. How is the taper.

It reads out at +/- 0.0005 across ~8in - I think I got lucky on machine alignment and my 1st use on a 4-jaw chuck.

 

[D.sebens]

Nice. Good job!

 

[verbotenwhisky]

Much nicer today!

1. Two passes 0.0025" DOC
2. 500rpm 0.004"/rev feed rate
3. HSS T-15 1/64 radius inserts
4. WD-40 cutting fluid

The 1st pass chipped and 2nd pass spun swarf - does this indicate the rough finish on 1st pass?

View attachment 466778

That looks good. I cannot seem to get the chips to break as nice on 6000 series aluminum; but, I found that it I am not happy with the chips I can vary F&S slightly to alter its behavior for different tooling. I thought I needed the lathe to be much faster when I bought it but I find it works best in most cases at the lower RPM.