Carbide tools + RPM

[Jordan Daoust]

Good morning!
I've been turning for just over a year, I use Rockler's 12-24 midi lathe and carbide turning tools. I've had a lot of success and have turned some beautiful pieces.

I mainly turn bowls/platters/boxes etc. usually less than 10" in diameter and 16" in length.

Here's where I want some feedback from the hive mind: When i'm turning, I find myself trying to get to the top rpm (~1,200) as quick as possible so I can turn efficiently and get a smooth finish although, I very often have to start at 80 grit when sanding and usually spend more time sanding than turning. I keep my carbide tools fresh and sharp as much as I can.

Thoughts? Advice?

 

[Alan Weinberg]

Not sure what type of carbide you use, but most are just scrapers. My advice, 3 years in, is to learn how to turn with traditional tools—gouges. Look at Hunter carbides if you decline to try gouges. And reaching 1200 rpm is not necessarily the goal—depends on wood type, wood shape, blank size. Find a mentor and join a group.

 

[Bill Alston]

There are a series of YouTube videos where one turner shows you how to cut rather than just scrape with carbide tipped tools. Here’s just one.

View: https://youtu.be/eUO98R-8JgI

 

[Robert Santore]

Here's where I want some feedback from the hive mind: When i'm turning, I find myself trying to get to the top rpm (~1,200) as quick as possible so I can turn efficiently and get a smooth finish although, I very often have to start at 80 grit when sanding and usually spend more time sanding than turning. I keep my carbide tools fresh and sharp as much as I can.

Are you having problems with certain types of wood, or is it across the board?

What issues are you sanding out? Is it tearout / end grain or are you seeing the same issues across the entire surface? You didn't mention spindle work but do you see the same issues? Understanding where things are going wrong might give you a good clue as to what you need to fix.

I've only been turning a few years myself but one thing that helped me a lot was to use every pass as a practice cut and diagnose what was happening, what worked and what didn't. Make a pass, stop, and evaluate. Don't wait to be at your final form before stopping and seeing how you're doing, cause at that point sandpaper is your only recourse.

I haven't tried carbides, and so my bag of tricks won't be helpful for you. But, things I play with are tool choice, sharpness, angle of presentation, bevel support, how aggressive the cut is. Play around and see if you can make incremental improvements.

 

[Jordan Daoust]

The main issue seems to be end grain tearout, Some woods have more "damage" than others, but it seems to be a recurring issue that i've been having.

I'll definitely start watching those videos, thank you for posting!

I took a class at WoodCraft and learned on traditional tools, but when it came to getting my own setup up and running, I chose carbide. I am definitely not against traditional tools, and I know they will be in my future, the only barrier is cost at this point.

 

[robo hippy]

The carbide tools are mostly used as scrapers, and while they do work, you still need gouge and skew skills. With scrapers and experience, you can get excellent results on end grain pieces, but on bowls, they leave a LOT to be desired, which is mostly tear out which requires a lot more sanding time. I don't think I have met any one who actually likes to sand. I sure don't. As for speed, there are all sorts of formulas. Since my first lathes had no rpm read outs on them, I learned to turn by speed. With bowls, I would not go much over about 1000 for a 6 inch diameter bowl, but that may be too fast, especially for a beginner. Spindles are usually done much faster, in the 2000 rpm range, and again, it depends on size. It is a feet/minute thing. Small spindles, as fast as your lathe can go, maybe. Rolling pin about 2 inch diameter, not more than 2000 rpm. Bowls, in the 600 to 1000 range, and all of this depends on the wood. I do not turn crappy wood, though some love the channelge.

robo hippy