Turning technique

[musicman]

Hey Penturners,
I'm fairly new to making pens, and made about 20 so far. I've done fairly well with no real issues. Recently, I have been having an issue with turning one of the ends to the bushing. It's always the left side, and it seems as though the chisel gets pulled downward thus cutting a gouge in the work. I use a round carbide tip chisel from rockler. Im using a very light touch when I get this close to the bushing and this close to finishing turning. I'm able to repair it with ca glue, but I would like to know what is causing this issue so I can avoid it in the future. Any suggestions will be greatly appreciated.

 

[elyk864]

Usually some sort of chatter due to the TBC being loose or the tube having an air pocket that allows the material to move ever so slightly. Make sure your carbide bit isn't loose either. Acrylic will do that if you get to aggressive on it.

 

[SteveG]

Do you readjust the tool rest closer to the work as you remove material? Also, since the issue happens on the L side only, try to analyze what you do different vs the R end of the blank. That difference may be your answer.

 

[ed4copies]

Are you always turning left to right? The diameter of the pen gets greater, as you climb from the left. It will be safer to "turn downhill".

Suggestion from Steve is also good--make sure the tool rest is as close as possible. With a round carbide, you should have the tool horizontal, not angled up or down.

Hope one of these hits the problem on the head.

Ed

 

[magpens]

Also, since the issue happens on the L side only, try to analyze what you do different vs the R end of the blank. That difference may be your answer.

I think Steve has a very good point here ... the Right - Left assymetry could very well be the reason. . When you analyze how you are holding the tool and how you are standing, it is quite possible that the tool is presenting itself to the workpiece in just a slightly different way on the two sides

Just to check this out, try doing one end of the blank first, say the right end. . I would suggest that you flip the blank over after doing the right end .

In this way, you will be actually turning two "right ends".

You could try this with a scrap piece, just to see what happens.

I also notice that your blank has a fairly large bulge on it. . When doing shapes like that, you have to make sure that your tool's cutting edge never goes above or below the centerline (the turning axis).

Also, the direction the tool is pointing. . When you are doing the right end of the blank, the tool should actually point slightly to the left, but when doing the left end, the tool should point slightly to the right. . When you are at the center of the blank, your tool points perpendicular to the turning axis. . So your tool direction changes as you make a cut along the length of the blank.

As Ed advised (above), you want the plane of the tool bit's upper flat surface to be perfectly horizontal. . Height of tool rest is critical in order to keep the tool cutting surface and the turning axis in a horizontal plane. . Advanced turners learn to depart from this rule, but beginners should not.
This is what I find to be the best when using a round carbide cutting tool.

Practice on some scrap pieces until you overcome the problem.

 

[mick]

I don't know if anyone's mentioned it to you yet but never cut toward the unsupported end of the blank. Always start you cut and move away from the end. A lot of blow outs are caused by this.

Sent from my SM-G955U using Tapatalk

 

[jttheclockman]

I don't know if anyone's mentioned it to you yet but never cut toward the unsupported end of the blank. Always start you cut and move away from the end. A lot of blow outs are caused by this.

Sent from my SM-G955U using Tapatalk

I get alot of flack when I point this out but I agree with you 100%. I and that is me always start from each end toward the center. The ends are unsupported and you see more blow outs and people wonder why. I believe what happens here is your tool hits the bushing which is harder material than the blank and when you compensate you dig in on the end. learn to move the tool both right and left.

 

[mick]

I get alot of flack when I point this out but I agree with you 100%. I and that is me always start from each end toward the center. The ends are unsupported and you see more blow outs and people wonder why. I believe what happens here is your tool hits the bushing which is harder material than the blank and when you compensate you dig in on the end. learn to move the tool both right and left.

First thing I learned!

Sent from my SM-G955U using Tapatalk

 

[Edgar]

Many people are able to use a round carbide tool for successful pen turning. I'm not one of them. I use an R2 tool. I find it much easier to control. After turning the blank round and about halfway to final size, I cant the tool about 45 degrees for more of a cutting rather than scraping action.

If you have an R2 tool, you might give it a try to see if it works better for you.

 

[mick]

Many people are able to use a round carbide tool for successful pen turning. I'm not one of them. I use an R2 tool. I find it much easier to control. After turning the blank round and about halfway to final size, I cant the tool about 45 degrees for more of a cutting rather than scraping action.

If you have an R2 tool, you might give it a try to see if it works better for you.

Edgar, help me with my ignorance. Edgar's a R2 tool?

Sent from my SM-G955U using Tapatalk

 

[musicman]

Thank you everyone for sharing your ideas, and I will definitely implement them. Can anybody suggest some reliable youtube videos that focuses on proper technique. There are so many videos out there and for someone who is fairly new to pen turning, it's difficult to separate the good ones from the others.

 

[ed4copies]

This guy is STUPENDOUS!!! (Tongue firmly in cheek)