gouge angle 45%

[devonwoody]

I had an accident last week turning, the mahogany type timber broke off at its edge (to a third of the bowl depth).

My gouges small medium and large (20mm largest) are all set to 45% bevel.
I definitely laid the bevel to the timber first and pulled the chisel handle up until I got a cut, but each time there was a catch, (well almost every time.)
Is there more bevel on a 55% setting and less chance of catch ups?

 

[CHJ]

John, the catch problem you are having/had has little to do with the angle of bevel but more to do with how you present the tool to the workpiece, although a slightly longer side bevel may help stopping the wings catching, you really need to visit with an established turner to get some basic approach info. Pity you have the luxury of living in the sunny south, there are more of us around who could help in the midlands.

 

[devonwoody]

Wizer is visiting the west country shortly and I have started making another tissue box in anticipation of his visit, I will lock him in the workshop with the lathe turned on and watch through the window and if all goes well I will creep in and get closer and closer.
That alright with you Tom?

 

[Paul.J]

Can you post a piccy of your gouges DW,and in particular the tips :?:

 

[wizer]

No problem John. I don't know what our schedule is yet. We are actually staying in Paignton so I should be able to sneak away for a couple of hours. Will contact you nearer the time.

 

[stevebuk]

who you got going round for tom to watch?? :lol: :lol: :lol:

 

[Richard Findley]

With Tom's turning your best watching from outside the workshop!! :lol: :lol: :wink: :wink:

Have fun both of you!!

On your original question, it sounds like your catch is on the entry cut into the rim of the bowl? If so, my top tip would be to mark a line with the tip of a skew (flat on the tool rest like a scraper) or a parting tool to give you a groove to locate the tip of your tool into, this will stop the skiding you are experiencing. It's all about the bevel of the tool having something to rest on. The actual angle, as Chas says, doesn't actually matter but if you're interested my bowl gouge is more like 65deg which suits my turning style.

HTH

Richard

 

[devonwoody]

Can you post a piccy of your gouges DW,and in particular the tips :?:

Are these pictures adequate?

They had just been resharpened.


BTW a better picture of the broken turning.

 

[Nick Arnull]

Hi DW,
I have looked at your tools and in the second image the 2nd tool from the left is a shallow fluted Spindle Roughing Gouge and should not be used on bowl work,
The other tools you have I have seen in my workshop many times "The Perform range" These are a budget range of tools and are ground with shallow flute shapes which means the tool does not enter the timber as well as a deep fluted gouge they also do not seem to hold thier edge very long at all the beval angle appears about correct but the point on the front is not going to help your technique it should be a gentle curve "no point"

There is another question that also needs to be addressed here,
"For every one " How are you measuring the angle of your bevel from what point to where and what is the Datum line you are using as this will change the way the angle read.
My bowl gouges are ground to somewhere around 45degrees.
This may open up some debate,
Hope this is of some help.
Nick Arnull.

 

[devonwoody]

Thanks Nick, very useful information there, especially the note re the roughing gouge, I shall mark the handle up on that one.
Yes some of those tools of mine are a bit pointed.

I have also got a gouge with my pen turning set and the wheel on my tormek made hardly any impression on the blade, it just wore the stone. The pen turning set is the standard Axminster 3 piece pen turning set.

I wasnt impressed with my Tormek white grindstone, I lost 5mm of circumference on 4 gouges. (I have got a poly bag of white grout that came out of the Tormek water trough, saving it for abrasive cleaning of tools :wink: )

 

[Richard Findley]

Hi DW,

I think Nick covered it pretty well. The main reason for your difficulty is not so much your gring angle as the tools you have. Really you seem to have a selection of spindle tools. What you need is a nice shinny new Bowl Gouge!!! (which as Nick says, has a deeper flute and is designed for turning bowls.)

Nick, I draw a straight line, vertically on a piece of board and then draw a selection of lines from it at recognisable angles:

|
\|
|/
|

Apologies for rubbish "drawing" I then lay my gouge on the vertical line and the bevel shows against the other lines what the angle is.

Hope that makes sense!!

Cheers

Richard

 

[CHJ]

These might help:

And These:

And a couple of simple angle checking templates,---printed on Photo paper and glued to some thin sheet brass/ali'/plastic. (from turningtools.co.uk)

Edit:- a couple of other sketches that might be useful as starting points.

 

[Paul.J]

Which one of those tools were you using when you had the catch,if it was a catch, DW :?:
Also DW it is best to shape the outer before taking the middle out,or is that the required shape that you have in the piccy.
Take a look at the how to again.
The tips of the gouges do look too pointed,so i would reshape em again to a nice curve.

 

[devonwoody]

Thanks all again for information re angles.

PJ, I think I was using no. 4 or no. 5., I had started the turning on the outside of the bowl which initially went fairly well, but then started getting dig ins. Then switched to the inside which again cut cleanly. I left the bowl on the lathe for around 4 weeks, (doing boxes) and went back inside and I got a catch nearly every turn.

 

[CHJ]

.... I left the bowl on the lathe for around 4 weeks, ..... and went back inside and I got a catch nearly every turn.

Major mistake John, it is almost guarantied that even left for a few hours let alone over night or longer that a partially turned item will have moved out of round, as a new turner not having developed a technique for coping with this it will cause you major problems in itself because of poor bevel contact.

IMO the only safe way for a new starter to tackle this problem is to true it up with scrapers when restarting. Work below centre on the outside and above centre on the inside, then any tendency to catch drives the tool into space not dig it deeper into the wood.

 

[Richard Findley]

Well done Chas. Picture 2 is what I was going on about!!!

Cheers

Richard

 

[devonwoody]

Thanks chas, I thought that might be a contributing factor.

 

[Sportique]

Chas

many thanks for those very handy tips, just what we beginners need.
=D>

Dave