Thread: 'What flute profile does this gouge have?

First of all, do you think that this old gouge might follow the accepted standard patterns of the London Pattern Book?
Ashley Iles, Henry Taylor, Stubai, Auroioux, Pfeil, Narex and others sing from the same page.
The sweep numbers run up into the 70's for carving gouges.
I don't own a complete copy of the LPB.
I suspect that turning profiles have their own page.


If it was a carving tool:
It isn't a #9 which is a 'U' but tall and parallel wings and not a #11 for the sweep.
What is the angle between the wings?
#12 = 60 degrees
#13 = 90
#14 = 55
#15 = 45
#16 = 35

Originally Posted by Robson Valley

What is the angle between the wings?
#12 = 60 degrees
#13 = 90
#14 = 55
#15 = 45
#16 = 35

Hi RV

The terms U and V are now common terminology to describe the flute profile of a bowl gouges, but as far as I know these terms have just evolved as a way of describing the profile without there being any commonly agreed definition. I'm not about to take on that task, just wanting to get opinions about this particular gouge so the new owner won't get confused by me using loose terminology.

The internal angle between the wings is 35deg, but I have never heard of that system being applied to turning tools. It is also an Australian made gouge, so perhaps unlikely to adhere to a UK pattern.

Thanks for your contribution.

High Neil
As far as I know the only difference between a V and a U shape is the angle of the sides and the radius at the bottom of the Flute.
A V gouge has a greater angle between the wings and a tight radius at the bottom.
A U gouge has almost parallel sides and a larger radius at the bottom.
Different manufacturers make all sorts of variations between the two.
A U flute is meant to clog less but the V flute gives a better cut. I think Doug Thomson who makes both prefers a V flute. I have only used Doug's V profile

You are correct that V & U flutes produce different wing profiles on a swept back grind.

However the last style you show is quite different to both the V & U profiles. The V & U profiles both have straight sides to the flute and this affects the shape of the wing on a swept back grind.

I prefer the parabolic grind with curved flute sides preferring the swept back wings produced by this shape. The parabolic flute was as far as I know first developed by Roy Child and manufactured by Henry Taylor and sold under the Superflute label. It has been around for a long time and has stood the test of time. They are now quite expensive but a really worth a try.
Cheers
Ron

Originally Posted by ronboult

However the last style you show is quite different to both the V & U profiles. The V & U profiles both have straight sides to the flute and this affects the shape of the wing on a swept back grind.

I prefer the parabolic grind with curved flute sides preferring the swept back wings produced by this shape. The parabolic flute was as far as I know first developed by Roy Child and manufactured by Henry Taylor and sold under the Superflute label. It has been around for a long time and has stood the test of time. They are now quite expensive but a really worth a try.
Cheers
Ron

Ron, thanks for your contribution.

I agree with your analysis.

On the Henry Taylor profile, yes that is its history. I think that the Glaser Hitec bowl gouge range may also use that profile, or a variation of it. There are probably others. I think the HT has a catenary profile. Vicmarc say theirs is parabolic. There is a slight difference between the catenary and parabolic profile, but in practice you wouldn't notice the difference.

Catenary-Parabola.gif

In practice (that is in use at the lathe) there is negligible difference between a strictly V and parabolic profile, but a considerable difference between U & V.

Like you, Ron, I prefer the swept back grind that you can get on the V & parabolic flute profiles.

From memory, the small wing angle on the P&N (first image) won't take a very aggressive swept back grind and behaves more like a U profile.

Any pics and comments from forum members of the grind on their P&N BGs would be most welcome.

Neil
Here are some photos of the bowl gouges in my collection.

The fist photos are of my Superflute gouges- old ( around 1980-5) and new (2017). The photo is somewhat misleading in that the gouge on the left is my working gouge ground with swept back wings while the gouge on the right is brand new and still ground straight across. In actual fact in real life the newer gouge flute is ground almost identical to the original grind when first manufactured. Measured the flutes are identical but the swept back grind makes the steel at the bottom of the flute LOOK much thicker on the old gouge. ( Both have 5mm thick steel below the flute and are 11m across the top of the flute. However more expensive to now buy in Au now.

P1020884.jpgAnd from above P1020876.jpg And my most used and "worn out Old" Superflute from the side P1020881.jpg

Since I like "parabolic" flutes I tried to buy some new gouges in more high tech steel.

My next gouge purchases were both made by Doug Thompson tools. Firstly a Thompson 5/8V and an imported Lyle Jamison "Signature gouge" ( Also made by Doug Thompson).
The reason I imported the Jamison gouge is that on Lyles website he states and I quote
"This has a better flute configuration—Not a “V”, not a “U” shape—It is 12 inches long with a 7 inch long flute —It has a wider, parabolic flute shape than any other gouge made today—The flute change translates into easier, safer, better control"
Unfortunately as you can see from the pictures the flute shape of both the Thompson (expected) & Jamison Gouges (Unexpected) are both V flutes and not parabolic.

P1020874.jpg Thompson on left, Jamison on right. Again the flutes look slightly different, because the length of the wings are different, but are close to identical flute shape.
P1020873.jpg Jamison above Thompson below.
From the side P1020880.jpg Thompson above - Jamison below.

Quite different. It will be interesting to try both these gouges to see how they perform. I have not used either yet and will have to workout the Oneway Jig settings to maintain there shape.


Next are from Hamlet 25mm and 10mm gouges. P1020877.jpgP1020879.jpgBoth very similar but quite different to a Thompson flute in that the sides are more vertical and the bottom of the flute much much more rounded. More a U shaped flute. I am not so keen on these gouges and don't use them very often. The 25mm overkill and is really too large for most of my work.

Ron
PS Sorry for font changes but they seem to happen spontaneously

I voted a U, glad I'm not alone now!!! The difference in opinion is starting to make me think it is a hybrid

Neil
Could you please post a clearer picture of the Ellsworth Signature 5/5 Bowl gouge. Its a bit difficult to see the flute profile in your first post
Cheers
Ron

Originally Posted by ronboult

Neil
Could you please post a clearer picture of the Ellsworth Signature 5/5 Bowl gouge. Its a bit difficult to see the flute profile in your first post
Cheers
Ron

Will do, but I may not get to my workshop tomorrow, so it might be some time before I can do that.

Excellent lot of photos of yours, Ron.

Will post some comments on those profiles when I can later on .

OK, here are some better photos of the flute on the Ellsworth Sig BG from Crown.

Ellsworth Sig No1 5-8th in - sm.jpg Ellsworth Sig No2 5-8th in -sm.jpg

I have two of those, so a photo of each. I would call that flute profile catenary or parabolic.

I also took a close-up of the Woodcut, which I reckon on closer inspection it is also parabolic. So, I looked at their website and they state that this bowl gouge has "a parabolic 'U' shape flute"

Woodcut 0.5in sm.jpg

This highlights the purpose of this thread. There is not an uniform or agreed terminology for describing flute profiles.

I reckon that all of the flute profiles above on this posting are parabolic, along with the Henry Taylor in my first posting and in Ron's.

As defined by Ron, the U flute profile has parallel sides, with an half circle bottom. Type capital 'U' and you have it.

A V flute profile has straight sides that can be at a variety of angles to one another that form a tangent to a part circular at the bottom of the flute that can be of varying relative diameters to the bar size.

So, the three terms U, V and Parabolic describe three distinct profiles. If only manufacturers and us turners could use these terms more precisely there would be less confusion.

PS - I include catenary and hyperbolic profiles under parabolic, ie the sides are not straight and they have a continuous curve that conforms to some geometric principal (as in conics) or law of physics as is the case with the catenary profile

Thanks for the pictures Neil. Pleased to see that the Crown Ellsworth SG is parabolic. Cant help myself - will just have to try one.
Had a closer look at the new Superflute that I just purchased and was a little dissapointed to observe that the flute is not quite symetrical. Wonder where they are now made?
Are either of your gouges Ellsworth Powder Metal? If so do you think it is an advantage over HSS?
Also are those gouges straight off what grit CBN assuming you are using a CBN wheel?
Ron

I have the same P&N bowl gouge. I bought it about 1994 I think. The box it came in describes it as a 16mm bowl gouge M2 HSS. I am not sure how to describe the flute but it works for me.

20171002_192632.jpg 20171003_212344.jpg

Michael

Originally Posted by ronboult

Had a closer look at the new Superflute that I just purchased and was a little dissapointed to observe that the flute is not quite symmetrical.

I have also had to grind a bit off the top of one side of a bowl gouge that I have so that it sits square in my sharpening jig.

Are either of your gouges Ellsworth Powder Metal? If so do you think it is an advantage over HSS?

One definitely is, and another Pro-PM that I have is the poorest performing bowl gouge on my tool rack, so no, I don't think that it is always better or worth the extra $s. Overrated, IMO.

In my experience, the amount of vanadium in the steel alloy (eg 10% or 15%) improves edge durability although it doesn't take as fine an edge as some other steel alloys. Great for hogging off bulk amounts

Not sure what is in the D-way gouges, but they take the finest edge of all of the HSS gouges I have used. Beautiful for doing finishing cuts.

Also, are those gouges straight off what grit CBN assuming you are using a CBN wheel?

Ron, all straight off an 8" Woodriver 120 grit diamond wheel. I also have an 8" 180 grit CBN wheel for reshaping my tools, but despite the lower grit the Woodriver gives a much finer finish and takes off next to no unnecessary metal to give a fresh sharp edge.

.............

Originally Posted by BamBam53

I have the same P&N bowl gouge. I bought it about 1994 I think. The box it came in describes it as a 16mm bowl gouge M2 HSS. I am not sure how to describe the flute but it works for me.

20171002_192632.jpg 20171003_212344.jpg

Michael

Thanks for posting, Michael.

Yes, a similar vintage to mine.

Interesting to see the grind you have used.

That P&N M2 HSS is a good performer for the $s.

Sure looks like yours has done a lot more work than mine...

Originally Posted by BamBam53

20171003_212344.jpg

Michael, looking at your P&N it appears to have the grind that is close to the one that it originally came with; ie a more straight across grind. Am I seeing (and remembering) that right?

That straight across grind is typically used on U fluted bowl gouges. Some turners prefer that grind for the inside bottom of bowls and platters.



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