Thread: 'What flute profile does this gouge have?

Originally Posted by ronboult

My first observation was that your Crown Ellsworth gouges have a much wider open flute than the Woodcut perhaps even wider/ open than the Superflute. Do you notice any difference in the wings or how they cut.

The flute profile on the Woodcut is very similar to the bowl gouge profile in Peter Child's 1970s book, see image followng... so has good pedigree...

BG flute prpfile in P Child 1970s book - crop.jpg

The way I turn is to sharpen all of my bowl gouges in batch mode and use them one after the other as each becomes blunt. I can't say that I have notice much difference between any of them other than the Henry Taylor Superflute that has that very wide parabolic flute. It takes a different grind to the others on my standard swept back grind jig setting. It does a good job on the inside of bowls (like a U flute) so I mainly use it for that.

You can see the different grind in the following two photos; the HT is on the right and on the top in the second photo. The wings are shorter.

Thom - EllsW - Dway - HT 5-8in top view sm.jpg HT - Dway - EllsW - Thom 5-8in side view sm.jpg

And, here is the Woodcut (on left and bottom) alongside the HT S-f, both 1/2".

Woodcut - HT 0.5in top view sm.jpg Woodcut - HT 0.5in side view sm.jpg

As you can see they are very similar and I don't notice any significant difference between the two in use. If anything, the Woodcut holds an edge for longer.

Originally Posted by ronboult

The second was that you are using a diamond wheel. I thought (perhaps wrongly) that the general advice was that diamond wheels were not generally recommended for woodturning gouges because of the brittleness of diamonds and their tendency to shatter and breakdown. One of the reasons that CBN was introduced was because of their toughness

All I can say is that I have been using my diamond wheel constantly for years now and it has had minimal loss of grit and at the rate I am wearing it down I expect to keep using it for many years yet.

Originally Posted by ronboult

I really appreciate the grinding improvement that occured when I changed to a 180grit CBN from Al oxide but still find the 180 CBN a bit coarse and agressive so was considering a finer CBN for a second wheel. Also considered changing to a slow speed grinder for same reasons.
Maybe I should consider a diamond wheel instead.
Any advice?

Unless you are expecting to sharpen tungsten I would go for a higher grit CBN wheel if you want a higher grit finish. The price of CBN wheels has come down nowadays and they are very good.

I'm not convinced there is any advantage with slower speed grinding on HSS. Different matter if you are grinding high carbon steel blades.

Apologies (on behalf of the Forum software) for the missing images in that last post.... FIXED NOW, had to upload them again!

Yes, a PITB. It has been very temperamental today! The images were there in preview but not when I posted.

Originally Posted by NeilS

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...

It has not done that much work really. I bought a 16mm and a 10mm at the same time, they both sat unused for 15 years. The 16mm in the photo is dirty from roughing out some green bowls last weekend. I will give it a sharpen and post another photo so the profile is clearer.

I sharpen with a Woodcut Tru Grind jig on an 8 inch 220 grit CBN wheel. The grind is 45 degrees on setting 2 for the arm. I can't remember what the original P&N grind was but I think the wings are swept back a bit more. I have an old Teknatool 12mm bowl gouge ground at 55 degrees straight across and it is brilliant for the bottoms of bowls.

Michael

Originally Posted by ronboult

...as far as I know first developed by Roy Child and manufactured by Henry Taylor and sold under the Superflute label.

I went back to check on the history of the Superflute and the following webpage chronicles Roy Child's development of it.

http://www.peterchild.co.uk/info1/sflute.htm

So:

• The parabolic (my use of term) flute profile predates the Superflute and was initially forged in high carbon steel. See example from Peter Child's 1970s book in my posting above.

• Roy Child developed the profile that was to be later called the Superflute and that was first made by Peter Child & Son and ground and tempered in high carbon steel.

• Henry Taylor took over the manufacture of it in M2 HSS and called it the Superflute.

• After this the U flute profile, which is a cheaper profile to manufacture, started to be made by various tool makers. Confusingly, it became known as the 'traditional profile'.

• The V profile became yet another later development.

Before purpose-made hand forged bowl gouges we turners adapted gouges that were primarily used for spindle work and made more extensive use of scrapers. I started turning in the late sixties and I can say that any bowl gouge of any profile that you can buy now is better that what we had then!

I am adding a Vicmarc bowl gouge to my arsenal. Just arrived today.

Their site describes it as having a parabolic flute profile. My reading of it is that it is closer to having a catenary profile (with a= ~2) than parabolic, but that is a moot point. See earlier posts for the small difference.

For comparisons, its profile is close to that of the Henry Taylor Superflute and Woodcut gouges, profiles that I like.

As received, the following images are of the gouge from end on, top down and oblique view. Also included is a detail photo of the surface grind.

VM - grind end view - sm.jpgVM - grind top view.jpg
VM - pre-grind - sm.jpg VM - flute grind - sm.jpg

I have some opinions about the gouge before using it, but I will reserve any comments until I have modified the grind to my preferred profile and used it.

High Neil
Waiting to hear your impressions on the Vicmarc gouge. Do you know what type of steel they are made of?Was intrigued by your last cryptic comment.
Ron

The finish of the VicMarc flute looks a bit rough. Or is that just the pic? To me it looks like you'll need to do a fair bit of polishing in the flute before you'll manage a reliable edge. (Maybe they bought out some P&N stock? )

Personally, I tend to simplify things. Gouges that are pressed from flat stock I label U-flutes. If the flute is milled into solid stock, that's a V-flute. I've yet to see a stamped gouge with a V-flute and I can't think of any milled gouges with U-flutes.

They both probably exist, but I don't own any. Which is fine with me. Keeps my life simple.

Originally Posted by NeilS

I will reserve any comments until I have modified the grind to my preferred profile and used it.

That's always best. I do like the pressed U-flutes for roughing work but they're sharpened with minimal wings so I can rotate the tool while roughing to 'find fresh edge.'

For final shaping and finishing I've developed my own grind. Basically an ellsworth 'done wrong,' but it works very nicely for me. Unfortunately, it doesn't take much change in the flute profile to make 'my' grind unsuitable so I've sort of backed myself into a corner when it comes to buying new tools to grind to that profile.

Must be time to unlearn some bad habits and re-generalise my skill set...

Skew
Since when have HSS gouges been pressed from flat stock?

Originally Posted by ronboult

Skew
Since when have HSS gouges been pressed from flat stock?

You've never had a chaiwanese HSS-stamped gouge blue semi-unexpectedly while sharpening and then behave exactly as low grade CS from then on?

Still, you ask a fair question. As I said prior, I don't have any milled gouges with a U-flute. Some come quite close but on close inspection are actually a catenary curve, hence are V-flutes to me.

Originally Posted by Skew ChiDAMN!!

The finish of the VicMarc flute looks a bit rough.

Yes, Andy, it looks rougher than what you would get as a finish on many makes of gouges, but perhaps not quite as rough as the P&Ns. About the same as the Thompsons. I'm yet to polish the flute so won't know how deep those milling/grinding marks are until I've done that. The only flutes I've never had to polish are the D-way (absolutely beautiful flute finish on those) and the Henry Taylor Superflutes. I'll report back on how it went when I've given the end of the flute a polish.

Ron, VM say that the steel they are using is Vandis 10 (see below), also known in the USA as A11. Doug Thompson also uses V10 steel. It's a powdered metal with about 10% vanadium. Doug does a "triple temper with a cryogenic treatment between the first and second temper".

I don't know what VM does on the tempering. Vanadis 10 is a Swedish steel made by Uddeholm. Here is their description:

UDDEHOLM VANADIS® 10 SUPERCLEAN

Uddeholm Vanadis 10 SuperClean is a high vanadium alloyed powder metallurgy tool steel offering a unique combination of an excellent abrasive wear resistance in combination with a good chipping resistance. It is manufactured according to the powder metallurgy process giving a very low amount of non-metallic inclusions.In tool making Uddeholm Vanadis 10 SuperClean offers a good machinability and grindability together with a good dimensional stability during heat treatment. It can normally be hardened to 60–65 HRC.

I gave the VM bowl gouge a test run with the grind as supplied and, as expected, it was not to my liking.

Keeping in mind that the grind that comes on a new gouge is just a starting point. The makers pick a middle of the road grind that is quick and easy for them to manufacture and the user modifies it from there to suit themselves. The only gouges that came close to my preferred grind as supplied are the Thompsons and I think the reason for that is that Doug Thompson follows the Jerry Glaser 'grind profile guidelines' (more on that later), which I also like.

So, I reground the VM to my preferred grind. The photo on the left is of the grind as supplied. The one on the right has been reground to my preferred grind for this flute profile, except for the 'cheek' of original grind left on the sides, which will diminish with future re-sharpenings. No need to waste steel unnecessarily!

VM supplied grind - sm.jpg VM after grind mod - sm.jpg

As you can see the new grind gives a sweeter convex curved edge that is more in keeping with its parabolic/catenary flute cross section. I found that the reground VM performed much better on the inside of some bowls, where I find the grind is most critical. Almost any grind will work on the outside of bowls with the bevel rubbing.

Note: Your experience and preferred grind may be very different from mine. Mine may not work for you, but for what it is worth to anyone I will explain more about my preferred grind in a separate posting or thread later.

More comments to come.

Most interesting and informative thread. Thanks to all.

Should have mentioned that the remaining thickness of the steel at the bottom of the flute on this VM (5/8" bowl gouge) is about 6.5mm.

In comparison with other gouges with a similar flute profile, this is on the thicker side with the Henry Taylor having 5.5mm and the Woodcut 7mm. I should also measure the Ellsworth signature gouge that has a very open parabolic/catenary flute to see how that compares with the others.

I mention this as I find that this variation in thickness does have some effect on how the bevel rubs through the 'transition area' inside a bowl.

Hi Neil
Thanks for the updates.

Two Q if I may.
You have obviously tried quite a few different bowl gouges. Do you have any views on which steel produces the sharpest edge and which has the longest lasting edge.

Secondly I have recently purchased the Hannes sharpening jig which if used like recommended produces a very narrow primary bevel and a rounded off heel. Have you tried this type of grind?
Cheers
Ron