Lyle Jamieson designed ⅝” bowl gouge made by Doug Thompson

[Neil Strong]

Having read positive comments on the forum about the Lyle Jamieson designed 5/8” bowl gouge, made by Doug Thompson, I decided I would give it a try. I have been a satisfied user of Doug’s gouges for many years, so I was familiar with the steel he uses and his cryogenic treatment of it.

For those who are not familiar with this gouge, it is made with the same powdered metal V10 HSS and cryogenic treatment as Doug’s other turning tools, but with Lyle’s flute design and comes with Lyle’s preferred grind for the students he teaches. He says of this grind that it will do all of the commonly used cuts and his students will only need this one gouge grind to do all of those cuts.

The gouge can only be purchased directly from Lyle…

https://lylejamieson.com/product/signature-jamieson-grind-bowl-gouge-thompson-handled/

Here is the grind that came on it…

Jamieson BG - side profile.jpg

I measured the nose bevel angle and it was just below 60 °…

Jamieson bevel angle.jpg

Here it is seen from above…

Jamieson BG - top view.jpg

The following photo is an end view of the Jamieson flute profile on the right and the standard Thompson V flute profile on the left...

Thompson & Jamieson - end view.jpg

As you can see, there are some differences between the two flute profiles, which do make a difference in the way each gouge performs, but whatever those differences are neither has a parabolic flute profile, which is how Lyle describes his flute design. Here is an interactive graph of possible parabolic profiles and no matter what value you put into the alpha parameter (other than zero) the sides of the parabola can approach a straight line but never become fully straight…

https://www.desmos.com/calculator/zukjgk9iry

There have been many bowl gouges with parabolic flute profiles since Roy Child (son of Peter Child) designed the original Superflute back in the 1970s that was subsequently manufactured by Henry Taylor.

The difference between the Thompson/Jamieson flutes and the Henry Taylor flute (on right) is very obvious when viewed end-on and side by side…

D-way, Jamieson & HT.jpg

Both the Thompson and Jamieson gouges have very straight sides. Neither is parabolic, hyperbolic, elliptical, or for that matter catenary. That is not a criticism of those two flute profiles (far from it), but a clarification in terminology.

The flute profile on Doug’s gouge has long been called a V flute and that term is an adequate description and avoids any confusion. Lyle’s flute is also a V with about the same angle between the straight sides (about 60 ° but that was just eyeballing it), but made wider to give a broader vertex (nose) and milled deeper to give a taller flute that is wider at the top. For want of a better description, I would call Lyle’s flute design as ‘whatever’ V to distinguish it from Doug’s… like ‘Big’ V, ‘Large’ V or just LV, as in Lyle’s V, or maybe Super-V… :~}

Having got all of that off my chest, back to looking at other things about the gouge. As you can see in the first end view photo and the following top view photo, there are some serious milling/grinding tracks in the Jamieson gouge, as received, that will need some work on them, as did all of my original Thompsons when they first came. See top view of gouge flute in photo above.

I didn’t bother polishing the tip end of the flute before giving it a test run, but will have to do that at some stage to get the best working edge out of this high vanadium PM steel.

Looking at the photos above you can see that the gouge as received faithfully follows Jerry Glaser’s guidance on mirroring the cutting edge (as seen from above) with the flute profile (as seen from the end view), so that is a good starting point.

One thing to note about the two gouges as seen side by side in the above photo is how deep the Jamieson flute goes down into the bottom of the gouge to achieve the wider flute. As a result, there is less metal left in the gouge which does leave it feeling less solid in the hand than the Thompson standard V.

Lyle states on his website that his gouge has the widest flute of any ⅝” bowl gouge being sold. It measured about 12mm across and is about 1.5mm wider than the standard Thomson 10V and up to 2mm wider than some of my other ⅝” bowl gouge (Thompson 15V - 11mm, Ellsworth Crown - 11mm, VM 11mm, Thompson 10V - 10.5mm, D-Way - 10.8 & 10.6mm, HT - 10.6mm, Woodcut - 9.8mm), so he is probably right with that claim.

Jamieson 12mm wide flute.jpg

Whether there is any benefit from that extra wide flute might become obvious when I give it a test run, which I will report on in my next post.

[Neil Strong]

For a test run I used the gouge as received on some very well seasoned oak blanks.

I like to give the gouge makers the courtesy of trying out the grind they send on their gouges before changing them to suit myself.

I must say that I don’t think Lyle’s grind will become my favourite, but, as I understand it, that grind has been chosen by Lyle for his novice student and it's been a very long time since I was a novice turner so it may not be surprising that I didn’t find that grind doing anything particularly well for me, so a bit of a compromise, which might be OK for new turners that need a grind that does most cuts while being “easier to control”.

I then changed the grind to my workhorse grind of 65° as that is closest to the 58° bevel grind that came on the gouge. This is the grind that I use for doing all of my hogging down green turning and for finishing the inside bottom of bowls when final turning and for final fine slicing cuts using the wings on the outside of bowls.

The change to 65° immediately improved the performance of the gouge for me on those cuts that I’m very familiar with and the gouge started to perform closer to the way my other Thompson bowl gouges (TBGs) do.

I then did a side by side comparison between the standard Thompson V and the Jamieson bowl gouge (JBG). As both are made from the same V10 powdered metal steel and cryogenic treatment by the same maker this was not about how long each would cut, but more about how the different flute profiles performed.

With both gouges ground to my 65° bevel grind, and taking alternating cuts with the two, I first did some hogging down push cuts. I found the JBG was noticeably more controllable and I was able to comfortably take 12mm wide cuts.

Hogging off 12mm push cuts JBG.jpg

This was a surprise to me as the JBG is lighter (and more flexing) than the TBG. Typically lighter gouges get buffeted about doing heavier cuts. So, obviously the more open flute profile on the JBG contributed to its stability in those heavier cuts. There was also a noticeable difference in the shavings that came off each gouge.

Shavings off hogging cuts - 65deg T lft J Rt.jpg
Shavings off hogging cuts
T left J Rt

I put that difference down again to the slightly more open flute profile on the Jamieson. For what it is worth, the TBG ejected its shavings much further than the JBG. Not that you would select a gouge specifically for that, but it was nice to not have to clean up so far away from the lathe with the JBG.

On finishing cuts on the outside, which I do with a slicing cut with the wings, the JBG gave an acceptable finish, albeit with wider fine shavings.

Finish on endgrain off slicing cut on wings.jpg

Shavings off slicing cut on wings - T on Lft J on Rt.jpg

With inside plunge/push cuts the JBG seemed to be less aggressive than the TBG, producing finer shavings and some vibration. Through the inside transition and across the bottom the JBG did as well if not better than the TBG. It also handles the reverse cut back out through the transition area quite well. Where the JBG struggled was with coming back up through the inside walls with a reverse scraping cut… it complained audibly at that.


55° Bevel Grind

I then reground both gouges to a 55° bevel. My impression with this grind was that the two gouges were much of a muchness. Here are the shavings off both from outside cuts, which indicates a similar cutting action.

Push cut with 55deg - T on left J on rt.jpg

I left the 55° grind there as it is is a bevel angle that I do use, but less frequently.


40:40° Bevel Grind

Skipping a 45° bevel and going straight to 40/40… if you are after an acute angle push cut why not go with a dedicated 40/40 grind. It won’t do anything else well other than a push cut, but it does that very well.

I don’t have the 40/40 grind on any of my TBGs, but do have it on my parabolic Vicmarc and Woodcut gouges. Stuart Batty, the proponent of this grind recommends parabolic or “elliptical” (his words) flute profiles for this grind. I don’t think the JBG has either of these flute profiles (as covered in my previous post) but some are giving their TBGs a 40/40 grind, so I tried it out on the JBG.

The resulting finish was more than satisfactory, including on an interrupted cut…

Finish off 40-40 cut - JBG.jpg

Finish off 40-40 with interrupt cut - JBG.jpg

If I do change the grind on the JBG from the current 40/40° I may step it back through 45° to see how that goes and if I do I will report on that.


Summary

Although the flute profile on the Jamieson and Thompson BGs are only slightly different they do perform very differently with some cuts.

• The lighter weight from the deeper and wider flute on the JBG complained a bit on some internal cuts, but was surprisingly up there with the TBG on outside hogging push cuts that were very controllable.
• I wouldn’t use it myself for shear scraping, but it does an adequate job at that. I found it equally satisfactory for fine finishing slicing cuts as the Thompson .
• If your preference is for a 55° grind you may find that there isn’t much difference between the two flute profiles.
• I haven’t tried a 45° grind on it yet, so can’t comment on that.
• The JBG performed very well with a 40/40° grind, but I can’t comment on how a TBG would go with that.
• On price there isn’t much difference between the two. I have found both Doug and Lyle gentlemen in my dealings with them.

Am I happy with my purchase? Yes, more than happy. I’m unlikely to leave the dedicated 40/40° grind on the Jamieson and will probably take it back to my preferred 65° grind now that I know how well it performs with that on outside hogging push cuts.

Of course, we all turn a little differently and others may have a different experience with this gouge. I will be interested to hear from any others on the forum who have both the Jamieson and Thompson V BGs

[John Kananis]

Neil, what a fantastic writeup. Thank you for passing along all this information.

[Neil Strong]

I did go on to change the grind on the Jamieson BG to 45° on its way back to 65°. I already had a Thompson ground to 45°, so was able to do a side by side comparison of the two gouges, again using the same very seasoned oak.

Doing push cuts up the outside with alternating gouges gave a good finish off both that was more than ready for sanding…

45 grind - alt with JBG & TBG.jpg

On the inside, the finish off the two gouges from push cuts down the upper inside of the test piece were also equally satisfactory, although the JBG did start to vibrate and complain at times.

However, there was a distinct difference between the two gouges when starting the inside cuts; the TBG was precise and crisp in starting each new cut at the rim even when taking the rim thickness down to 2-3mm, while the JBG was very inclined to want to ‘skate’ away from the selected entry point. That would come from the difference in the tip geometry of the two gouges.

[Reed Gray]

I think the reason that it is called a parabolic flute, even though it isn't, is that if you grind a slight arc in the wing, and then view it head on, it appears to have that shape. I do have one of Lyle's gouges. All of my V flute gouges are D Way or Thompson. They both work well for the 40/40 grind as well as the swept back grinds. I do not use a swept back grind at all any more, mostly because I have no use for it. I do all of my heavy roughing with the Big Ugly tool, which is a 1 inch wide scraper. Finish cuts on the outside are done with the 40/40, and then cleaned up with a shear scrape. I use dedicated scrapers for that with a burnished burr. On the inside of a bowl, I use the 40/40 for down the walls and several specialized BOB (bottom of bowl) gouges with a 70 degree bevel and almost no sweep to the nose, so ) shaped noses. The wings of a swept back gouge can be used for shear scraping, but I prefer the burnished burr on a scraper. Wood can be hogged off just as fast with a 40/40 as it can with a swept back gouge. The difference is that with the 40/40 you get a thicker shaving than you do with a swept back gouge. The difference being the amount of cutting edge you can get into the wood at one time. How much you can pull off in one go depends on your lathe and horse power. I haven't met a lathe I couldn't stall yet.....

Some where in my shop, I have one of the old Glaser V flute gouges. Didn't like it. One reason was that the V was so steep that it clogged up often. The other reason was the shot filled handles. If you are going to do a full day of turning, that is too much weight to be pushing around.

robo hippy

[David Delo]

Neil, what a fantastic writeup. Thank you for passing along all this information.

Agreed, very interesting read. Thanks for the effort Neil.

[Robert Hayward]

Thank you Neil for that very informative review.

[Neil Strong]

I think the reason that it is called a parabolic flute, even though it isn't, is that if you grind a slight arc in the wing, and then view it head on, it appears to have that shape. I do have one of Lyle's gouges. All of my V flute gouges are D Way or Thompson. They both work well for the 40/40 grind as well as the swept back grinds. I do not use a swept back grind at all any more, mostly because I have no use for it. I do all of my heavy roughing with the Big Ugly tool, which is a 1 inch wide scraper. Finish cuts on the outside are done with the 40/40, and then cleaned up with a shear scrape. I use dedicated scrapers for that with a burnished burr. On the inside of a bowl, I use the 40/40 for down the walls and several specialized BOB (bottom of bowl) gouges with a 70 degree bevel and almost no sweep to the nose, so ) shaped noses. The wings of a swept back gouge can be used for shear scraping, but I prefer the burnished burr on a scraper. Wood can be hogged off just as fast with a 40/40 as it can with a swept back gouge. The difference is that with the 40/40 you get a thicker shaving than you do with a swept back gouge. The difference being the amount of cutting edge you can get into the wood at one time. How much you can pull off in one go depends on your lathe and horse power. I haven't met a lathe I couldn't stall yet.....

Some where in my shop, I have one of the old Glaser V flute gouges. Didn't like it. One reason was that the V was so steep that it clogged up often. The other reason was the shot filled handles. If you are going to do a full day of turning, that is too much weight to be pushing around.

robo hippy

Thanks for the fulsome contribution, Robo.

I'm with you when it comes to heavy or lead shot filled handles. First thing I did with the Thompson handles was to remove the shot and more recently I have made my own lightweight (aluminium tubing) handles. As it is, I only manage a few hours of turning at a time nowadays, so don't need to turn it into a gym workout as well.

There is still a lot of confusion with the terminology used to describe flute profiles. It is one of my hobby horses to try to have us become more precise in our use of the commonly used terms, but I'm not sure that I'm winning with that. It doesn't help with makers/marketers using terms loosely and only showing the oblique view of the end of their flutes, which provide a better indication of the initial grind than the flute profile itself. With the exception of the promos for the Henry Taylor Superflute BGs and Brent's Turner's Edge at Robust is another (there may be others that I don't know about), most of the makers/manufacturers/marketers fail to give a direct end view or illustration of their flute profiles.

I maintain, and my findings reported here in this thread confirm, BG flute profiles do make a difference to how the gouge will perform. If you are buying your gouges at demos/trade shows you can inspect the flute profile yourself before buying it, but many of us can only buy out of catalogues or online and depend on accurate terminology and/or better visual information.

[Pat Scott]

Thanks for the write up Neil. I've always been skeptical of Lyle's gouges having a parabolic flute (as he says they are) since Thompson makes them. Common sense says that if Thompson made parabolic flute gouges for Lyle, why wouldn't Thompson sell them also?

[Neil Strong]

Thanks for the write up Neil. I've always been skeptical of Lyle's gouges having a parabolic flute (as he says they are) since Thompson makes them. Common sense says that if Thompson made parabolic flute gouges for Lyle, why wouldn't Thompson sell them also?

As I understand it, Doug made his first bowl gouges for himself to suit himself. I don't know, but surmise that he experimented with different flute profiles and the sweet spot between ease of manufacture and performance at the lathe, which Doug was well placed to asses, he being both an engineer and wood turner. From there he made more of them for others if they wanted what he was making for himself, which didn't include a parabolic flute option.

The Jamieson gouge is not a re-badged Thompson. It has a flute that is designed by Lyles and made by Doug. As far as I can tell, the signature range of gouges that Doug offers are all specific grinds added to Doug's standard flutes.

Again I don't know, just speculating, but maybe Lyle asked Doug to make him a more open flute profile that is more like the parabolics and the outcome was a deeper V with a slightly wider cutting area in bottom of the flute, which Lyle has found gives his students better tool control. Lyle and his students are happy with that, but Doug may not feel the need to change his successful V flute design or add Lyle's flute design to his offerings.

Had I known that Lyle's flute design wasn't parabolic at the time I was zooming with him to purchase the gouge I may have asked him more about this.

To be clear, I'm not in any way negative about V flute profiles, they are very good for what they do well. I'm just pushing for more accurate descriptions of the various flute profiles.

I had a P&N BG that was a bit similar to the Jamieson in that it had a much deeper V flute than the Thompson V, but a much narrower angle between the straight sides. See the end on view of the P&N on left and Thompson on right...

PN -Thomp V flute profiles.jpg

I never did like that P&N flute profile, the angle between the straight sides was too narrow (at about 30deg) and it was inclined to clog, especially in green wood, so I moved it on to someone who was happy to have it. I found the Thompsons had a much better V angle when they became available. The angle between the straight sides of the Jamieson look to be similar to the Thompson when just eyeballing them.

BTW, that P&N was incorrectly called a U flute by some, but the straight sides on a U flute are parallel, which they weren't on that P&N.

[Reed Gray]

I remember asking Doug once about why he didn't make a parabolic flute. I believe that it was some thing about the parabolic flute being far more difficult to mill, especially in the V10 metal. I believe the same thing is true with D Way. There are parabolic fluted M42 tools out there, and maybe I will have to experiment. If I remember correctly, Jimmy Clewes has a signature gouge that Doug makes as well.

robo hippy

[Neil Strong]

I remember asking Doug once about why he didn't make a parabolic flute. I believe that it was some thing about the parabolic flute being far more difficult to mill, especially in the V10 metal. I believe the same thing is true with D Way. There are parabolic fluted M42 tools out there, and maybe I will have to experiment. If I remember correctly, Jimmy Clewes has a signature gouge that Doug makes as well.

robo hippy

Thanks for that information, Reed.

I knew that making a parabolic flute would be a more complex process than V or U profiles. Those two profiles can be made with fewer stock-standard milling/grinding bits and with less bit changes, but hadn't known for sure that was a factor in Doug's decision making. After thirty years in the machining shops at Ford, Doug would have been in a good position to know that.

D-way describe their parabolic BGs (not their actual U flute line) as follows... "The flutes are a parabolic U shaped with tapered sides not a deep V." Yet another blow for keeping U as an accurate descriptor of flutes with parallel sides...


Here is the D-way flute... so, not parabolic or U! But, nevertheless, a very nice gouge to use...

Dway gouge flute profile.JPG

And, here is the D-way (on left) next to the Jamieson and the original Henry Taylor 'superflute' on the right, which is parabolic...

D-way, Jamieson & HT.jpg

So, the D-way is much closer to being parabolic, but not quite, than the Jamieson (which isn't at all), compared to the Henry Taylor on the right, which is parabolic. Flute profiles that are genuinely parabolic can vary from one another (that is the nature of conics) but none of them have straight sides and the curve changes continuously, for example they don't have a regular circular (fixed radius) curve at the bottom. The Ellsworth is another example of a flute that is close enough to be called parabolic..

Ellsworth gouge flute profile.JPG

Parabolic flutes are versatile and more forgiving for novice turners, but may not provide significant advantages for experienced turners. About half the BGs in my tool rack are parabolic, but they don't get used any more than any of the others, but I reckon every turner should try at least one during their turning lifetime, so they don't die wondering if life could have been better with them...

I understand that the Jimmy Clewes' sig gouge that Doug Thompson makes has the same V flute as Doug's.

[Neil Strong]

.
While on parabolic flutes, they are not new in woodturning and can be traced back at least as far as Peter Child in the 1970s. He has an image of his forged tool steel bowl gouge in his book that has a pure parabolic flute profile...

Forged flute used by Peter Child.jpg

And, it was Peter's son, Roy, who gave us the 'superflute' which was manufactured by Henry Taylor in Sheffield.

Both the Vicmarc (made in V10) on left and the Woodcut (made in M2) on right are also close to pure parabolic flute profiles...

IMG_1168.jpg Woodcut 0.5in.jpg

Others might like to add others that I don't have...

For the mathematicians: The shape formed by a hanging chain was called a parabola by Galileo, but has since been given its own status and called a catenary (after the Latin word for chain). Although different mathematically, the parabola and catenary are close enough for our practical purposes to us just to call the catenary a parabola. If Galileo got it wrong, we should be excused for that expediency. It is hard enough to get the term parabolic used correctly without any other splitting of hairs...