Thread: anyone trying the 40/40 grind ???

I started using Batty's methods a while back and it's basically all I use for dry timber, but for roughing out green timber I still prefer a more swept back grind and a pull cut (it's fast and fun!)
I find it an easy grind to do free hand (if you don't have a handle attached to the tool) and with a bit of practice you can touch up the edge quickly.
The finish straight off the tool is brilliant and speeds up the production work that I do, but I see people using other methods achieve fantastic results too. It's a grind that works for me and I think it's worth trying.

Originally Posted by Woodturnerjosh

i started using Batty's methods a while back and it's basically all I use for dry timber, but for roughing out green timber I still prefer a more swept back grind and a pull cut (it's fast and fun!)
I find it an easy grind to do free hand (if you don't have a handle attached to the tool) and with a bit of practice you can touch up the edge quickly.
The finish straight off the tool is brilliant and speeds up the production work that I do, but I see people using other methods achieve fantastic results too. It's a grind that works for me and I think it's worth trying.

Yeah , I agree , the pull cut works for me too! and fun
Just got to get my head around the push cut with this gouge
My handle does get In the way a bit , will have to get a quick
release set up .......

A handle system is great for free hand sharpening (for me anyway). I made some quick change handles using ER collet chucks I bought of ebay and used them for a couple of years until the tax man was kind to me and forked out a bit on the SB tools carbon fibre handles. They're not cheap but the best handles I've used (and before anyone asks, yes, I prefer them to timber handles) being light but very rigid and, as they are not round, I find them very comfortable and less fatiguing to use.
IMG_4613.JPG

p.s. yes that long one is ridiculously long

Sorry, this post is a little off topic to the 40/40 grind thing, here's a pic of my grind
IMG_2305.jpg

I'm with you on this one smiife, it's my preferred grind although I do have one gouge with a swept back grind. Have tried the bevel at 45 deg to see if the edge will last any longer cutting dry wood and cant really say if it does or not but it still seems to cut as well. Stuarts vid's all show him turning green timber with shavings flying off the tool like long strips of fettuccine but that's generally not the sort of wood I turn. I find that dry native blackwood doesn't lend itself to the pull cut that well and knocks the edge off the tool pretty quickly.

I use the double bevel Stuart talks about, putting the primary bevel on by eye using a 180 grit wheel, leaving about 1 mm of secondary bevel, and then use a Tormek gouge jig to grind the secondary. Have a 1200 grit wheel on the Tormek but as it is only grinding a bevel about 1 to 3 mm wide it only takes on light sweep to sharpen. Once the secondary bevel is more than about 3 mm wide, back to the 180 grit.
Cant say that I've mastered the push cut, always need to finish off with a negative rake scraper.

Josh has made some very helpful comments on this topic, all of which I agree with.

I also use a 40° bevel on my push cut bowl gouges, but modified as a result of using an Ellsworth style jig to sharpen (nowadays I prefer to sharpen with a jig). So, the bevel is 40° at the nose, but not all the way along the swept back edge as that style of jig can't maintain a constant bevel angle along the whole edge. See photo for profile taken from the side.

Yes, this bevel angle gives a very clean finish on any wood from the hardest to the punkiest you are likely to turn. It is less likely to pull end fibers out (Batty gives a good explanation why). It is also very good for final sheer cuts, if they are still needed.

However, it is not as suited to the transition and bottom areas inside a bowl. So, you need dedicated gouges for those areas with much higher bevel angles.

It is not a profile I would start turners on for several reasons. First being you need more than one BG and most beginners struggle to justify the cost of one good BG, let alone two.

Second, and probably more importantly, the push cut with a low bevel angle is more difficult cut to master. A novice can gain proficiency with a combination of pull and push cuts with a higher bevel angle much faster. Once proficient with that you might be ready to progress to and manage a Batty style push cut and grind profile.

Lastly, skilled freehand sharpening is bridge too far for many novice turners. At least with a jig one variable remains somewhat constant.

Cindy Drozda has a good video on the 40/40 grind if you are ready try this grind freehand.

https://m.youtube.com/watch?v=4_KDSIDAtGc

I also agree that removable handles make sharpening much easier, particularly if you are doing it freehand.

Last comment on freehand sharpening. Many professional woodturners and older woodturners like myself began sharpening before jigs came in. They are proficient at doing it freehand and it's quicker for them, but I notice that many of the professionals, like Glenn Lucas, use jigs to sharpen for/in their classes, which says something about the benefits of doing so for the novice or occasional turner.

I use jigs now wherever I can. The older I get the more I find that they are just as quick and I'm not spending time rectifying freehand angle drift or slips. Thus my modified 40° grind.









Sent from my ZTE T84 using Tapatalk

Originally Posted by Woodturnerjosh

A handle system is great for free hand sharpening (for me anyway). I made some quick change handles using ER collet chucks I bought of ebay and used them for a couple of years until the tax man was kind to me and forked out a bit on the SB tools carbon fibre handles. They're not cheap but the best handles I've used (and before anyone asks, yes, I prefer them to timber handles) being light but very rigid and, as they are not round, I find them very comfortable and less fatiguing to use.
IMG_4613.JPG

p.s. yes that long one is ridiculously long

Sorry, this post is a little off topic to the 40/40 grind thing, here's a pic of my grind
IMG_2305.jpg

Hi Josh, thats a great set up you have there , I tried to look up
SB tools to buy something similar but couldn, t find any , where did you
buy yours ? Thanks for your thoughts and photo,s
When you say they are not round , what shape are they ?

Originally Posted by tony_A

I'm with you on this one smiife, it's my preferred grind although I do have one gouge with a swept back grind. Have tried the bevel at 45 deg to see if the edge will last any longer cutting dry wood and cant really say if it does or not but it still seems to cut as well. Stuarts vid's all show him turning green timber with shavings flying off the tool like long strips of fettuccine but that's generally not the sort of wood I turn. I find that dry native blackwood doesn't lend itself to the pull cut that well and knocks the edge off the tool pretty quickly.

I use the double bevel Stuart talks about, putting the primary bevel on by eye using a 180 grit wheel, leaving about 1 mm of secondary bevel, and then use a Tormek gouge jig to grind the secondary. Have a 1200 grit wheel on the Tormek but as it is only grinding a bevel about 1 to 3 mm wide it only takes on light sweep to sharpen. Once the secondary bevel is more than about 3 mm wide, back to the 180 grit.
Cant say that I've mastered the push cut, always need to finish off with a negative rake scraper.

Hi tony , never thought about a double bevel , does the angle stay at 40º ?
I can, t say I have mastered this push cut , I only just tried it yesterday so
will keep on practicing , thanks for your comments

Originally Posted by NeilS

Josh has made some very helpful comments on this topic, all of which I agree with.

I also use a 40° bevel on my push cut bowl gouges, but modified as a result of using an Ellsworth style jig to sharpen (nowadays I prefer to sharpen with a jig). So, the bevel is 40° at the nose, but not all the way along the swept back edge as that style of jig can't maintain a constant bevel angle along the whole edge. See photo for profile taken from the side.

Yes, this bevel angle gives a very clean finish on any wood from the hardest to the punkiest you are likely to turn. It is less likely to pull end fibers out (Batty gives a good explanation why). It is also very good for final sheer cuts, if they are still needed.

However, it is not as suited to the transition and bottom areas inside a bowl. So, you need dedicated gouges for those areas with much higher bevel angles.

It is not a profile I would start turners on for several reasons. First being you need more than one BG and most beginners struggle to justify the cost of one good BG, let alone two.

Second, and probably more importantly, the push cut with a low bevel angle is more difficult cut to master. A novice can gain proficiency with a combination of pull and push cuts with a higher bevel angle much faster. Once proficient with that you might be ready to progress to and manage a Batty style push cut and grind profile.

Lastly, skilled freehand sharpening is bridge too far for many novice turners. At least with a jig one variable remains somewhat constant.

Cindy Drozda has a good video on the 40/40 grind if you are ready try this grind freehand.

https://m.youtube.com/watch?v=4_KDSIDAtGc

I also agree that removable handles make sharpening much easier, particularly if you are doing it freehand.

Last comment on freehand sharpening. Many professional woodturners and older woodturners like myself began sharpening before jigs came in. They are proficient at doing it freehand and it's quicker for them, but I notice that many of the professionals, like Glenn Lucas, use jigs to sharpen for/in their classes, which says something about the benefits of doing so for the novice or occasional turner.

I use jigs now wherever I can. The older I get the more I find that they are just as quick and I'm not spending time rectifying freehand angle drift or slips. Thus my modified 40° grind.









Sent from my ZTE T84 using Tapatalk

Hi neil , some good points there too , I did try and use my jigs , but not very sucessful , I had never tried to sharpen freehand before but thought i would try this 40/40 grind , took a bit of practice and a bit of metal , but got there in the end , well almost I think .......

Originally Posted by smiife

Hi Josh, thats a great set up you have there , I tried to look upSB tools to buy something similar but couldn, t find any , where did you buy yours ? Thanks for your thoughts and photo,sWhen you say they are not round , what shape are they ?

I purchased mine from Woodworkers Emporium in america. I ordered a fair bit at once to make the postage sting less and as they are carbon fibre they are light enough to keep the cost down.
They're a kind lobed-hexagonal shape
IMG_4493.jpg

Originally Posted by Woodturnerjosh

I purchased mine from Woodworkers Emporium in america. I ordered a fair bit at once to make the postage sting less and as they are carbon fibre they are light enough to keep the cost down.
They're a kind lobed-hexagonal shape
IMG_4493.jpg

Cool thanks mate , off to the www.

When I first started using this grind I did it freehand first, then tried to get something close using a jig and with the Tormek jig (and probably others) you can get close. The downside for me was that I found it very easy to over grind the wing portion when using the jig and switched back to free hand grinding.
Like Neil said, I wouldn't recommend free hand grinding unless you already have a few years of turning under your belt and I wouldn't even bother if my tools had fixed handles

Here is a comparison of the finish off a 40° bevel BG. Closeup of finish in 2nd Photo. The wood is very spalted, punky and includes a soft pith centre.

Finish off 40deg gouge.JPG Finish off 40deg gouge - detail.JPG

And, the finish off a 65° bevel BG in next photo.

Finish off 65deg gouge - detail.JPG

As you can see, the 40° bevel can produce a finish that has no end grain tear out on this challenging piece of wood. In comparison, the 65° bevel gives a torn out finish on the end grain.

I should have also mentioned, like Josh, I use high angle BGs (mine are at 65-70°) to do the bulk of my green and rough turning, using pull cuts, where finish on the end grain is not an issue at that stage of turning. I find them quicker and easier for this.

Originally Posted by smiife

Cool thanks mate , off to the www.

Make sure you're sitting down

Originally Posted by smiife

Hi tony , never thought about a double bevel , does the angle stay at 40º ?
I can, t say I have mastered this push cut , I only just tried it yesterday so
will keep on practicing , thanks for your comments

G'day smiife
I grind the primary bevel by eye but went and measured the angle out of interest and it was very close to 30. I see that Josh is using a double bevel in the photo of his gouge above. Two advantages from my perspective, it relieves the heel of the grind and allows the gouge to better follow the transition curve on the inside of a bowl, and allows me to easily sharpen a gouge on a 1200 grit wheel. The secondary bevel only needs to be a mm or so wide to do a bevel riding cut. From memory Cindy Drozda covers it and I think Stuart does as well in one of his vids.

Tony