Sharpening jigs, wing and nose angles

I built a homemade fixed arm sharpening jig and a sliding arm fixture which definitely improved my sharpening and turning abilities but it seems that to control the angle of the nose and wings that I need a movable arm jig.

Lyle Jamieson and another well known turner explained that the basket length from the grinder set the angle for one, the angle of the arm set the angle for the other. Where it gets confusing is that one said that the nose angle was set by the distance the basket was from the wheel and the wing angle was set by the angle of the arm. The other turner said exactly the opposite! Which is correct, A or B or neither completely accurate?

A: nose angle set by distance of bucket from grinding wheel, wing angle set by jig arm angle.

B. nose angle set by jig arm angle and wing angle set by distance of bucket from wheel.

To add to my confusion once Lyle had the jig and bucket set up for one grind, he said just shimming the bucket, effectively changing the bucket location, made the angles correct for other grinds. While I can see how moving up on the wheel would adjust the angles, it seems likely that it would still require some tweaking of the jig arm to have both nose bevel and wing bevel identical again.

Which leads to the final question: What is the baseline to measure wing angle? Is it measured in the direction of the grind, in relation to the centerline of the shaft of the gouge, in relation to the flute, or something else?

reference video: http://www.youtube.com/watch?v=0zUph9zEjck
Jig set-up starts at about 3:30.

Thanks for any enlightenment!

Hu

 

The basket determines the nose angle as well as changing the arm angle. The arm angle does have more effect on the side grind. My suggestion is to start with the angles that Doug Thompson gives in his PDF and use those. Then if you want to experiment you have a good starting point. Personally that's what I use. I think it's more important to just turn a lot and then if the angles don't seem to work for you, change one of them.
I went through the stage of playing with all the different arm angles and tip angles. I learned some things but mostly what I learned was just about anything works. It's more about how you use the tool than the angles. After you really get familiar with the tool then you change an able here and there to work better with the kinds of cuts you use.
Putting a space in the V arm changes the nose angle mostly and the wings very slightly. I made a video on sharpening tricks as well as sharpening problems. Maybe they will answer some of your questions.
https://www.youtube.com/watch?v=Xbggxj2kgyc
https://www.youtube.com/watch?v=M9G16ylEZHQ

 

Thanks, and a bit more information

John,

I think I have watched your video, unfortunately I can't until after midnight right now. I am on satellite and have used my monthly high speed allotment. Video won't play at .12Mbps.

I am not trying to cut a bunch of different grinds right now, just trying to get one right. I have Thompson's PDF and a handful of other documentation. From what I see most signature grinds are very slight variations on the same grind with a few exceptions. Just measured the angle from Thompson's PDF. I can't see the end that rides in the bucket but it looks very close to forty degrees arm angle. That is one of the confusing things, different people recommend arm angles everywhere from 22 to 45 degrees with the same bucket relationship to the wheel. No doubt each angle works for the user but I'm seeking one grind to use until I feel competent with it. I am only using one bowl gouge and a cut off tool right now, all the tools I own other than a ST2000 tool that is put away and a piece of 1/2" cold roll or drill rod that becomes whatever I need at the moment to get me out of a bind created by making too tight of an inside corner or similar issues.

One of the things I have discovered the hard way is that the nose profile is a little more critical than I thought. I knew I didn't want it pointy but had to find out for myself that too blunt of a nose can cause catches when having to extend fairly far over the tool rest too.

I am not sure that wing angle is even that critical as long as it is similar to the nose angle and flows together. Hoping to clarify some of these things with this thread.

Thank you for your post and the video links. I will watch them soon, probably tonight. Sometimes I'm not up that late, depends on how my day goes.

Hu

 

Thanks, have this document too

Al,

This is where I got confused. DeHeer and Jamieson seem to be saying nearly the opposite when talking about what controls wing angles. I could have arbitrarily decided one or the other was right but it seemed smarter to come ask. If I understand you correctly and I think to make myself clearer maybe I should be asking what has the most effect on wing angles.

Notice also that DeHeer chooses twenty-three degrees as the perfect jig arm setting for all grinds while Thompson chooses forty degrees best I can measure. Measuring off of Jamieson's video which I posted a link to it also seems like the jig arm angle he arrives at by an experimental method is right around 40-45 degrees.

A question, when you refer to the jig vertex, are you talking about where the lines through the center of the adjustment arm and the gouge bottom would meet?

Thank you for your post! This does get right to my area of confusion. Perhaps the easiest way for me to sort things out is to ask, exactly how is wing angle measured? If I can measure wing angle correctly grinding on my round scrap should answer my questions.

Hu

 

Well, for another view on this, I haven't used a gouge jig in years. In retrospect, the jigs are kind of limiting in that they determine how little you can roll the tool to grind the wings, and to me, the wings get ground with a sharper angle than the nose. This is why you can not grind the Stuart Batty/Mike Mahoney 40/40 grind on them, you just can't roll the tool over far enough.

http://www.youtube.com/watch?v=UQ7w6yFhw4c

Nose shape is determined by flute shape. A more V shaped flute will have a more pointy nose, and a more U shaped flute will have a more rounded nose, and the ) flute will be very broad. lf you are having problems with a more rounded nose catching, then you need to roll the gouge on its side. If the flutes are more up, the wing that is towards the wood will catch and roll. This is 'the part of the gouge that is cutting needs to be directly resting on the tool rest' concept. If the tool is not 'balanced'm then it will into a balance all byitself, usually with a catch. I find the more V shapes cut better with the wings, and the more ) shapes cut better on the nose, or more properly with the lower half of the flute, just like a skew chisel. The V flute has a very small sweet spot on the nose, and the ) shape has a huge sweet spot for a very high shear angle.

Other than that, the more ) shapes are more suited to cutting with the handle pretty level, and the more U and V shapes cut better with the handle dropped.

robo hippy

 

trying to avoid reinventing the wheel

Al,

Trying to solve for the differentials or trying to discover things experimentally without narrowing things down by using readily available information is exactly what I am trying to avoid. Some things are good to know and have direct practical application. Some things are interesting to know but knowing these things has little affect on how we are able to function. I once knew far more than the average bear about how the internet functioned, all networks. Somebody that knew how to log onto the net, search, navigate, and type got just as much practical use out of the net as I did.

Your thought that the distance between the wing and vertex having the most effect on wing angle is of great interest. It is also interesting that the angle changes as you move along the wing. These thoughts combined seem to indicate that compromises must be made concerning wing angles, or possibly some compound grinding done. Don't want to over complicate things but perhaps something as simple as Lyle Jamieson's spacer block dropped in to finish a grind on a wing might minimize the angle change. I wouldn't think it would be something as thick as he was using and the entire idea may be without merit. I'm looking for the best way to grind without overcomplicating things to the point that I am spending too much of my turning time setting up to grind and grinding instead of turning.

Thank you very much, all of your posts have added something to my knowledge.

Robo,

I was able to watch your video, already had it downloaded and saved. I do plan to have platform grinding capabilities, I have the Veritas platform now but need to either make some quick set up guides similar to the Raptor or purchase something like your platform with the holes and pin to make things quickly repeatable. However right now I would rather have an easily repeatable grind that works than one that may be better but I may not always create it as accurately so I get more variables. I may be mistaken but I believe that the vari-grind type jigs make things a little more dummy proof.

Trying to determine how to get the wings at very close to the same angle as the nose is why this thread was started. Some indication that it isn't possible to get exact, then the question becomes how close can we come and how smooth and gentle the transition. The gouge tip on my ST2000 tool had distinct, almost sharp cornered transitions between the nose angle and the wing angle. That can be blended of course but trying to keep things simple. Perhaps something similar to the Vector sharpening system with the multiple jig arm anchor points at the same distance accomplishes my goal or one would with a similar set-up but the holes closer together. I don't know but if I can understand the basics of how things work then I can try to get a jig to perform to suit me. Ultimately I may find that platform grinding is the only option or indeed the best option. I once was a pretty good hand grinder and metal shaper but that was a long time ago. I'm finding that skills I haven't used in a few decades no longer exist and I'm dealing with issues that makes remastering them far more difficult than learning them the first time.

I have the Crown blond handled bowl gouge that was originally square across the front. I don't know rather to call it a deep U shape or modified V shape. A little hard to define where nose ends and wings begin but I think I have about a quarter inch wide nose on a five-eighths diameter gouge.

What is the status on your sharpening DVD?

Thank you for your post. It is very helpful. It presents an alternative and food for thought regardless of what route I choose. Ultimately that is what all of my efforts on the internet seek to do, educate me enough to make good choices for myself.

Hu

 

Hu,

Is there a reason why you are trying to get a jig set-up to make the wings the same angle as the nose?

Once you find a set-up, it will really only work with one tool unless you have all the same brand and flute style. If not then you will need to change the set-up for every tool and that will become a bit of a pain in the butt. You want your sharpening to be easy so that you will do it often enough to keep a sharp tool.

For me, I find it easier to find a grind that gets the most used portion of the tool, the nose, shaped well for the cut and then worry about the wings over time as you figure out what you want to do with them. You may find that you like very long wings, or short and that is more a function of your turning style and how you like to present the tool.

If you are going to try and do shear cuts with the wings, then you will likely want to grind them so that there is not a pronounced hump in the wing from the nose to the top of the flute as that makes if very awkward to get a consistent cut and can be very grabby.

On a tool with a more V shaped flute, The wings tend to be a bit straighter in the flute than would be a U shaped flute. This puts differing amount of steel outside the flute, and that affects the grind. and wing cutting edge angle.

You will likely end up with one fixed pocket position, and fixed jig arm angle and change the extension of the tool a bit to change the nose angle (barring wheel diameter changes over time). Making the wing grind useful is where finding that initial set-up for you comes in. You have several suggested starting points, and your own experiences will lead you from there.

Lloyd

 

Just a starting point

Lloyd,

What I am trying to do at the moment is find a baseline, a consistent starting point. Different very good turners do things quite a bit differently and some use considerably different tooling so obviously I can't copy all of them or take everyone's advice at the same time. I am working towards a fairly simple grind right now and one of the things the person who uses this as his signature grind emphasized is that the wings and nose should be ground at the same angle. Something else he talks about is avoiding that pronounced hump in the wings, seems you and he are very much on the same page.

I am paying a great deal of attention to what everyone says in their posts and I spend a fair amount of time searching the web for more information. A bit of information overload but much like my days in R&D, after awhile patterns begin to emerge. Once the information has been somewhat organized and distilled down then it is presented to a design team for their comments and refinements. This cycle may be repeated multiple times as new information is added and some old information is discarded. The extremely knowledgeable members of this forum are serving as my design team when they respond to this thread, including yourself.

At present I think that I want the medium nose I have on the gouge now with what is the common long wing. I have seen extremely long wings longer than say an Ellsworth or Jamieson grind but I am thinking something in that neighborhood with the wing cutting edge being just convex enough to be consistently convex, very little hump. I'm inclined to relieve the back of the bevel on the wings a little removing some of the flare of metal that seems to serve no purpose but will wait until I have used the basic design awhile before deciding about that. Once I have finalized the design there will be very little fiddling with it unless I find that it obviously isn't working for some reason which will almost certainly be in my execution of the grind or in my presentation of the tool to the workpiece. Possibly as you point out, the grind I am trying to use might not work well with my flute. Another possibility, I may not be able to really utilize some grinds with the fairly lightweight lathe I have, an old Craftsman 15x38. No sense cutting an edge to deliver inch wide shavings when neither my machine or my skills are ready for something like that.

I think I have a lot of good information already, a lot right here in this thread. However, every new piece of information either serves to confirm information I have already gathered or leads to a new area to explore.

I gain from and very much appreciate every post, yours was very helpful also. Thank you for your contribution to the thread!

Hu

 

You have helped quite a bit too!

Bill,

We hired a new engineer on a project I was mechanical designer on years ago, a little spun up furrin guy. He spent a day reviewing the design of a backpack system and came to me all excited at the end of the day. "Mr Hu, big problem! Mr Lee's design is wrong!" Got him calmed down enough to explain the problem, according to his measurements two nipples that were to be connected by two inches of rubber hose were 0.10" out of line. The components were to be hung on an aluminum frame that was hand fabricated and welded together. I told him forget about it, it didn't matter. Either the fabricator would catch it and fix it or we would open up some mounting screw holes or the prototype would never be ran long enough for one-tenth offset in two inches of rubber hose to be an issue between components in rigid mounts anyway.

I don't want to make mountains out of molehills here either but I figure I need a good simple design for me to try to execute with my homemade jigs and fixtures. Once I have the theory grasped I can figure out if my finish grind, which will probably not be exactly what it started out to be despite my best intentions, will still be workable.

I have read back sixty pages on the main forum and one of the things I have found of value is your measurement of 9-3/4" from the tip of the tool to the tip of the arm. I'm using my third generation jig and fixing to create my fourth with an adjustable arm angle. I have found that regardless of arm angle that 9-3/4" measurement and either raising or lowering the bucket anchoring point gets me a usable grind. I think my wing bevel angles could be better though. Perhaps moving the tool in and out with a corresponding change in bucket distance from the wheel would help that, perhaps I need an adjustable arm angle. With a little luck I'll get my gen4 jig built tomorrow and find out.

Thank you for your current post and for many posts I have read that you posted long ago!

Hu

 

helpful indeed!

John,

As expected I wasn't able to watch your videos until after midnight. I had watched them before but both were very helpful especially in context with the other information in this thread. I see you have some other video I want to watch too, have to be another night or next month after they reset my download limitations. Been a long day today.

edit: Well, as usual I had to watch one more video, a few times! Then I felt obliged to come back here and comment on the excellent quality of your videos and the fine job you do of explaining things simply and clearly. I will get around to watching all of your video. Thank you for your posts here and the videos you have put on youtube. Excellent material!

Hu

 

Hu,
I recently went through similar machinations over setting up a new grinding jig, albeit without the engineer intensity, including trying to justify the variable expert recommendations. One unexpected difference in them I discovered is that they do not use the same height distance from the center of the wheel to the top of the sliding pocket.
My recommendation would be that you pick one system, follow it, and go turn a whole bunch of wood. If after 100 bowls you decide it's not working for you, you can make adjustments based on really knowing your needs, your style of turning and your tools.

 

Thank you for the additional info, and a little for you

Al,

Thanks for the breakdown. I like the Michelsen grind and Hannes is happy with the version of it that can be cut with the Vector sharpening system.

http://www.youtube.com/watch?v=5GX64_hHNmo

I have a Michelsen grind cut on one of my pieces of round bar right now, or something very close to it that I ground just to experiment with grinding. The only reason I am not going to a Michelsen grind right now is that it is, as you indicate, relatively uncommon.

If I use the Ellsworth grind or the Jamieson which is very similar except with a little less hump and have issues many people can advise me with first hand knowledge of the grind or very similar grinds. If I cut the Michelsen grind, which can probably remove material as fast as I need to with my lightweight lathe, I am out on a limb alone compared to using a more popular grind. When I meet local turners there is an excellent chance some will be using the Ellsworth grind or very similar. Less likely to have someone nearby using the Michelsen grind. If I were to find a local mentor using the Michelsen grind I would probably give it a try. Otherwise I plan to do just as you suggest and cut a profile I am happy with and stick with it. If I find reason to, I may adjust slightly from one signature to another but not radically different grinds or new grinds of the day or week.

I have what I think is the traditional English grind on a brand new tip for the ST2000 tool so it will be available for use if I need it. Another tip has moderately laid back wings about halfway between an English grind and an Ellsworth grind if I had to guess, and a hollowing tip with the potential to remove huge masses of wood which I haven't figured out how is even supposed to be used. The ST2000 is stowed away but as I gain experience it may come out for specific little tasks or a scraper may help me out of trouble now and then. The goal is to learn to use gouges properly and laying the wings back on my Crown gouge seems to be a large step in the right direction. They are very similar in angle to the ST2000 tip with moderate wing rake at the moment but I plan to sweep them on back to the Ellsworth length.

What I do need to purchase in the fairly near future is a 3/8" spindle gouge from almost all reports. A question for you: From what I read above perhaps a Michelsen grind on this gouge would serve the same purposes I plan to use the spindle gouge for. What is your opinion? Perhaps I can have both grinds I am interested in.

Your posts and the posts of everyone in the threads I start seeking information continue to amaze me. I have gotten too familiar with forums for other activities where intelligent discourse is impossible. The wealth of information clearly and civilly presented here is fantastic! Impossible to overstate how much I appreciate these threads as a struggling beginning wood turner.

Hu

 

The variables are indeed considerable!

Dean,

The wide variance in bucket height and jig arm angle do make things tough to wade through as a beginner. The reason for spending so much time trying to decide on the original jig set up and grind is because once I settle on a grind I intend to stick with it until I am reasonably proficient turning as you suggest and things evolve naturally.

I have had many hobbies over the years, almost all some form of competition. Some I started with poor equipment or poorly chosen equipment, some I started with the proper equipment. I found that the learning curve was vastly shortened when I wasn't fighting the equipment and when I wasn't getting bad feedback from my equipment. Trying to consider all the variables before selecting one is basically working through my trial and error on paper so I don't have to do it on steel. I did start turning with the "here is a lathe, here is a piece of wood, here is a piece of steel, make wood go away" procedure. Didn't take me long to figure out I needed advice from experienced turners!

Thank you for your post. Excellent advice and it is the path I intend to take. Threads like this are just the preliminary before deciding what that baseline gouge I start with is going to be.

Hu

 

Hu,
I do wish I could get you in my shop for a day or two, and yes, you may be obsessed with little things that make little difference.

I don't think there is any thing critical about having the wings at the same bevel angle as the nose, and some times it would be worse for wear and tear. For the 40/40 grind, it has to be done free hand, and the 40 degree bevel on the side is nice and sturdy. If you have a 70 degree bevel on the nose, and 70 on the wings, that steep of a bevel will be weak because there is little metal left to support the cutting edge. So, 70 on the nose is fine for a bottom of the bowl gouge, and a 45 degree bevel on the wings will perform just fine, and be very strong. Again, here the gouge jigs do not let you roll the tool all the way over.

Some times the wings are used for a scraping cut where the flutes are on their sides, and the handle pretty much level. You need a sturdy bevel for this cut. I prefer a scraper for this cut because what better tool is there for a scraping cut than a scraper. When you drop the handle, you get a compound miter type angle. For this type of shear scrape, or shear cut (depends on rubbing or non bevel rubbing cut) you don't need the bulk.

I was a fan of the swept back gouges for a while, till I learned how to really use scrapers. I have a number of 3/8 thick by 1 inch plus wide scrapers, and most of them are swept back, like 1/2 of a swept back gouge. I use the nose for roughing, and the wing for shear cuts. Much longer sweet spot/cutting surface than most swept back designs. I also like the extra weight and stiffness of the tool. The burr is used for the cutting, and I have had CBN wheels for 8 plus years. The CBN wheel leaves a far better burr than the standard AO wheels. I have one scraper, traditionally called 'the Big Ugly' which is tantung (very hard cast metal) brazed onto cold rolled steel. It has a ) profile. I use it for a scraper and as a skew, and for shear scrapes. It keeps an edge almost as long as carbide.

I guess the point of the above rant is that as long as you turn from rough wood to finished product, there are many ways to get there. If you have blow ups, and things going into orbit, you are doing some thing wrong, that is dangerous and needs to be fixed. Other than that, there is no really wrong way to turn.

I have been working on a bowl turning DVD for 2 years now. It takes the approach of how to use all the various tools rather than this is how I turn bowls. I have to put it off for a bit, and will get back to it in the mid to late summer. Weapons of Mass Destruction for Bowl Turning, and How to Use Them.......

robo hippy

 

little things add up

Robo,

I have your video's that you have posted on youtube and have watched them. You do think a little outside the box, a good thing. I wish I could spend some time in your shop, the shop of any highly skilled woodturner to be honest but you are one of the turners I would particularly like to spend some time with. Unfortunately it seems that the woodturners I would like to visit all live far away from where I do in Louisiana! I can't travel right now regardless, a handful of reasons.

The threads on AAW are just one facet of what is going on in my life. I'm taking care of business on a farm, reworked my Reeves drive again yesterday, working on hopefully my final generation of homemade jig, a handful of other things. Gathering information on the net is just one small part of what is going on. Every post in this thread seems to add a little, like your discussion of 70 and 40 degree grinds here. Also I would have thought that a 70 degree nose and 45 degree wings would be likely to force an awkward transition much like one of the tips of my ST2000 tool had. In the future I will remember that you don't consider that an issue. I do gather all of these things to weigh in my decisions as I move forward.

While little things may not be critical the sum of the parts can be substantial. I have built winning circle track cars, rifles, and pistols. Dozens of little details, none important by themselves, integrated into a total package that did matter enough to make my equipment better than most. I have a basic handicap, a lathe that is far less than optimum. That means that I need it and everything around it working at their best. I do routine maintenance on the lathe about once a week and have made some modifications and am in the process of making other small modifications. Nothing radical, nothing absolutely necessary, but the lathe is easier and safer to use with the mod's.

I am going to have very few turning tools for some time to come. It just seems reasonable that I do everything I can to optimize them too for the type of things I turn and the manner in which I want to turn. While my official time in R&D was just a few years in the late eighties and early nineties I have been researching and designing my own components for hobby and business use since the early seventies. While I don't plan to actually design a gouge or my own unique grind, understanding the one I choose means that I do the same homework I would do if I planned to design my own. Nose profiles and things that are often not even mentioned in discussion of grinds I am finding to be important. No doubt experienced turners take such things for granted and not worthy of discussion. I had to find out the hard way that for my equipment, the wood I am turning, and the way I am turning nose profiles are a bit more involved than "don't make it too pointy".

Every reply I have received has value and most added a little to my technical understanding of the bowl gouge, flutes, or grinds, maybe all three. I also learn a little more about lathe technique and grinding jigs and fixtures from some of the posts.

I don't have much in the way of resources, learning all I can and looking before I leap makes best use of those I do have.

Thank you very much for this post and all of your posts and video's. I gain understanding from all of the sources you offer.

Hu

 

Too bad you are not using the Michelson grind because it is not popular. The vector fixture duplicates the type of grind you seek. The nose and side bevels are very close to being the same.

 

might use it yet . . .

Richard,

A lot of things I like about the Michelsen grind, based on theory and what I have read. I'm currently debating the wisdom of using a grind I'm not as interested in just to try to match local support which is nonexistent at the moment and may always be rather than simply cutting the Michelsen grind and learning with it.

When I first started racing back in 1970 I built a small block Ford. While there were some things available for it, there were things that offered real advantages that weren't even available for the Ford that I could get for the small block Chevy. Too, there was probably ten times the amount of research and development dedicated to the small block Chevy as there was to the small block Ford. I still consider the small block Ford to have advantages over the small block Chevy but all of my following cars with the exception of one big block Chevy were all small block Chevy powered.

I don't know that this really applies with bowl gouges other than getting the initial grind correct however. Seems like pretty much any type of cut that can be done with an Ellsworth style grind can be done with the Michelsen. I am planning to use the Jamieson grind which sounds identical or very close to the O'Neill grind however when the time comes I may opt for the Michelsen after all. I think I see advantages to the nose and flute reliefs and in actual use a broad bevel seems to be just a place for sap and small bits of wood to accumulate. At what point a narrow bevel becomes too narrow is a question I don't have an answer to, and will almost certainly have to find out for myself with my wood, turning style, and equipment if I go with less than a full width bevel.

I don't care what is or isn't popular, I am just concerned with a possible lack of people able to advise me in my early period of wood turning if I choose the Michelsen grind. I wasn't successful with my small block Chevy engines by doing everything exactly like other people but going with the "Coca Cola" did give a good starting point. I don't know if that is a real issue here or not though.

I remain befuddled and undecided but I must say I believe I am befuddled and undecided on a much higher level now!

Hu

 

A very big Thank You to All!

The people in this thread, the people in the other similar thread started by someone else, "bowl gouge what to buy", the links provided, the PM's, and several hours spent on the phone by a very patient individual have finally given me I think a pretty solid understanding of what I am trying to accomplish with a grind and at least how to go about it in theory. Up to me to make things actually work but as always this forum and the members have came through in a big way when I needed help.

Thank you one and all!

Hu