Hi Tormek experts!
I've just put through an order for a Tormek T8. I should have it in a few days. It's for my school so we can stop sending all our chisels, plane blades etc to a sharpener at the end of the school year for a new edge. I'm keen to get in the habit of touching things up often to avoid the cost of professional sharpening and so my kids can have the best edge possible when they need it. I'm pretty excited to see what it can do in person.
I've watched heaps of videos and I think I get the idea but they always seem to take one chisel through the process of sharpening. I suppose my concern right now is having to setup the angle for each chisel. I'm hoping there are some simple ways to set it up once and put all the chisels through it. Is it as simple as leaving the jig on the rail and pushing each chisel down to meet the stone to set the correct height in the jig?
Do you have any tips and techniques to take a couple of dozen chisels and plane blades through the sharpening process?
Thanks in advance!
First thoughts, it will get easier once you have done it the first time or two.
Next, are all the chisels the same style and brand, as that could have some effect on how they fit the jig. (also different mortise chisel from bench chisel)
Third, I could see you setting up with a couple pieces of scrap, a jig that you set the blades protrusion through, so they are the same settings (similar to the turners TTS-100), as well as some scrap wood blocks, so the bar is the same distance from the stone.
LCAC, welcome to the forum! :)
Your investment in T8 has perfect justification, congrats to your wise decision. :)
Setting the edge angle for chisels is easy and the same setting can be used for dozens of chisels or plane blades. I assume you are familiar with the chapter Square edge jig SE-77 of the handbook.
1) You have to decide about the chisel protrusion P, which will be suitable for the whole set of your chisels. The usual chisel protrusion P is from the interval 50 to 75 mm.
2) When the protrusion is set, than the edge angle is defined by the height of the Universal support and grindstone radius. The edge angle is set using the AngleMaster WM-200.
3) It is easy to automatize the protrusion setting for another chisel by using e.g. suitable wooden block. This can also check the squarness of the montage into the jig.
Good luck!
Jan
Welcome to the forum. Lewis.
Yes, we can help you. First of all, assuming you have a number of chisels, avoid the temptation to begin with the narrow chisels. That is a recipe for disaster. Begin with the 3/4" chisel in the best condition. Work slowly. The careful time you spend with this chisel will be well repaid.
My personal method is slightly different than the customary Tormek method. If we standardize the length of the tool protrusion from the SE-77, and the distance between the universal support remain constant, you can sharpen fifty chisels and they will be identical.
I must close, temporarily. Half day at school for my grandchildren, and I am the taxi. More soon.
Ken
Lewis,
I hope you have the opportunity to spend some quiet time with your Tormek before being deluged with students and a deadline for sharp tools.
I suggest you start by learning how to true your grinding wheel. Do this before even thinking of allowing any tools to get near your Tormek. Watch the TT-50 video on tormek.com a couple times. Fill your water trough to the line and let the grinding wheel run for a couple minutes. Add water as needed to keep the water to the fill line and water running over the grinding wheel.
Once this is done, mount the TT-50 on the support. Set the support bar height so that the diamond cluster just clears the grinding wheel. Lower it until it almost touches the grinding wheel. Turn on your Tormek and make a pass across the wheel. You will probably touch only intermittently, which is good. Lower the support bar about half a number and make another pass. You should hear and feel a little more contact with the grinding wheel. Continue these very light cuts until you are lightly cutting across the entire length and circumference of the grinding wheel. At that point, your wheel is trued.
By making very light cuts, you are learning this skill safely and in control. Truing your grinding wheel is a fundamental skill. Learn it first. Learn it slowly. Learn it well and thoroughly. Use it often. With twenty four edges to maintain, you will probably want to true the wheel either after of before each session.
Having a true wheel eliminates many gremlins.
Do not be concerned about wearing out your precious grinding wheel. Like brake shoes, it is consumable. What is precious is your students.
I must stop to taxi my grandchildren to the orthodontist. When I continue, I will modifythis post and add to it.
Ken
Hi Lewis
May I suggest that you troll through the forum looking at the trials and tribulations of the learning curves which some have us endured with regard to sharpening chisel and plane blades. It's the small differences to note particularly with regard to set up, recognising the causes of angular errors resulting in non-square edges. With the new SE77 jig, a lot of the angular issues should be readily correctable, but just be aware of them.
In addition to Ken's sound advice above, I would suggest that the first thing you do with a batch of chisels is get all the backs flattened and polished, and I would suggest that you do that on a waterstone. Then polish the backs - free hand - on the leather honing wheel of the Tormek. There's advice on the Forum with regard to preparing the honing wheel.
I would then use a fixed protrusion (I generally use 50mm) for all chisels, so as Ken said make a wee jig. Also use a marker pen on the chisel back for additional reference line. Assuming that the pupils would use chisels with a primary 25 degree bevel and 30 degree secondary bevel for general woodwork, I would do all the primary bevels, and then reset for 30 degree secondary bevels.
Cover the bevel area to be ground with felt marker (and keep applying it) - it will quickly show how the grinding is progressing. It only needs a brief touch on the wheel to give a quick indicator.
When doing the secondary bevel, regrade the wheel to fine and use light pressure so that the resulting striations in the bevel are fine.
Then polish the secondary bevels on the honing wheel, this time using the SE77. Do not press hard otherwise you will roll over the cutting edge and resulting in a poor cutting edge.
Take your time, a light touch all round with plenty checking of progress is the way to success.
Any problems, put them on the Forum as there's plenty of members who can advise.
Awesome. Thanks for your info. Lots of reading, learning and practice to do. I used a Tormek a few years ago but that was only doing a couple of chisels for my major design project at uni. It helped get the edge I needed with some additional honing on a stone. My aim is to have the Tormek setup and have a few higher grit stones for some additional honing if needed.
All of the chisels we have are these ones:
(http://www.garrettwade.com/media/catalog/product/cache/1/image/730x/0dc2d03fe217f8c83829496872af24a0/1/0/10T1601_59.jpg)
It should make it easy to make some jigs to help measure the protrusion and keep that angle the same.
Eventually I'll get the jigs for the turning tools and if I'm feeling particularly brave, the jointer blades as well.
Quote from: Ken S on October 05, 2016, 07:21:29 PM
I hope you have the opportunity to spend some quiet time with your Tormek before being deluged with students and a deadline for sharp tools.
Do not be concerned about wearing out your precious grinding wheel. Like brake shoes, it is consumable. What is precious is your students.
We are close to the end of our school year and there will only be a a small amount of students that will need chisels. I'll try a few out and keep them aside for those who need them. I'll have plenty of practice between now and next year - I've got a few projects in mind that will require chisels and having the Tormek will make all the difference between a mediocre and a great join (I hope!).
The only thing I get concerned about wearing out (in regards to sharpening) is the chisels themselves. I've never had good technique with a bench grinder and always seem to wreck the angle and burn the tool. Hence why I've gone down the path of the T8.
Again, thanks for the info, I'll continue searching the forum and watching videos. I'm feeling a big frustrated waiting for the courier to show up!
Lewis,
In our enthusiasm to help, we have proceeded without all the facts. It would help us fine tune our thoughts if we knew smething more about your program and you. As an example, we might give you more complicated advice if you are a shop teacher with many years of experience. We might concentrate more on essential basics if you happen to be the Head of School or art teacher valiently attempting to improve the program. We are more than happy to help in either case.
I write this because we have had at least one situation where, in spite of our best intentions and many posts, the program failed. There were several complicating factors in that situation which we no longer have. I look forward to you having a very successful program.
Ken
I did not see your last post before posting. If you read the first (imbedded) topic about beginning with a chisel, you will see that your Irwin Blue Chip chisels are exactly the chisels I recommend for learning the Tormek. You are off to a grand start! Please put the chisels narrower than half an inch aside. Narrow chisels are more difficult to sharpen. Become fluent with the middle range and then the widest chisels first.
Australia must be on a different calendar than the US. When does your school year start and end?
My compliments on your photography. That will make it easier to convey information.
One of the strengths of the Tormek system is the ability to accurately replicate an edge. That translates to removing the minimum amount of steel, and longer life for your tools.
Ken
Thanks Ken.
We call it Design and Technology over here. I've been teaching it for 3 years. We have students from grade 7 (12yrs) to grade 12 (17yrs) going through our program with a variety of projects going on. I'm not quite sure of the system in the States. Our school year consists of 4 terms of about 10 weeks and starts around January 30 and finishes around December 10. Yr's 7/8 have mandatory subjects and we cover basic timber, metals and plastics. As they go up in the years and choose the subject, we give them more complicated projects with a couple of free choice projects (in a simplified nutshell).
This year, I've got some of my older students making longboards, cosplay weapons and side tables. One of my senior students got to design and make a rocking chair. It's a simple one but it turned out really well. We get a bit of variety which keeps me learning plenty of different processes.
One of my aims to get get my younger students completing a few projects with some finer woodworking skills. Another aim is to foster some awareness and appreciation of fine woodworking in the younger years with the hope it stays with them as they get older. Having sharp tools is high on the list of making this happen. I know how frustrating using dull tools can be.
Lewis,
Your school program sounds fascinating. I have always believed that education should prepare a person for life both on and off the job. In the US, most schools leave students unprepared for technical jobs. I use the word "technical" in its original Greek sense, (technos), meaning one who uses tools. I am all for academic education, however, we must not overlook the satisfying and essential career areas of designing, building and repairing the things which make everyday life possible and enjoyable.
A popular new show on our public television channel is "The Miss Fisher Mysteries". The latest episode involved several murders during "Christmas in July". We northern beings often forget that our seasons are inverted from our southern neighbors.
Sharpening chisels was what first drew me to the Tormek. Like many of us, I spent years with oilstones, water stones, sandpaper and a dry grinder. I have come to appreciate the no heat, no spark, and no grinding dust environment of the Tormek. The Tormek is very safe, versatile, and repeatably precise. You are correct in looking for efficient workflow strategies. Good setup increases accuracy and definitely saves time.
I started developing efficient set up strategies by using the Tormek TTS-100. It is a marvelous tool for setting up turning tools. I use it for chisels and planes. It combines solid trig theory with sharpening, quite amazing for a little piece of plastic. I use the B hole to set the distance from the gringing wheel to the universal support bar. This eliminates the vagaries and variables of one leg of the sharpening triangle. Using the protrusion slots sets the tool protrusion side of the triangle. (I use a piece of white labelmaker tape in one of the slots with lines scribed for 25 and 30 degree bevels.) With this seemingly simple tool, the tools we sharpen in Melbourne, Prague, Stockholm, London, New York, or the Yukon will be identical year in and year out with no tedious measuring.
The two small wheels automatically correct for wear differences in grinding wheels. (Mark a single spoke in each of the two wheels with a black marker. It makes it easy to see when the wheels make contact.)
Tormek invented the TTS-100 to set up turning tools. In my opinion, when combined with Tormek's new 186 gouge jig, it is their best combination. I do not understand why Tormek has not adapted it for other tools. (We have done so on the forum.) I would highly recommend purchasing a TTS-100 quickly. It will speed accurate sharpening of your chisels and plane blades. And, it will amaze you when you start sharpening your turning tools.
You will read many opinions on this forum. Combining many life experiences is the real strength of the forum. I welcome and respect other opinions. I also stand firmly behind my belief in the TTS-100. for the record, while I have sharpened turning tools, I am not an active turner.
Sharp tools will help create sharp minded students. Keep up the good work!
Ken
Lewis,
My approach may seem slow paced to you. I would compare it to learning how to drive. Most are eager to actually drive. I prefer to learn the location and purpose of the controls and the rules of the road before moving.
My thoughts on basics like learning how to use the truing tool and tips on things like using the water trough are based on real world difficulties experienced by forum members and usually by me. I believe time spent carefully mastering the basics will get you to the finish line more consistently and more quickly.
The T8 has a very nice redesigned water trough. The trick to removing it is to pivot the bottom outward. Don't lift, just pivot. Spending a few minutes getting accustomed to the trough while still empty and before the grinding wheel is attached will stand by you well.
Look at the arrows on the EZYlock nut. You should never need Channelock pliers to remove the nut and grinding wheel. The shaft has a left hand thread. It works beautifully if you remember that!
Tormek solved a long problem with the T8 by providing oil for the leather honing wheel and directions. Great idea, long overdue.
By advice on the chisel backs will probably generate some disagreement. My Irwin Blue Chip chisels all have some hollow in the back. While not as theoretically perfect as dead flat, a hollow in the back will not cause any problems. A belly is not so good. I suggest you hold a straight edge (a combination square blade is fine) against the back the long way. If the blade is flat or touches both the tip and the far end, march on. When you have tested all of your chisels, polish the last inch or so on the leather honing wheel. Try to keep the chisel flat on the leather honing wheel. The goal is to make the back as smooth as the bevel where they intersect. Sharpness depends on both faces being smooth.
I see no advantage for you with two bevel angles. Twenty five degrees is traditional for high carbon steel. (Your Irwin chisels, like most chisels, are high carbon steel.) Two bevel angles reflects dry grinder and sharpening stones thinking. Grinding the entire bevel is standard operating practice with the Tormek. It also saves the time involved in the second set up. When you feel a burr the entire length of the bevel, you are through grinding.
Become accustomed to grading the grinding wheel from coarse to fine. The finely graded grinding wheel will remove many of the scratches left by the coarse wheel. Do not skip this step.
Step three is the leather honing wheel. Work slowly and carefully learning this skill. Most Tormekers use the leather honing wheel freehand. It is a skill worth learning.
If you can easily cut paper at this point, you are done. Start with your 3/4" chisels. Move up and down in size gradually, saving the narrow chisels for last.
Before closing for tonight, I would like to recommend you acquire a good black marker and a turkey baster. The black marker helps check your grinding. The turkey baster is the best way I know for removing water from the trough.
Enough for tonight.
Ken
Ken, Do you work for Tormek? If you do, thanks for your awesome advice. If you don't, you deserve to be knighted.
So...The courier arrived today. I had a class in the afternoon so I had to wait a few hours before unpacking and setting up. I took my time and became familiar with the machine and parts. The first thing I did was oil the leather and rub some compound in. Seemed easy enough. After that, I figured the truing tool out and probably took off a bit more than needed to but no harm done.
I found the Anglemaster, set a chisel up in the jig to 25 degrees, used a sharpie on the bevel and went for it. My first impressions of the Tormek have been fantastic. It was slow, I expected this but I was setting a new angle. After setting the new angle, the chisel had a new life in it. I graded the stone and polished the edge a bit more and then used the leather wheel by hand. I found it quicker than setting the jig up again.
I'm extremely happy with the edge it helped create. A few practice cuts on some pine told me it was ready to go. Money well spent for easy (slightly slow) results. I suppose that's my only complaint. The speed. However, once the new angles are set on the chisels, it shouldn't be hard to maintain with a protrusion jig of some sort.
I've attached a picture of my first chisel. The top is what I came from and the bottom is freshly honed. I'll have my work cut out for me to get through the rest of them but the results will be worth it!
(http://i924.photobucket.com/albums/ad87/lewiscaclark/IMG_3837.jpg)
Bravo, Lewis!
Isn't it nice when a plan comes together. Do not be at all concerned if the set up seems slow; we have a cure. Once you standardize the distance from the universal support to the grinding wheel and the protrusion of the blade, set up is very quick. That will be in the next post.
You know what Tormek sharp can and should be. You are up and running. Your enthusiasm and very sharp tools will inspire your students.
For the record, I do not work for Tormek. (Stig is our resident Tormek employee. He also runs Tormek support. support.tormek.se) I did demonstrate the Tormek for Affinity Tool, the US importer, for one weekend, and am on call should they need a demonstrator. Mostly I am a very interested amateur. I review new Tormek products for the forum. I enjoy being part of this helpful and innovative group. Ideas get bounced all around the world. As a group we enjoy making things work better and, especially, helping members go from perplexed to proficient. Welcome aboard.
Ken
Good start Lewis. I bet you feel like the dog's .....!
I previously said that you would probably use primary and secondary bevels on the chisels, and that was before your original photograph of the group of chisels. They appeared to be single bevel only. It may save you time if you measure the original bevels eg 30 degrees, and just grind/hone them at the same angle. The point of two bevels was to save having to re-sharpen the whole bevel face which was the case when using oil/waterstones and elbow grease.
With the Tormek you can just re-hone the whole bevel for re-sharpening. You don't need to re-grind each time. I would advise against free hand honing the bevel as it is more liable to induce rounding of the edge; likewise pressing too hard. (Been there done it - several times!)
Some of my chisels are 25 degrees, and some at 30 degrees. I don't have any with secondary bevels.
I use the 25 degrees when paring, and 30 degrees if chopping out, although the difference is barely noticeable. The wood itself can have a bigger effect.
Once you have been through a few chisels, and using Ken's blocks and standard sizing, your speed will increase noticeably.
Congrats to your nice result. :)
When mastered, please demonstrate the sharpening procedure to your students. It may positively influence their whole woodworking careers. ;)
Jan
Finally, the set up post. Imagine a triangle. One side is the Distance from the top of the universal support to the grinding wheel. One side is the Protrusion from the side of the support bar away from the grinding wheel to the edge of the blade. The third side (imagine it is flat) is the cord of the grinding wheel between the Distance point and the Protrusion point.
If you remove the chisel or plane blade and duplicate the lengths of Distance and Protrusion, the bevel angle would be identical. This all relates to trigonometry, which I have not studied since 1966. Fortunately, we have some very capable math people on the forum.
If you decide upon a fixed Distance or Protrusion, the side not chosen will remain constant once you find it. My preference, as stated in an earlier post, is to set the Distance using the TNT-100. Then I find the protrusion using the Anglemaster. Once you find this, make a gage. It can be as simple as a piece of cardboard with a pencil line. A stop block will require a couple minutes to make up, and be more permanent.
If you prefer to fix the protrusion, set it for whatever length you desire. Fifty mm is a good starting point. Use the anglemaster to set the Distance. (I have made up a PDF with photos explaining this. It is posted somewhere on the forum. The easiest way to find it is to send me a PM with your email address and I will email you the report with photos. Or, one of the members more skilled with searching than I am may post a link.)
Once you reach this point, set the Distance. There is no need to change this. It will be the same for all of your chisels and plane blades. If you do change it for some reason, your kenjig (made up from a scrap piece of wood or cardboard in less time than you spend reading the article.
Set the Protrusion of your first chisel and sharpen.
For the second and following chisels, just set the Protrusion using the piece of cardboard or your stop block.
Follow the last two paragraphs if you need to sharpen chisels at a later date. No need for the black marker or the angle master. Your bevels will be identical. You can store your black marker and anglemaster.
(For the inner teacher in you, this procedure is an excellent example of the value of trig.)
Please post your thoughts, or questions if I have not stated things clearly. This really needs a youtube, however, my last moving picture experience was 16mm football films in high school. :(
Ken
ps Here is the link to my PDF. If you skip through to page six of seven, you will see a photo showing the Distance setting tool in use. The photo shows the knife setting tool. A tool like this for chisels would be shorter. The principle is the same. Just make the initial measurement with a combination square and transfer it to the wooden (or cardboard) tool. The PDF explains the process focused on knives, however, the process is the same for chisels and planes.
https://drive.google.com/file/d/0Bye-818SN85DdzB3bU9aUU81eTg/view?usp=sharing
Thanks RobinW, Jan and Ken.
Robin - I'll try a few chisels out at 30 degrees. If it makes no/not much difference, it should be quicker and easier to maintain it. Most of the timber we use is pine with the occasional hardwood thrown in. As I get more experienced, I'll start experimenting with some the secondary bevel.
Jan - Hopefully, if I can find some interested enough students, they can do some sharpening when they need it. It would give them a few more skills and save me some time.
Ken - Again, thanks. I'll read through the document and see what I can come up with. I'll experiment with your ideas and see if I can make them my own. If I discover anything, I'll share my ideas back on the forum.
Hello,
I'm rather new in this forum but a long time Tormek user (since 2008). Being more a handtool- and furniture maker than a turner, the main use my Tormek gets is the sharpening of chisels and plane blades. Since the very beginning I had some trouble with the SE 76 jig concerning the squareness of the edges (I know that's an old hat for you) ;) I found my way that suits me for about 8 years well. To make sure the squareness of the blade and to get the protrusion of the blade constant, I built a jig that will be shown in the following pic. It has 2 fences, one for longer western irons, one for shorter Japanese irons.
(https://4.bp.blogspot.com/-saxmDtFVBh4/ThjfIosrNaI/AAAAAAAABT8/MbyUet6luS0/s640/Tormek%2B068.jpg)
(https://3.bp.blogspot.com/-o5bgEKD-CD0/ThjfHlgSxgI/AAAAAAAABT0/YixhdralM1s/s640/Tormek%2B067.jpg)
Later on an additional fence for narrow blades was added.
(https://1.bp.blogspot.com/_8mxkzBCYMc4/S2ff2meZY0I/AAAAAAAAAQ8/Q8APum42PQY/s1600/CIMG1452.JPG)
(https://2.bp.blogspot.com/_8mxkzBCYMc4/S2ff2OxQ0PI/AAAAAAAAAQ0/g9amvV2R-pQ/s1600/CIMG1451.JPG)
For setting up the universal support, I use some simple distance wooden pieces.
(https://4.bp.blogspot.com/-1C7er4mVW0k/ThlbUMiMx8I/AAAAAAAABUU/ZPS4OOfAFq8/s1600/P1020881.jpg)
(https://2.bp.blogspot.com/-k0pdVSSU-aQ/ThlbUwrrquI/AAAAAAAABUc/mHIaBE1EwYg/s1600/P1020882.jpg)
With this jig, I hadn't squareness issues any longer and, important as well, the set up for refreshing the blades is done in no time. The angle will be repeated perfectly every time for all blades.
Klaus
Welcome to the forum, Klaus (Waterstone).
Your fixtures and very designed, built and photographed. I especially like your set up for narrow chisels. They are the nost difficult to align; your set up looks like it does that very well.
I look forward to future posts from you.
Ken
Klaus (Waterstone), welcome to the forum and thanks for sharing images of your nice and useful jig. :) It is inspiring!
What protrusions do you use?
When your grindstone wears down you will have to slightly increase the wooden blocks for setting the same angle via the grindstone – USB distance. ;)
Jan
Quote from: Jan on October 19, 2016, 05:02:40 PM
When your grindstone wears down you will have to slightly increase the wooden blocks for setting the same angle via the grindstone – USB distance. ;)
Jan
Jan I am actually building something similar, but maybe less fancy. My stones (SG/SB and SJ do not longer have identical diameters. And the distance necessary behaves as you decribe. I guess after one truing of the wheel the distance becomes so different that one would need another distance block. Using the WM 200 seems to me more appropriate and will not consume much more time.
Rolf
Rolf (Hatchcanyon) fortunately the decrease of grindstone diameter has quite small influence on the edge angle when the protrusion is the same. :)
E.g. for 250 mm grindstone diameter, 139 mm kenjig/ knife jig protrusion and 30° edge angel the USB – grindstone distance should be 79 mm. For 240 mm grindstone diameter the USB – grindstone distance should increase to 80 mm only.
The example is valid for knife jig, for square edge jig the figures will be different, but I hope not dramatically. ;)
The resume is, that a hobby sharpener can live with one wooden distance block quite a long time. :)
May be you have read my chisel topic "Setting 25 degree edge angle with TTS-100".
http://forum.tormek.com/index.php?topic=2731.msg14578#msg14578
Jan
Quote from: Jan on October 19, 2016, 06:12:18 PM
Rolf (Hatchcanyon) fortunately the decrease of grindstone diameter has quite small influence on the edge angle when the protrusion is the same. :)
Jan
Jan,
I measured recently a height difference of 1,2 Millimeter for two stonen of an estimated diameter difference of 3 Millimeter. Have to remeasure the difference in anle.
Rolf
Rolf, I can calculate it, but please let me know if it was for the square edge jig or the knife jig. I need also the diameter, the protrusion and the edge angle. ;)
Jan
Quote from: Jan on October 19, 2016, 05:02:40 PM
What protrusions do you use?
When your grindstone wears down you will have to slightly increase the wooden blocks for setting the same angle via the grindstone – USB distance. ;)
Jan
Hello Jan,
the protrusions are 53 and 33 mm. Works well with long and short blades.
I take always the same distance pieces regardless of the decreasing diameter. Since I use only one stone, it doesn't matter if the angle gets slightly steeper by time. It's not all that much. The stone wears slowly. This year I replaced it the first time after 8 years of use.
Klaus
Quote from: Jan on October 19, 2016, 08:41:49 PM
Rolf, I can calculate it, but please let me know if it was for the square edge jig or the knife jig. I need also the diameter, the protrusion and the edge angle. ;)
Jan
Jan,
I tried to mesaure again:
SB und SG stone 246 mm
SJ stone 244 mm
Protrusion (SE-77) 35 mm
Using the Universal Support unchanged in height for example with first SG and then SJ will change the bevel angle about 1,4 - 1,5°. That means an effective polishing with the SJ is not possible without resetting the Universal Support. The height above stone circumference has to be adjusted by 0,2(5) mm to have the same angle.
These measurements may be a bit crude, but the light gap method with an WM-200 tells me the change in angle.
Rolf
Rolf, thanks for providing your data. :)
My script was built for SE-76 jig geometry and I do not have the new SE-77 jig. Because I am not sure how much the geometry was changed I would like to ask you to measure for me two distances on the new jig SE-77.
The two lengths I need are shown in the picture below:
A is the distance between the front edge of the upper base and the USB axis shown in red (measured as vertical projection) and
B is the distance between the flat upper base and the USB axis shown in red.
Thanks in advance.
Jan
P.S.: For SE-76 jig the distances are following: A = 23.7 mm and B = 31 mm.
I#ll try to find that out tomorrow.
Rolf
Quote from: Jan on October 20, 2016, 08:16:38 PM
he new jig SE-77.
The two lengths I need are shown in the picture below:
A is the distance between the front edge of the upper base and the USB axis shown in red (measured as vertical projection) and
B is the distance between the flat upper base and the USB axis shown in red.
Thanks in advance.
Jan
P.S.: For SE-76 jig the distances are following: A = 23.7 mm and B = 31 mm.
Hello Jan,
for the SE-77 A=17,5 mm, B=30 mm.
Rolf
Rolf, tanks for your measurements on the SE-77 jig. :)
For an edge angle of 30° and your protrusion 35 mm I have got the following results:
When you go from the SG stone (246 mm) to the SJ stone (244 mm) without changing the height of the USB, then the edge angle will increase to 30.9°.
To keep the same edge angle (30°) also for the smaller SJ stone you would have to increase the distance between the stone and the USB by 0.12 mm.
Jan
Jan,
my test setup was for 25° and measuring of angle and height change quick and dirty.
Thanks for your explanation! ;)
Rolf
For the edge angle of 25° and your protrusion 35 mm are the results very similar: :)
When you go from the SG stone (246 mm) to the SJ stone (244 mm) without changing the height of the USB, then the edge angle will increase to 25.8°.
To keep the same edge angle (25°) also for the smaller SJ stone you would have to increase the distance between the stone and the USB by 0.13 mm.
Jan
Quote from: Waterstone on October 19, 2016, 09:51:34 PM
Hello Jan,
the protrusions are 53 and 33 mm. Works well with long and short blades.
I take always the same distance pieces regardless of the decreasing diameter. Since I use only one stone, it doesn't matter if the angle gets slightly steeper by time. It's not all that much. The stone wears slowly. This year I replaced it the first time after 8 years of use.
Klaus
Since I have read Waterstone's remark that he uses the same spacer block for chisel edge angle replication regardless grindstone diameter, I have been wondering how this influences the desired edge angle of 25°. :-\
Below there is a graph showing that the edge angle is decreasing from 25° for a 250 mm grind stone diameter to 18.5° for a 180 mm grind stone diameter. I have assumed that for setting the USB a spacer block with a height of 23.3 mm was used for all grindstone diameters.
Jan
Klaus,
Changing wheel diameter with wear is why I use the TTS-100. Your chisel holding devices are leagues ahead of my primitive marking tape lines for setting the Protrusion.
However, I think your device to set the Distance between the universal support and the grinding wheel could benefit from some modification. If you take a look at the kenjig, the Distance is set by placing the Universal support in the groove. The length of the groove determines the Distance. As this simple piece of plywood is not self correcting for diameter changes, lengthening the groove approximately one millimeter for each ten millimeters of wheel loss will keep the bevel angle consistent (within reason).
We can simply correct this in two ways:
1) "Assign" the jig to the grinding wheel. Lengthen the groove to match the wear of the grinding wheel. Eventually you will need to replace both. Your replacement material cost will be a 30mm x 150mm piece of cardboard or plywood.
2) Make a set of jigs, one for each ten mm of wear.
I favor the first choice.
A third choice is one of the more sophisticated forum designed jigs.
Ken
To compensate for changing wheel diameter with wear we have to increase the height of the spacer block. The attached graph shows the situation for a desired edge angle 25° and chisel protrusion 53 mm. :)
Jan
Hi Ken, Hi Jan,
I really wasn't aware that the decreasing stone diameter does have so much influence on the blade angle. Thanks for enlightening me. Looks that I've been a little careless in this regard. And yes, some chisel blades actually have rather 26 degrees than the intended 30 degrees. Since this was a slow process I didn't realize it. So I will have to change my strategy and skip the distance pieces. But it will be easy enough to set up the US by using the WM-200 at the correct distance. If a few chisels have to be sharpened, the adjustment has to be done only once.
The main reason to build the jig was my trouble with the SE-76 concerning the squareness. While using my jig the squareness of the blade will be made sure by using the edge as a reference. Only narrow irons can't be set up this way. That was the reason to make an additional removable side fence. Both ways are working very reliably. I don't have any irons out of square in my shop any more.
Thanks to both of you!
Klaus
Klaus
Klaus,
Your jig works fine for setting Protrusion. It just needs a bit more support setting the Distance.
By the way, I am used to making jigs for knives with longer Distances. If you use the same 150mm piece of plywood for chisels (with shorter Distances), you can saw off enough wood to begin again with several wheels. Just make sure you leave instructions for making a new jig with your grandson.
Jan,
An old factory joke is sending an apprentice to the tool room looking for a "putting on tool". Instead of "putting on" the Distance gage block as the wheel decreases, I think it is easier to make the negative space of the groove more negative. :)
Ken
Klaus, you are welcome! :)
I am glad to read my script works well. One spacer block is not enough, but three suitable spacer blocks may be enough for the whole life span of the grindstone.
For your convenience I am attaching a graph for the edge angle 30° and your protrusion 53 mm.
Ken,
when preparing the script for the square edge jig I felt like an apprentice also, because this is more complicated than knife jig. Please be so kind and test if it works for the new SE-77 also. ;)
Jan
Jan,
I will do that during my next sharpening session.
Ken