Ruler Trick - SS Variation

Re: Ruler Trick - SS Variation

Joe Rogers, Northern Virginia

>Good Job Dave! How did you mark the position of the magnet to assure repositioning it accurately? I would think a light scribe mark would work. I assume the magnet didn't ride on the abrasive surface. If you drop the magnet into a film can(plastic)you can hoover the swarf off of the paper also (no credit to me ...just retelling a best idea tip)JR

Good idea!

Dave (Arlington, VA)

>Hi Joe -

On the placement of the magnet: I simply lined it up so that it was centered and the edge of the magnet was lined up with the top of the blade slot.

And, yes, the "magnet end" of the blade simply slid on the top of my scary sharp glass while the bevel end was abraded on a strip of sandpaper. I didn't have to press too hard to get it clean up the pitting and make a smallish flat plane.

I have used the magnets - directly - before to clean up the swarf from scary sharping, but I had never put it in a film case. I'll have to give that a try. Cleaning the filings directly off the magnet is a bit of a pain. Thanks for the tip.

Regards -

Dave

Re: Ruler Trick - SS Variation

David Charlesworth

>Dave,

Great variation on my ruler trick with the magnet!

Clogging in the mouth or 'Choking' is almost always due to chipbreaker edge faults.

See pages 30 to 32 of my first book.

Horrors.....there is a mistake. It is essential that the front edge of the c/b upper surface is sharp and NOT steeper than 45 degrees.

best wishes,

david charlesworth

question

bill tindall

>I am not entirely sure I understand given that I am unfamiliar with the ruler trick, so this question may be off base. If the "flat" side of the iron has this long bevel will it not interfer with the iron bedding snuggly against the frog , especially right at the mouth where good bedding is essential?

Thanks!....Clogging....Book!!!!

Dave (Arlington, VA)

>Hi David -

Thanks for your post. I am beginning to think this might work. I have another flea market blade that was in such bad shape that after hours of working on the back I'd given up on it (and put in a replacement blade). Now I think I may try this technique on that one, as well.

On the clogging. Thanks for the thoughts. I didn't know for sure, but I had similar suspicions that at least part of my problem might be with the chipbreaker. So, last night I went down and took at a careful look at it - and found that the side where the clogging seems to start: (1) was not sharp - but kinda flat (not much, but noticeable) and, (2) there is a small (1/16 th) chip in that corner of the chipbreaker.

I worked on both of these things with sandpaper in progressive grits and even somewhat polished (i.e. smoothed) the leading portion of the chipbreaker. Of course, I couldn't eliminate the small chip in the chipbreaker, but I was trying to eliminate the possibility of chips catching on it.

The result: not a final solution, but a definite improvement. Chips still fill the mouth, but now rather than being so tightly packed they were difficult to dislodge without removing the blade from the plane, to where they can be poked out relatively easily with a small piece of plastic. Annoying but tolerable.

After seeing your post, I then checked on the angle of my chipbreaker, and right where it meets the blade is awfully close to 45 degrees - maybe more. So now I'm thinking I should try to reduce this angle somewhat. I'm not sure what's the best way - sandpaper or gentle pesuasion with a mallet. I'm leaning toward the sandpaper.

On your books, I'm ashamed to say while I have thumbed through them repeated at the book store, they have not yet found their way into my library. However, Father's Day is around the corners, and who knows!

Again, thanks for your post.

Regards -

Dave

Ruler trick and bedding

Dave (Arlington, VA)

>Hi Bill -

In a nutshell, the ruler trick (as David Charlesworth has made famous) - and as I understand it - involves the placement of a thin ruler on the edge of a waterstone such when you "flatten" the back of your blade it is ever so slightly elevated (because part of it is being rubbed across the top of the ruler). This enables you to create a flat plane on the back of the blade near the edge of the blade that can intersect with the bevel to create the cutting edge of the blade. However, this small flat section is not flat relative to the rest of the back of the blade - and this raises reproduceability issues that I was trying to overcome in the case of the magnet and scary sharp approach.

Sorry. I'm sure my description is not very clear. As I understand it you could see this demonstrated in one of David Charlesworth's videos available through L-N, or you could see it in principle in a diagram in Leonard Lee's book (a box on page 17) - if you have that book.

I probably have misunderstood your question. So let me start with an apology if I have. But the blade I used this one was for a bevel-down transitional. Since what I am creating is a "back" bevel and not a "micro" bevel, the bedding of the blade is unaffected because the bevel side of the blade continues to rest on the frog as always. However, your question does raise an interesting point as this process might relate to bevel up plane.

For a bevel down plane (i.e. most bench planes) an important consideration would be: has the creation of this back bevel created an imprecise/loose/gappy fit for the chipbreaker near the edge of the blade when it is put on and tightened. In my case, did check and can't see any light between the chipbreaker and the blade.

I hope this at least addresses your question, even if it doesn't answer it.

Regards -

Dave

Re: Ruler Trick - SS Variation

Skip in Falls Church

>Hi Dave,

I've used plastic toilet basin bolts to put back bevels on some of my blades. I don't remember who came up with the idea either - but it worked for me. I had to use a die to run the threads all the way down and the plastic washers that came with the bolts work great for shims. If the bolt head were too high - it could be taken down a bit with a rasp or file.

I have a scroll saw protractor that I use to set the angles. I've done dedicated back bevels and the set up works great for that. I just love the old Sweetheart blades - but most of them come pitted at the location the chip breaker was left in.

The laminated Sweetheart blades seem to hold up well with a back bevel on it. I haven't had as much luck with the older non-laminated blades at a high bevel angle. I tried one at 10 degree back bevel and the edge rolled right over on me.

BTW, I use SS as well. I just keep the bolt on my plate and the blade on the paper. It usually doesn't take long and seems to be fairly repeatable. So there's now a couple of toilet basin bolts in with my sharpening stuff. :)

Skip

Re: Ruler Trick - SS Variation

Dave (Arlington, VA)

>Hi Skip -

Cool. What do you think is the back bevel angle your're putting on your blades? Sounds like your intentially trying to make them into high angle (York pitch) type blades.

If you decide to put a fairly steep back bevel on your blade can you put a higher angle on the bevel so that the edge isn't so thin? That might keep it from folding.

For me - with the magnets - I was looking for repeatablity and ease-of-use. I wanted to be able to put the same angle on each time, and I wanted it to be easy and fast to do.

I am experimenting with some freehand sharpening (limited success) and chasing the burr with this approach is easy.

Thanks for your post.

Regards -

Dave

P.S. I'm not sure I commented at the time, but your saw handles looked great!!! Well done.

your answer was very clear

bill tindall

>and it all make good sense

Re: Ruler Trick - SS Variation

Skip in Falls Church

>I've done 5 and 10 degree back bevels as a last resort to save some badly pitted blades that I felt couldn't be saved any other way. As I say - I have a weak spot for Sweetheart blades and I've done this to make them useful again.

When I do back bevels on blades I usually maintain a 30 degree bevel on the front. As I understand it the maximum bevel you should use on the front is 35 degrees to leave a 10 degree clearance. That gives me 5 degrees for a secondary bevel if I think I need it. The Sweethearts I've sharpened don't seem to need it though.

I will admit that having a 50 degree smoother is nice as something between the Baily styles and my HNT Gordon. I tend to limit my freehand sharpening to when I absolutely have to - I *like* jigs. :)

Skip