dovetail saw drift

J

jlandis

Member
I have four back saws.  It doesn't seem to matter which I use, they vary in error, but all seem to drift to my right. Even if I do the best I can and the saw follows the line down the front, around back the kerf drifts to the right. I ran the teeth of the saws over a norton yellow waterstone, the saw laying on its right side and there seemed to be no differance, in some cases it seemed to worsten the problem. I love to use these saws! The problem is more than likely my technique, so I am ready for your advice.
                                                                      Jim Landis
 
It seems strange that all four saws are behaving the same way.  Did you sharpen/set these saws yourself? 
 
  The saws vary in degree of drift, but all error is to the right. No, I have done nothing to the saws except applying them to the yellow stone. The saws are; L.N. rip, L.N. crosscut, Wenzloff sash, and a pax dovetail. ( since Mike is a member here, I would say his saw has the least drift. The tool is a gem and worth every penny) Also, the Wenzloff saw worked fine when I got it, I don't remember any problems. The drift seemed to develop over time, but all the other saws drifted from the start.

                                    Jim Landis
 
Jim -- Have you checked to see if the backs are bent?  Turn the saw upside down and sight down the blade.  It should be perfectly straight.  If there is any bend, even the slightest deviation, it can exhibit drift. 
 
Jim,
Be sure you are not trying to correct the direction of the cut. Once you start sawing with one of these saws you are committed to sawing in a straight line. You cannot change the direction of the cut. That being said if you set the saw up on a piece of wood and saw straight down letting the saw "steer" itself does it cut straight or on a curve? Have someone else try it does it act the same way for them? Why 4 saws by  different makers would act the same way is odd. Has anyone else used the saws, or do you store them on concrete with the left side down?;) Since it is off at the back and straight in the front I would be tempted to say you are steering the front of the saw to stay on the line and twisting the blade in the cut. I could be wrong. They could just be getting dull. Maybe you could try it in one of those wooden Miter boxes to be sure? Good luck
Mike
 
  I did some checking. I could not see any bends in the saw blades, but I did experiment with my sawing technique. I'm happy to say that your advice worked Mike. I believe that I was ever so slightly twisting the saws to get back on the line, and yes doing that did produce the greater deveation on the back of the board. After sawing about 40 trials taking light cuts, the results were almost perfect. I appreciate your help. As I suspected the problem was me, not the tools.

                                                          Regards,

                                                              Jim
 
Jim,

This was my issue years ago and the error was the user not the saws.  It may just take some practice, but one technique I used to use is use both hands.  My technique I used was saw in a normal way right foot in front of the left and saw with both hands coming to center of your stomach ( center of gravity ).  This technique helps me saw perfect straight lines.  This may or may not help.  Good luck!

Freddy
 
I think you would be better off sawing toe up, sawing the corners out.  Putting the saw on the line and hoping for the best is not a technique, it's a stunt.  Guys like Mike can pull it off.  He's a gifted craftsman with years of experience.  But sawing the corners out is a simple technique that you can use for all of your sawing and anyone can learn it in 30 minutes.  I like techniques like that.  And after many years of sawing myself, I still use.

I also think stances, grips, or incantations are not good soultions to this problem.  Inevitably, you will find you can't force the work into your prefered stance.  I have to saw things at all sorts of angles, holding the saw sideways, by the spine, whatever.  All of this is easily accomplished by sawing the corners out.  And because all of the sawing I do uses this technique, every saw cut I make helps my dovetails or tenons or whatever.

I just finished reading the last Narnia book to my kids.  I think sawing has it's own "deep magic"; those ancient truths, set down by our creator.  One is most definitely that one must see the line to saw to it.  Japanese craftsmen don't saw the way many of us do with Japanese saws.  You must see the cut, which, with a pull saw, is happening on the back side of the work.  No question there are some or many who can pull off this stunt, substituing pull saws for push saws on western style benches. 

My take is similar to the question I asked Mack Headley in Wmsburg this year- "Is te technique you are presenting reflective of what you do after 30 years of experience, or what you suggest WE do having no experience?"  I wasn't crazy about the answer by the way. 

I think this is a question woodworkers should be asking their teachers, authors, and even respected forum members.

Adam
 
Thanks for your input Freddy, I'll try anything to keep me from planing an eighth inch, double beveled wedge off the cheek of a tenon again! Being somewhat new to this business, I don't have many bad habits to break, so tying new techniques is not petting the cat backwards to me yet.
  Like a calf staring at a new gate, I'm with Howard. Adam, you lost me, I was wondering if you could explane the technique you have in more detail. What is "toe up", and "corners out"?- I don't think I'm interested in the incantations part though.
                                              Regards ,

                                                          Jim
   
 
Here are Chris Schwarz's "9 rules of sawing" He has a couple of good article and DVDs about sawing too.

Nine Rules of Sawing
1. Use a relaxed grip on the tote. Clenching the handle will push you off your line. Pretend you are holding a baby bird and that you are trying to keep it in your hand without crushing it. That’s about right.

2. Extend your index finger out on the tote. The handle was built for a three-fingered grip, and extending your index finger is good to do with any user-guided tool.

3. Always work so your sawing elbow swings free like a steam locomotive. Don’t work with your arm rubbing your body or move it at an angle to the back of your saw.

4. Whenever possible, work so you can see your line. Try not to let the blade of the saw obscure the line.

5. Use minimal downward pressure. Allow the saw’s weight to carry the cut.

6. Always imagine the saw is longer than it really is. This will fool you into using longer strokes, which will allow you to saw faster and wear your teeth evenly.

7. Whenever possible, advance on two lines (tenons, crosscutting, dovetailing at times). This increases your accuracy.

8. Always work right against a line. Never saw a certain distance away from a line.

9. Lifting the saw a tad on the return stroke clears your line of sawdust.
 
Adam Cherubini said:
I think you would be better off sawing toe up, sawing the corners out.  Putting the saw on the line and hoping for the best is not a technique, it's a stunt.  Guys like Mike can pull it off. ...
Click to expand...
Oh, I wouldn't call it a stunt. I taught 50 people at WIA and the recent LN Hand Tool Event in LA to simply start flat on the line. Both--sawing the corners and flat--are good methods and not necessarily interchangeable, depending on what one is sawing.

For instance, sawing tenon cheeks I saw the corners out simply so I can do what Schwarz says in rule #7. I don't, however, flip the stock and saw the other corner out and then flatten out to cut the bottom. By the time I have sawn the first corner, I am either on the line properly or off without much chance of correction.

But for other joinery tasks--DTs, haunches, box joints, etc,--one would do with a typically finer pitched saw, I do start flat. Drawing the saw back to begin a cut or angling the saw handle down to cut the corner from the front, or angling it up to saw the corner at the rear is more difficult for me.

Plus, drawing the saw back with firm pressure like many do actually creates a series of ripples in the kerf in most woods that correspond to the PPI of the saw. When one pushes forward, the teeth of the saw go down into those ripples and one must push harder than simply starting flat.

When starting flat, one should merely have the saw's toothline held lightly to the edge of the board, and with the forward push, increase in pressure through the stroke. Thumb or other digit that is guiding the saw can be removed and saw away.

Take care, Mike
 
Hi Jim--sorry for coming to the forum so late. I am pleased you have got it sorted out.

Three words...practice, practice, practice. Which is what I consider *every* opportunity to saw. Even if all I am doing is quickly breaking down a plank, I consider it an opportunity to get better for the joinery I will eventually be doing.

Take care, Mike
 
I start most saw cus at the corner.  Nick the corner with a forward stroke, then advance on both lines simultaneously.  With such a short kerf, corrections are simple in these first few strokes.  As the cut progresses, corrections are easy to make (because the cut is not yet full thickness).  What I do is stop advancing on the good line (but continue to use it to guide the saw) then lay the saw down into the bad line, correcting it.  Once the bad kerf is corrected, you can resume cutting both lines. 

When you are down to the gauged line and across the end grain (as shown in the picture) you can either flip your stock and repeat the process from the far side (but this time using the cut across the end grain to guide the face cut, or you can just use the kerf to finish the cut (using "zen").  I can do this with dts or when the stock is thin.  But when the stock is thick, it really does make sense to turn the board around.

I use this same technique for precision cross cuts or to start rip operations.  It's not the only way to saw, but it is an effective way to get great results quickly.  And unlike a honing jig, if you start sawing this way, you will generate the skill you need to saw however you wish in the future.

Mack was doing low relief carving- something he is really really REALLY good at.  The text books all tell you to chase around your design with a veiner, then do your boasting (ground work) to that.  You stab in the design and clean up to it.  The small amount of wood (between the stab and the veiner/v-gouge cut) is easier to clean up and results in a crisper (uncompressed) edge. 

There are several advantages to this approach, but speed is not one of them.  Shortly after I asked the question, he did exactly what I have done about 25 times so far.  The work piece slipped and he cut past the stab line, lifting out a section of the carving.

He sorta dismissed the question, saying something like "this is how I do it".  (I have it on video and could find out exactly what he said if anybody is interested)  I think he's a self taught carver.  It's possible he skipped the "baby steps".  He may not have known about them or may have forgotten, having passed this stage in his carving 30 years ago.  He's also funny about stuff like this.  He doesn't have much to say about his tools.  I think artists don't think much about their paintbrushes either. 

Adam
 

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All was well until this morning,

                  I got up early to work on some side rails for a queen anne chair, the rails are large;2 3/4" wide. feeling a sense of confidence in all the sawing practise I have done, I jumped right in. The depth of cut was maybe an inch or so. There was much more drag on the saw than with the 3/4" stock I was practising on.
      Requiring more effort, I tryed to maintain all those new rules, and finished the cut. It looked fine on the front, but around back the kerf had drifted, again to the right! I did maintain the cutting rules, could the error be caused from the increased effort? If so does anyone know the solution?
        I made a few more cuts with the same results, then gave up and finished on the band saw.

                                                Thanks for you time,

                                                                      Jim
     
           
 
Sorry Adam,

      Your reply was on page 2, I didn't see it before I posted my last reply.
You said something about turning the board around on larger stock, is that because of the same problem I had or for some other reason?
       
 
Jim,

Yeah, you're doing something wrong that's causing this.  I can't diagnose the problem without seeing you saw.

Absolutely, flipping the board will help you.  Worst case, you end up holding the lines but the interior surface is lumpy.  Easy to fix with a chisel an beter luck next time. 

Focus on the lines you see before you.  Lay your saw down to correct, never twist the saw (it just doesn't work).  Smooth even strokes, very little presure, have the saw so lose in your hand that if you held it looser, it would fall.  To make my point, I've sawn stock holding the saw handl between only my thumb and forefinger.  The weight of teh saw is typically more than enough. 

The goal is to be able to hold the line.  In time, you should try to saw to the line, saw it out, or remove half of the line.  This is not only possible, it's required to work effectively with hand saws.  The goal should be to not have to pare or plane every sawn surface.  Not only can you do it, it won't take that long to get this good.  Use the sawing the corners out technique, relax, and concentrate.    I used to just go into my shop after dinner and cross cut slivers off a pine board until it was gone.  What else do you have to do?  TV sucks anyway.  Spend 30 minutes a night and you'll be awesome in a month.  Probably less!

Adam
 
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