Look here for the first post in this series.
This post investigates the relative position of the hammer of the saw set and the saw's teeth. In the following picture, you can see that the top of the hammer is at about the same height as the top of the saw tooth.
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| Setting a tooth: note position of hammer on the tooth |
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| Close-up of the above pic |
This is how I believe it is supposed to be. However this saw set had a little problem. After setting thousands of teeth, a groove was worn in the underside of the casting. I suspect this is a common problem among old saw sets.
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| Dental tool pointing to the groove worn into the casting |
That groove is in the middle of a flat area that is meant to rest on the teeth while using the saw set. In the next picture, I've placed a ruler on the flat part (not in the groove) and the top of the hammer is just about even with the top of the ruler. Think of the top of the ruler as the line representing the tips of the teeth.
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| Top of hammer at top of ruler (toothline) |
But the groove worn into the casting changes things. In effect, it raises the toothline relative to the hammer, so the hammer sits lower.
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| With the ruler (representing the toothline) in the groove, ... |
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| ... the hammer sits about 1/32" below the top of the ruler |
This problem is why, when setting teeth, one should pick up the set rather than dragging it across to the next tooth.
Here's how it was fixed.
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| Mixed up a little J-B Weld and filled the groove ... |
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| ... when it dried, leveled it with chisel, file and/or sandpaper |
This worked well, but after setting the teeth on a saw, the groove is reforming. I guess the J-B Weld is just too soft.
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| Tooth marks in the filled groove |
I had to use some epoxy the other day, so I left some extra to dry on a piece of plastic. The next day it seemed harder than the J-B Weld. Perhaps that would've been a better choice. If anybody reading this has another solution, I'd love to hear about it.
Last thing about the #42 saw set: there is too much room between the saw plate and the saw plate brace (the part contacting the saw plate in next photo).
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| Saw plate being "clamped" in the saw set |
The saw plate does not actually get clamped in the set. When the hammer engages the saw tooth, the plate is forced at an angle until it contacts the saw plate brace. I don't know if the angle at which the set bends a tooth takes this into account.
I know the Stanley #42X solves this problem. In that set, when the handle is squeezed, the saw plate brace moves forward to clamp the plate, then the hammer moves forward to set the tooth.
For now though, I'm happy with how it works.
I suppose that you could have glued down some shim stock with the JB weld. I have used JOB weld in the past and have learned the same lesson as you have. It's an adhesive, not a filler
ReplyDeleteI thought about a shim. Maybe I'll try something like that if / when the groove wears in again.
DeleteThe important part to position on your set relative to the tooth is the anvil. The punch or hammer is at a fixed angle , the anvil has a break line on it the lower the break line the more set you will have.
ReplyDeleteThanks for that, Mike. If I understand what you mean, that "break line" is what one would normally place 1/3 to 1/2-way down from the top of the tooth. Still, I wonder if it is important to have the top of the hammer at the top of the tooth for full support. Thoughts?
DeleteI would try to epoxy a small piece of metal so to fill the groove. While epoxy is very hard when fully set (and it takes a week at normal temperature to fully set) it is still more subject to wear than a piece of metal. Maybe cutting a small piece of hack saw blade and use epoxy to glue it in place would do the trick.
ReplyDeleteI have two saw sets, one for big teeth one for small teeth, still I am wondering about the numbering on the wheel to fix the set, is there any unit with these numbers or just a mark to show from smallest to largest.
I like that idea of gluing in a metal piece. It might take some prep time to excavate the groove and then later to file the glued-in metal flush, but sounds like a good idea.
DeleteRegarding the numbers on a saw set dial, I don't think there is any correlation between the dial setting and the number of thousandths of an inch the set will be. That's because different size saw teeth will not get the same set at the same dial setting. My Somax set for fine teeth has the dial. I almost exclusively use the setting for the smallest amount of set. Also, some people think there is a correlation between the dial numbers and the number of teeth - there is not!