Putting Lead in a saw

A forum about crosscut saw filing

Re: Putting Lead in a saw

Postby Jim_Thode » November 15th, 2012, 9:40 am

Jeff,
For a recent thread on the question of swaging or not swaging see:
viewtopic.php?f=4&t=602
It would be nice to see a scientific comparison other then just the impression of the sawyer.

On the issue of the depth of cut. It makes sense that if a raker has a longer leading point, that would seem pull the saw deeper into the cut. And it also makes sense that if a raker has a shorter leading point, that would seem make a shallower cut. Then it also follows that if a raker has points that are equal length that that raker would not tend to cause the saw to cut deeper or shallower, the rakers are just going along for the ride and kicking out whatever the cutters give it. Just kind of the middle of the road with other things like the shape of the raker, the down force on the saw, the shape of the overall saw face, how sharp and what the shape of the cutters are actually controlling the depth of cut.

Then of course the relation of the raker to the cutters will have some effect too. I think if the raker is longer or shorter then required by the spring back of the wood it will just make the saw less efficient. That is if the raker is too long it would start to pull wiskers, it will be harder to pull and not cut as clean. If the rakers are too short, then the raker will not kick out the full depth of the wood that the cutters have cut, the effort to cut the wood will be wasted.

I don't know for sure, just what makes sense to me.

Jim
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Re: Putting Lead in a saw

Postby SalmonCreek » November 15th, 2012, 9:55 am

I have two saws identical to each other, with identical stamp marks, guessing the original sawyer bought the two at the same time. One I have sharpened, with swaged rakers. The other one I haven't sharpened yet, but it does have one broken raker I need to weld up. I could sharpen it non swaged and see what difference in sawing performance swaged vs. non swaged is.

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Re: Putting Lead in a saw

Postby SalmonCreek » November 15th, 2012, 10:06 am

Then of course the relation of the raker to the cutters will have some effect too. I think if the raker is longer or shorter then required by the spring back of the wood it will just make the saw less efficient. That is if the raker is too long it would start to pull wiskers, it will be harder to pull and not cut as clean. If the rakers are too short, then the raker will not kick out the full depth of the wood that the cutters have cut, the effort to cut the wood will be wasted.


I would agree with this Jim. I wish I really understood better raker height to how aggressive the cutters are filed. I have one bucking saw, with very steep filed cutters. With two good sawyers, it cuts fast. But in the hands of so-so sawyers, it hangs up alot. I wouldn't think the few thousandths the cutters are in the wood, that the steepness of the filing would make that big of difference. But maybe the cutters are really cutting just enough deeper to make for a fast, and temperamental cutting saw.

Sometimes it boggles my mind, sometimes it frustrates me, how such a simple cutting device, can be so complicated!

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Re: Putting Lead in a saw

Postby moosecreektrails » December 5th, 2014, 10:21 pm

Image
Image
Image
Cut off Bucker, with lead from a known filer from Canada,Raker Heights on Vise. .008 tooth set. Cut like a chainsaw
It was not my saw,got the chance to run It.
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Re: Putting Lead in a saw

Postby trailcrew » December 8th, 2014, 2:18 pm

So if I'm interpretting those numbers right, the filer wanted it to be aggressive on the pull and most aggressive near the handles? Also looks like they left the raker tips pretty stout, wonder if they were softened pretty significantly or hot swaged.
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Re: Putting Lead in a saw

Postby BD Rec » December 9th, 2014, 8:08 pm

Moose Creek, is that a single or double buck? I know of the filer and do have great respect for his knowledge. (His saw at your brothers shop was incredible!). I would think that the lead would be different for a single vs double. I have see jack and Jill saws with the less aggressive set on the weaker side. I am very curious about single bucks and the set on the push stroke towards the tip. Thanks for sharing this!
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Re: Putting Lead in a saw

Postby Jim_Thode » December 9th, 2014, 10:17 pm

I saw in an Anderson Saw Gauge saw filing instruction book that they suggested putting a lead on the last three or four rakers at the end of the saw (two man saw I assume). That is, the points on the end side of the rakers would be 3 or 4 thousands longer then the points on the side toward the middle of the saw. No reason was given but it would make some sense especially on larger logs where the saw length may not be twice the diameter of the log. The lead would tend to kick shaving out of the kerf rather then pulling the shavings into the center of the log.

In another hand written note from an experienced filer about 1929 he recommended the a lead (same as the Anderson Saw Gauge) on the end of bucking saws.

Jim
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Re: Putting Lead in a saw

Postby moosecreektrails » December 11th, 2014, 11:06 am

Should Have posted a better Picture, Its a cut down bucker.
Several local People run his saws, and I finally Got a chance run one he was selling, I was impressed, Going to send a couple 5' buckers to him to file.
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Re: Putting Lead in a saw

Postby Dale Torma » May 30th, 2016, 2:28 am

I'm not sure I subscribe to the " springback theory" even though it works in practice with regards to filing, I think other progressive cutting is going on, or something more than meets the eye. Even though I am a newbie to this crosscut saw stuff , I have worked with wood for over 40 years, and I can't quite wrap my head around springback.

I think the progressive raker depth should work well, thinking a bit out of the box is good, and theories that prevent innovative thinking may be flawed.

Just my 2 cents
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Re: Putting Lead in a saw

Postby Jim_Thode » June 2nd, 2016, 9:17 pm

Dale Torma wrote:I'm not sure I subscribe to the " springback theory" even though it works in practice with regards to filing, I think other progressive cutting is going on, or something more than meets the eye. Even though I am a newbie to this crosscut saw stuff , I have worked with wood for over 40 years, and I can't quite wrap my head around springback.

I think the progressive raker depth should work well, thinking a bit out of the box is good, and theories that prevent innovative thinking may be flawed.

Just my 2 cents



Dale,
I agree with your thoughts on the springback theory. My posts in this thread were before I came up with my idea on how a saw cuts and moves down through the wood. I don't know when or who originally came up with the springback theory as a reason for shorter rakers but it just does not make sense to me. Look at this thread for more info on why rakers need to be shorter then the cutters: viewtopic.php?f=4&t=1056

With regard the this thread on lead there is some springback of the trailing raker tip and changing he length of the one of the raker tips in relation to the other will have an impact or how much the trailing raker controls the depth of cut. If you look at my "How a Saw Cuts" drawing ( http://www.pbase.com/jimthode/how_a_crosscut_saw_cuts ) you will see some springback at the trailing raker tip. If you look closely at a well used saw you will see wear on the inside surface of the raker "V" near the tip. This is caused by the trailing raker rubbing hard on the bottom of the saw kerf. If there was no springback on the trailing raker tip (or no lead) the saw would not cut when the saw is operated as designed. Saws are designed and work best when the saw is rocked so that all the teeth are in contact with the wood at all times.

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