saw sharpening ???

[jim hedgpeth]

If I understand correctly, rake angle of a crosscut saw is a compromise between easy start (neg. rake), and aggressive cut(pos. rake).

If that is right, would it be a good idea to make the fist few inches more neg. to start easier, and then progress toward a bit more neutral/positive (relatively) rake to cut quickly?

Thanks,
Jim

[Jim Koepke]

If I understand correctly, rake angle of a crosscut saw is a compromise between easy start (neg. rake), and aggressive cut(pos. rake).

If that is right, would it be a good idea to make the fist few inches more neg. to start easier, and then progress toward a bit more neutral/positive (relatively) rake to cut quickly?

Thanks,
Jim

This is a good reason to buy a few junk saws at garage sales or where ever. Then, you can experiment and find what works best for you. If it only cost $2, it doesn't hurt as much if you have to start all over. When you spent $30 to $200 for a saw, you may not want to get close to it with a file.

With a crosscut saw, you are also working with a fleam angle.

There are saws today made with progressive pitch to make starting easier. So, it may not be a new idea, but it does seem like a good idea.

jim

[Robert Rozaieski]

If I understand correctly, rake angle of a crosscut saw is a compromise between easy start (neg. rake), and aggressive cut(pos. rake).

If that is right, would it be a good idea to make the fist few inches more neg. to start easier, and then progress toward a bit more neutral/positive (relatively) rake to cut quickly?

Thanks,
Jim

Jim,
I think you have the angles mixed up, but the concept right. The more negative the rake angle, the more aggressive the saw will be. Here are a few pics I put together recently for a podcast I did on saw sharpening.

This first one describes rake angle.
128401

The rake angle is the angle that the front of the tooth makes with the toothline. A saw with zero rake has the front of the tooth perpendicular to the tooth line. Positive rake leans toward the heel of the saw. This saw has 10 degrees of positive rake. More positive rake makes the saw easier to start and smoother in the cut, but cut slower. Negative rake leans toward the toe. Western hand saws with negative rake are rare. Negative rake is more commonly seen in Japanese saws and in band saw blades. A western hand saw with negative rake can be very challenging to use. All saws, whether crosscut or rip, have rake. Rip saws typically have lower rake angles (0-10 degrees maybe) and crosscut saws typically have higher rake angles (over 10 degrees typically).

What really distringuishes a rip saw from a crosscut saw is fleam. The next two pictures show fleam.
128402

In this picture, the top (crosscut saw) has fleam and the bottom (rip saw) does not. Fleam can be thought of as a bevel angle to the tooth that helps it to slice cross grain fibers rather than tear (or rip) them. Fleam is the angle that the front of the tooth makes with the side of the saw plate. Higher fleam angles will make the saw slice smoother cross grain, but will make the teeth more fragile and cause the saw to dull faster. Lower fleam angles make the edge more durable but cut rougher.

Here's a top view of fleam. The top saw (rip) has no fleam, the bottom saw (crosscut) has 25 degrees of fleam.
128403

Now that I've beat completely around the bush, I'll answer your question directly. What you are referring to is commonly done and is called progressive rake. This is where the rake starts higher (more relaxed) at the toe and gets progressively lower (more aggressive) as you get closer to the heel of the saw. I never really saw the usefulness in this and it is more difficult to file this way because you are constantly changing the rake angle.

Instead, in my opinion, a better way is to file the first few inches at the toe of the saw with a higher rake angle (i.e. teeth leaning more toward the heel) to make starting the cut easier and then file the rest of the teeth with a consistent lower rake angle (standing more toward vertical) to make those teeth cut faster. I'm not sure what the term for this would be (multi-rake?). Filing this way would be easier to do because you would only be concerned with two rake angles rather than a constantly changing rake angle.

It also makes more sense to me from a use perspective. The more relaxed rake is really only needed to start the cut, so keeping it just at the first few inches of the saw makes sense. Once the cut is started, you no longer need those more relaxed teeth, so having the rest of the saw filed more aggressively will make for much faster cutting. This is really desired in a rip saw where you might be making 8' long rips. Personally, I want the fastest, most aggressive saw I can get for long rips (not sure it makes a huge difference in a crosscut saw).

With a saw that has progressive rake, you will be using less aggressive teeth more of the time because the closer you get to the toe, the less aggressive the teeth get. With a "multi-rake" filed saw, once the cut is started with the more relaxed front teeth, you can use the most agressive teeth on the remainder of the saw for the rest of the cut, maximizing the saws cutting speed.

Progressive pitch, as Jim mentions, is another way to solve this problem. With a progressive pitch saw, the first few inches of the saw have more, smaller teeth per inch, and the teeth get bigger and fewer per inch as you get closer to the heel of the saw. Again, this to me doesn't make a lot of sense from a use or ease in filing perspective. I think a better and easier way to file is the way Rob Cosman files his dovetail saws. A fixed (i.e. not progressively changing) but higher pitch (number of TPI) at the toe and a fixed but lower pitch for the rest of the saw. The result is similar to the "multi-rake" filed saw mentioned above.

Just my 2¢.

Sorry for the long winded reply :o:).

[Paul Saffold]

Thanks, Bob, for the very clear, simple but thorough, explanation.

Paul

[jim hedgpeth]

Thanks for the explanation Bob. I was aware of progressive pitch, just not progressive rake.

I see what you are saying about two distinct tooth patterns vs. progressive. What I had in mind is more like you are saying, I think. Start with 2" of easy start teeth on the toe, like you were saying, then over 6-8 tooth area change to a more aggressive tooth for the rest. Just "easing" the transition a bit, instead of all at once. I am not going to try anything like that till I get passably good at sharpening though.

I just wondered if it was a good/bad idea tried before. I have read/watched a lot about sharpening lately (including your videos Bob:D) and never saw any mention of rake alterations.

[Joel Moskowitz]

I think you are going to find that with a hand sharpened saw you can file far more aggressively but the saw still cuts sweet and easy. The minor variations in even excellent hand saw sharpening really makes a difference and really overshadow the need for progressive anything.

Japanese saws which do sometimes have progressive teeth use positive rake teeth which are incredible aggressive - (far more so than western teeth) so an argument for an easier starting section can be more easily justified.

[Dan Andrews]

I have sharpened three saws using instructions given on a vintage saw website. The first saw was only a little dull and sharpened up nicely. The second saw was very dull and needed jointing and then sharpening. That saw turned out well. The third saw was far out of joint and required jointing untill a few teeth were almost gone. That is when I ran into trouble. I filed so much that I almost filed away some teeth while leaving others large. By the time I filed enough to have all the teeth come to a point, I had some gullets much deeper than others. Now I have a mess. I think I will have to take it to a saw sharpener and have new teeth cut. I think from now on I will sharpen dull saws and have out of shape saws recut. Setting with a Morrill's #1B was difficult. Partly because I am not sure how to set it up properly, and partly because it is hard to see what I am doing while it is on the saw.

Any thoughts and suggestions on beginners saw sharpening would be appreciated. (I have seen recommendations for the Stanley #42X saw set but have had a problem parting with about $40. to buy one). I would like to learn to use the Morrills If I am able to.

[Wilbur Pan]

Instead, in my opinion, a better way is to file the first few inches at the toe of the saw with a higher rake angle (i.e. teeth leaning more toward the heel) to make starting the cut easier and then file the rest of the teeth with a consistent lower rake angle (standing more toward vertical) to make those teeth cut faster. I'm not sure what the term for this would be (multi-rake?).

Since there are two rake angles, maybe it should be called bi-rake? ;)

Of course, that sounds a bit like the saw is going to fall apart, so I would go with poly-rake. ;)

[jim hedgpeth]

I have heard the Stanley 42x is best as well. can anyone explain why, and which other models are close to as good??

Jim

[Robert Rozaieski]

I use an old Disston plier type set that I paid like $10 for and it seems to work just fine. I think like anything else with the Stanley name, the prices are driven up by the name. There are plenty of others that work as well. Joel sells new ones that are supposed to be good and I think they are like $25 or so for a set of two for different sized saws. I haven't used them but from what I've heard they do the job just fine.

Of course I'd love to learn to hammer set like the Grammercy saws are done, but that's a skill that I just don't have time to work on right now.

I do have to agree with Joel though that a hand filed saw feels different than one with perfect machine cut teeth. While I described two different ways that makers commonly ease the teeth at the toe of the saw in my post above, I don't personally do it to any of my saws. I think the minor inconsistencies that work their way into the teeth simply from the process of hand filing are enough to make them cut really sweet. I have no problems starting any of my saws and I file a pretty aggressive rake on my rip saws (about 3-4 degrees).

[Jim Koepke]

I have heard the Stanley 42x is best as well. can anyone explain why, and which other models are close to as good??

Jim


The Stanley 42x has a smaller plunger area contacting the teeth than many of the other saw sets.

If you keep searching on eBay, you may be able to snag one at a deal. One seller recently had one listed as a key cutter.

Just missed one once with a buy it know at less than $20.

Set up an automatic search and check your email regularly. You can even search all results from your email just to keep up on new listings. Cast a broad net and see what you get.

jim

[jim hedgpeth]

I don't know how to set a search like that, but I check on my breaks at work often enough I wont miss one when I have the money.

Sounds like I'll start watching for a 42x soon though.

Thanks guys,

Jim

[Phillip Pattee]

I think some of the confusion for those learning to sharpen saws (like me!) is in the terms used. Pitch is used these days to refer to the number of teeth per inch (http://www.toolsforworkingwood.com/Merchant/merchant.mvc?Screen=NEXT&StoreCode=toolstore&nextpage=/extra/blogpage.html&BlogID=86) and that is how it seems to me that Robert uses the term. This is consistent with the way Lie-Nielsen uses the term to describe their progressive pitch dovetail saw. Rob Cosman's saw has 22 tpi at the toe and 15 tpi over the remainder of the blade. He avoids using the term pitch, so I can't say how he would describe progressive pitch.

The older manuals: "Grimshaw on Saws," pg. 11; Holly, "Art of Saw Filing," pg. 18; Hodgson, "Handsaws, Their use Care and Abuse," pg 19, and Taintor, "Hints on the Care of Saws," pg. 5 all use the term pitch to refer to the angle made by the front of the cutting tooth with a line draw across the points of the teeth. Taintor specifically mentions this is synonomous with rake, sometimes also called hook. Hodgson specifically states that pitch does not refer to the interval between the teeth as in the threads of a screw, pg. 19.

I'm to the point where if someone refers to progressive pitch, I have no idea whether they are referring to varying the number of teeth per inch or varying the rake of the teeth unless I can actually see the saw.

Can someone explain how the term pitch changed? It seems pretty clear in the old manuals published prior to WWI.

[Robert Rozaieski]

I think some of the confusion for those learning to sharpen saws (like me!) is in the terms used. Pitch is used these days to refer to the number of teeth per inch (http://www.toolsforworkingwood.com/Merchant/merchant.mvc?Screen=NEXT&StoreCode=toolstore&nextpage=/extra/blogpage.html&BlogID=86) and that is how it seems to me that Robert uses the term. This is consistent with the way Lie-Nielsen uses the term to describe their progressive pitch dovetail saw. Rob Cosman's saw has 22 tpi at the toe and 15 tpi over the remainder of the blade. He avoids using the term pitch, so I can't say how he would describe progressive pitch.

The older manuals: "Grimshaw on Saws," pg. 11; Holly, "Art of Saw Filing," pg. 18; Hodgson, "Handsaws, Their use Care and Abuse," pg 19, and Taintor, "Hints on the Care of Saws," pg. 5 all use the term pitch to refer to the angle made by the front of the cutting tooth with a line draw across the points of the teeth. Taintor specifically mentions this is synonomous with rake, sometimes also called hook. Hodgson specifically states that pitch does not refer to the interval between the teeth as in the threads of a screw, pg. 19.

I'm to the point where if someone refers to progressive pitch, I have no idea whether they are referring to varying the number of teeth per inch or varying the rake of the teeth unless I can actually see the saw.

Can someone explain how the term pitch changed? It seems pretty clear in the old manuals published prior to WWI.

Not sure when the term pitch was coined to mean number of PPI but it's the way I've always understood it. Disstonian Institute refers to it this way as well as many other references I've seen. I have seen the Taintor reference as well though in which he says that pitch is synonymous with rake so honestly I can't say which is correct. Maybe all of the above?

On the other hand, re-reading my post, I realized I got the entire positive vs. negative thing backwards :o:o:o:o:o (this smily should be glowing red, not violet). Sorry about that! That is why I shouldn't be responding to these types of posts before I've had my coffee :rolleyes:.

Since I can't edit the original post any longer I'll attempt to clarify here. POSITIVE rake means the tooth is leaning toward the toe and is more aggressive. NEGATIVE rake means it is leaning toward the heel and is less aggressive. However, in the world of Western saws, we typically only refer to it as increasing or decreasing rake because a Western saw typically only has NEGATIVE rake. Japanese saws often have positive rake.

So to make a saw easier to start, we increase the NEGATIVE rake. To make it more aggressive, we decrease the NEGATIVE rake.

Now that I've completely clouded the entire discussion, I better go get another cup of coffee. :confused:

[Bob Smalser]

The Stanley 42x has a smaller plunger area contacting the teeth than many of the other saw sets.



Mythology.

I forget the maker....Climax?....but the modern cast-aluminum sawset sold by Highland and others comes in two different sizes..coarse and fine.

And it works as well as the fabled 42X. Here the "coarse" sawset is shown beside a 42X. Both work fine....if function is the goal, beating the bushes for a 42X is a waste of time and money. I actually prefer the aluminum one for my finer saws.

http://pic20.picturetrail.com/VOL12/1104763/9131162/278344687.jpg






...The third saw was far out of joint and required jointing untill a few teeth were almost gone. That is when I ran into trouble. I filed so much that I almost filed away some teeth while leaving others large. By the time I filed enough to have all the teeth come to a point, I had some gullets much deeper than others. Now I have a mess....



That's exactly why progressive pitch was used by sawmakers instead of progressive rake....because shallow-raked teeth wear faster than steep-raked teeth, and you have to reshape teeth in an earlier resharpening job than necessary.

Have that saw retoothed as shown below, and next time shape all the teeth to uniform size before trying to file rake and fleam angles, checking the joint as you go. You'll file in a rake angle during the process but don't fuss over getting it perfect. Concentrate on shaping teeth of uniform heights and gullet depth, then go back and finalize your angles.

http://pic20.picturetrail.com/VOL12/1104763/17430481/270960405.jpg

[Wilbur Pan]

Since I can't edit the original post any longer I'll attempt to clarify here. POSITIVE rake means the tooth is leaning toward the toe and is more aggressive. NEGATIVE rake means it is leaning toward the heel and is less aggressive. However, in the world of Western saws, we typically only refer to it as increasing or decreasing rake because a Western saw typically only has NEGATIVE rake. Japanese saws often have positive rake.

Maybe an easier way of defining rake is in relation to the direction that the saw is moving. Positive rake is the tooth leaning in the direction of the cut, negative rake is the tooth leaning away from the direction of the cut. This covers both Japanese and western saws, and you don't have to remember where the heel is as opposed to the toe, or which saw you pull and which one gets pushed.

[Jim Koepke]

I don't know how to set a search like that, but I check on my breaks at work often enough I wont miss one when I have the money.

Sounds like I'll start watching for a 42x soon though.

Thanks guys,

Jim

When you are signed in to ebay and do a search on something like > Stanley < you are given an option near the top of the listings to save the search. This will then send you an email once a day for as long as you choose to get the new listings that have the criteria you have put in the search.

A search on Stanley will get you about 15,000 items.

Figuring how to filter the search is the hard part. Too tight a filter and you will miss some. Too loose and you will be looking through a lot of stuff you do not want.

I have a regular search for > Stanley blade, iron, cutter <. All the time I get hits for Stanley cup Iron on patches. But, I do not miss many of the blades I am looking for.

jim