Saw sharpening troubleshoot

[milkman]

I sharpened and set my saw. Boy does it feel sharp! boy does it look well set!
Problem is it totally jams on the cutting stroke. Its not binding, its the teeth, they're digging in I think.
Wierdly it makes a fantastic rip saw but that's not what I wanted.

Has anyone any thoughts on this?

 

[Alf]

Sounds potentially like not enough rake - assuming that you're letting the saw do the work and not forcing it into the cut? That can be a stumbling block with a fresh sharpening job when you're used to trying to get a blunt saw to cut. Mike'll probably do a much better troubleshooting job on it than I though.

Cheers, Alf

 

[Colin C]

A pic would help to if you can post one

 

[MikeW]

Hi Milkman,

Don't think I'll do any better. And I don't mean to insult you by seeming too basic here.

And a good primer on sharpening is here.

My assumptions are the following:
This is a suppose to be a cross cut saw;
There is about 20 degrees of rake or more;
There is the bevel on the face of each tooth, called fleam.

As long as those assumptions are true, and you are sawing a relatively soft piece of wood, I suspect you may have filed the saw with too much fleam, fleam greater than 25 degrees or so. That's what I take digging in too much to mean.

But you mention it makes a great rip, so perhaps if the rake of the tooth leans back 15 to 25 degrees, then perhaps there is not fleam angle at all. I would describe this as a saw which cuts roughly on a cross cut--jumpy even. But that is the opposite of digging in.

The former paragraph describes a saw which when cross cutting softer wood will allow the teeth to sink in further than you may wish, the latter describes a saw which when cross cutting softer or harder wood will not allow the teeth to sink in enough.

BugBear has good gadgets and instructions and links to instructions on his web site you can make to help you keep the file in both proper aspects: rotated back for rake and angled for fleam. It's here.

Further info as to my assumptions could be helpful to be more specific from our end.

Take care, Mike

 

[bugbear]

Sounds potentially like not enough rake

I think you mean too much - although some people use "90" to mean a vertical tooth front, and some people say "0", which isn't helpful.

I think the teeth in the jamming saw have fronts that are too steep.

oh yeah - random tit-bit from the week end. My rake control indicator is accurate to around 2 degrees.

I made 3 reference blocks, at 25, 26, 27 degrees. Having set the rake things vertical on the 25 block, I couldn't (*really* ...) convince myself I could reliably see the "error" on the 26 block, but it was quite clearly "off vertical" when placed on the 27 block.

So I think I can control rake to around plus/minus 1 or 2 degrees, if I were as careful when sharpening a saw as a I was during this experiment.

(reference blocks were cut on a Nobex 202 mitre saw)

BugBear

 

[Alf]

Sounds potentially like not enough rake

I think you mean too much - although some people use "90" to mean a vertical tooth front, and some people say "0", which isn't helpful.

Well I meant not enough, but evidentally from a different starting point... :roll: Too sheer a cliff face on the front of the tooth is der bunny I was meaning.

Cheers, Alf

 

[milkman]

Thanks for the tips and thoughts.
I haven't the saw with me but I can tell you that it fleams like a mother! : )

Specifically the exaggerated diagram on vintage saws' site is not far off from what I see on anything I crosscut, very defined fleam marks along the sides of the cut

http://www.vintagesaws.com/library/prim ... utting.JPG

Will get back with any pertinent info

 

[milkman]

Rakes progress…

Well I finally got to refiling and you were dead on, too little rake, it was 12°. I've gone for 15° rake and 20° fleam and its not quite as enthusiastic but cuts smoothly and doesn't dig in.

Thanks for the pointers everybody, excellent.