Fret saw binding

ljzimmer · #1 05-07-2009, 05:23 AM

I went to the shop last night and got slots for some lines for my fingerboard cut. About an 1/8" in the saw felt like it was binding really badly. To the point that I was moving the entire bench.

Is this normal?

The only item in question in my mind is this. I purchased a stew mac miter box. Upon arrival I quickly realized that my fingerboard wouldn't fit in it, so I did the only thing I could think of. I purchased a piece of aluminum to make a wider deck. I drilled and tapped holes in it and attached the side pieces. Here is a pic:

Could it be that my modded jig is causing me heart ache?

I loosened the jig a couple of times so that the saw was pretty free, and it still got bound up pretty good.

Thanks for any insight!

Loren

leswatts · #2 05-07-2009, 06:04 AM

Hi Loren

Hmm I can only offer a couple guesses.

Are you familiar with tooth set?

Binding in saws is often due to improper or uneven tooth set.
The new wider deck is making it such that the back of the blade (nearer the handle) is getting more use. If that part of the blade has a different set than the outer part it could cause the problem.

Did it bind with test pieces before you made the modification?

To check you could make your wooden angle part a bit wider so the fingerboard is centered in the box, and see what happens.

Les

roberthabraken · #3 05-07-2009, 06:27 AM

Yeah,.. I had it too. I made my own miter box to cut the first passes and then cut them again freehand (!) to the appropriate depth. But still, it felt like the saw got stuck after 1/8" or so.

And cutting freehand also made me cutting skewed / not perpendicular to the fb.. so it was a really difficult and unpleasant job to be honest..

My guess is that it's not your box or adjustments. But I'm very curious to hear the answer to make my next build somewhat more pleasant!

Son of Magni · #4 05-07-2009, 07:08 AM

That looks like the same saw that I used to use. It seemed like after two or three slots the saw heated up and started binding. I was using a different jig though. If you stop and wait 5 minutes can you cut a couple of slots again before you have the problem?

Mikey R · #5 05-07-2009, 07:50 AM

I had a similar problem, I assumed it was becuase my modified gents saw was getting blunt. And I didnt use a mitre box, I used a squared scrap of maple to guide one side of the saw.

Quote:

Originally Posted by Son of Magni

That looks like the same saw that I used to use. It seemed like after two or three slots the saw heated up and started binding. I was using a different jig though. If you stop and wait 5 minutes can you cut a couple of slots again before you have the problem?

Now you mention that, it kinda seems to make sense. I dont think saws are like planes and shouldnt really need sharpening every use.

scottyd · #6 05-07-2009, 08:06 AM

Run the saw through a candle to get a thin coating of wax on the blade, it will cut much easier and smoother, you may have to do this a couple of times. The wax acts as a lubricant.

roberthabraken · #7 05-07-2009, 08:13 AM

Quote:

Originally Posted by scottyd

Run the saw through a candle to get a thin coating of wax on the blade, it will cut much easier and smoother, you may have to do this a couple of times. The wax acts as a lubricant.

Wonderful idea! Thanks!

leswatts · #8 05-07-2009, 09:22 AM

Wow, this seems a common problem. The lube idea is a good one.

Makes me wonder how much tooth set the SM saw has. Anyone measure the blade thickness (away from the teeth) with a micrometer or caliper? Perhaps it has no set at all!

For a long time I have not used fret saws, but I used to. Now I use cnc. But this makes me wonder. The old little german fret saw I used had only 0.003" of set. Several of my back saws happen to be right at .023" blade thickness, but are set to .035 or so to not bind. I wonder if the SM is a standard back saw with pull cut teeth and no set. That would explain all that binding.

It also makes me think of a hollow ground blade in the tooth area to provide clearance (rather than set) just like the circular slitting saws I use.

Les

scottyd · #9 05-07-2009, 09:45 AM

Quote:

Originally Posted by leswatts

Wow, this seems a common problem. The lube idea is a good one.

Makes me wonder how much tooth set the SM saw has. Anyone measure the blade thickness (away from the teeth) with a micrometer or caliper? Perhaps it has no set at all!

For a long time I have not used fret saws, but I used to. Now I use cnc. But this makes me wonder. The old little german fret saw I used had only 0.003" of set. Several of my back saws happen to be right at .023" blade thickness, but are set to .035 or so to not bind. I wonder if the SM is a standard back saw with pull cut teeth and no set. That would explain all that binding.

It also makes me think of a hollow ground blade in the tooth area to provide clearance (rather than set) just like the circular slitting saws I use.

Les

Your probably on to something with the back saw thing. I've found that most of the tools sold at luthiers supplys are not special tools but mostly altered common tools with a special price.

Stealth · #10 05-07-2009, 09:46 AM

Quote:

Originally Posted by scottyd

Run the saw through a candle to get a thin coating of wax on the blade, it will cut much easier and smoother, you may have to do this a couple of times. The wax acts as a lubricant.

True, works for any saw. Alternately, a old soapbar works as well. And by that I don't mean the pickup.

Mikey R · #11 05-07-2009, 09:49 AM

Quote:

Originally Posted by scottyd

Your probably on to something with the back saw thing. I've found that most of the tools sold at luthiers supplys are not special tools but mostly altered common tools with a special price.

My luthiers supplier actually suggested I modify a small backsaw rather than buy one of theirs.

I like the idea of a taper-ground backsaw but I suspect it would be hard to find one this small and not in the rather-nice dovetail saw price range.

ljzimmer · #12 05-08-2009, 07:36 PM

Quote:

Originally Posted by Son of Magni

That looks like the same saw that I used to use. It seemed like after two or three slots the saw heated up and started binding. I was using a different jig though. If you stop and wait 5 minutes can you cut a couple of slots again before you have the problem?

My saw got hot too. But it would bind almost immediately. I think I will try some candle wax and report back. I don't think any of the slots are deep enough yet. Nor are they parallel to the bottom of the fingerboard.

Stone Age · #13 05-08-2009, 09:22 PM

I fixed this problem with the stewmac table saw blade and a radial arm saw.

meandi · #14 05-09-2009, 07:19 AM

Quote:

Originally Posted by Stone Age

I fixed this problem with the stewmac table saw blade and a radial arm saw.

I use the stewmac blade as well, but built a jig for my table saw.
It incorporates the stewmac fret slotting template that locates on a pin in the base of the jig.
I can slot an entire fingerboard now in less time that I use to spend cutting one slot by hand.

singdooba · #15 06-25-2009, 12:06 PM

I had the same problem,but there is a very easy trick...
My old grand ma, told me how to do..
Get an old kind of classic handsoap,nothing fancy,something cheap would work...
Keep it dry...and before you are going to make a cut in the fretboard,run the teeth through the soap, and it will make the woodcutting much easyer...
It will work...Thanks to Grand Ma...

Beauchene Implements · #16 06-25-2009, 12:36 PM

I have a small block of beeswax I use for this very issue. Just cut into the wax block a little, then get to work. Reapply when things get tight again.

ljzimmer · #17 06-26-2009, 09:51 AM

funny thing was that went and got a candle. When the guy saw what I was doing, he said,"oh, I've got some wax in the tool room for that very purpose" Doh! Oh well the candle worked like a charm and now my tool bag smells nice!

joeyl · #18 06-26-2009, 11:42 AM

you can also get a wax ring used for toilets, and keep it in the shop, it works great and is soft to rub stuff in, like screws

Dirk Diggler · #19 06-26-2009, 09:22 PM

On one of my first builds I was having a binding issue with a Ziricote fingerboard, the solution was to tighten the truss rod and it was smooth sailing, well smooth is still relative with Ziricote.

But I see you only have the fingerboard by it's self, you could put something in the middle and clamp both ends to get the same effect.
Oh yeah also never had any issues since I bought the Stew blade for my sliding miter saw.

Worth every penny especially on fans.
Good luck,
Dirk