crashmans' O-Top 12 build is finally under way!!

[el_ingeniero]

I just replaced the saw blade with a 142 tooth, 7 1/4" blade with a 0.090 Kerf. What do you think Bill?
~Patrick~

Avanti? I have, used it once and got a Diablo. This is definitely a case of buy once, cry once.

[NCcrashman]

I will say this too though I have no clue how it could matter, but the saw manual say's to use a 7 1/4" blade and what I just took off was nooooo 7 1/4" blade. The one I just replaced it with is!!
~Patrick~

[NCcrashman]

I just replaced the saw blade with a 142 tooth, 7 1/4" blade with a 0.090 Kerf. What do you think Bill?
~Patrick~

Avanti? I have, used it once and got a Diablo. This is definitely a case of buy once, cry once.

No..not Avanti..it's a off name brand. I'll get the Diablo.

[NCcrashman]

EL, not at ALL questioning you or anything but just so I'll know, why does the blade matter so much??

[NCcrashman]

Funny enough, I cut the wood for the cut table perfect. It's as true and square as you could make it..lol. that's what's so frustrating.
~Patrick~

[Jon Barnhardt]

A good blade makes a big difference in chipping and straight cuts, but a 1/16th of an inch is usually not the end of the world, depending on which cut it is...

[NCcrashman]

A good blade makes a big difference in chipping and straight cuts, but a 1/16th of an inch is usually not the end of the world, depending on which cut it is...

Mostly a 1/8th and some have been even more. I also think cutting on the furthest part of the line I draw is important too. I've always wondered about what part of the line to cut on. I say the furthest edge since the pencil lead is so much larger. Newly cut as much as I can make it. I also bought a titanium, like a scratch awe that looks like a pen. Makes a much thinner line.

Thanx for all the help guy's.
~Patrick~

[Jon Barnhardt]

check out eurekazone.com

I have a tracksaw table from them (DIY table) and it takes the guesswork out of cutting straight, accurate cuts.

[Frederic Gelinas]

How can you be off by 1/8 with a cutting sled? Maybe you are doing something wrong. You clamp your guide on the piece you measured and want to keep. Your saw is supposed to slide on your guide, the blade cutting exactly on the edge. This method should be very accurate.

[Bill Fitzmaurice]

I just replaced the saw blade with a 142 tooth, 7 1/4" blade with a 0.090 Kerf. What do you think Bill?
~Patrick~

That would be a steel 'plywood blade', which I never use. Steel blades dull quickly, then they get hot and warp and you can't cut a straight line. You should have a carbide blade, 40 to 60 tooth. Freud Diablo is very nice.
http://www.mcfeelys.com/product/DIABLO- ... ish-Blades

[Rune Bivrin]

How can you be off by 1/8 with a cutting sled? Maybe you are doing something wrong. You clamp your guide on the piece you measured and want to keep. Your saw is supposed to slide on your guide, the blade cutting exactly on the edge. This method should be very accurate.

It's possible if the edge of the shoe isn't exactly parallel with the blade. I had that issue with a crappy B&D circular saw. Messed up every single cut by varying degrees depending mainly on the length of the cut.

[Bruce Weldy]

The balde to the edge of the saw shoe measure 1 3/8. I've measured it God only knows how many times so I know it's right.

This statement alone tells me that you didn't build a sled. With a sled, the size of the shoe isn't important. Also, you talk about using scribe lines vs. a pencil - that too tells me you don't have a sled. With a sled, you only need to measure and make a mark on each side of the panel, then lay the sled on those two marks.

In the amount of time that you try to line up and make 4 cuts with a guide board, you could build a sled that would be much more accurate and way faster.

[el_ingeniero]

EL, not at ALL questioning you or anything but just so I'll know, why does the blade matter so much??

I use a battery operated saw with a 7-1/4" blade (although I've let my folks know I really want a Festool track saw for Christmas;)). This means that the saw blade and technique have a huge impact on battery life and my productivity.

The Diablo finish blades have a few things going for them over standard type blades:

* thin kerf (the poart of the work piece that becomes sawdust)
* that red color is an anti friction coating
* the slots cut into the blade and the gaps in the edge without teeth reduce vibration
* the teeth have a better profile for cutting

All of that reduces the cutting resistance quite a lot.

Technically, I've found 2 things important:

1) Setting the depth so that the saw just barely pokes through the workpiece by a 1/16th inch or so. This makes it so 2 or 3 times more teeth are cutting through the wood at the same time, each tooth cutting a much smaller swath and overall the saw doesn't work as hard.

2) Making sure the workpiece is well supported so the blade doesn't pinch. That means there is something every 12 to 24 inches, and within 6 or 8 inches from the ends. The classic way to do this is to cut on a sacrificial surface (or just raise the piece off your work bench with scrap lumber). Sacrificial surfaces do make for nicer cuts on the bottom. Some people go so far as to build work benches with a sacrificial top or supports, and at least 2 companies sell such benches: EurekaZone (EZ-Smart table) and Festool (MFT/3). Radial arm saws are just giant circular saws on arms, and they have a sacrificial surface as part of the design.

[el_ingeniero]

The balde to the edge of the saw shoe measure 1 3/8. I've measured it God only knows how many times so I know it's right.

This statement alone tells me that you didn't build a sled. With a sled, the size of the shoe isn't important. Also, you talk about using scribe lines vs. a pencil - that too tells me you don't have a sled. With a sled, you only need to measure and make a mark on each side of the panel, then lay the sled on those two marks.

In the amount of time that you try to line up and make 4 cuts with a guide board, you could build a sled that would be much more accurate and way faster.

My Skill brand battery operated saw has its blade to the right of the handle with the cutting direction away from me. With the blade set at 0 degrees, the distance from the left edge of the shoe to the blade is exactly 5 inches, and that's the part that sits on top of the sled.

[AntonZ]

It's possible if the edge of the shoe isn't exactly parallel with the blade. I had that issue with a crappy B&D circular saw. Messed up every single cut by varying degrees depending mainly on the length of the cut.

+1
Yours must have been from the same batch as mine. It burned out before it saw any serious use. In hindsight I'm glad it did. Couldn't make a straight cut *with saw sled*. Bought a new saw (different brand), made a new sled. Nice straight cuts ever since.


I think it is likely that your circular saw is the source of the problems NCCrash, not the blade or the sled. Since you are low on cash, I'd look for a cheap or free way to find out about your saw. Can you borrow a circular saw from someone for one day? Make a sled and try a few cuts. You would know right away when that makes good cuts.