Track saw blade for cross cut

[Chris152]

Hi All

Would this be a decent/ cheap clean-cutting cross cut blade?

http://www.screwfix.com/p/triton-tct-pl ... -60t/7534r

It's for a Titan plunge saw, and is the same dimensions as the one that came in the box. But the screwfix website just describes it as being for plunge cutting - no mention of cross cutting, so wondering if it has the right configuration of teeth/ gullet or whatever it needs.

 

[Roughcut]

Looks ok but looking at the other Titan Blades which should be the same as on your saw they have a kerf of 1.7mm where as the Triton blade you linked to has a 2.2mm kerf.

 

[Chris152]

Thanks Roughcut, that's a real help. The blade that came with the saw says 165 x 2.2 mm (with 20mm bore). I don't want to go any thinner as I've already cut the chip breaking / guide strip on the track, so I guess the Triton will be the one to go for, and it's cheap (tho I wouldn't mind paying more if I could find one the right width and better!).

edit - This one's the same dimensions but less teeth - could I expect a cleaner cut?
http://www.screwfix.com/p/makita-tct-pl ... -48t/9914r

Cheers

 

[Roughcut]

Thanks Roughcut, that's a real help. The blade that came with the saw says 165 x 2.2 mm (with 20mm bore). I don't want to go any thinner as I've already cut the chip breaking / guide strip on the track, so I guess the Triton will be the one to go for, and it's cheap (tho I wouldn't mind paying more if I could find one the right width and better!).

edit - This one's the same dimensions but less teeth - could I expect a cleaner cut?
http://www.screwfix.com/p/makita-tct-pl ... -48t/9914r

Cheers

Sorry Chris I didn't mean to confuse you, but could only find dimensions for other Titan blades.
That sounds as if the Triton should be fine for your purpose and give a nice clean cut.

 

[Chris152]

It's only £15 so has to be worth a try - really appreciate your thoughts Roughcut.

Chris

 

[Eric The Viking]

Regarding the rubber anti-splinter strip, what matters is the kerf and thickness of the saw plate. The latter is rarely specified but crucial.

The arbour (whizzing-round bit driven by the motor) stays in the same place all the time WRT the rubber strip.
The blade's centreline is pushed outwards by 1/2 the thickness of the saw plate ("P").
The actual cutting edge (that might hit the strip) is pushed back towards the rubber by 1/2 the kerf ("K"), from the centreline.

So to work out exactly the position where the strip gets cut ("X") from the datum surface of the arbour, there's a simple equation:

X = (K-P) / 2 .

There are implications if your blade isn't exactly the same as the original one: on the higher quality saws there is a "virtual" pivot point, exactly on the bottom edge (arris) of the rubber strip. This is so that when you cut bevels, the rubber strip still aligns with the point where the cut enters the workpiece. It only works if the blade's dimensions are the same as the intended blade for the saw (the blade diameter doesn't matter but the saw plate and kerf thicknesses do). If your blade cuts further into the rubber than the original, it will undercut the rubber strip too (i.e. bevel it), AND the top edge of the bevel cut on the workpiece won't start on any marked line taken off the rubber strip - the workpiece under the track will be cut shorter/narrower than intended.

It's not by much, but it is enough to be very annoying. DAMHIKT.

E.

 

[Chris152]

Regarding the rubber anti-splinter strip, what matters is the kerf and thickness of the saw plate. The latter is rarely specified but crucial.

The arbour (whizzing-round bit driven by the motor) stays in the same place all the time WRT the rubber strip.
The blade's centreline is pushed outwards by 1/2 the thickness of the saw plate ("P").
The actual cutting edge (that might hit the strip) is pushed back towards the rubber by 1/2 the kerf ("K"), from the centreline.

So to work out exactly the position where the strip gets cut ("X") from the datum surface of the arbour, there's a simple equation:

X = (K-P) / 2 .

There are implications if your blade isn't exactly the same as the original one: on the higher quality saws there is a "virtual" pivot point, exactly on the bottom edge (arris) of the rubber strip. This is so that when you cut bevels, the rubber strip still aligns with the point where the cut enters the workpiece. It only works if the blade's dimensions are the same as the intended blade for the saw (the blade diameter doesn't matter but the saw plate and kerf thicknesses do). If your blade cuts further into the rubber than the original, it will undercut the rubber strip too (i.e. bevel it), AND the top edge of the bevel cut on the workpiece won't start on any marked line taken off the rubber strip - the workpiece under the track will be cut shorter/narrower than intended.

It's not by much, but it is enough to be very annoying. DAMHIKT.

E.

I had to put the computer down and think about that a while, but I *might* have a picture of it now. Maybe. Neither of the blades I linked to above nor the original have info on P! I'm not planning to do any bevel cuts so I'm safe to not know P?

 

[Eric The Viking]

I had to put the computer down and think about that a while, but I *might* have a picture of it now. Maybe. Neither of the blades I linked to above nor the original have info on P! I'm not planning to do any bevel cuts so I'm safe to not know P?

I try. It makes sense if you just draw it out on a bit of paper.

To answer your question, it's why "thin kerf" blades will often dig into the rubber strip more than the corrrect ones - they have really thin saw plates, and the teeth (making the kerf) overhang more. The overhang moves the "inside" edge of the kerf further over.

Because of this I've just had to buy 6m of rubber strip from Axminster. I managed to wreck the rubber strip on three rails (including my 3m one) by using a cheap "thin kerf" blade.

This won't matter to you if the "ZCI" aspect of the rubber strip and/or dead-on accurate alignment of rubber strip and edge of kerf aren't important. It will matter if you want to swap between two types of blade: almost certainly one will be right and the other not.

Regarding cutting bevels, it's not something you need very often, but for jobs like laying flooring or anything where the cut edge goes next to a wall or ceiling it is really useful. The bevel (undercut out of sight at the back) lets you drop the last piece in easily, or adjust with a sander or rasp or whatever if necessary.

 

[Chris152]

I now know what ZCI stands for, thanks to google! ha. And I think I'll be doing some drawing this evening. The saw came with 2 x 70cm sections of track that you join, which isn't ideal for what I need - 70's a bit short and 140's a bit long and potentially less stable/ smooth, so I wouldn't mind too much to get a better length track and recut once I've found the right blade for cross cutting. And I do have a potential use for bevel cuts in future, I've been wondering about working with ply to create a Z-shaped table stand/ legs, but that's another story.
Thanks!

 

[Steve Maskery]

If you change the blade, you can get a bit more life out of the rubber ZCI strip. Just peel it off (try a hairdryer if it fights backs), spray on some heavy-duty adhesive and stick it back a bit further over. Then run your saw down the track and Robert is your relative.

 

[Chris152]

If you change the blade, you can get a bit more life out of the rubber ZCI strip. Just peel it off (try a hairdryer if it fights backs), spray on some heavy-duty adhesive and stick it back a bit further over. Then run your saw down the track and Robert is your relative.

I'm collecting the new blade tomorrow - fingers crossed there'll be no need to get my daughter's hairdryer on the job. But that'll be one to try if the ZCI is in any way compromised - thanks Steve.

Now, have I got the root of the problem clear in this drawing?

 

[Steve Maskery]

Yes.

 

[Nelsun]

I cheaped out on some Trend crosscut blades for the tracksaw and nibbled off a whopping .2mm of my zero clearance strips. The OCD couldn't take it so I bit the bullet and bought the correct blade to match the plate thickness and kerf of my rip blade and redid all my strips. They came off easy enough (taking care not to lay them sticky side down) and after a quick cleaning and drying of the track, they went back on easy enough and haven't budged since. So you may get lucky depending on the stickiness of the strips... at least moving them the first time.

 

[Jseymour]

it's why "thin kerf" blades will often dig into the rubber strip more than the corrrect ones

Damn! I wondered why that happened. Was wondering about blade deflection of the thin kerf blades? It's very handy to be able to trim accurately tiny slices. Don't want a jigsaw blade effect.
The thin kerf blades have more teeth combos. I don't want to be cutting 50mm in air dried oak with a 40+ t blade....smoke everywhere

 

[Eric The Viking]

I know this is contentious, but I don't think a tracksaw (or a tablesaw, for that matter) is a good choice for ripping any timber that might have tension stored in it - a bandsaw would be far better.

As I think I said here, I have had nasty experiences, including a cut closing up behind the blade (in 100 year old deal skirting!).

 

[AJB Temple]

I know this is contentious, but I don't think a tracksaw (or a tablesaw, for that matter) is a good choice for ripping any timber that might have tension stored in it - a bandsaw would be far better.

As I think I said here, I have had nasty experiences, including a cut closing up behind the blade (in 100 year old deal skirting!).

Why is it an issue in a table saw? The riving knife helps and if concerned a wedge can be put in the cut well clear of the blade. I track saw moves through the wood so does leave a cut gap behind it. Again it could be wedged I suppose. I din't use my track saw for ripping solid timber - just sheet goods so no issue. Mine is Mafell and does not have a riving knife.