Thread: Best tool for breaking down slabs?

55mm is the limit on a lot of track/plunge saws however I know Hare and Forbes have a model that will cut to a max depth of 75mm. Could be worth a look.

W884 | PL-75 Circular Plunge & Mitre Cut Saw - Package | For Sale Sydney Brisbane Melbourne Perth | Buy Workshop Equipment & Machinery online at machineryhouse.com.au

Originally Posted by bueller

55mm is the limit on a lot of track/plunge saws however I know Hare and Forbes have a model that will cut to a max depth of 75mm. Could be worth a look.

W884 | PL-75 Circular Plunge & Mitre Cut Saw - Package | For Sale Sydney Brisbane Melbourne Perth | Buy Workshop Equipment & Machinery online at machineryhouse.com.au

I'm a bit wary of scheppach - had one of their tormek knock-offs, and did not enjoy it! But maybe I was unlucky.

The problem with the Sheppach is that its only 1600 W which is fine in softwoods but will struggle in hardwood. It's also only a 70.5mm deep cut with with the track.

If it's just for breaking up a slab the accuracy provided by a track saw is probably overkill and regular circular and length of RH Al is all that is needed.
Several manufacturers make larger hand held circulars but unfortunately they don't stack up power wise.
Makita make a 270 mm circular with a genuine 100 mm deep cut but it's only 1700W.

what about a second hand Makita 5009B. Ive had one for years - built like brick outhouse.

The ultimate tool has to be a Protool sword saw with it's 200mm depth of cut !-- but I'm not sure if they are still available in AUS.


BUT I can't stress enough the importance of replacing the standard circular saw blade -- which is primarily intended for cross cutting -- with a dedicated ripping blade.
For example, the standard blade supplied with a Festool TS 55 has 48 teeth. the dedicated ripping blade has 12

Originally Posted by ian

The ultimate tool has to be a Protool sword saw with it's 200mm depth of cut !

The OP only needs 60mm deep.

Yeah, that protool looks great, but probably overkill for my needs.

According to a couple of websites the Sword saw is no longer available Oz.
I was quite interested in the Sword when it first came out as I had some ideas of cobbling together a similar gizmo using a conventional petrol chainsaw.

From looking at videos of the Sword in softwoods it seemed a bit on the slow side which meant it would be even slower on Aussie hardwoods.
This made sense given the power output of the motor is only 2HP , which is the same problem as the under powered circulars

Although the Sword is a slightly more precise product with built in tracking and reduced chance of kickback, the ~$1000 price tag made it quite an expensive tool.
An 1800W Makita Chainsaw and a Granberg mini mill would be <1/3 of that price and achieve most of the same outcomes.
If you are prepared to work outside and noise is not an issue, for $1000 you could get a Granberg mini mill and a 46cc 3HP Stihl 251, and then have a really useful chainsaw to play.

Originally Posted by safari

what about a second hand Makita 5009B. Ive had one for years - built like brick outhouse.

That's what I have - great saw but ~5m of ripping over a few minutes, in ~ 50 mm thick hardwood, and it really needs to cool down.
In fact I always let it cool down after about 2m of ripping.
I use a 24T ripping blade but should probably look for an 18T.

I have an old Festo AXP85, 1600W and 85 mm depth of cut. I use it exclusively for ripping and since it can run on a rail with a cut from both sides you can do 170 mm slabs.

These are an old model but they come up on the internet. I picked mine up for $100 mounted in a Festo CMS table.

Originally Posted by Chris Parks

The OP only needs 60mm deep.

he can get that easily with a standard circular saw and a proper ripping blade

My 5009B is mounted upside down as a table saw. With a 12 tooth blade I rip 2.4 and 3 m lengths of 45mm Merbau. I just take it easy and listen to the saw.

The following shows the effect of "cutting depth" compared to the "length of cut contact" being made by a circular saw blade while cutting wood.

I will use the Makita 5009B as the exemplar.

The blade has a nominal diameter of 235 mm or a radius of 117 mm
The maximum depth of cut is 85mm which means at full depth the ongoing "length of cut contact " being made by the circular is the blue line = 151mm

Making a 45 mm deep cut with the blade full extended means the "length of cut contact " being made by the circular is the red line and this is = 55 mm

So even though the 45 mm deep cut is 53% of the max depth of cut the "length of cut contact" made by the 45mm deep cut is only about 36% that of the full depth cut.
In other words the deeper the cut the even greater the "length of cut contact "
This why 45 mm might seem OK, but a 60 mm deep cut seems disproportionately less easy and 85mm might even be a "no-go" zone ripping in some woods.

Screen Shot 2017-04-11 at 10.23.53 PM.png

Now comes some fine detail.
Are we cross cutting or ripping - I will restrict the discussion to ripping since this is largely what this thread is about.
Much of the work load comes from cutting through wood fibres and this is not affected by the "length of cut contact" since every mm of depth has the same number of fibres.
So an 80 mm depth of cut will indeed have double the numbers of fibres to cut than a 40 mm deep cut and so should represent double the load.
OTOH there is some cutting with the grain which adds a small load, and general friction and saw dust clearance do depend directly on "length of cut contact" so all this adds to the load in proportion to the "length of cut contact".

The sawdust clearance can be significantly improved by fewer teeth with bigger gullets but over all the loads are disproportionately higher for greater depths of cut.

A chain saw offers you all sorts of versatility. A track saw does a rotten job of pruning trees.
BobL's monorail mill in #6 will save you many hours of grief.
I rarely need to cut big wood, maybe to reduce log pieces for large wood carvings.
Might just make that. One of those "just in case" jigs.