Thread: Saw Blade Adapter

I've never seen one and why would you want to do that? - the motor will seriously get in the way of the blade and reduce the cutting depth.

Yep it would reduce cutting depth, so you'd need to go a bigger blade.
I thought the higher end saws had the blade mounted directly on to the motor?

Originally Posted by Fonix

Yep it would reduce cutting depth, so you'd need to go a bigger blade.
I thought the higher end saws had the blade mounted directly on to the motor?

Sure but they're talking about a 7-70Hp+ 3Phase jobbie.
What size blade are you looking at?
You can't just put a 14 or 16" blade on a 3HP motor - well you can but it won't have enough torque to cut.

Originally Posted by Fonix

Yep it would reduce cutting depth, so you'd need to go a bigger blade.

So you'd need to waste significantly more money on a large blade that you can't take advantage of.

Originally Posted by Fonix

I thought the higher end saws had the blade mounted directly on to the motor?

See above for why they're not.

Sounds almost like a radial arm saw, the inner blade flange fits onto a keyed motor shaft. But they at least have a flat bottomed motor for clearance.

So is there a chart that suggests blade size for each engine.
My brother wants to build a basic saw bench, he has some idea of cutting small sleepers in to bricks - and yeah there's ten tools that'd do the job better and as a tradie he probably has all of them, but he wants to go in this direction.

Originally Posted by Fonix

So is there a chart that suggests blade size for each engine.
My brother wants to build a basic saw bench, he has some idea of cutting small sleepers in to bricks - and yeah there's ten tools that'd do the job better and as a tradie he probably has all of them, but he wants to go in this direction.

What's a small sleeper?

Standard real sleepers come in 200, 250 and 300 x 125 , 150 mm
There's lots of other things that hardware stores call sleepers but they are just thick boards.

What sort of timber? A rough guide for Aussie hardwood if you don'y want to be standing there all day is about 1HP per inch of depth of cut.
So blade has to have a radius of 5" Plus has half the diameter of the motor. If will be a big motor so maybe 8" across, 4" diameter so 9" radius blade so 18" blade and you'll need about 9HP motor. Thats a 3Phase motor on a 32A line. Cost wise it adds up fairly quickly

What abut a small chainsaw?

Originally Posted by BobL

A rough guide for Aussie hardwood if you don'y want to be standing there all day is about 1HP per inch of depth of cut.
So blade has to have a radius of 5" Plus has half the diameter of the motor. If will be a big motor so maybe 8" across, 4" diameter so 9" radius blade so 18" blade and you'll need about 9HP motor.

You’d be able to get away with a 5 HP motor, because four inches of blade is to get past the motor, and you’re cutting the other five.

Originally Posted by Colin62

You’d be able to get away with a 5 HP motor, because four inches of blade is to get past the motor, and you’re cutting the other five.

It's not cutting just 5", its cutting a up to 10" long curve that still has to be cut by the outer edge of the 18" blade.

Taken to an extreme. A 30" blade on a 5HP motor will be slowed down a lot easier than a 18" blade because the constant torque of the motor delivers less force over the longer radius.

The docking saws I have seen at saw mills to dock sleepers have typically been about 10HP. Less can be used but it will take a lot longer.

In other words, the rule of 1HP per inch of depth of cut isn’t quite correct then?

Originally Posted by Colin62

In other words, the rule of 1HP per inch of depth of cut isn’t quite correct then?

Yeah I guess so - its a very rough rule. Some people are patient enough to nibble slowly away at a large piece of wood with a small motor on a large blade so can get any away with a lot less.

Originally Posted by BobL

It's not cutting just 5", its cutting a up to 10" long curve that still has to be cut by the outer edge of the 18" blade.

Taken to an extreme. A 30" blade on a 5HP motor will be slowed down a lot easier than a 18" blade because the constant torque of the motor delivers less force over the longer radius.

The docking saws I have seen at saw mills to dock sleepers have typically been about 10HP. Less can be used but it will take a lot longer.

I bet they only had about 12-14 teeth on those blades too. Like a swing blade mill, fewer teeth in the kerf helps. Once you're getting up to those diameters, the kerf width is about 5.5mm which is close to a thin kerf chainsaw.

Originally Posted by richmond68

I bet they only had about 12-14 teeth on those blades too. Like a swing blade mill, fewer teeth in the kerf helps. Once you're getting up to those diameters, the kerf width is about 5.5mm which is close to a thin kerf chainsaw.

Some did but most didn't.
The following were taken at a mill in British Columbia.
This is a small diameter log docking saw, it has an ~12" depth of cut and uses a 17HP motor.

CirS.jpg

The logs being processed were no larger than about 10" in diameter usually from land clearing

The logs were debarked, planed square and cut into up to 4, 4x4" cross section pieces of wood were extracted from them. in a one pass operation.

Debarker.
debarker.jpg

Two 30HP powered double sided planers, one did the top and bottom, and the one below did the sides
motors.jpg

Then a pair of bandsaws ripped teh logs to size.

Nearly all this timber was shipped to china.

Originally Posted by Fonix

So is there a chart that suggests blade size for each engine.
My brother wants to build a basic saw bench, he has some idea of cutting small sleepers in to bricks - and yeah there's ten tools that'd do the job better and as a tradie he probably has all of them, but he wants to go in this direction.

sounds like your brother wants one of these

Mafell MKS 185Ec Circular Saw -- 185 mm depth of cut at 90 degrees.

or a Makita 5402 16-5/16" circular saw.


in terms of a chart depth of cut vs size of saw, have a look at page 20 of this catalog https://www.timberwolftools.com/docu...y-Machines.pdf