Widening a sawmill

[Isaac Carlson]

I bought a small hudson mill a number of years ago. It woks well, but isn't big enough for some of the logs I get. I would like to split it and make it wider. I would like to know how how much hp is required for each inch/foot of cutting width. I did a few things on the motor and it has a few extra hp now and runs a bit faster. It doesn't seem to struggle at all with full capacity logs, it just keeps on singing.
i would like to cut 30'' or maybe a touch bigger. I have seen mills on youtube with small engines cutting larger logs and have also seen some silly offerings from manufacturers with 3x the industry hp. Does anyone have a 'rule of thumb' for hp/mill/band size?

[Martin Siebert]

I don't know of any "rule" regarding horsepower to size of logs, but I can tell you that I have a 36" Hudson and it has a 23 hp engine on it. It has plenty of power and I have no complaints, but it will bog down on a big full size log if I try to go too fast. The key is to listen to the sound of the engine and slow down some when it is starting to bog down. As long as you don't try to force it I don't think horse power is going to be a big issue, up to a point.
I would be more worried about the bearing sizes and how well they hold up after you add a much longer larger blade than any exact match of power to size. Again, less power or not quite enough power for the size log just means you are going to have to slow down so it's not bogging down. It seems like you are going to have to go with larger diameter wheels too in order to be able to get the full potential of the cut.
It seems like no matter how big a machine is you will always want/need one that is bigger. We've all been there. I am still there!!!

[Dennis Ford]

I don't think a "rule" applies to hp vs width of cut. I do think that a "rule" could apply if it considered band speed and width of cut. Each tooth needs to cut some amount of wood to avoid wearing out making powdered dust, making that happen through a wide cut takes quite a bit of force. Force x speed = power.
To Martin's point, wide cuts need high tension and work better with wide blades, both of which stress bearings, shafts and the frame. You may need to beef up the whole saw-head while you are making it wider.

[Isaac Carlson]

I try to keep the blade nice and tight, to where I can barely twist/deflect it at all by hand. ~2,000-3,000 lbs on the tensioner.

[Jim Andrew]

My Cooks MP32 will cut a 32" log if perfectly straight. That does not mean it will cut 32". I can take some off the top, then turn the log and take a little off the top, keep turning, and pretty soon just slice up the whole remainder. Like you, would like to have a bigger mill, now they are turning out these "wide" mills.