What's an acceptable blade speed for a bandsaw mill?

[redprospector]

I know Suffolk's says 5800 SFPM, and Cooks says 5500 SFPM, but what do you say?

The reason I ask is I am thinking of converting my mill to hydraulic drive for the blade. I'm looking at different hydraulic motors and to get the speed the torque drops off real fast.
Maybe a better question would have been; How much torque is required to run a bandsaw mill and get good production?
My wheels measure 20" so 5.236 feet per revolution. I found a motor that will turn 962 rpm. and produce 78.5 ft. lb. of torque. That would be 5037 SFPM, which is 463 SFPM less than what Cooks recommends.

Tell me what you guys think about this set up.

[york]

Red,what Band do you intend to use?You should get to there tech. support and ask.....

[drobertson]

use it, or find a different source, design is best left to those with resources that can figure with available information that will produce the required results. Thinking and advice come cheap, experience and knowledge come with a price. There may be an easy answer, but research and trials is about the only way to hit it the first time, and then there will still be more trials. jmo

[bandmiller2]

Red, look up the torque of commonly used engines on your size mill that should give you an idea. Don't be afrade of band speed a little lower than advertised in other words better a little slower than faster. Its important to match pump to motor. We had an old aerial ladder truck that used what was called a hydraulic PTO it used a Hydreco gear pump, transmission driven, and the same gear pump as a motor under the turntable. Some gear pumps can be used for motors it depends on the seal design.  Wobble and gearotor type motors tend to be slow speed high torque. It is doable with the right combo. As an added benefit you can have a pressure gauge in the circuit and tell when your band starts to dull. Frank C.

[Mill_Control]

Your hydraulic motor comes out at just north of 14 HP using this formula. HP = Torque * RPM / 5252. And it'll only make that if you've got a power unit up to the task.

Also I'm curious why you're wanting to convert to hydraulic direct drive? Is it better than conventional drives or just a more convenient power source for you?

[redprospector]

Red,what Band do you intend to use?You should get to there tech. support and ask.....

I've been using Cooks Supersharp blades. I'll probably call them and see what they say before I spend a lot of money.

use it, or find a different source, design is best left to those with resources that can figure with available information that will produce the required results. Thinking and advice come cheap, experience and knowledge come with a price. There may be an easy answer, but research and trials is about the only way to hit it the first time, and then there will still be more trials. jmo

Truer words have seldom been spoken.
I built this mill from scratch, and every time I turn around I seem to be paying the price for knowledge acquired.

Red, look up the torque of commonly used engines on your size mill that should give you an idea. Don't be afrade of band speed a little lower than advertised in other words better a little slower than faster. Its important to match pump to motor. We had an old aerial ladder truck that used what was called a hydraulic PTO it used a Hydreco gear pump, transmission driven, and the same gear pump as a motor under the turntable. Some gear pumps can be used for motors it depends on the seal design.  Wobble and gearotor type motors tend to be slow speed high torque. It is doable with the right combo. As an added benefit you can have a pressure gauge in the circuit and tell when your band starts to dull. Frank C.

My mill is uncommon.  :D I used a 1600cc VW engine to power it with. I haven't been able to find a torque chart for it so I'm not sure about that end, but I think the dual port engine is just over 50 hp. From what I think I know, it won't matter too much being under speed a few hundred SFPM, if you have the torque to hold it there. I do know that I can slow the VW down some if I try real hard.

Your hydraulic motor comes out at just north of 14 HP using this formula. HP = Torque * RPM / 5252. And it'll only make that if you've got a power unit up to the task.

Also I'm curious why you're wanting to convert to hydraulic direct drive? Is it better than conventional drives or just a more convenient power source for you?

That's kind of what I was looking for, but HP is kind of subjective. What I'm talking about is the difference between the HP of a gas engine, a diesel engine, an electric motor, and a hydraulic motor. From what I think I understand to match a 14 horse electric motor you would need in the neighborhood of a 28 HP gas engine. Not exactly sure where hydraulic motors fall into that line of thinking though. The power unit I'm wanting to use is a 50 HP Mitsubishi diesel that has 2 hydrostatic pumps on it. It's from a Toro Reelmaster 450D fairway mower that I picked up. According to the book I got with the mower, I'll have to tear it down a ways to get to the pumps to get the numbers, but it's pulling 5 reels off of one pump which is going to take some decent flow.
As for why? Because it's there.  :D No, really, I'm going to set my mill up stationary rather than on an axle. I'd like to have it in a shed, and I figured that if the pumps and engine are hoss enough, I could put the engine outside the saw shed to reduce noise, and heat, and such, and then the second pump could power the hydraulics on the bed, a live deck, and maybe a conveyor or such. If this engine's not big enough for the task, I've got a l05 horse power Perkapillar that I may get a pump big enough to do the task.

I know there are, or were some mills out there that used a hydraulic drive. Logmaster LM-6 maybe? I'll just keep researching, it's a lot cheaper than buying parts.  :D I'll tear into the mower as soon as my Elk hunt is over. Which could be anywhere from tomorrow to the 10th, depending on luck.