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General Forestry => Alternative methods and solutions => Topic started by: Francis Nabrink on January 23, 2019, 04:56:35 PM

Title: Multiple saw system for cross cutting
Post by: Francis Nabrink on January 23, 2019, 04:56:35 PM
I need to cut Eucalyptos logs into smaller logs. The log usualy have 15 inches of diameter and I wold need to cut them to a lenght of 8 inches.
I was plannig on building a multiple saw system, either with circular saws os chainsaws. Maybe 5 or more saws in a row.
Has anyone here ever done it? Is it possible?
What about the HP needed? How can I do the math?
Title: Re: Multiple saw system for cross cutting
Post by: Corley5 on January 23, 2019, 07:51:48 PM
I think you'd have a problem with the blocks wedging between the saws if all the saws come down together.
Title: Re: Multiple saw system for cross cutting
Post by: Southside on January 23, 2019, 09:18:47 PM
Just another thought, run the saws up from under the chain drive on a single shaft system, basically a giant gang rip.  Connect each saw with short shafts and a love joy type coupling so you can remove a saw if necessary without disassembling the entire system.  Would also allow you to run pillow block bearings on short shafts for ease of replacement when necessary.  This eliminates any need for the saws to retract or hang up on a knot or other log irregularity.  Simple, less moving parts, can be run on electric or a single diesel power unit as a PTO shaft assembly.  
Title: Re: Multiple saw system for cross cutting
Post by: Corley5 on January 23, 2019, 11:35:26 PM
  If the logs aren't perfectly straight and the saws are coming down or up for the cut in a gang the saws before the belly and after the belly will cut all the way through and the ones others won't.  You'll have blocks that aren't cut all the way and others that aren't cut square that will be more likely to wedge between the saws causing all kinds of issues.  Heating saws and flying blocks of wood are a couple possibilities  If multiple saws work independently of each other that's not an issue.  A circle saw firewood processor would make a lot of blocks in a days time.
Title: Re: Multiple saw system for cross cutting
Post by: Francis Nabrink on January 24, 2019, 07:51:46 AM
Quote from: Southside logger on January 23, 2019, 09:18:47 PM
Just another thought, run the saws up from under the chain drive on a single shaft system, basically a giant gang rip.  Connect each saw with short shafts and a love joy type coupling so you can remove a saw if necessary without disassembling the entire system.  Would also allow you to run pillow block bearings on short shafts for ease of replacement when necessary.  This eliminates any need for the saws to retract or hang up on a knot or other log irregularity.  Simple, less moving parts, can be run on electric or a single diesel power unit as a PTO shaft assembly.  
Awesome ideia! It would make the system a lot easier to build.
Do you have any ideia on how can I calculate the power needed for the diesel motor?
Title: Re: Multiple saw system for cross cutting
Post by: Francis Nabrink on January 24, 2019, 07:52:43 AM
Quote from: Corley5 on January 23, 2019, 11:35:26 PM
 If the logs aren't perfectly straight and the saws are coming down or up for the cut in a gang the saws before the belly and after the belly will cut all the way through and the ones others won't.  You'll have blocks that aren't cut all the way and others that aren't cut square that will be more likely to wedge between the saws causing all kinds of issues.  Heating saws and flying blocks of wood are a couple possibilities  If multiple saws work independently of each other that's not an issue.  A circle saw firewood processor would make a lot of blocks in a days time.
Yes, thats a real problem! Eucalyptos is a prety straight tree, but it might just happen! Thankyou for the tip! 
Title: Re: Multiple saw system for cross cutting
Post by: thecfarm on January 24, 2019, 09:03:59 AM
I'm just wodering what the 8 inch pieces will be used for?  :)
Title: Re: Multiple saw system for cross cutting
Post by: Corley5 on January 24, 2019, 09:51:06 AM
  A clamping/dogging system for a round wood gang saw crosscut system would be an issue.  How are the blocks in the middle going to be held?  Especially when the saws retract.  Fairly sizable saws will be required too.  You want to cut 15" diameter wood plus 3" for a 6" saw collar and you're into 36" diameter saws at a minimum.  Forty inch would be better.
  What you want to do is cut short firewood.  There's a reason no one manufactures a gang saw firewood machine for round logs ;) :)
  Here's a link to a little slab gang saw.  Notice how the sticks are placed flat side down and square edge to the feed.  The fact that the works are all in a cage...   
Title: Re: Multiple saw system for cross cutting
Post by: Southside on January 24, 2019, 10:30:47 AM
I am trying to think this through given that input, not sure why other than the challenge of it.  If the pull chain has two dogs on it per block - one on either side of each saw - that would keep the blocks going through the saw and if you had a down pressure finger system like that used in a square hay baler intake to keep the hay flat you could keep the blocks in constant contact with the pusher chain while allowing for differences in the diameter if each finger is independently sprung or air bagged.  I would not retract the saws, leave them in place, if binding is a fear have two or three gangs running parallel to each other so that you are cutting one in three final pieces with each gang.  
Title: Re: Multiple saw system for cross cutting
Post by: Francis Nabrink on January 24, 2019, 03:30:28 PM
Quote from: thecfarm on January 24, 2019, 09:03:59 AM
I'm just wodering what the 8 inch pieces will be used for?  :)
I working for a company that is building a experimental charcoal plant for steel production.
8 inch pieces will theoretically produce better quality charcoal. 
Title: Re: Multiple saw system for cross cutting
Post by: Hilltop366 on January 24, 2019, 04:05:36 PM
Binding is going to be an issue with multiple saws cutting at the same time as well as requiring lots of power and steel to do it so how about multiple logs and one saw?

Thinking a vertical band saw on a short track may work better, several logs lined up on a tray with flat belt conveyer feed and log stop and hold downs then run the saw down the track to make the cuts and repeat.
Title: Re: Multiple saw system for cross cutting
Post by: moodnacreek on January 24, 2019, 07:42:37 PM
Agreeing with Corley #5; a firewood style cut off rig , what I call a trough and saw. We have one here, chainsaw style and also an old cornell slab wood saw. I often thought about a double end trimmer, old manual, big buzz saws for cutting pedestals from cedar butts for display stands.
Title: Re: Multiple saw system for cross cutting
Post by: Gearbox on January 24, 2019, 08:18:33 PM
Near us they tried to make chopsticks . Had a single arbor saw rotating the wrong way put a log through the roof . Turned the saws around and kicked out the breaker . ended up with 4 or 5 shafts with 1 or 2 saws each . I would cut in half first then half that now you will have straightened out any crooks .
Title: Re: Multiple saw system for cross cutting
Post by: thecfarm on January 24, 2019, 10:03:20 PM
I suppose a shear,shears, would not work?
Title: Re: Multiple saw system for cross cutting
Post by: Wudman on January 25, 2019, 10:00:05 AM
Don't know the scale of the project, but what about something like a Curry Saw that was used at the pulpmills years ago.  It was a massive chainsaw style bow saw that would buck tree length material to length while still on the truck.  Have a cradle for the wood and the saw mounted on a gantry that moved. 

Second thought not to reinvent the wheel is a conventional sawbuck as used in the southern US today.  A good loader operator could buck a lot of wood in a day.

Finally, a circular saw firewood processor.

Wudman
Title: Re: Multiple saw system for cross cutting
Post by: Haleiwa on February 03, 2019, 06:38:48 PM
Don't reinvent the wheel.  A CTL head on an excavator or a firewood processor with the wedge removed will do what you want.