I own a somewhat industrial Rosebery 2C hopper cooled rig with a steel frame saw. I have a selection of blades from 1m (3') through 3m (10') for different sized logs. It is great fun (but seriously hard and dangerous work) to run a sawing operation at a show.
In addition to the saw you will need
- a couple of logging wedges (a little like an axe head)
- a big hammer (A BFH if you like)
- an axe and/or log splitting axe
- a log :) - I like a nice meaty 2 - 3 ft diameter log
- saw blade lubricant (water works fine - but if you like a little flair for the dramatic, a friend of mine who shows saws and who likes to keep a little mystery in them makes bottles of what he calls "saw elixir" - this is actually water which has been standing with leaves in it for months and is quite black - it does not help the cutting any more than plain water but it looks good :)
- some metal pickets to hold the log (stops it from rolling away) - I use star posts - (metal fence posts with a star cross-section)
- dogs and chains for moving the log
- a cant hook for rolling the log around
- a crow (or breaker) bar
- an on-call tractor is useful if the log is really big
- an 2nd person
I always work in a team of two - you really need two people to help move everything around, there is a lot of equipment to look after and it can be hard to place the saw on a big log. The saw operator most devote 100% of their attention to the job at hand. When sawing you develop quite a crowd as it is rare to see a saw running at a show. The 2nd guy keeps the crowd happy by explaining the operation and how things are going so the first guy is not distracted by questions. I usually make a cut every 15 to 20 minutes so the log will last out the show.
Before I get into the procedure - this is dangerous - it can be done safely if you are careful and devote 100% of your attention to the job - these tips are not enough for a first timer to run a rig, try and find someone else who regularly cuts to help you the first few times
This magnificent saw belonged to a member of the Yarra Valley Machinery Preservation Society. This unit is considerably older than mine.
To make a cut I follow this procedure
- brace the log with pickets
- inspect the area to be cut to make sure there are no nails, or steel posts embedded in the log
- place the saw blade onto the log and run it back and forth to make sure it will extend through the whole log and not get stuck
- remove the bark around the area of the cut (this is not necessary to cut but does stop it being thrown into the crowd, into your face, or onto other exhibitors)
- inspect around the cutting area, remove any tools, chains, etc which might foul the saw
- inspect the saw for broken or bent teeth - broken wont matter much, but bent will - fix any before starting
- inspect the saw for straightness - if it is bent have a blacksmith straighten it
- inspect the teeth for sharpness - if they are blunt have them sharpened some time
- inspect the saw rig and engine (belts, pulleys etc) - grease where necessary, apply belt dressing where necessary - make sure the rig goes in and out of idle smoothly
- set the saw to idle
- use the hook and pin on the saw rig to firmly attach the rig to the log, hammer the hook in a little then use the lever to pull the rig down and hammer the pin into the log - if you have a locking ring use it - if you have brakes on the cart apply them (on mine you tighten the wheel-nuts until the wheels will not turn any more) - I've been warned not to chock the cart as if the saw gets stuck, the whole rig can be pushed backwards or pulled forwards until the engine stalls, if you chock it, it might turn over and snap the blade
- start the engine (let it warm up)
now the fun starts - be really careful here
- while holding the handle on the saw blade to hold it clear of the log, use your other hand to engage the belt onto the driving pulley just enough to get the saw moving slowly with the belt slipping
- guide the saw so on the first couple of strokes it brushes the wood and makes a cut line, after it starts to bite in let go and engage the drive fully (at all times through the cut stay close to the lever so you can pull it to idle quickly if you need to)
the cut begins
- once the saw has cut in down to half its depth poor in a little lubricant (water) - each time the saw progresses this much poor in more lubricant
- once the saw has cut down to 1.5 times its own depth, hammer in a wedge being careful not to drive it so far that it hits the blade (this will jam the saw and might break the blade or belt) - every time you lubricate or when the saw seems to be labouring give the wedge a whack with the hammer - as you get further in you may need a second wider wedge to replace the first one (I had a black smith make me one at a show which starts at a point like a chisel and ends up like the back of an axe head - it is perfect)
- repeat k & l as much as you need to - you cannot over lubricate
- when the saw just starts to brush the dirt put it back to idle immediately
- stop the engine
- there is a good chance the log is not cut through yet, especially if it is big and heavy and the dirt is soft
- drive your wedge in with the BFH until the remainder of the log splits off and falls over (watch your legs and feet)
- (optional) use your axe to split the round up and stack it for firewood away from your working area
- loosen the tension on your chain, remove the hook and pull the pin (dig it out if you need to)
- lift the saw away from the log (be careful it can be hot)
- pull the saw rig back from the log in preparation for the next cut
- have fun!
Above all else, remember this is really dangerous, my saw will cut through a 3' log in a few minutes, it will cut through your leg in about 10 seconds. At the first sign of trouble you must intervene and stop the saw if it is safe to do so. You will have about 1/10th of a second to make that call. If it is not safe, just stand clear and warn everyone else to do the same.
If the saw has jammed, pull the lever to idle and stop the engine before attempting to loosen the blade. My rig is very well designed in that you can put enough pressure on the idler pulley to run the belt, but not so much that the rig will move if the blade jams - the belt just slips (and smokes) - shut it down quick and there will be do damage.
If anyone has any comments on how I run my saw, I'd love to hear them and discuss any thoughts you have - I try to be as safe as possible and I try to force myself to follow my procedure. I also make sure that my 2nd has been instructed in handling the saw particularly shutting down both the saw and the engine just in case the saw gets me.
I do know that a commercial operator of this sort of saw would not go to the extent that I do, but I'm there to have fun, to instruct the crowd, and to come home with the same number of bodily attachments I went there with :)
At the 1999 Upper Yarra Draught Horse and Olde Time Festival was the first show that I had run my saw. Although I had cut some wood with it, I really had little idea how to go about it - I understood the mechanics well enough but it was not until I met up with Alan Shepherd a member of the Yarra Valley Machinery Preservation Society that I really gained an understanding on how to run the machine reasonably safely. I owe a great debt to Alan for steering me right. On the day of the show, a few moments into my first cut Alan asked me to stop so he could take a look at the belt as he thought it did not "sound right". Sure enough, the belt was too long and allowed the idle pulley to rub on the drive pulley during the forward stroke of the saw. I had heard the same noise but thought nothing of it. Just after this I managed to snap the belt, and again Alan came to the rescue. Teamed up with Graeme Reid another member of the club the belt was removed, trimmed, new combs selected, fitted, and finally joined using only the tools a bush wood cutter would have had with him (axe, knife, wedge and of course, fencing wire!). Please read more about fixing the belt..
Disclaimer: The tips contained in this document outlay how I run a saw rig. This is not necessarily the right or only way to run a rig. The document does not provide enough information to run a saw rig without further help or instruction from an experienced person.
Finally, if anyone has any books or documentation on any brand/type of saw rig that they would like to share with me, please e-mail me.
This is one of Allan's machines, a Ronaldson Tippet Drag Saw with wood frame driven by a Rosebery 2C 2hp vertical hopper cooled engine. This machine dates from the 30's I understand. It was seen in action in 1995 at the inaugural Science Works Power Of The Past in Spotswood (just outside Melbourne) Victoria. Sorry for the picture quality, but as you may have guessed the quality of digital cameras just was not the same back then :)