Rocking cradle V's Moving blade sawbench?

[Peasgood]

Nearly all sawbenches are rocking cradle, what's wrong with moving blade instead?

I see a few processors with moving blade, is that just because the cradle can't really move due to the splitter ram setup?

 

Reason I am asking is because I want to build my own sawbench and the design in my head is moving blade.

[log on tommy]

moving blade must be more complex as the drive for the blade must either be a hydraulic motor at the pivot point or a belt drive which is able to pivot with the saw and maintain correct tension throughout the arc. both are achievable as various youtube videos will testify but there's a reason that most manufacturers go for a fixed blade and that's because its simple.

[Logan]

Safety when it comes to tossing the last piece of log past the blade, if you're hand feeding? If you're pulling blade by hand this last toss of log might mean you cross arms?

[Peasgood]

Safety when it comes to tossing the last piece of log past the blade, if you're hand feeding? If you're pulling blade by hand this last toss of log might mean you cross arms?

 

I think the potential for that mishap is there on either version.

My idea is to have the pull down handle used right handed and "flow" of logs to the right. Blade would be to the right of the handle. I think that way you are more likely to put the blade up (spring operated) before using right hand to throw the last log.

I get your point though and it is that very action that introduces danger into either mechanism.

 

I think I have sussed the pivot point issue too, mount the gearbox in such a way that the pulley is inline with the pivot point. Tensioner and tension release (safety cutout) mounted on the swinging arm with a belt driven blade.

 

Main reason for doing it is so I can hopefully do some of the larger diameter logs. Cut through to depth of blade then turn the log with a peavey/cant stick to then finish the cut.

A fixed table with no movement is the only safe way to do that I think.

 

I can cut 13" diameter with one cut on my old Fergie bench. At that diameter the logs are getting a bit too heavy to lift and I don't feel in full control, especially with the wobbly table on there. If I could safely turn them over after cutting most of the way through I reckon 15-16" diameter is a big advantage to me. That would cover nearly all the wood I deal with.

I am only a domestic user at the mo but do have thoughts on going commercial. All part of a big plan I have.

 

Thanks for the replies

[Logan]

Either way the log needs holding. With fixed blade you get to use both hands to hold the log, bracing the whole cradle and log against the top of your thigh etc. Once cradle pulled clear of blade the last piece gets dumped off the cradle. With one hand pulling a moving blade, it will be a challenge to hold a log still with the other hand, going by my experience with chop saws. Good luck tho. Can you build a hydraulic chop saw about 4 foot minimum diameter blade with adjustable length cradle and hydraulic butt board, as I want to get such a thing for cutting logs 1.1m long and feed by log loader?!

[Graham w]

Can you build a hydraulic chop saw about 4 foot minimum diameter blade with adjustable length cradle and hydraulic butt board, as I want to get such a thing for cutting logs 1.1m long and feed by log loader?!

 

i saw a hydraulic slasher saw forsale in USA, it was used for lengthing yank size saw logs??? i will try find some more info as they are available

[Logan]

cheers graham. The Yankee ones are built large tho, as you say for big old saw logs. Chainsawing the bigger logs is ok productive, it's the run of the mill average firewood size cord that takes most time. I'm bit surprised that Peasgood wants to cut larger logs with circle saw, you reckon it's quicker (less chain sharpening!?)

[Peasgood]

I don't know what a butt board is, hydraulic or otherwise. If I knew what one was, yes I probably could build one. Not that I have the time unfortunately.

I watched a Youtube clip of a processor that was fed with a hydraulic sliding table. Can't find it now but that sounds like what you mean

I think up to maybe 16" a circular saw would be quicker than a chainsaw. Maybe I'm wrong and maybe it depends what saw you have anyway. From experience with my chainsaw and my circular saw on the wood i use (leylandii) I reckon it will work.

I have endless supply of straight grown timber and all I want to do with it is burn it. If I found a good, efficient way to process bigger quantities it could well be a commercial venture.

Maybe you have more experience with hardwoods and they are quicker with a chainsaw (I don't know).

If you don't mind me asking, if a chainsaw is quicker why do you want a 4' circular saw?

 

I have the blade, spindle and pto gearbox. All I need is some metal for the frame and to get my finger out and get on with it. I guess if it doesn't do what I want I can chop it up and go back to a rocking cradle.

I'm probably over thinking the thing as usual.

[Logan]

Yes, time sadly restricts these projects.

 

Well, for large volumes, if you swing a log off the heap and it's "larger" diameter stuff e.g. >14" or larger, then the crane is handling a good fast load, and for cutting say a 4.4m log into 4 x 1.1m bits, for one tape measure hook up and 3 thigh level cuts ( where you can rest on the saw for a while as it's doing it's job...) you get 200kg cut to length in fairly enjoyable fashion.

If its all 4" or 6" or 8" run of mill firewood, it's a lot of creeping around measuring and cutting, you have to make maybe 24 cuts (per 200kg) all down nearer the ground, not always as enjoyable if you're working through 100 tonnes.

So one answer is like a large sawhorse, drop the log(s) in, the larger ends all up the saw end where a hydraulic gate then swings up hopefully pushing the ends together then the saw drops down and cuts the ends off to whatever length it's set to. Crane off cut bits, move logs along to butt board, cut and go again. Beauty.

 

So the 4' circle saw would handle several 8" diameter logs in the cradle. Maybe.

Cheers, John

Edited October 12, 2014 by Logan

[Peasgood]

It sounds like you already built yours in your head too.

I get the 4' blade now too, I am happy to do one 8" log at a time. Mine are already 6' lengths and I want to saw them down to 18" logs for splitting.

6' because I can handle them on my own, either by hand or by fork lift for the big ones and you get 4x18" logs. My fires fit 18" logs, so do my splitters.

When I am rich and famous and have established my log selling empire i can cut them to 9" instead so all my customers are happy.

In my head of course.