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Firewood processor build circler saw

Started by hiluxpig, November 10, 2012, 06:53:25 AM

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hiluxpig

What are the reasons all the people building circular saw firewood processor are using hydraulic motors to drive the blade. Why doesn't anyone use belts/pulleys and a clutch driven strait off the engine?

Brad

bill m

You would need a big hp motor to keep it turning in the cut.
NH tc55da Metavic 4x4 trailer Stihl and Husky saws

hiluxpig

So they are using the hydraulics in the form of a torque converter? So with a saw bench feeding the log in by hand is ok for a pulley setup (consent load) but no good when the blade is being forced in to the wood (load ramps up). Thanks for the reply

Has anyone got the details of hydraulics needed to run a 48" dia circler saw blade eg what hydraulic motors, schematic drawings

Thanks Brad

blackfoot griz

Quote from: hiluxpig on November 10, 2012, 06:53:25 AM
What are the reasons all the people building circular saw firewood processor are using hydraulic motors to drive the blade. Why doesn't anyone use belts/pulleys and a clutch driven strait off the engine?

Brad
Brad
Most of the commercial firewood processors using a circular blade  (Cord King, CRD Metalworks etc) the sawblade pivots into the log making the cut.  It is pretty easy to hook up a hydraulic motor to a shaft with flexible lines.  This would be tough to do directly off the engine. Also, most of the other functions on the big firewood processors use hydraulics to control the other functions, live deck, splitter, log trough, conveyor.
The cool part of hydraulics is that you can send the power where you need it when you need it.

North River Energy


Direct drive slasher. (A very large machine).

http://www.youtube.com/watch?v=eM6NYAEE4A4&feature=related

One could surmise (ala Blackfoot G,) that the use of hydraulics provides greater flexibility in machine layout.  The hydraulic plant can go anywhere, to the extent that it may not be mounted on the same chassis as the rest of the processor.

(Bar saw.  Hydro drive detail around 1:40)
http://www.youtube.com/watch?v=6IHTqlLc1QA


Direct drive is simpler, possibly cheaper (in terms of component cost) and may be more fuel efficient.

10-15 HP?
http://www.youtube.com/watch?v=Rs-QYM494RU&feature=related

My homebuilt uses a 60hp(?) diesel, a lineshaft, three pumps, one hydro motor, a gearbox, two belt drives and a flywheel.  Not ideal by any stretch, but I'm refining within the confines of the original builders vision, on a minimalist budget.



johndeerkiwi

Hi Brad, I know this post has been posted some time ago, but your question is still relevant.
As has been pointed out it's easier to use a hydraulic motor, and the relief valve system of a hydraulic motor offers a great overload system.
It is possible to direct drive a saw though,  and there is not the large  losses with direct drive(typically about 20% in any hydraulic system), so you get more power to the shaft.
The two best options are probably a long universal shaft (or PTO shaft)directly driving the saw arbour, so the saw can move, or alternatively, pivoting the saw on bearings on the driveshaft itself, running vee belts to the arbour. Of course if the saw is stationary, it's quite easy,but then you've got the problem of moving the log.
I have built a cut-off saw that took up to about 12" dia logs, on a vee-belt driven shaft with a slip clutch off a baler, and it worked well. I suggest you use a slip clutch in the drive if possible, or at least a shear bolt protected drive-shaft or vee belts or even all of these, as you need something to give if the saw ever hangs(jambs)
"Many a man has failed to see what is too simple for a complicated mindset, and too inexpensive for an unlimited budget"

DavidtheMainer

I am helping a friend of mine build a firewood processor with a shaft driven chainsaw head, 31" 404 Oregon Bar.  I can tell you from what I have seen that the shaft driven saw-heads seem to require way less power to run than their hydraulic counterparts, are cheaper to maintain, and are much more durable.

beenthere

Welcome to the Forestry Forum.

Tell us about the "shaft driven" chainsaw head and more about how it is better. Am sure we'd be interested in hearing more how you do it correctly.

Sounds like you are or have built a processor. We do like pics.  :)
south central Wisconsin
It may be that my sole purpose in life is simply to serve as a warning to others

DavidtheMainer

Quote from: beenthere on August 28, 2014, 02:30:30 PM
Welcome to the Forestry Forum.

Tell us about the "shaft driven" chainsaw head and more about how it is better. Am sure we'd be interested in hearing more how you do it correctly.

Sounds like you are or have built a processor. We do like pics.  :)

Sorry, I should not have used the word correctly.  I should have said durably.  I am sure there are many methods of doing it durably.  I will post some pics.

beenthere

 :)  I didn't mean that as a challenge, but am interested in how you fabricated the shaft driven, and how it is better.
I don't understand "durably" much at all.   ;D
south central Wisconsin
It may be that my sole purpose in life is simply to serve as a warning to others

DavidtheMainer

Quote from: beenthere on August 29, 2014, 03:39:09 PM
:)  I didn't mean that as a challenge, but am interested in how you fabricated the shaft driven, and how it is better.
I don't understand "durably" much at all.   ;D

Poor wording on my part. 
The basics are:

The shaft drive runs off of a naturally aspirated 4 cylinder diesel turning at 1600 rpm with approx. 40 hp and 70 ft pds of torque at that rpm.  It is geared to 3000 rpm to turn the splitter pump.  A pulley turns the electromagnetic belt clutch which in turn runs the auxiliary saw head drive shaft at 6000 rpm.  We have been slowly ramping up saw head shaft RPM as we test it by increasing pulley size and engine rpm.  The saw-head pivots on the bearings that also allow the shaft to rotate.

The auxiliary shaft is a 1" shaft that we put on the lathe at 1 end to mill down to 25mm to accept the harvester sprocket then is reduced in size to 3/4 to accept a 3/4 bearing on the very end.  The reason for going to 3/4 is that they are more available than a 25mm bearing and are readily available at 7 day a week box stores as well as the regular 5 day a week automation and steel suppliers around here.

Benefits:
- Total drive-shaft setup cost from the end of the gearbox to the tip of the bar is $460
- Theoretical torque and horsepower at the bar are much higher than with an F11.   
- No pump, hoses, or motor to go bad, only belts and bearings.
- Broken or worn belts and bearings can be individually replaced
- Saw-head is supported on both sides by bearings.
- Lower capacity hydraulic reservoir needed
- Can run a low power engine at a lower rpm driving the shaft
- Repairs are very economical
- Affordable to stock up on expendable bearings and belts.

Downsides are:
- Additional safety shielding is needed to cover the shaft and bearings.
- Additional space taken up by shaft and pulley assembly
- Bearings need to be greased every day.
- Changing the chain takes about an hour versus 5 or 10 minutes on an open-head hydraulic saw.
- Much easier to slap on a hydraulic saw than fabricate this.

Unknowns -
- There is no specification on the number of on off cycles that clutch can handle at that rpm and horsepower although the clutch is engaging and disengaging with virtually no load other than the rotational load and the engagement does not seem violent in any way just a small belt surge.
- Lifespan on bearings and belts, at this point they seem perfectly fine.

So far we have about 30 cords through the machine just testing it.  I am sure we will find all sorts of problems with it as we progress.  If bearings become an issue he will invest in needle bearings.  If there is an issue with the clutch it will be switched to an automation hydrocoupler which while costing close to an F11 has an almost infinite lifespan and needs little flow and pressure.

I have seen plenty of costly hydraulic problems over the years and am in the middle of rebuilding a Bobcat right now where one problem with a relief valve on a metering block ruined one side of a hydrostat, a charge pump, and a drive motor.   Hydraulics are great but I see this as being able to deliver more power at a lower cost.  If you have the ability to fabricate a processor yourself, trying this might be worth the extra time and effort.  And I will hopefully get some pics up this weekend and start working on a video.

beenthere

south central Wisconsin
It may be that my sole purpose in life is simply to serve as a warning to others

DavidtheMainer

I found a couple of pics on my old phone of some of the build.  I wish I had actually taken videos and pictures as well as some of the people on here have done.  Anyways, I have a picture of the auxiliary shaft and head design as we started building it.  A picture of it mounted and a picture of the bearing supports.  I would say about 66% of this machine is built out of recycled components and steel.

DavidtheMainer


Hilltop366

I have wondered if a front wheel drive wheel bearing assembly and cv shaft would make a good mechanically driven saw bearing and mount? 

DavidtheMainer

Quote from: Hilltop366 on September 05, 2014, 04:19:19 PM
I have wondered if a front wheel drive wheel bearing assembly and cv shaft would make a good mechanically driven saw bearing and mount?

I am sure you could make it work.  Probably take some fabrication of the hub to accept whatever style saw you went with.  Maybe fabricate and test with one out of junk and if it works go buy a new hub and cv to actually use??   Would definitely be interesting to see it

DavidtheMainer

This is a quick run we did today after bringing the saw speed up 5%.


On a side note does anyone know how to post the videos right in the forum?

beenthere

That is pretty respectable processing, I'd say.  8)
south central Wisconsin
It may be that my sole purpose in life is simply to serve as a warning to others

DavidtheMainer

Here is a video of the drive assembly up close:

DavidtheMainer

Here is one more on about 7 - 8" diameter wood.

Mooseherder

David,
I took the S off your link after the http and it embeds your paste.
You can modify your other links if you wish.
Welcome to the Forestry Forum. :)

DavidtheMainer


thecfarm

Model 6020-20hp Manual Thomas bandsaw,TC40A 4wd 40 hp New Holland tractor, 450 Norse Winch, Heatmor 400 OWB,YCC 1978-79

BargeMonkey

 Sounds like youve got it figured out. I hate to say it but the drive motor if fed clean oil is probably the last thing to go on a processor, mine has 6800hrs so far. What kind of a power plant and how big of a pump do you have ?

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