Hi there!
First of all, let me introduce myself.
I`m Demetrio, 27 years old, from northern Italy. My family has a small farm, even if it's not a full time job. We grow mainly poplar trees for the paper industry. We used to grow corn/rice/wheat/sojia but it's a lot of work if you have only week ends, while growing trees is easier. Been on tractors since I was 7, including chainsaw work (I started that later) and gardening work. Chainsaw work is necessary since we have a quite big house with a heating system which is fed with firewood. Here we mainly burn black locust, oak and poplar, log size is rarely > 30'' (very rarely 40'').
I was planning to build a firewood processor to unburden my father back; he's getting old and I have less and less time to help him with firewood (I do not live with my parents anymore). That being said I would like to share with who's interested some ideas/doubts and to get some advices from people who knows surely better than me.
My plan was to use the tractor rear PTO as power source; than I would have a gearbox (ratio 1:3) to increase the output shaft speed to which a single stage gear pump is connected (something around 23gpm at 2800 rpm, 33cc of displacement, max pressure is around 3500psi). The cutting is performed by a hydraulic motor (gear motor, around 4000rpm with 23gpm, 20cc of displacement) powered chainsaw. This configuration would provide a chain speed of 75 feet/s considering a big enough chain sprocket (4'' diameter). For the log splitter I was planning to use a 4'' bore cylinder which would provide a 20 tonnes force (considering 3500psi). Biggest logs are cross split, while logs under 10'' are half-split. Cutting length has to be around 20''.
Let's start with the frame.
First obstacle is the log conveyor. I initially sketched a frame for a roller log conveyor (see attached sketch); then, for simplicity, I changed my mind towards a chain conveyor (see sketch). Indeed, there's quite a bit of cutting/welding work to make the rollers, while it seems easier with chains. Moreover I might recover 2 hand chains from combine harvesters for free from a friend. Sketches below are only drafts (incomplete); my constraints are the wheeled frame I already have (see pics) and the steel beams which I already have too (H beams and C beams). Also, I think that it is easier to power one single chain running along the conveyor rather than a bunch of rollers. But then you have to consider that crooked logs migth stall with a chain, while maybe they won't with rollers. My idea was also to cut more than one log at a time, if they're small enough. What about two chains running in parallel and being clamped together with some protruding mounts which can grip onto the logs? what cross section shape is best fo the conveyor? V shape, U shape with flat bottom, flat only? Also, what is the clamping system (to clamp the log prior cutting) in your opinion? I would really appreciate if someone has some experience/advice to share. In the next days I'll try to see what size are the chain I can get. To give you an idea the frame in the sketches is 10 feet long.
Sorry if I made some mistakes with the unit measures, I'm not used to the imperial measure system! :laugh:
Cheers
Demetrio
(https://forestryforum.com/gallery/albums/userpics/60719/Cattura1.JPG?easyrotate_cache=1589547251)
(https://forestryforum.com/gallery/albums/userpics/60719/Cattura2.JPG?easyrotate_cache=1589548041)
(https://forestryforum.com/gallery/albums/userpics/60719/IMG_20200515_124142.jpg?easyrotate_cache=1589547163)
(https://forestryforum.com/gallery/albums/userpics/60719/IMG_20200515_124152.jpg?easyrotate_cache=1589547128)
Welcome Demetrio. I think many will start to chime in in a bout 8 hours or so. work day just started here. some may jump in sooner. looks like a neat project. not my expertise.
Hi Demetrio:
I made my processor with live rollers and a 10 foot belt at the saw end. I have lately been cutting longer logs (almost 28 feet) and have started breaking the standard 40 chain that powers them. I can only say build it about 3x stronger than any calculations say you need to.
I agree that chain is a good infeed method but dont go light on it - you will be replacing it.
I will give a summary of my findings when I get some time to detail them.
Your designs look good - keep us posted!
jmur1
Demetrio Welcome to the forum. I built a homemade processor around five years ago. I have been making changes to it ever since. I use live rollers that are big chain sprockets for the conveyor. It works ok but crooked logs are always a issue.Look at Multi tech over head shuttle that sides the logs ahead. I use a hyd chain saw I built but you end up with a lot of money in a hyd saw. Search the forum and U tube for BT-6870 fire wood processor to see a simple processor that works good without a bunch of hyds. Build it at least three times heavier than you think it needs to be. Processing wood is hard on equipment and people.
Thanks everybody for the advices and for welcoming me! I approve the philosophy of building it 3 times stronger than the worst case scenario calculations say, that's the reason why old equipment still runs strong!
Quote from: hedgerow on May 15, 2020, 11:24:00 AM
Demetrio Welcome to the forum. I built a homemade processor around five years ago. I have been making changes to it ever since. I use live rollers that are big chain sprockets for the conveyor. It works ok but crooked logs are always a issue.Look at Multi tech over head shuttle that sides the logs ahead. I use a hyd chain saw I built but you end up with a lot of money in a hyd saw. Search the forum and U tube for BT-6870 fire wood processor to see a simple processor that works good without a bunch of hyds. Build it at least three times heavier than you think it needs to be. Processing wood is hard on equipment and people.
@hedgerow (https://forestryforum.com/board/index.php?action=profile;u=28463) I checked the BT-6870 firewood processor, that's a nice piece of equipment, strong and smart (and cheap!)
Quote from: jmur1 on May 15, 2020, 10:39:52 AM
Hi Demetrio:
I made my processor with live rollers and a 10 foot belt at the saw end. I have lately been cutting longer logs (almost 28 feet) and have started breaking the standard 40 chain that powers them. I can only say build it about 3x stronger than any calculations say you need to.
I agree that chain is a good infeed method but dont go light on it - you will be replacing it.
I will give a summary of my findings when I get some time to detail them.
Your designs look good - keep us posted!
jmur1
@jmur1 (https://forestryforum.com/board/index.php?action=profile;u=34322) Thanks, I'll try to not save on steel to keep everything strong!
I'll keep you guys updated!
Demetrio
Hello and welcome . I am the guy that built the BT6870 . It is getting a splitter rebuild this summer .The splitter was a little slower than the 394 Huskvarna [about 4 seconds ] got a new cylinder with a 3 inch rod .By the calculator it should be at 7 seconds for a 24 inch cycle . The push plate feed works well if your logs are some what the same length . Oil tank Make sure you use a big enough tank for your future pump needs . One gallon of tank for each gallon of pump flow . Go big on the tank more oil will run cooler .
Quote from: Gearbox on May 15, 2020, 08:40:52 PM
Hello and welcome . I am the guy that built the BT6870 . It is getting a splitter rebuild this summer .The splitter was a little slower than the 394 Huskvarna [about 4 seconds ] got a new cylinder with a 3 inch rod .By the calculator it should be at 7 seconds for a 24 inch cycle . The push plate feed works well if your logs are some what the same length . Oil tank Make sure you use a big enough tank for your future pump needs . One gallon of tank for each gallon of pump flow . Go big on the tank more oil will run cooler .
Hi @Gearbox (https://forestryforum.com/board/index.php?action=profile;u=26274) , thanks for the infos. According to my calculations, considering a 24 inch stroke with a 4 inch cylinder bore and 22gpm I would approximately have a 4s cycle. I was considering a 60 liters oil tank (16gallons) which is smaller than what you suggests (bigger tanks are pretty expensive, I need to find some second hand tank). I'll see then if there's necessity of an oil cooler.
Really appreciate the help!
Demetrio
speed is about trade off . 4 seconds is faster than most . that same cylinder with a 16 gallon pump would be a 13 and your tank would be good . I stayed at 16 gallons and changed out the cylinder to a 4 inch with a 3 inc rod and went from 13 to 7 seconds . A 7 seconds I have to enclose my cylinder from the push plate back . The return speed is 2.3 seconds if something falls behind the plate I would not be able to stop before it started breaking hoses and fittings . hope this helps
Thanks @Gearbox (https://forestryforum.com/board/index.php?action=profile;u=26274) , you're right, compromise is very often the way to go. I'll try to keep the right scale between the pump and the tank and all the stuff depending on what I can find second hand... Maybe I can find a big enough tank from some farm equipment at a low cost. Appreciate your help!
Quote from: Demetrio on May 16, 2020, 04:18:48 AM
Hi @Gearbox (https://forestryforum.com/board/index.php?action=profile;u=26274) , thanks for the infos. According to my calculations, considering a 24 inch stroke with a 4 inch cylinder bore and 22gpm I would approximately have a 4s cycle. I was considering a 60 liters oil tank (16gallons) which is smaller than what you suggests (bigger tanks are pretty expensive, I need to find some second hand tank). I'll see then if there's necessity of an oil cooler.
Really appreciate the help!
Demetrio
Hi Demetrio:
When you wrote 4s cycle did you means 4s for extension time?. I think you are nearly double that for a full cycle. And if you are using a two stage pump it will be slower than that based on other losses (fittings, valves, filters, friction, hp).
Just wanted to make sure we were comparing the same things!
jmur1
i think that hydraulic tanks can be confusing. there is a total volume and a functional volume that is less. i have a 26 gallon that holds 19 to show full on the sight glass.
Quote from: jmur1 on May 22, 2020, 02:13:49 PM
Quote from: Demetrio on May 16, 2020, 04:18:48 AM
Hi @Gearbox (https://forestryforum.com/board/index.php?action=profile;u=26274) , thanks for the infos. According to my calculations, considering a 24 inch stroke with a 4 inch cylinder bore and 22gpm I would approximately have a 4s cycle. I was considering a 60 liters oil tank (16gallons) which is smaller than what you suggests (bigger tanks are pretty expensive, I need to find some second hand tank). I'll see then if there's necessity of an oil cooler.
Really appreciate the help!
Demetrio
Hi Demetrio:
When you wrote 4s cycle did you means 4s for extension time?. I think you are nearly double that for a full cycle. And if you are using a two stage pump it will be slower than that based on other losses (fittings, valves, filters, friction, hp).
Just wanted to make sure we were comparing the same things!
jmur1
Hi @jmur1 (https://forestryforum.com/board/index.php?action=profile;u=34322) , I meant 4 s in total, extension + retraction. Retraction is of course much faster since the cylinder chamber volume is lower due to the rod volume. For now I'm sticking to a one stage pump; cycle length calculations are based considering that all the pump flow rate is used for the log splitter cylinder (also, I need to consider the pressure drops/energy losses along the path). Power is not a big deal, I can use a 100hp tractor to power the thing (I think that 50hp are more than enough).
@doc henderson (https://forestryforum.com/board/index.php?action=profile;u=41041) Thanks for pointing that out! I would say that tank volume has to be rougly 30% than the oil volume inside to account for volume changes due to temperature.
Appreciate you help guys! I'll soon update you!
Hi Demetrio:
Volume of cylinder =πr^2 x h = 300 in^3 which is total volume of cylinder oil to pipe in for 1 stroke. (Note the backward n is a pie for the volume)
convert to 1.3 gallon of oil.
divide that by 22 and get .06 of a minute and times by 60sec/min to get 3.6 seconds. That is for the out stroke only.
Wouldnt be the first time if the mistake is on my side! Let me know how you calculated it.
jmur1
Quote from: jmur1 on May 23, 2020, 10:05:44 PM
Hi Demetrio:
Volume of cylinder =πr^2 x h = 300 in^3 which is total volume of cylinder oil to pipe in for 1 stroke. (Note the backward n is a pie for the volume)
convert to 1.3 gallon of oil.
divide that by 22 and get .06 of a minute and times by 60sec/min to get 3.6 seconds. That is for the out stroke only.
Wouldnt be the first time if the mistake is on my side! Let me know how you calculated it.
jmur1
Hi @jmur1 (https://forestryforum.com/board/index.php?action=profile;u=34322) , that's correct! For the retraction is the same, except that the volume of the cylinder is lesser, since you have to subtract the volume of the rod! Equations follow:
Cyl_vol_extension = pi * (r^2) * h
Cyl_vol_retraction = [pi * (r^2 - r_rod^2)] * h, where r is the cylinder radius, while r_rod is the rod radius.
So I get (I'll use dm and liters :D):
Cyl_vol_extension = pi * (1^2) * 6 = 4.71 l
Cyl_vol_retraction = [pi * (1^2 - 0.56^2)] * 6 = 0.91 l
extension_time = Cyl_vol_extension / pump_flow = 4.71 / 1.39 = 3.4s
retraction_time = Cyl_vol_retraction / pump_flow = 0.91 / 1.39 = 0.65s
where flow is in liter/s. We have sligtly different times for the extension due to the unit measures. I used a 100 mm cylinder bore (600mm stroke) with a 56mm rod diameter. Pump flow is 22 gal/min, or 83 l/min.
I think that you weren't considering the rod volume for the retraction stroke, am I rigth? Or maybe I'm doing something wrong :-\
Demetrio
Hi Demetrio:
I think the return stroke will be abit faster as you have calculated but dont forget you have to evacuate the opposite oil in the cylinder through your control valve as well. This means the pump has to push that volume out of the cylinder through the control circuit and back to tank. In my experience ths will fall somewhere in between the two calculated values. Ill have to run some tests on my machine to back up my thoughts. I previously had a 5" diameter cylinder that i had specially modifyied larger ram that did improve cycle time but was really noticeable after i added a piloted return line to tank. I am now running a 4" that has a standard ram and the return is similar to the out stroke.
Jmur1
I will spare you further math on a Sunday of Memorial day. I would say lots of people have made splitter/processors with that combo of flow rate and cylinder size. My 28 gpm pump and 5 inch cylinder with a 1.5 inch rod, cycles fast enough that I often run it at half throttle, and it is fast enough. you understand the variables that speed that up and the consequences of doing them. it appears! :) . I have considered a dump valve for mine, but it is expensive and will complicate the plumbing that I tried to keep simple.
Quote from: jmur1 on May 24, 2020, 07:05:57 AM
Hi Demetrio:
I think the return stroke will be abit faster as you have calculated but dont forget you have to evacuate the opposite oil in the cylinder through your control valve as well. This means the pump has to push that volume out of the cylinder through the control circuit and back to tank. In my experience ths will fall somewhere in between the two calculated values. Ill have to run some tests on my machine to back up my thoughts. I previously had a 5" diameter cylinder that i had specially modifyied larger ram that did improve cycle time but was really noticeable after i added a piloted return line to tank. I am now running a 4" that has a standard ram and the return is similar to the out stroke.
Jmur1
Hi @jmur1 (https://forestryforum.com/board/index.php?action=profile;u=34322) , you're making a good point, these are rough calculations and one should account for the pressure drops along the circuit which inevitably reduce the flow. But then the same applies for the extension stroke, where you have to evacuate the low pressure cylinder chamber into the tank, doesn't it? Actually I've a lot of farm equipment which uses hydraulic cylinders and I didn't really noticed such a difference between the extension and retraction strokes (I must say that I didn't pay attention to that too).
Regenerative valves seem an interesting solution! Throw a look!
If you get a chance to measure the extension/retraction stroke times let me know please!
Quote from: doc henderson on May 24, 2020, 09:05:55 AM
I will spare you further math on a Sunday of Memorial day. I would say lots of people have made splitter/processors with that combo of flow rate and cylinder size. My 28 gpm pump and 5 inch cylinder with a 1.5 inch rod, cycles fast enough that I often run it at half throttle, and it is fast enough. you understand the variables that speed that up and the consequences of doing them. it appears! :) . I have considered a dump valve for mine, but it is expensive and will complicate the plumbing that I tried to keep simple.
Hi @doc henderson (https://forestryforum.com/board/index.php?action=profile;u=41041) , thanks, I'd appreciate any sort of material you have. I'm trying to keep things simple. You can't break what is not there :D.
Demetrio
There are online calculators like this one that will give you lots of info. https://www.tss.trelleborg.com/apps/hydraulic_cylinder/ (https://www.tss.trelleborg.com/apps/hydraulic_cylinder/)
Out of curiosity I put in the calculator a 4" X 24" cylinder with a 1.75" rod and a 3500 psi X 33 gpm pump. The difference in extension and retract time is less than ½ second and a 4.29 second cycle time.
A 3" rod changes it to 3.42 second cycle time with all the change on the return (rod) side of coarse. With a difference of 1.34 seconds between exertion and retract. A difference of .87 seconds between a 1.75" and 3" rod diameter.
I wonder if it would be chasing expensive fractions of a second for not much gain in processing time in the big picture, the little bit of gain in cycle time is irrelevant if you are advancing the log and starting the next cut while it is returning as long as the splitter is retracted in time to finish the next cut.
Quote from: Hilltop366 on May 24, 2020, 11:17:19 AM
There are online calculators like this one that will give you lots of info. https://www.tss.trelleborg.com/apps/hydraulic_cylinder/ (https://www.tss.trelleborg.com/apps/hydraulic_cylinder/)
Out of curiosity I put in the calculator a 4" X 24" cylinder with a 1.75" rod and a 3500 psi X 33 gpm pump. The difference in extension and retract time is less than ½ second and a 4.29 second cycle time.
A 3" rod changes it to 3.42 second cycle time with all the change on the return (rod) side of coarse. With a difference of 1.34 seconds between exertion and retract. A difference of .87 seconds between a 1.75" and 3" rod diameter.
I wonder if it would be chasing expensive fractions of a second for not much gain in processing time in the big picture, the little bit of gain in cycle time is irrelevant if you are advancing the log and starting the next cut while it is returning as long as the splitter is retracted in time to finish the next cut.
Hi @Hilltop366 (https://forestryforum.com/board/index.php?action=profile;u=8975) , just checked out the site. That's truly useful. As you said fractions of second are irrelevant (especially to me). It's more for the sake of curiosity!
Quote from: jmur1 on May 24, 2020, 07:05:57 AM
Hi Demetrio:
I think the return stroke will be abit faster as you have calculated but dont forget you have to evacuate the opposite oil in the cylinder through your control valve as well. This means the pump has to push that volume out of the cylinder through the control circuit and back to tank. In my experience ths will fall somewhere in between the two calculated values. Ill have to run some tests on my machine to back up my thoughts. I previously had a 5" diameter cylinder that i had specially modifyied larger ram that did improve cycle time but was really noticeable after i added a piloted return line to tank. I am now running a 4" that has a standard ram and the return is similar to the out stroke.
Jmur1
@Jmur1 I just noticed that I made a mistake in the calculations I posted. Formulas are correct but I put the wrong numbers when calculating the retraction stroke. Cyl_vol_retraction is 3.2 liters and then the retraction time is equal to 2.3 s. Cycle time is now almost 6s. My mistake :-\. Just in case I checked the math with the calculator suggested by @Hilltop366 (https://forestryforum.com/board/index.php?action=profile;u=8975) and numbers are the same.
Demetrio
You will need to enclose the cylinder so when it is extended no wood can fall behind the push plate . The new splitter for mine will be at 7 seconds full cycle 2.3 on retract no way with all that's going on will I be able to react in time to keep from ripping fittings and hoses .
Quote from: Gearbox on May 24, 2020, 08:38:50 PM
You will need to enclose the cylinder so when it is extended no wood can fall behind the push plate . The new splitter for mine will be at 7 seconds full cycle 2.3 on retract no way with all that's going on will I be able to react in time to keep from ripping fittings and hoses .
Hi @Gearbox (https://forestryforum.com/board/index.php?action=profile;u=26274) , yeah I need to consider that. I think that the best solution would be as in the following YT video: Hakki Pilke Falcon 35 - Efficient firewood processor with low maintenance - YouTube (https://www.youtube.com/watch?v=nLmg9NsLixY) , where the cylinder is embedded into a steel casing with no possibility for the logs to fall behind the push plate and cause damage. Anyway a 7s cycle seems pretty reasonable.
Demetrio
I think building a purpose build splitting chamber like the one in the video you posted makes since. Making sure the log pieces center in the chamber is big. I would use a over size rod cylinder to build your processor. It really speeds up the splitter. They cost more up front but its worth it. I got lucky and found a surplus new cylinder that had a over sized rod in it when I built mine.
Quote from: hedgerow on May 26, 2020, 12:44:58 PM
I think building a purpose build splitting chamber like the one in the video you posted makes since. Making sure the log pieces center in the chamber is big. I would use a over size rod cylinder to build your processor. It really speeds up the splitter. They cost more up front but its worth it. I got lucky and found a surplus new cylinder that had a over sized rod in it when I built mine.
Hi @hedgerow (https://forestryforum.com/board/index.php?action=profile;u=28463) , I'll throw a look around to see if I can be as lucky as you and find a surplus/second hand cylinder. I had a quote for a new one (anterior flange, 100mm bore, 600mm stroke, 60mm rod, 1/2 inch ports) and it would cost something around 400$.
That's not a bad price. I would look for 3/4 ports for better flow. Surplus cylinders can be a crap shoot. I got one that was "new/old stock. Split less than 5 cord and seals went. Now I have more than your new price....
Hi Demetrio:
The video above made me think of another feature that I have on mine that can cut some serious waiting time. I have made my knife (splitter) block distance from the hydraulic ram plate adjustable. This means when I am cutting 12 inch I make the drop bay 14" in length and when I cut 16" I make the drop bay 18" in length and so on. This means the time for the 24" cylinder is not always running a significant longer time to get the logs to the splitter. Now depending on your setup that may not matter but for mine it works quite well.
It looks like you are in the starting phase still so make sure you take the time to consider all possible options available.
Also make sure your infeed is wide enough to accept crooked logs. Make any live rollers nice and wide. (recommend 2 feet width (600mm))
For my tank I was running low on oil for a long time no realizing the heat and the air bubbles. The tank return line should dip into the oil so you reduce splashing and air bubbles, with enough air space at the top to allow for flow/volume changes. If you plan to use a homemade tank do your research on that and pre install a thermometer and level guage -I learned that one the expensive way!
I detailed my design with a some notes in this forum. You can see it on the thread:
https://forestryforum.com/board/index.php?topic=97365.0 (https://forestryforum.com/board/index.php?topic=97365.0)
jmur1
Quote from: Demetrio on May 26, 2020, 01:05:57 PM
Hi @hedgerow (https://forestryforum.com/board/index.php?action=profile;u=28463) , I'll throw a look around to see if I can be as lucky as you and find a surplus/second hand cylinder. I had a quote for a new one (anterior flange, 100mm bore, 600mm stroke, 60mm rod, 1/2 inch ports) and it would cost something around 400$.
I wouldn't think that was a bad price but I would have it built with 3/4 ports also. I did get lucky and bought this cylinder cheap. It was new but had been setting for years so it went to the hyd shop and was honed and had heavier seals and glad rings installed before it went on the processor. Its a six and half inch cylinder with a four and half inch rod it has a 36 inch stroke but I only use 24 inch most of the time. It actually has two one inch ports and I feed it with two pumps and engines to get the speed up.
Hi wiam, I'll look if I can have bigger ports. Yeah, I think that 400$ is not that bad, especially considering that you have something brand new.
Hi jmur1, that's clever, even if I do not have the necessity of cutting different lengths (I would cut 18-20 inches). I totally agree with you, it's better to spent time in the design phase and then start the build. I'm considering 600mm rollers (maybe slightly less/more). I'll keep an eye on the tank design as soon as I start to sketch the hydraulic circuit. Thanks for all the valuable infos! I've seen your firewood processor; that's a hell of a job! Really nice design! I'm still considering the benefits of using a circular saw, even if it feel less safe to me (but that's only a feeling).
Hi hedgerow, changing the seals wouldn't be a problem for me, I've already done it and it's a cheap operation. I'm more afraid of finding rust/corrosion inside the cylinder which would be a serious issue.
Thanks for the help guys!
Demetrio
Demetrio
I was a little worried about rust and corrosion but the cylinder was within driving distance 200 miles and still had pipe plugs in it been stored inside. So when I got there we pulled two of the plugs and hung the cylinder on a fork lift so it could be extended and the rod could be inspected. Rod looked like the day it came out of the factory. I to would be worried on buying a surplus cylinder spending the money and freight and it shows up full of rust. I wanted a six inch plus cylinder with a over size rod and getting one built wasn't in budget. If your not going to be cutting huge dia wood I sure would look real hard at using a circular saw. The cost of a making hyd chain saw adds up quick.
Or the rarely spoken about option 3, bandsaw. I wonder how it holds up?
Malkas skaldÄ«tÄjs - procesors Mottimaster XL - YouTube (https://www.youtube.com/watch?v=Wlvp-IjmB8w&list=WL&index=6&t=0s)
Hi hedgerow,
my main fear with a used hydraulic cylinder would be rust inside the cylinder. I had (still have) a cylinder from an excavator which looked pretty rigth from the rod, but had serious corrosion inside the cylinder. That would be hard to inspect before buying, unless you have the opportunity to disassemble it. But I guess it is not worth, unless it comes very cheap and close to home. Another practical way to test a cylinder would be to put pressure in it and close a port (close the lower port). If there's any leakage the rod will extend. But then you don't know if it is due to the seals or to some corrosion inside. I was considering a circular saw mainly because I find it easier to design/build; but it's limiting, since you need a diameter which is at least twice and a half the size of the average log. Yeah, I'm experiencing the hyd chain costs ramping up quickly :D
Hi Hilltop366,
I was also wondering why almost no one is using bandsaws. I have one vertical bandsaw and the main issue is to keep the piece of wood straigth during the cut (no torsion on the saw blade), otherwise you'll break the blade/stop the blade. I think that's the main reason. It would be hard to keep the log perfectly still while cutting, especially if it is crooked (indeed in the video they're cutting a pole basically). I see no other cons. Anyway it's an interesting solution, far more efficient than the most common ones, and safer I'd say. I've seen also guillottine systems, but they're pointless in my opinion.
Demetrio
Bandsaw? Never seen that before.
I have been happy with my belt driven chainsaw on mine.
I was impressed by the bandsaw video. I had thrown around that idea when I got started my build, but I knew how it fails on dirt and bark (from my woodmizer exposure) so I didn't pursue it far! It would need sharpening every 2 hours or so. 50 ways to skin a....
The guillotine option also grabbed my attention but the hp and cylinder size show a built in slowness for any large logs. I am pretty sure the two main (efficient) options are circular or chain.
I wonder if there is a water jet version yet?
jmur1,
I don't think that wj would work easily, unless you keep the nozzle fixed and you rotate the log around its axis (the nozzle has to be very near to the surface to be cut, otherwise you'll loose too much energy due to the interaction with the air). Also it would be quite overkill for the job :D. And it's extremely costly to operate. It works fine when you have planar pieces to cut, and not extremely thick. Plus it does not heat up the piece, spoiling mechanical properties as laser cut would do. Would be funny to try though ;D. Anyway I found a crazy video:
ULTRA HIGH-PRESSURE WATER CUTS THROUGH LOG www.TrashBinCleanersDirect.com - YouTube (https://www.youtube.com/watch?v=UF8uytY9jRw)
Quote from: wiam on May 30, 2020, 08:13:34 AM
I have been happy with my belt driven chainsaw on mine.
If I were building mine again today I would go belt drive using a AC clutch off a york compressor. Save a ton of money over building a hyd saw.Now that I am done with a lot of the larger locust wood I had to process I wish mine was a circle saw. I just get tired of dealing with chains and the oily mess saw dust. Processors are like most pieces of equipment one size doesn't fit all. If I knew what I know now I probably wouldn't have built a processor. With my operation were I come off the processor and stack in trailers that hold around three cord working wood by myself just doesn't work that well. I have to stop the processor and conveyor and stack wood in the trailer if I just conveyor pile in the trailer the load is too small. Honestly the best way for me is if one of my two helpers come out after work and I hold logs up with the skid loader and it just bucks the wood to get around two or three cord and then an a Saturday he and another buddy of mine show up and we split and load and stack in the trailer. Having the blocks ready really makes doing three cord split and stack a nice day for three older guys.
Hi hedgerow, how would you eventually power the belt driven chainsaw? I might need to add a belt transmission between the hydraulic motor and the chain sprocket in order to reach the proper cutting speed. But then I would also need a system to tension the belts, and I don't really like the idea. I've red that the ideal chain cutting speed is somewhere around 80 feet/s, which is hard to hit using a hyd gear motor directly driving the sprocket (even considering the biggest sprocket).
Demetrio I didn't explain very well. If I was building one today I would belt drive it direct from a gas engine and cut the hyd motor out to save a bunch of money on hyd's. I used a surplus bent axis fixed displacement piston motor I found to run mine so I have a lot of speed and power but it takes a lot of hyd power to make it happen. It makes a 40 HP motor get down and pull. Look up Danzco saw on the internet he builds hyd saws using gear motors and he gets enough speed out of them to direct drive them. He won't sell you just a motor but he is a good source for chain sprockets and I did buy mine from him. Nice people but they aren't going to give away all there secrets. It complete saws were out of my budget. Search on this forum there are a couple of firewood processor builds that used gear motors and there saws work.
hedgerow, I couldn't agree more, Parker has some hyd motors specifically meant for firewood processors (f series, bent axis fixed displacement piston motor, high speed), but they are over 1000$, which is a lot of money. That's the reason why I decided to switch to gear motors. Only problem is the max rotating speed. So I was considering: 1) a transmission drive to increase cutting speed; 2) direct drive with sub optimal cutting speed. Rigth now I'm leaning toward the latter, since it wouldn't be a big deal. Thanks for the advices, I'll throw a look at Danzco systems.
This thread shows my belt drive https://forestryforum.com/board/index.php?topic=104672.0 (https://forestryforum.com/board/index.php?topic=104672.0)
Single 5/8 belt was not enough. My motor is fixed, which is why I went with link. Still slipped so I added an idler/tightened.
I can still slip the double belts if I push it too fast.
Thanks wiam, you've done a great job with your processor! My idea is still to use the hyd motor to power the saw. Almost surely I'll have to add a belt drive (double belt) to increase the sprocket rpm, but I was thinking of a more compact design. I'll post progresses soon!
You can vary your chain speed quite considerably with different tooth count drive sprockets.
Hi wiam, I agree, but even with the biggest sprocket (18 teeth is the biggest I found) I'm still pretty under the desired speed. Also, a big sprocket would require a proper bar. I just need to find the best compromise between perfomance and costs.
Don't forget to add raker depth in to the equation, a .404 harvester chain has a tall tooth with a 50 thousand inch raker depth and well take a big bite compared to a regular saw chain that would be 25 to 30 thousands. The cutting speed may surprise you even at a slower chain speed.
Hi Hilltop366, I was not really considering that. Thanks! I think that I'll go the direct-drive way then!