DIY Fellerbuncher

[northforker]

Greetings,

I'm new to the forum but have stopped in for a look several times over the years and have picked up lots of useful information from the knowledgeable folks here. I'm not a professional logger or a fabricator, just a guy who has about 50 acres of trees and tired of harvesting them by hand. That said, here's some pics of a fellerbuncher attachment for a skidsteer I recently completed. I only had time to test it with a dozen or so trees before the snow flew, but it seems to work real well and zips right through. It's your basic hotsaw or disc saw scaled way down. The disc is 5/8" X 36" dia T1 steel with 12 Quadco 1-1/8" teeth mounted on the rim. I use my ASV's 25 gpm circuit to spin the disc at 900-1000 rpm and the other circuit for the grab arm. I'll fab a bunching arm for it over the winter. I've designed it to cut a 14" stump maximum for safety's sake. I can't wait 'til spring to use it more!

[islandlogger]

Welcome to this here forum northforker!
Say, that's some nice fabricating you done there! Nice looking unit, I can see you will have plenty of fun with that come Spring!!

[mad murdock]

Welcome northforker. That is serious skookum you got on that tracksteer loader nice job!!

[sprucebunny]

Welcome to the forum !
That is too cool 
Any guesses what it cost you to make ? What was the hardest part ?
I think I've found a winter project !!!

[thecfarm]

northforker,welcome to the forum. With a nice looking project like that one,there must be others?

[Piston]

Nice looking project and welcome.  I'd get in trouble with one of those things! 

Look forward to more action shots!

[chevytaHOE5674]

I'd get in trouble with one of those things! 

Very nice work. I too would get in trouble with that. I would have the entire farm treeless just because it was so fun to play with. hahaha 

[Raider Bill]

All I have to say it WOW!!! I like it!!!!

[northforker]

Thanks for the comments guys! Yeah, my wife saw the "Here's Johnny" look in my eyes the first time I fired it up and was very concerned for her trees. Yes, you do just want to cut everything down just for fun, kinda shaking like a junkie looking for his next fix.

I'd say the hardest part of building this thing was just figuring out how to do it. I went back and forth between building a tree shear, a bar saw feller, and the disc saw. Each has its set of pros and cons and that's why all of these solutions have been around for a long time. Because I have a relatively light carrier, weight played a big part in my decision. I wanted to build something sturdy, but have enough payload left over to actually carry a stem or two without tipping over. This ruled out a shear type of buncher as the high capacity ones (Dymax, Ryans, etc.) weigh in at around 1800 lbs. plus.

The bar saw feller is probably the most lightweight solution as there's no element of brute force to do the cutting. However, even a simple bar saw design ends up being relatively complex and requires a minimum of 3 hydraulic functions, 1 to turn the chain, 2 to grab the tree, and 3 to move the bar through the tree. Then there are the issues of oiling the chain, maintaining proper chain tension, and modulating the bar feed speed with chain speed. It's a fun to think about how to solve these little mechanical challenges, but I wanted to be cutting trees not tweaking a design until I got it functioning right. It seemed that the disc saw is the best combination of light weight and simplicity, just a big spinning disc and an arm basically. Cost-wise, I think all would end up being similar, with the shear being the cheapest and the bar and disc designs costing about the same.

I spent a lot of time just figuring out a workable design and what components I would use. Most fabrication time was spent on turning down the old truck axle. It is hard, hard stuff, probably 4140 chrome moly, and I have a cheap chinese 3-1 machine to do the work. I finally figured out that turning very slowly with carbide tool bits and lots of coolant worked taking off only a few 1000's at a time. Even drilling dimples for the setscrews in this stuff was impossible with HSS drill bits. I finally tried carbide tipped masonry bits (a few bucks at the hardware store) that worked very well.

Cost-wise, I figure I'm in the $2500 range on this project when you add it all up. The most expensive component was the hydraulic motor (~ $700) and the heavy duty type E Moline flange bearings (~ $400 for two). The Quadco teeth were about $150 at Baileys and steel was probably another 6-700 bucks or so. Throw in a few hundred more for hydraulic hose/fittings, double crossover relief valve, nuts/bolts, etc. Adding a bunching arm will cost a couple of hundred more for the cost of a small cylinder plus some kind of circuit splitter/selector valve.  Anyway, not too bad considering that a shiny new one built by real fabricators cost north of $25,000. I'd love to have one of those but, well you know...

[Coon]

That would be a nice rig to play on, however, on my land you would end up doing just as much if not more hand felling due to timber size and also due to the windfalls and such. 

Why wait for spring? A man's gotta get his fix of sawdust ya know.   

[Raider Bill]

That would sure work for me as a weekend/monthly wannabe logger trying to thin out my land. Hat's off to you northforker!

[barbender]

Very nice work! I'd like to build a bar saw dangle head for my skid steer. My problem is I only have one hydraulic circuit, and it is only 16 gpm.

[thecfarm]

northforker,if Raider Bill ask to borrow it say NO or he'll return it all burnt up. 

[semologger]

from were did you learn to do fab work that well at? Very well done.

[simplicityguy92]

did you build or by the saw?

[Banjo picker]

That is one cool build.  And welcome to the forum.  Banjo

[treefarmer87]

welcome to the forum very, very nice job

[northforker]

Thank You all again for your comments. Here's a couple more pics from the build. As you can see if you look close, I'm not a great fabricator. My goals are always simple, things that are made to stick together should stay stuck together, things should m/l work as they are designed to, and that nobody gets hurt. Anyway, as my Dad always said, "If you can't learn to be a good welder, learn to be a good grinder."

[northforker]

BB, You can do a lot with 16 gpm as long as you don't want to do it fast or do it all at once. An advantage of the bar saw design is that you grab on to the tree first. This allows you to take as much time as you need to saw through. Have you seen Danzco'z website (http://www.danzcoinc.com/html/standard_saw_components.html)? They sell hydraulic chainsaws and components that you could incorporate in a design. Their basic chainsaws are powered by gear motors using from 10 gpm up to 30 gpm. I have no idea what they charge. I think they are using Cross gear motors that will run a couple of hundred bucks new that you could source yourself. One thing I'd be interested in if I was making a bar saw is their feed and motor control valve. This stuff becomes more important with lower gpm/psi available.

Very nice work! I'd like to build a bar saw dangle head for my skid steer. My problem is I only have one hydraulic circuit, and it is only 16 gpm.

[northforker]

Why wait for spring? A man's gotta get his fix of sawdust ya know.   

I hear you on that, but most of my trees are 7+ miles off any kind of plowed road and the snow is *deep*. This is what we use to get there in the winter:

[northforker]

northforker,welcome to the forum. With a nice looking project like that one,there must be others?

Oh I do some stuff here and there. Here's a snowblower I built for the ASV 9 years ago. It's still going strong. I usually bust off a fan blade or two every season or something, but I just cut out a new one and weld it on.

[sandhills]

I'm very impressed with the fabrication to say the least!  Welcome to the forum, and with skills like that I think I'd be fabricating some windows for that ASV if I were you  .

[northforker]

Gimme a break! I've only owned this thing for like 11 years now

I'm very impressed with the fabrication to say the least!  Welcome to the forum, and with skills like that I think I'd be fabricating some windows for that ASV if I were you  .

[reride82]

With a name like Northforker in the NW corner of Montana, would I venture a guess you are on the North Fork of the Flathead River?

[northforker]

That sounds reasonable.

With a name like Northforker in the NW corner of Montana, would I venture a guess you are on the North Fork of the Flathead River?

[semologger]

northforker you didnt stop at the red light in your first video.

[barbender]

Northforker- I have seen that Danzco website. I'll look into it more when I get more serious about the project. BTW, I wouldn't make any apologies about your fabrication skills.

[Taylortractornut]

Northforker I d say you fall into the Fabricator bracket to.   I have a 14 gpm loader Id like to build a bar sawhead for it.     I worked in a yard that had  one that ran  was set up on one circuit.  for the saw.  The saw bar had a line teed to the cylinder it then  went to the motor.   The bar would push out as the motor had a restrictor orifice  it that let the fluid go to the cylinder first.  Then the chain hit the trun the chain would run.    The return for the bar cylinder was run off the  grapple opening.

[barbender]

Taylor, what was that bar saw on?

[northforker]

How well did that bar saw work Taylor? I wondering in the split hydraulic circuit you describe, what would happen if the saw started to bog? It seems to me that more PSI would push the bar out faster in that case and then cause the saw to slow even more. Wouldn't you want the bar feed to slow as sawing becomes difficult? I guess if the saw has plenty of power it's not an issue.

[Ron Scott]

Well done on the DIY Fellerbuncher. Do you have a lot of mountain beetle killed trees to work it on where you are located?

[northforker]

Thanks Ron. The beetles are not quite here yet but are getting very close. I wouldn't be surprised to see them here next summer. Anybody have any luck with Verbenone?

[Taylortractornut]

They had it on 2 setups.  THe first one was a  small shear head frame on an old Melroe Bobcat.  Then later had it on a  knuckle boom grapple one tim for bucking logs.     I haven seen it in a while. It worked out pretty good.    When the bar slowed down a the cylinder pushed a bit harder then the resistance from the cylinder would make the motor spin faster.    It seemed to work really well.   I think the one line and the set up actually metered itself better than 2 circuits. 

[northforker]

Thanks Taylor. That's intriguing. Anyway, it's simple enough to give it a shot and I'm all for simplicity. I use a simple circuit for the hydraulic chute rotator on my snowblower that might work too that used a single circuit. I run the auger through the valve body of an old log splitter valve. This would be in the P-T circuit so it's running all the time that I have the Aux circuit engaged. The motor that rotates the chute uses the work ports on the valve. By feathering the valve lever, I can move the chute fast or slow without robbing the auger motor of much flow at all. I think this could work for a bar saw setup as well, where I would use a bar cylinder in place of the chute rotator motor.

[mad murdock]

The beetles are not quite here yet but are getting very close. I wouldn't be surprised to see them here next summer. Anybody have any luck with Verbenone?

 
We did 5 years of research application for private timber co's and the USFS on test plots in CA, WA, ID, and MT using verbenone, the results were very good.  When the first large(ish) job came up for bid in 2010, The Government awarded the job to a company that had never applied the product, but because they had written a book on how they were going to do a good job, they got the bid, even though we were a bit under them in price.  I don't know if it was because of poor application results on that upscaled job, or if it was because of the government funding woes, either way, there has not been any more of that work.  The results on all of the test plots we had done, were excellent.  The disrupter flakes worked very well it stopping the beetle propagation.  BTW, I would not be ashamed of your fab work either!

[jr-transport]

I'd get in trouble with one of those things! 

Very nice work. I too would get in trouble with that. I would have the entire farm treeless just because it was so fun to play with. hahaha 

Ditto.
Looks good, and welcom here!

[snowstorm]

Thanks Taylor. That's intriguing. Anyway, it's simple enough to give it a shot and I'm all for simplicity. I use a simple circuit for the hydraulic chute rotator on my snowblower that might work too that used a single circuit. I run the auger through the valve body of an old log splitter valve. This would be in the P-T circuit so it's running all the time that I have the Aux circuit engaged. The motor that rotates the chute uses the work ports on the valve. By feathering the valve lever, I can move the chute fast or slow without robbing the auger motor of much flow at all. I think this could work for a bar saw setup as well, where I would use a bar cylinder in place of the chute rotator motor.

a priority valve would help.load sensing pressure compensated valves would be even better

[northforker]

Thanks Murdock. I've not heard of the flakes and will have to read up on that. Good, so the Verbenone works. The downside is that it's a bit pricey, at least for consumers. It seems cost ~ $20+ for a 2 pack. I read somewhere that you should hang 35 per acre. The $ adds up quick!

The beetles are not quite here yet but are getting very close. I wouldn't be surprised to see them here next summer. Anybody have any luck with Verbenone?

 
We did 5 years of research application for private timber co's and the USFS on test plots in CA, WA, ID, and MT using verbenone, the results were very good.  When the first large(ish) job came up for bid in 2010, The Government awarded the job to a company that had never applied the product, but because they had written a book on how they were going to do a good job, they got the bid, even though we were a bit under them in price.  I don't know if it was because of poor application results on that upscaled job, or if it was because of the government funding woes, either way, there has not been any more of that work.  The results on all of the test plots we had done, were excellent.  The disrupter flakes worked very well it stopping the beetle propagation.  BTW, I would not be ashamed of your fab work either!

[northforker]

a priority valve would help.load sensing pressure compensated valves would be even better

Good stuff for me to think about. Now you guys have me half starting another project! I get how a priority valve apportions the flow between the saw motor and bar, but would this work if the bar is moved by a double acting cylinder, or would you have to put in a directional valve downstream of the divider on the bar circuit? I'll have to do some more reading on the load-sensing pressure compensated valves. The ones I'm familiar with are used in conjunction with a variable displacement pump. Without knowing anything else (which I don't) ideally you'd be in tall cotton if you had a valve that could sense delta-P across the saw motor and inversely meter flow to the bar cylinder - so that if delta-P increases, bar advances slower and vice versa. Thoughts?

[snowstorm]

rexroth made load sensing pressure compensatered valves  valmet used them. with an open center gear pump. am surprised you have power enought with only 25gpm. what psi are you at?

[northforker]

Thanks Snowstorm. I'll look into the Rexroth valve. The saw seems to have plenty of power. Bear in mind that I'm not cutting down 20" hardwood or anything, just up to about 14" softwood. The aux. high-flow hydraulics on my machine are rated for 3000 PSI, but I'm sure I never get close to that. The saw is designed to cut mostly with angular momentum, just a disc weighing a couple of hundred pounds spinning at nearly 1000 rpm. By the time the disc start to lose momentum, I'm already through the tree. I use small teeth (1-1/8") for a relatively narrow kerf too which cuts down on the power requirements.

rexroth made load sensing pressure compensatered valves  valmet used them. with an open center gear pump. am surprised you have power enought with only 25gpm. what psi are you at?

[customsawyer]

Nice looking work. You certainly do fine on the fab work IMHO.

[sjfarkas]

Nice job.  I like your ingenuity.  I wish I had time to build attachments for skid steers.  A bar saw would be cool too.

[John Mc]

rexroth made load sensing pressure compensatered valves  valmet used them. with an open center gear pump. am surprised you have power enought with only 25gpm. what psi are you at?

Wouldn't the flow rate just affect the speed? I'd guess the torque would be more a function of pressure.

[snowstorm]

rexroth made load sensing pressure compensatered valves  valmet used them. with an open center gear pump. am surprised you have power enought with only 25gpm. what psi are you at?

Wouldn't the flow rate just affect the speed? I'd guess the torque would be more a function of pressure.

well sort of. on a cyl. the more the gpm then it should be faster. with a hydr. motor a little different. lets say you have a pulp loader with a 25gpm pump 2100psi. the main boom will lift a lot. but the bucket rotator dose not have a lot of turn power. most full size hot saws run what 70gpm??? at 4500psi???. at one time i had a morbark shear 14" rapid buncher it stood up well worked good and was happy with 25gpm. there used to be quite a few around here

[northforker]

well sort of. on a cyl. the more the gpm then it should be faster. with a hydr. motor a little different. lets say you have a pulp loader with a 25gpm pump 2100psi. the main boom will lift a lot. but the bucket rotator dose not have a lot of turn power. most full size hot saws run what 70gpm??? at 4500psi???. at one time i had a morbark shear 14" rapid buncher it stood up well worked good and was happy with 25gpm. there used to be quite a few around here

It's all a matter of scale. Let's look at it this way, a Quadco C series 52" disk (their smallest) weight with teeth and holders is 604 lbs. My 36" disk with teeth is ~ 200 lbs. We can calculate the moment of inertia (discs' resistance to change in rotation) with the formula 1/2*mass*r^2. The Quadco's moment of inertia works out to be ~1409 lbft^2 whereas my disc's moment is only 225 lbft^2. The Quadco disc's moment is 6.26 times greater than mine. Now, given that torque=moment of inertia*acceleration, it follows that to accelerate either disc to any equal speed requires the motor driving the Quadco disc to supply 6.26 as much torque as my motor, and that much more torque to keep the disc spinning at a constant speed when encountering any resistance during cutting. So the big hotsaws require much more power and torque just to get them up to speed compared with mine, this is before anything is cut.

Obviously, the moment of inertia works in the larger saws favor as once that sucker is spinning, it's going to take that much more cutting resistance to slow it down. Once my little saw starts bogging down, it will rely more on the torque of the motor as opposed to disc momentum. That's why if I scaled it to cut let's say 20" trees it probably would not work well - I wouldn't be through the cut before the disc lost momentum. I would probably have to stop halfway through to let the blade speed up again. However, for the small timber I'm working with, softwood up to 14" or so, this hasn't been an issue so far.

Thanks again to everybody for the comments. Have a Merry Christmas and Happy sawdust-filled New Year!

[snowstorm]

all the math makwes my head hurt. i know the vp at quadco. interesting guy

[northforker]

Yeah, mine too. I was hoping someone would check it for me! What a cool job it would be to work at a place like Quadco. Imagine getting paid to do this stuff.

all the math makwes my head hurt. i know the vp at quadco. interesting guy

[John Mc]

Northforker -

I believe those moment of inertia formulas only work if all of the mass is concentrated right at the rim of the disk. To find the true moment, you have to do integration (integrate as r goes from 0 to 26" for the Quadco disk). It's been too long since I've had to do that to even attempt it.

Also, you may be missing a time variable in your torque calculations: "to accelerate either disc to any equal speed" in the same amount of time...
With identical torque, if you were willing to wait a whole lot longer for the Quadco disk to come up to speed.

The last time I dealt with this stuff was a couple years out of college (and I probably had to look it up then), so I may be all wet on this...

[northforker]

 Thanks for checking John! Nope, it's not that complicated. Start here. Moment of inertia for a point mass is just the mass multiplied by the distance between the point and the rotational axis squared, that is to say I=M*r². The same equation can be used for an infinitely thin hollow cylinder with mass M with radius r, no? Okay, one step further. Let's suppose we have a hollow cylinder with a finite thickness rotating about its axis. It's moment of inertia will be the mass of the cylinder multiplied by the radius of the average thickness of the cylinder or I=1/2M*(cylinder's inside radius² + cylinder's outside radius²) or I=1/2M*(ri²+ro²). Okay? Now last step, let's look at a solid cylinder (a disc in our case). Let's take the last formula and substitute "0" for r_i since our cylinder is no longer hollow. That leaves us with I=1/2M*(0+r_o²) or as I put it earlier I=1/2M*r²  .

Yes, you are exactly right about the time variable that is what I meant to imply "in the same amount of time." There's no doubt that I could get the Quadco disc up to speed eventually, but life is short. Plus, what would I do once I cut through a 20" tree grasped by my little ASV loader... ? Okay, enough geek stuff for 2011 already.

[Ron Scott]

Northforker: Are you located near Polebridge, MT?

[northforker]

Yes Ron, pretty close. My home is south of P'bridge and have a cabin north of there. Are you familiar with the area?

Northforker: Are you located near Polebridge, MT?

[barbender]

Wow, you fellas get talking about moment of inertia and all, I have to tap out My wife and I went to NW Montana on our honeymoon back in '98. We stayed at a B n B in Eureka. I was amazed at all the logging and mills out there at that time.

[northforker]

You'll see a lot less logging and mills up there if you were to see it now. Stimson pulled out of the old Libby Mill in 2003 I think. What was left burned to the ground in 2010. Owens and Hurst in Eureka closed some time ago as well. The area ran out of timber sales and trucking in trees from Idaho was too expensive. The American mill in Olney shut down too as did Trout Creek over in Thompson Falls. I'm sure there are others that I forgot about but needless to say there's hard times for Lincoln County now.

Wow, you fellas get talking about moment of inertia and all, I have to tap out My wife and I went to NW Montana on our honeymoon back in '98. We stayed at a B n B in Eureka. I was amazed at all the logging and mills out there at that time.

[Ron Scott]

Yes Ron, pretty close. My home is south of P'bridge and have a cabin north of there. Are you familiar with the area?

Northforker: Are you located near Polebridge, MT?

I've been to Polebridge a few times and out to Bowman Lake, etc.so know the area some. A neat place. There have been several forest fires in the area and my son Todd lived in Whitefish as a fishing and rafting guide on the Flathead and worked at Big Mountain. I also have some good  friends that live in Whitefish and Kalispell.

My son Todd and his wife live in Bozeman now. He and his wife were here over Chritmas and just left here today.

[northforker]

Ron, Your son did a fine job of pairing his interests with geography. Smart kid. We had big fires up here in 2001 (Moose) and 2003 (Wedge,Robert). 2003 was a bad year for us but could have been a lot worse, The Wedge fire started a few miles from our cabin and was about a mile away when we went up and evacuated what we could and brought it home and put the stuff in the garage. Five days later, the Robert fire started and came within 1/4 mi. from our house on its initial run. We had to evac in a hurry. It's not a good feeling looking in the rearview mirror and wondering if your house was up in that cloud of smoke. Tough summer as the fires started early and burned nearby for a couple of months. Both our home and cabin survived thanks to the work of the firefighters and a little luck in wind direction.

Give me a holler if you make it out this way again.