Hydraulic limb saw project.

[npalen]

Yeah, I can see where the angle is needed for best orientation. The leaf spring concept could be adapted with them on the topside and underside of the pivot but it would require a major overhaul.

A pair of extension springs, one above and one below the arm pivot might be easier to adapt. The spring above would need to be heavier or adjusted with more preload to support the weight of the saw when not cutting.

I'm sure you've probably considered gas springs also.

Regardless of how your design ends up, it is very interesting and you've done a great job of putting plans into action!

 

[airbiscuit]

So that last silver part is simply a lever extension for the bungee cords to attach to?

 

[Smokeydog]

So that last silver part is simply a lever extension for the bungee cords to attach to?

White holely thing on top.
Now red.

 

[npalen]

Should have been white to go with the red and blue!

 

[dstig1]

You could also consider aluminum for some items, though that eliminates welding if you aren't set up for it. I could see that big box cover in aluminum for sure.

I've been following the build but haven't commented until now. Nice work!

 

[2manyrocks]

Had to read the entire thread just to make sure the bungee thing was for real. I wouldn't trust a bungee for anything. I would guess they'd become more stretchy as soon as it gets summer when the sun beats down on them.

FWIW, there's a youtube video of a guy rigging a chainsaw in a tall tree that he controlled remotely.

.

 

[airbiscuit]

There is so much that is cringeworthy in that video.

 

[2manyrocks]

My only thought in posting it was it showed someone else's attempts to maintain tension on the chainsaw as it made the cut.

I suspect that's the similar issue here with the hydraulic saw is how to maintain the right amount of tension on the saw? OP must be planning something to have built that plate assembly because I don't think he'd build anything like that just to put a few bungees on it.

 

[Smokeydog]

Share some experience cutting.

Not relying on bungees. They do help controlling bar weight on thick stuff. Jury still out if really needed. Like any new tool, time and experience required to master.

Ash blow down this week. Could make a couple of cuts but not the best tool for cutting trees on the ground. Do like the reach and ability take weight off the high stuff.

This saw configuration is a lot stronger and faster than a Husqvarna 372XP. It eats wood like a beaver. Can stall it like any saw. The chain sprocket does have a 1/8” square key on the motor shaft which hopefully is the weak link.

Do like being able to see thru the grapple VS bucket on some cuts.

Have kept the FEL soft ride engaged. While not much of a load for the tractor it dampens movement using and travel.

Like the blade on the left. Motor outlets on the side give thinner profile.

Camera might help at first but experience helps too.

Haven’t been able to notice oil loss from the tractor yet. Chain getting oil. May reduce to one drop per 15-30 seconds? The strength and durability of the chain and bar is certainly being tested. Easily tighten the chain with screwdriver thru the hole on the bar. New chain adjusted twice.

Nice being able to safely and easily cut back all the cab slappers and face floggers. In a couple of hours you can generate a day+ amount of brush to carry off. Have miles to work on. Certainly very happy with the results and will be a valuable tool helping maintain the farm. Been a fun and rewarding project.

 

[D2Cat]

Various saw designs use a nylon strap to keep the hinged saw part from flopping down while getting the saw in position on a limb. There is a preferred angle and it's adjustable by the strap ratchet. When the saw is on top of the limb the boom is lowered until the nylon strap has a bit of slack, indicating the saw is setting on the limb and ready to cut. As the saw is powered the saw weight is the force being applied and allowing to saw to go through the limb.

(This is in response to the comment about the bungies.)

 

[2manyrocks]

Whole thing is interesting from the viewpoint that there are all these tree cutting services that rely on a bucket truck and a man in the bucket using a hydraulic powered polesaw. If you could come up with something that did the same job without having to raise a person 40' in the air, that could be a major cost saver.

 

[charles todd]

That looks awkward AF...

CT

 

[D2Cat]

Looks can be deceiving!

 

[Smokeydog]

Update.

Now with more experience under the chain. Short learning curve techniques to use. Rugged, no build failures. Motor has plenty power but can be stalled without damage. Chain still sharp. Have not gotten stuck without being able to back out.

Doesn’t take long to generate considerable amount of limbs to haul off. With miles of roads, pasture perimeters have plenty to trim.

Can reach and cut bigger limbs I couldn’t do with a pole saw. My half mile green tunnel is getting trimmed. Even small long horizontal beech limbs can be cut. Having reach off to the side road advantageous.

Enjoyed building as much as using. It’s too heavy to lift far for me. Storing on a tubing stand can store and slide on easy enough.

Mounted to a grapple OK. Had to move a few big limbs to keep trimming without removing the saw. Didn’t or see advantage of carrying off limbs while installed. Too much to watch out for. Do like the vertical or lean back position when in transport mode. Adding a HD receiver hitch to regular bucket for an extra mounting option.

 

[2manyrocks]

Trees don't look that big until they are on the ground and one has to find a place for the debris.

 

[Smokeydog]

Carving my green tunnel there are hundred+ of long thin ~1” branches projecting into the driveway. Some starting high and sweeping down. Use both sides of the chainsaw driving the tractor and using the FEL hydraulics to hedge clip these off. Works good up to about 1.5”. Have to be aware when cutting with the top of the bar that the limb has to give or spring. Cutting while rolling back with the hinge more forgiving. Some cuts would have been a challenge with manual 20’ polesaw with the spring pole effect. Chainsaw cuts easy. Over 1.5” or close to the trunk have to lay on and hinge. Cutting the small stuff appreciate added weight and strength of the build.

The 20” Tsumura chainsaw bar is a first for me. It has really taken lots of side to side flexing and always come back true. Don’t try to flex but part of the telemetry hazards of using.

The armor around the motor is showing some battle scars. Particularly going in and cutting the small branches. Glad it’s 1/4” CR plate. Can see where a stick could come in from the backside and hit the metering valve. Need to close that opening up some with a plate. After operating for several hours the motor is only warm to the touch. The saw only running a small percentage of the time. Running tractor about 1100rpm seems to be the sweet spot for maneuvering and cutting.

 

[Xfaxman]

 

[npalen]

Carving my green tunnel there are hundred+ of long thin ~1” branches projecting into the driveway. Some starting high and sweeping down. Use both sides of the chainsaw driving the tractor and using the FEL hydraulics to hedge clip these off. Works good up to about 1.5”. Have to be aware when cutting with the top of the bar that the limb has to give or spring. Cutting while rolling back with the hinge more forgiving. Some cuts would have been a challenge with manual 20’ polesaw with the spring pole effect. Chainsaw cuts easy. Over 1.5” or close to the trunk have to lay on and hinge. Cutting the small stuff appreciate added weight and strength of the build.

The 20” Tsumura chainsaw bar is a first for me. It has really taken lots of side to side flexing and always come back true. Don’t try to flex but part of the telemetry hazards of using.

The armor around the motor is showing some battle scars. Particularly going in and cutting the small branches. Glad it’s 1/4” CR plate. Can see where a stick could come in from the backside and hit the metering valve. Need to close that opening up some with a plate. After operating for several hours the motor is only warm to the touch. The saw only running a small percentage of the time. Running tractor about 1100rpm seems to be the sweet spot for maneuvering and cutting.

Cutting while rolling back with the hinge more forgiving.

I think I understand your methods except the above.

 

[Smokeydog]

Cutting while rolling back with the hinge more forgiving.

I think I understand your methods except the above.

The saw arm is hinged to the boom. Held at angle with 2” tie down strap. Most cuts the saw bar is set down on limb, the polesaw is then lowered to have only the hinge saw arm weight on on the saw bar. This limits the saw pressure or weight independent of hydraulic position.

If cutting backward the saw arm still can swing up if pulled on too hard. Cutting this way is slow and careful with small moves.

Guess one could undo the strap and let the saw arm pendulum down. Give forward and back swing cutting if doing more hedge type trimming? IDK. Most of my cutting today was a combination and laid down a bunch of limbs. Cutting back the vegetation is a routine maintenance item for decades. Never been this easy.

 

[Gordon Gould]

Cutting back the vegetation is a routine maintenance item for decades. Never been this easy.

gg