Has anyone built a hydraulic chainsaw?

[Mack84]

Hi everyone, I made a little more progress today, it's getting closer , once guards and hydraulics are done I'll make a extended linkage for the thumb to get it at the right angle and also fabricate a whole new beak for it similar to a hardwood fork grab

 

[VroomVroom]

I worked on a 690 john deere excavator with a fab tech forestry harvesting head in it to cut, limb, and then cut to length for pulp. Out of all the functions on the machine such as opening and closing the knives, rolling the tree through the head, spinning the head and even the boom and track functions on the machine, believe it or not but that saw seemed to take the most power. Sawing the tree off to length seemed to bog the machine down more than any other hydraulic function.

 

[Mack84]

Hi everyone, I gave the saw grab a quick trial run, just gotta set limits and flows then start fabrication of guards, and extend alter the log forks about so saw handle and hoses clear the ground when say is in rest position, video is to large to post so here is my link to the first trial run on YouTube,

Cheers
Mack84

 

[Mack84]

 

[VroomVroom]

Seems like it works well. It does seem to take a lot of power doesn’t it. The machine I worked on also had a tiny piston putting tension on the bar to keep the chain tight.

 

[Smokeydog]

20” bar limbsaw.
Surplus Center Parker motor.
Adjustable chain oiler.

Controlling bar speed and or pressure a concern.

 

[Mack84]

View attachment 752439
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20” bar limbsaw.
Surplus Center Parker motor.
Adjustable chain oiler.

Controlling bar speed and or pressure a concern.

Smokeydog, I have put these flow control valves on that ram of mine to adjust drop rate of cylinder, you could install the same or similar to control flow to saw if you needed

 

[Mack84]

It's not too bad considering its only on a 1.5 ton excavator. Hopefully the last trip to the hydraulic shop today to get a inline check valve then I can finish the rest of it off and give you all a finished product next week.

 

[Smokeydog]

The top (red) section is simply hinged so weight and gravity controls the downward force on the bar.

Forward, reverse saw gets out of a bind.

Currently 9/16”, 0.325, 0.063 on 7 spur drive gear. Gathering some broaches to use 3/8 chain drive rims. Hard to find drives to fit small hydraulic motors. If I recall correctly at 12gpm, 2500psi, 5,000rpm makes about 15 hp.

 

[airbiscuit]

Here is Smokeydog's hydraulic chainsaw build it thread. Pretty good read.

Hydraulic limb saw project.