Stump puller

[tree grower]

Greetings all, from a new guy on the site. I am a Christmas tree grower, and find that I fabricate as many attachment as I buy. My current need is for a stump puller which attaches to my Bobcat 742B. I have rented a small Kobelco excavator with thumb several times, but it digs too much dirt, and the thumb doesn't have enough travel. There are several manufacturers of root grapples for skid steers, but they are designed for picking up debris which is mostly on top of the ground. I have Googled and researched for two years, and concluded that what I need isn't made commercially, so let's fire up the torches and welder!

I envision a mechanism which looks like a cross between a root grapple and a log loader grapple. The purpose is to extricate a single Christmas tree stump with minimal soil excavation. This will be fabricated as a universal skid steer mount using heavy channel and angle iron, not a full-face plate--I need to see through it. I am thinking of using box blade shanks (AgriSupply), two on the mounting plate and three arranged to act as a thumb. Max width for the three tines is 12" (6" apart), and travel so that they by-pass a little when closed. The mounting plate has 117 degrees of travel from -8 @ full roll-back to 109 @ full roll-out. I plan to mount the grapple assembly (think ice tongs) so it 'hangs' plumb when the mounting plate is rolled out @ 45 degrees. This will maximize my travel options.

I picture the operation as follows: approach a stump with the plate rolled out to 45 degrees, and the opposing tines (thumb) fully retracted. Dive in under the stump with the tines on the plate, roll back a little to get under it, then activate the thumb to clamp the stump. With a little forward-and-back with the machine, and some roll-back and roll-out with the mount, the stump is loosed and can be lifted up easily. Only 587 more to go!

This all sounds too easy, so I need some feedback to identify flaws in my design. Thanks in advance

[wedge40]

I think I know what you're trying to do
Here is link to thread from a few years back that might be of some help.
But instead of lifting the whole stump out your break the roots below the ground and then remove the stump.

Check it out.
http://www.tractorbynet.com/forums/b...t=ripper+tooth

[czechsonofagun]

Welcome, tree_grower!

Just thinking out loud - dont you want to apply tension to the stump, and then cut under it to interrupt roots?

[tree grower]

Keep the feedback coming. I have a root-rot problem which is best addressed by removing the entire root system of the harvested trees. I need to remove as many of the roots as possible (within reason), not cut them off. As far as applying pressure to the stump, you're thinking of leverage which requires some stump height. There's not much stump left after cutting a Christmas tree.

[BarryinMN]

Do you think your Bobcat has enough lifting/breakout force to pull that tap root up? Might need one of those tracked skidsteers.

Some of those center tap roots give my full size backhoe a workout!

[MrJimi]

How about a skinny , long tooth grapple. Some thing with 3 or four fingers on the bottom and a few less on top, that way you could pull it out like a dentist pulls a tooth and most of the dirt would stay in the hole after you shake it some

Jim

[philbuilt]

How about using some leverage. Think of the claw ona hammer. If you could fab somthing that has a simular shape. Drive into the stump and then lift and drive forward while rolling the stump out. I'll try and draw a picture.
Phil
tree stump claw.pdf

I hope this helps Perhaps it should be approximatly 30" long and about 12" wide at the end and as wide as you can make it towards the tractor.

[Redbug]

Possibly something like this?

Stump Grapple

[tree grower]

Thanks guys, keep em coming. I have checked out the X-treme stump grapple and similar units, but they are designed to function when the machine is moving forward, and they are more of a bucket than tongs. My land is all side-hill, and it's hard to push uphill. The machine is so well-balanced that when facing downhill, any weight on the front pulls it over on its nose. I need to approach the stumps from below and have the working forces on the front countered by the machine weight behind. The machine won't pull a stump by the grab-and-tug method, but works fine with the grab-and-wiggle-and-wigglesomemore-then-tug method. Fortunately I am not dealing with taproots. My trees are all balsam and fraser fir with 3-6 lateral roots seldom more than a foot deep.

One concern I have deals with gripping pressure of the thumb tines. If the opposing tines are hinged at the top, and activated by a cylinder mounted above, just like an excavator thumb, will there be enough pressure? It has been suggested I mount the cylinder below, like the door closer on a storm door. The theory is that there is more pressure brought to bear if the tines are pulled together, rather than pushed together. What think you ???

PS-Phil, what is the software you use to make the drawing? Auto cad? I would love to find a simple, Windows-based application for making quick line drawings.

[MrJimi]

You need something like these
Jim