log grapple design/dynamics? 3 pt

[K5lwq]

I look forward to seeing the progress. Not sure why some are trying to convince you not to build something you are interested in doing. Keep the pictures coming.

 

[Smokeydog]

Smart Grapple out of Montana used to make 3pt and ssqa grapples. Bypass tongs would completely close. Could easily pull up small trees. Optional hydraulic winches.
Very well made and very expensive.

Bought a ssqa model going out of business sale. modified to 3pt hitch also. 3pt works best with hydraulic top link. Local tree service company made me an offer I couldn’t refuse. They love it for moving big wood on tight customer’s property with minimal ground damage. Loading logs long ways into the back of their chip trucks. They feed big limbs into their big chippers with it. Hugh manpower saver. They got the county contract to clear high hazard trees along the roads.

I see them every once in while. Still using it almost daily for 15 years. Had to rebuild winch (Warn) once.

 

[Rockbadchild]

I totally disagree with that, what do you do with that grapple arm when you can't get the tree through a muddy spot, or up a hill?? With a winch, no problem at all!

I'd MUCH rather have the winch on that small tractor...

SR

Good point, the winch definitely as its perks, the combination of both would be optimal. ... I simply see the practicality/productivity of simply being able to back up to a log close the clamp and leave, then being able to open the clamp to drop the log without getting off the tractor.

 

[Rustyiron]

3pt works best with hydraulic top link.

This is crucial
Also easy to build.
I have 3 sets of remotes and still run 2 diverter valves on my little setup.

 

[arrow]

I totally disagree with that, what do you do with that grapple arm when you can't get the tree through a muddy spot, or up a hill?? With a winch, no problem at all!

I'd MUCH rather have the winch on that small tractor...

SR

This is why I much preferred the cable skidders over the grapple ones to drive.
They were the only type my boss would get. Logging buddies were a mixed bag of opinion at the time but the advantage of the grapples was that you could eliminate the ground guy who choked up stems.
Getting off a tractor to do so, is much easier than climbing in and out of a skidder hence the separate choke setter.
As with everything, big grapple skidders have their place but my heart leans toward the cable type which kind of has become a dinosaur.
Actually, so has the ground logger here in the north east relinquishing to all kinds of machinery.

 

[MTGreen]

To answer a question, I am wanting it to grab a bunch of 6'-10' logs that the logger left scattered all over my friends property. I used my winch to skid the longer stuff out but it's a pain to use it on all the short stuff. I'm not even sure why they cut it into such pieces, maybe to get it off the usable log underneath or something. I have a grapple on the front so I have hydraulics on board, I too thing the tractor is too light to have this on the front although I'm not opposed to the idea but I have limited lifting capacity and having the log out there another 2'-3' isn't going to help. I don't have to drag them far, 50'-100' tops to the landing area. It's a small piece of property.

You asked about construction and not about practicalities. I would think that the 6-10 diameter of your logs would determine the curvature of the grapple arms. Maybe size for 12 in diameter on the inside and opening out at least 16 in. You might think about making the claws somewhere in the 18 inch long range. I would think it would be prudent to make the business edges serrated for better grip. I would also offset one claw slightly versus the other so the two can scissor to some degree and not come together exactly. This can be done by making one claw wider than the other and will allow you to hold smaller logs. You will also need to take into account what kind of cylinder here -with the sizes and duties that you are looking at here and maybe using 1/4" plate, I would guess off the cuff that you be using something like a 1.5"-2 inch cylinder. Go too big and you're going to mangle your fabrication.

I would suggest you make a mock up of the mechanism out of something like particle board or MDF or even stiff cardboard, glue it together, and make sure it articulates like you want it to, doesn't interfere, and covers the range of sizes you are interested in. Then you can trace the pieces on the plate for the plasma cutter. I recall somebody saying he likes using "CAD" -"cardboard aided design" for these sorts of things and I think it's appropriate here.

Good luck with your project and make sure you post pics

 

[Rustyiron]

The majority of loggers around here are highly mechanized. With the feller buncher making tidy piles of sorted (by market) wood, in the woods ready for the grapple skidded to haul off to the landing.... grapple sliders make perfect sense.
A friend who hand cuts runs a winch skidder that also has a grapple. But he bought it used but does take advantage of both methods.

 

[Sawyer Rob]

The majority of loggers around here are highly mechanized. With the feller buncher making tidy piles of sorted (by market) wood, in the woods ready for the grapple skidded to haul off to the landing.... grapple sliders make perfect sense.
A friend who hand cuts runs a winch skidder that also has a grapple. But he bought it used but does take advantage of both methods.

Keep in mind, the OP is talking about a 25hp tractor not a couple hundred hp skidder.

There's no doubt in my mind, that a skidding winch would be a MUCH better performer on a little tractor over a 3 point grapple, that is IF he wants to actually get something done. On top of that, the winch is so much more useful for many other things

I don't think this is about what actually works better...

SR

 

[davedj1]

Keep in mind, the OP is talking about a 25hp tractor not a couple hundred hp skidder.

There's no doubt in my mind, that a skidding winch would be a MUCH better performer on a little tractor over a 3 point grapple, that is IF he wants to actually get something done. On top of that, the winch is so much more useful for many other things

I don't think this is about what actually works better...

SR

I have a winch as well but it's a pain to use alone for these short logs. I plan on adding a couple of sliders on the cable of the winch so I can drag at least three of them at once.
Said winch:

 

[ROUSTABOUT]

This grapple just has two 1" arms and they bypass to close to zero. One cylinder in top makes it happen. No rotator. I don't see the need for one. We put a hydraulic winch on it, now the tractor stays out of so much junk.