Author Topic: Help/advice in choosing a 3pt grapple for small time tractor logging? (Read 3018 times)

bill m · « **Reply #40 on:** February 03, 2012, 09:32:02 pm »

Piston, All of my logs are sold to a mill. This is my 3rd winter on this job and I won't finish before mud season. I also have a lot of other jobs, with big timber on them, lined up. Enough for at least the next 5 or 6 years. As for the trailers you and Spalted Dog are going to build I don't think the idea of running the loader from the tractor seat would be very practical. When loading logs a lot of times you will need to trim stubs that were on the bottom of the logs. Often times you will leave the tree full length because you can only reach one end. You will have to pull it to you, get off and cut the first log then pull the tree again, cut another log and so on. A awful lot of up and down from the drivers seat.

shinnlinger · « **Reply #41 on:** February 03, 2012, 10:54:52 pm »

I'm following this thread with interest as I currently have a8k electric winch mounted on my rear blade which is fine for the $ invested but am always open to other ideas..
On a related side note, I'm on my family farm I quasi inherited and my family owns land on the coast in Maine my 6th great grandad got for fighting in the revolution...cousins all around as the original parcel got pared down. not everyday you can hang with your forth and fith cousins and know it...

Piston · « **Reply #42 on:** February 04, 2012, 04:41:31 am »

Quote from: bill m on February 03, 2012, 09:32:02 pm

....When loading logs a lot of times you will need to trim stubs that were on the bottom of the logs. Often times you will leave the tree full length because you can only reach one end. You will have to pull it to you, get off and cut the first log then pull the tree again, cut another log and so on. A awful lot of up and down from the drivers seat.

Never thought of that!

Shinnlinger,
That's awesome you have a connection like that to your land!

Piston · « **Reply #43 on:** February 04, 2012, 04:54:26 am »

So I've been thinking about, IF I were to try and build a 'skidder grapple' what sort of things I would want incorporated into it.

I came up with a quick sketch (roughly to scale, but certainly not exact) of what I would want.

I basically took the attributes that I liked from all the grapples, and combined them into one, with an emphasis on the least amount of stress I could put on the top link. One of the major helpers here is obviously being as close to the tractor as practically possible. I know the stress is exponential the further away the weight is behind the tractor.

I made a basic frame that would attach to the 3 pt hitch. From there, I made a pivot point so the rest of the grapple assembly could swing freely side to side. I would add stops so it can't swing so far as to hit the tires. I would also add an engageable 'lock' so when the grapple was empty it wouldn't swing around, or possibly some heavy duty springs, which I don't love the idea of as there is a lot of potential energy stored very close to the tractor seat! I also thought of another hydraulic ram for the side to side, with a float position. That's getting too far ahead though

The problem that arises with a short 'boom' is that there won't be enough up/down movement to reach a log sitting on the ground, and get it high enough where it will clear the ground, so what I did is add another hinge point for up/down movement, and add a hydraulic cylinder there. This way, with the combination of the hydraulic top link and the up down of the boom, I would have plenty of vertical travel.
-Another advantage to this, would be that a lot more weight is concentrated on the bottom of the frame, at the lift arms, versus having everything supported by the pulling force of the top link, up high. Although, am I correct in that reasoning?

I could forgo the hydraulic up/down ram if I had enough vertical travel with the top link alone, and replace it with a steel knee brace for support.

The distance from the forward most part of the frame, to where the grapple is hanging, is approximately 3 and half feet.

shinnlinger · « **Reply #44 on:** February 04, 2012, 07:57:58 am »

You can also install a winch above your grapple, be it electric or hydraulic for the occasional times you need little more reach

Piston · « **Reply #45 on:** February 04, 2012, 09:28:52 am »

Good Idea,
I just finished wiring in an auxiliary plug for the winch that I'm adding to my log arch, so I could just weld another 2" receiver hitch onto the top of it.

The plug is the little gray one inside the fender. The downside is that my winch is only 4,500lbs.

beenthere · « **Reply #46 on:** February 04, 2012, 10:26:19 am »

Add a hyd. top arm for the up/down and remove the one on the grapple arm (it will not stand up to being a log bumper to a log in the grapple).

Move the "side to side swing" pivot point forward and in a plane between the 3 ph attachments (i.e. incorporate the pivot within that frame). As you say, the more you can move forward the bigger load you can lift.

Good on your progress.

Piston · « **Reply #47 on:** February 04, 2012, 11:12:28 am »

If I move the hydraulic up/down to the top of the unit, would that be putting more pulling strain on my top link? It seems it would? I see what you mean about the ram not standing up to a log as it is now though, good observation

I could weld a heavy guard in front of it possibly? My thinking is that if I'm pushing up from the bottom on the main boom, there will be more force directed to the bottom of the frame and the lower links, whereas if I'm pulling the boom up from the top, I'll have more tension stress on the mounting holes for the top link.

beenthere · « **Reply #48 on:** February 04, 2012, 11:19:46 am »

I'd replace the top link with an hydraulic cylinder.

What size tractor do you have? From the pic the 3 ph rocker arms look a bit light duty for the grapple build you are planning.

Piston · « **Reply #49 on:** February 04, 2012, 11:23:27 am »

Quote from: beenthere on February 04, 2012, 10:26:19 am

Move the "side to side swing" pivot point forward and in a plane between the 3 ph attachments (i.e. incorporate the pivot within that frame). As you say, the more you can move forward the bigger load you can lift.

Great idea beenthere

Maybe I can recess the hinge point in more or possibly make more of a V shape with it.

One of my thoughts, and don't be afraid to tell me it's a stupid idea

, was to make the main frame of the attachment able to rest down onto my main drawbar (not the bar that goes between the links, but the one you would normally pull a heavy load with, I don't know the real name for it)

I was thinking I could attach the unit to my 3pt hitch, lift it up off the ground, then install my drawbar, or rather pull it out a bit, so that I can then lower the 3pt hitch slightly until it sort of 'rests' onto my drawbar, transferring some of the weight to the drawbar, then use the hyd up/down to raise the log instead of the 3pt hitch.
Does this sound like a recipe for disaster, or a good idea?

Piston · « **Reply #50 on:** February 04, 2012, 11:25:17 am »

Quote from: beenthere on February 04, 2012, 11:19:46 am

I'd replace the top link with an hydraulic cylinder.

What size tractor do you have? From the pic the 3 ph rocker arms look a bit light duty for the grapple build you are planning.

That's what I'm worried about. It is a lighter duty tractor and possibly I'm just asking for trouble if I do go through with this, but that's what you guys are here for

It's a 45hp tractor, but being a Kubota, is NOT the more heavy duty of the tractors out there....

I do have a hydraulic top link in transit

Reddog · « **Reply #51 on:** February 04, 2012, 11:40:30 am »

I think you have over designed your current drawings.

I would lean towards building a lighter version of the Addington 3point with your winch mounted on top.

What are the max lift weights listed for your 3point?

Piston · « **Reply #52 on:** February 04, 2012, 11:53:29 am »

Lift capacity at lift point … 2870 LB

Lift capacity at 24" lift point … 2310 LB

Piston · « **Reply #53 on:** February 04, 2012, 11:53:54 am »

I think I need a bigger tractor....

beenthere · « **Reply #54 on:** February 04, 2012, 12:24:19 pm »

Quote from: Piston on February 04, 2012, 11:23:27 am

.......One of my thoughts, and don't be afraid to tell me it's a stupid idea , was to make the main frame of the attachment able to rest down onto my main drawbar (not the bar that goes between the links, but the one you would normally pull a heavy load with, I don't know the real name for it)

.......

That name is correct.

Don't think that idea will gain you much given the extra work to install the drawbar or move it out of the way when not needed.
Myself, I'd not go the 3pt grapple route with that size tractor. The winch like the Farmi, Norse, Valme, etc would be the best way to go. IMO

Reddog · « **Reply #55 on:** February 04, 2012, 03:02:03 pm »

Quote from: Piston on February 04, 2012, 11:53:29 am

Lift capacity at lift point … 2870 LB

Lift capacity at 24" lift point … 2310 LB

My M6800 has a 4550# lift capacity at the point.
So figuring you are only lifting half the log weight, 2000#'s is a pretty good size log.
But a 351 winch will be much tighter to the arm point.

mroldstyle · « **Reply #56 on:** February 05, 2012, 06:10:21 pm »

Piston
If your on TBN check out the thread I started on "a different kind of grapple" you'll see the 3pt grapple I built.
You definately want a hydraulic side swing.