Grapple project OPEN SOURCE
- Thread starter polemidis
- Start date
LD1
Epic Contributor
remember you are not sacrificing anything. Just giving up force in the desired direction. All the while redirecting the excess force in the wrong direction working to rip your grapple lid right off its hinges. Going to a bigger cylinder and a less than ideal angle....not necessarily a good thing.
Dang it....
No worries as long as it does what you need it to do.
What make/model/brand is your grapple?
Now that I have a better understanding of the geometry etc, I had to deside at a few things. Go smaller to fit the 4" cylinder better, or going bigger and but a 6" cylinder. I tried bigger. By 3" in length and about 2" in height.
This is what I have now. (Some components are missing and others are out place, and I believe I have to buff up the hinges, put dont mind that for now). Bore size 2.5"
2490lbs at the closed position,
1190lbs at the opened
36.25in opening mouth
13ｰ the cylinder at closed end
6.2ｰ at the the opened
The grid is 4". If thats good enough I will start working on the material/hinge shape and add some dimensional drawings too. You suggest 3/8" thickness? I was thinking for 5/16" and just put gussets at the risky to bend places.:confused3:
Are these numbers more than enough? I mean I could make it a couple more inches bigger and lower these numbers. With the 6" cylinder I have space. Or try the other approach and go for a smaller grapple?
This is what I have now. (Some components are missing and others are out place, and I believe I have to buff up the hinges, put dont mind that for now). Bore size 2.5"
2490lbs at the closed position,
1190lbs at the opened
36.25in opening mouth
13ｰ the cylinder at closed end
6.2ｰ at the the opened
The grid is 4". If thats good enough I will start working on the material/hinge shape and add some dimensional drawings too. You suggest 3/8" thickness? I was thinking for 5/16" and just put gussets at the risky to bend places.:confused3:
Are these numbers more than enough? I mean I could make it a couple more inches bigger and lower these numbers. With the 6" cylinder I have space. Or try the other approach and go for a smaller grapple?
Last edited:
ovrszd
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I built a double claw grapple onto a Bobcat LoPro bucket. It works very well and has hundreds of hours of hard use under it's belt.
As I've stated earlier, I'm totally a practical application guy. Your approach is over my comprehension level. So I design by the desired end result. In my case I wanted a large opening. That created the position of my cylinders. I had no idea how much bite force I was going to have until I put it into action. I don't need more force. I'm just a bit disappointed that my design doesn't score any higher.
I struggled a lot with position of the cylinder tabs. Tack welded, cut loose, moved, tack welded, many times to get where I ended up. When fully open and rolled back my claws parallel my FEL frame and curl cylinders so I couldn't open any wider. This "big mouth" design gives me the ability to push loose brush up in a pile, then roll the grapple forward until the claws span most of the pile. Clamp, compress and pick up a huge pile of brush. In the other side I have ability to clamp onto thin material such as plate steel, steel fence posts, or whatever.
Still, just disappointed in my force numbers..... :ashamed:
Xfaxman
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No, don't go smaller. especially if used on brush.
Have you seen the medium duty from Loflin Fabrication? Loflin Fabrication
ovrszd
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That's what I should have done. Made my frame mount tab taller and more forward, then used a shorter stouter cylinder. Famous last words!!!
Do you know what the stroke length is on that cylinder?
Edit: Never mind, I checked out your link. They say 10". My pea size brain can't figure out how to make that work on mine. My claws and apron must be shorter than theirs. I'll have to take some more measurements of mine.
LD1
Epic Contributor
Not sure why you are still so adamant on wanting to use a 4" or 6" stroke cylinder....when all the mfgs that spend thousands on designing and engineering all use 8" or 10" stroke cylinders.
Why re-invent the wheel.
But you have designing software ability. So whatever works for you.
I'd go no less than 3/8". That's pretty much standard on light and medium grapples.
Why re-invent the wheel.
But you have designing software ability. So whatever works for you.
I'd go no less than 3/8". That's pretty much standard on light and medium grapples.
LD1
Epic Contributor
Nothing to be disappointed about. You designed it and made it work to your satisfaction...so what more can you ask?
deanocraft
Silver Member
I'm following this thread and I really have enjoyed the mathematical approach. I wish one of my high school math teachers had used a real world example approach to show how math can be used after you pass the test... I think it would have really held the interest of many students. I did fine in math, but I remember thinking how I would never use that in real life!
Now I haven't checked the math for accuracy... Nor have I confirmed that the formulas are proper... But I like the approach!
Now I haven't checked the math for accuracy... Nor have I confirmed that the formulas are proper... But I like the approach!