HELP mounting cylinders on grapple

[4440]

I have been working on a grapple for a skidsteer for the last couple of days. I have it nearly complete however the placement of the cylinders is killing me. I have tacked it together however the grapple didnt open enough to please me. I would like it to open as close to 90 degrees as possible. I am working with a cylinder that is 24 inches fully extended or 18 retracted. Could someone please assist in the calculations.

 

[MikeD74T]

Couldn't open your attachment??

Start by making a cardboard template of your grapple profile. Attach the pivot to another piece of cardboard/plywood & mark the desired swing path. Locate an arc perpendicular to the radius that has about a 6" arc length ( which you indicated is the range of your piston). This will be the travel path of your moving cylinder end. That arc can be relocated as desired. Wish I could draw it out as it's really quite simple. MikeD74T

 

[J_J]

It is going to be trial and error. If you already have the cylinder, then you know the stroke. You now have to find two points on the frame and the grapple, that will raise and close the grapple to your satisfaction. You could put the cylinder on top of the grapple or behind the bucket, pushing or pulling a short leg past the roll over point.

 

[MJPetersen]

I have never done this but I have read lots here on TBN that will help you in setting this up. First you can do a search in the "build-it-yourself" forum on two words "grapple" and "3RRL". 3RRL is a professional machinist and has give copious amounts of advice to amateurs like me thorough his write ups of his projects.

One of the threads that you will pull up in the search above is the answer to your exact question. http://www.tractorbynet.com/forums/build-yourself/143484-grapple-cylinder-placement.html Rob, 3RRL, explains in detail the process of setting the brackets for the grapple.

Mike

 

[HarleyScooter]

4440, I know what you are going through I just did my grapple. I can tell you what I did. For me it was like JJ said trial error. Get some 1" X (3-4") wood, use the same width as your cylinder dia. when test fitting it will make sure you do not have any clearance problems with the cylinder hitting the grapple. Cut one piece to 26" and drill three 1/4" holes or what ever size bolts you have. One at each end 1" in this will be your open length 24" and another hole 6" in from either end hole this is your closed length (18"). Cut another piece of wood so the pivot hole will be about 3" (starting point) higher than the grapple mount pivots, then one more piece for the cylinder mount on the grapple. From there you can test fit your mounting locations open and closed. I was also having trouble getting the grapple to open far enough, I found that the height and location of the front mount on the grapple itself made the biggest difference in how far it opened. I know this seems low tech, but wood is a whole lot easier to cut than steel.