Grapple questions

Rio_Grande · Dec 26, 2007

I have read till my eyes hurt about grapple design. One of the things I have unanswered is: I need the grapple to open to 90 deg in relation to the bucket sitting flat. My orignal plan was to build a grapple to fit my bucket. Then figure out what cylinder mount I need. Problem is I can't have the tractor down for more than a few days.

I have the basic design, but need to figure out how to get the full stroke out of the grapple to go from 90deg to closed.

KAB · Dec 27, 2007

Create a templete of desired shape of the side arm. Create a templete of the mounting bracket for the side arm (only 1 side is needed). (those items will remain constant) Then using approximate templetes of the cylinder mounting points, and somewahy to get an accurate reading between 2 points. (I tried to use a tape measure but working by myself it just did not work. I ended up using the top link and marking reference points on it to get the correct measurements) With everthing attached to the bucket start taking measurements of the open and closed positions of the grapple. You will find that as you move the cylinder mounting positions around that you can change the lenght of the cylinder as well as the stroke. This process actually took the longest for me.

Check this post for an idea of how I did mine. http://www.tractorbynet.com/forums/build-yourself/102733-another-grapple.html?

Or you can find somebody that is good with a CAD program and have them do the calculations for you.

I should also note that the tractor was never down the whole time.

Kurt

SPIKER · Dec 27, 2007

easiest way is to get some strong card board, a goof box cutter and some duct tape. cut out what you think will work and tape it on, make hinges using some wire coat hanger, simply poke the wire through both hunks of cardboard. if you make one that is short just tape more to the short part to extend it. too long then cut it back

Mark

3RRL · Dec 27, 2007

Rio_Grande said:
I have read till my eyes hurt about grapple design. One of the things I have unanswered is: I need the grapple to open to 90 deg in relation to the bucket sitting flat. My orignal plan was to build a grapple to fit my bucket. Then figure out what cylinder mount I need. Problem is I can't have the tractor down for more than a few days.

I have the basic design, but need to figure out how to get the full stroke out of the grapple to go from 90deg to closed.

Can you post a picture of your basic design? And exactly what it is you are trying to accomplish?
I presume you mean you want the grapple jaws 90 degrees straight up from the ground, right? Will your jaws have a curve in them?
The biggest problem in order to get enough rotation will be that when the grapple is fully open, you still maintain a "push off angle" of some sort. So that the grapple will not flop over backwards or "lock up" when fully open.
Why do you need the full 90 degrees?

Rio_Grande · Dec 28, 2007

Kab I had read your thread and that is basicly what I have in mind for design. I want to raise my munts up higher and opposed to forward.

The reason I need it to stand straight up is because I don't want to loose any bucket capacity. The Items I will be picking up are often irregulary shapped and often the grapple will only be used to keep items inside the bucket or balance them on the bucket.

I use this loader to move engines and framing. Often that means I need to get almost the entire bucket inside a piece to pick it up. With the grapple I may have more freedom but every inch that grapple leans forward is another inch that weight is pushed away from the center of the tractor. I often tax the capacites of the loader. The tractor has plenty of grunt but the loader needs all the help to balance the loads it can get.

KAB · Dec 31, 2007

Look at the link to Pineridges grapple. Instead of mounting the grapple directly to the bucket, make a mount that goes across the top of the bucket and then attach the grapple to that. Can be seen here http://www.tractorbynet.com/forums/...6667-question-about-grapple-573085-thurs2.jpg . I almost used that style but I needed to keep weight down.

Keep in mind that the arms will need to clear the edge of the bucket. That either means the fixed mount has to be in front of the bucket, or creating a P style grapple arm that will allow the arm to "wrap" around the bucket. The probem that I could see with that making sure that the cylinder will clear the bucket. (I almost had that issue).

Depending on how often that you will need the grapple and move engines, could you just unbolt the grapple when not needed?

Kurt