Grapple Design Ideas

[DanR67]

</font><font color="blue" class="small">( DanR67,
That does fit nice. I like that. I think that will work out well for you. You may find all sorts of things you can do with that attachment. )</font>

Funny thing is - I got the two pieces of steel from two different scrap yards several weeks apart - can't really ask for more! /forums/images/graemlins/laugh.gif (Well, OK - the steel did have to spend the winter outside under a tarp - so I've got to clean everything up with a wire wheel...Kubotabilly looks like he was working with "freshly minted" steel!)

</font><font color="blue" class="small">( I like your toplink too. I have never noticed a bar being used like that on the tractor side. Neat. )</font>

This was a bit of a necessity - as the original, thread-adjust toplink fit into a bracket - the hydraulic cylinder came with a clevis (?) / fork attachment at each end. SO...I basically had to come up with a "gender-changer" to adapt the cylinder - here a detailed picture. The original toplink rod was attached at the bottom pin IIRC.

</font><font color="blue" class="small">( A little clarification on the crushing issue. I think the design should be done such that the cylinder bottoms just as the arms snugs up tight. This still will not prevent the item you pick up (non-compressible like a log) from crushing your implement. So, IMHO you must have strength to use the tractor's relief valve or add a lower pressure one on the cylinder. )</font>

Yep - I understand this as well. Having the piston bottom is purely to prevent the grapple from crunching when doing an "air grab". The cylinder mount, bucket reinforcement, pivot points / final leverage / moments, and pressure limiting valves all must be designed / matched to the task at hand. I do want to try to make this "idiot proof" so I don't hose something because I stayed on the valve just a bit too long... /forums/images/graemlins/blush.gif


</font><font color="blue" class="small">( I wonder if you could use a 4 x 3 piece of angle iron attached to the top of the bucket's folded lip. Put the 4" inside the bucket. Put your grapple pivots on the 3" vertical side. Build your rear cylinder support on a plate that bolts on the back of the bucket and through to the angle iron along the top. If the 3" cyl strength is controlled, that should be strong enough and give a very low profile. The next time I am by the B, I'll have to look and see if I think this will work. This is all probably as clear as mud. /forums/images/graemlins/confused.gif /forums/images/graemlins/smile.gif

BTW: I think 125# is a reasonable weight.)</font>

I had to re-read this several times - but I get your drift. I like the idea of mounting the grapple pivots to the angle iron - that way the bucket stays nearly untouched - save for some mounting holes. I had also thought of doing some general kind of "bolt through" cylinder mount / reinforcement plate - your idea is just more specific - thanks! /forums/images/graemlins/smile.gif

Re: 125 lb weight: that's my guess-ti-mate. Now thinking about the angle iron and bolt-through reinforcing plates - the whole assembly may go up as high as 150 lbs. Still within reason, I feel.

Long term - one of the options that I have in mind is to build some kind of "quick-attach" system for my FEL bucket - so I could add some front forks in addition to my 3PH forks - don't want to fiddle with bolt-ons, because I think the weight will be too far forward. I plan to move small pallet loads of wood pellets in the front as well as the back - halving my trips. Each pallet weighs: 17 bags x 40 lbs = 680 lbs + the "mini-pallet" (pallets cut in half on the short axis). They are delivered one ton / full pallet (50 bags) - which I cannot move with my B7610 - so I restack them onto 3 "minis" - takes @ 10 - 12 minutes / ton.

If I get around to this - then I would "clean sheet" the grapple - as I would not have the crushing concerns nor geometry / clearance concerns of the FEL bucket to contend with. This would likely also negate the "weight penalty" - as any "pure grapple" would likely weigh less than the FEL bucket.

</font><font color="blue" class="small">( Another note, you get better open/close geometry with closely mounted pivots. When you spread them apart, it limits how much you can open. Not good in my opinion.)</font>

This is the ONE thing my larger cylinder works in my favor for: with the higher forces it can produce - I can place the pivot points closer together and get more "swing" (grapple jaw opening) distance - while producing the same amount of grapple force as a smaller cylinder.

</font><font color="blue" class="small">( Good stuff, hope you don't mind my opinions... )</font>

Thanks - am enjoying your input - as well as seeing / reading the many talents of our fellow TBNers only helps crystalize my ideas. Keep the feedback coming!

Cheers,

Dan

 

[WhiteRock]

Here is rough draft drawing of my grapple fork design. I have made several design changes that aren't reflected here. In this drawing, I didn't cut the plate off on the forks in the CAD program.

The square pipe holding the tines is a 6" X 6" X 1/2" X 87". I plan to use 14 tines 42" long, 1.5" diameter, solid. The back plate is not updated and has been changed somewhat.

I am a little concerned about the strength of the 1.5" tines. To avoid bending, I plan to use a 8" X 1/4" plate along the bottom of the tines. I thought I would sharpen this plate so I could push it along the ground and shear small bushes etc. as I get brush.

I am <font color="blue">looking for input </font> on how far back I should place the plate? Anyone have any opinions? I want the tines to be effective, but I don't want to put the plate far enough back to make them weak. I was thinking about 8" from the tip.

 

[dummy]

Take a look at what these guys are building jack bucket I don't see it now, but he was talking about a rotator plate so you could turn the thing upside down or sideways for demolition work to "skim" ceilings or walls. Coupled with a grapple, it is a heckuva design for demoing anything inside or outside.. If you have some time to kill (like an hour or two) call the office @ 218-692-5535 Ask for Del.

Instead of sharpening one edge, maybe you could use a bucket cutting edge?

 

[WhiteRock]

This is quite an implement. That one is a lot larger and heavier duty than what I am trying to build. I thought my weight was going to be high! /forums/images/graemlins/grin.gif I just have a lot of clearing to do on my place. So I plan to just be piling a lot of trees for burning.

I thought about using a blade edge, but the shearing function is secondary. I just thought it wouldn't take much to configure during the construction phase.

 

[WhiteRock]

Grapple users....

Can you tell me if you always use your grapple arms? Do you really need to hold the load on, or can you pull it out with the rake, then pick it up and carry it away?

I had assumed that the arms need to open to a full vertical position. Do you find this to be the case?

Thanks.

 

[WhiteRock]

I am starting to think about the hydraulics for my grapple. I am thinking about adding a selector valve ( I think it is also being called a diverter valve) to my bucket curl circuit like PineRidge has.

Can anyone tell me if the buck shifts under load while activating the grapple selector valve?

The reason I ask is that in reading the specs, it looks like the new circuit starts to open as the other side starts to close. Looks like there would be crossflow causing a pressure release. Is this the case, how does this work?

<font color="blue">Answered: I found the answer to my own question in a previous forum " Electric Hydraulic Valve Kit From W.R. Long - ??? "</font>

 

[JRP]

This is on my M6800. I like it a lot, but unlike I imagined, I can't just drive along and the branches jump up onto the thing. It slips over some forks I made.

I recomend the slip over the forks concept. It has been very good. Two steel clips hold it on so it won't slip off. I want to make install / remove tool less.

 

[dummy]

That's a pretty slick idea. The clips go around the back side of the forks? More details maybe? Thanks

 

[WhiteRock]

That's pretty neat. Looks like a nice addition to your forks.

I had thought about making some flexible options for my grapple, but I have decided to make it a dedicated unit. My tines will be about 5" apart which give me 14 tines. To make the tines stronger, I plan to weld the bottom plate to effectively tie them together. Further, I plan to weld small angle iron supports from the tines to the plate.

I also got some addtitional ideas by plowing through some of the older forums as well. One was to make the grapple drop through the tines about 4". This way I can back drag brush with the rake flat.

So I have decided to put the plate back about 8" from the end of the tines. As the grapple come down through the tines, I will have it stop on the plate at the end of the cylinder travel. This will cause the grapple force to push back on all the tines instead of down on them.

My current ideas......

 

[DanR67]

Hi all -

Just to keep ideas flowing: while I'm not prepared to make up a table / calculation for various geometries of grapple cylinders - I do realize - based on Kubotabillys' grapple project - that some planning is in order - mostly because *real estate* for mounting the hydraulic cylinder is at a premium . My problem stems from the cylindrical "cross tube" that connects the FEL arms.

To that end - I though first of making some "scale drawings" / lever models - but when I considered that I would eventually have to recalculate everything....I decided it is much easier to model at 1:1 / full size.

So....here's pic #1 - tracing bucket outline