Grapple project OPEN SOURCE

[LD1]

These come in handy
Baum Hydraulics Corp :: Spec Calculator

 

[marchanna]

Cool project. In Canada, the price of implements are ridiculous, definitely an advantage to building your own.

 

[Zebrafive]

Oh ok, this is formula I think: Force = Initial pressure * (3.14 * diameter of cylinder^2)/4
So yes almost 11000 with 2.5", 7065 with 2"



Ok, I am back so many days without electricity. Too excusted to do anything, so many things to catch up. But I will finish that thing, it will be sooo useful. I have so much brush everywhere.
I need a little help. Can someone put a link of the pivot pin One that can take grease? I think I am slow, I cannot find it. Or else I will use just plain bolts.

The hinges of my grapple has solid pins, a washer welded on one end and other drilled for lynch pin. The tube of the hinge has a grease fitting at the middle.
My cylinders have greasable pivot pins. Not sure the source.
A lot of loaders have pins that are greasable through the pin (end has grease fitting) you may have to go to tractor dealer and look at their loaders and see if there is a pin you can adapt. This will be expense, probably cheaper to have a machine shop make you greasable pins

 

[ovrszd]

These come in handy
Baum Hydraulics Corp :: Spec Calculator

Good stuff right there. Saved. Thanks!!!!

 

[ovrszd]

The hinges of my grapple has solid pins, a washer welded on one end and other drilled for lynch pin. The tube of the hinge has a grease fitting at the middle.
My cylinders have greasable pivot pins. Not sure the source.
A lot of loaders have pins that are greasable through the pin (end has grease fitting) you may have to go to tractor dealer and look at their loaders and see if there is a pin you can adapt. This will be expense, probably cheaper to have a machine shop make you greasable pins

I prefer your style and consider them stronger.

 

[Viny]

Sorry, I'm a little bit late to this conversation. I just saw this thread and read a few of the early posts and thought I'd add my 2 cents. I'm kind of coming at this from a slightly different angle. I have a Kubota M4700 with a LA1001 FL. I have screw on (pinch) forks that I have used for years for carrying brush to and fro. A few years ago I had the dealer add a grapple to the loader and have this kind of frankenstein set up that has worked OK for some time.

Finally, I am converting my loader to skid steer hookup. I am removing the bucket, attaching a SS hookup plate and installing a SS plate to the bucket. With this conversion, I will be taking my forks and grapple and creating a new more (brush-centric?) efficient setup. I have been looking at many images of brush/root grapples on the internets and believe I will end up with a far better setup than I currently have. I will post pictures of the completed unit and will be happy to share any info I learn along the way...

 

[polemidis]

The hinges of my grapple has solid pins, a washer welded on one end and other drilled for lynch pin. The tube of the hinge has a grease fitting at the middle.
My cylinders have greasable pivot pins. Not sure the source.
A lot of loaders have pins that are greasable through the pin (end has grease fitting) you may have to go to tractor dealer and look at their loaders and see if there is a pin you can adapt. This will be expense, probably cheaper to have a machine shop make you greasable pins

I would like something that will be easy replicable. Something that whoever wants to replicate it, will see the link, and just buy it. I want to avoid that route that you mention. Thanks for your input, but I want to make it as easy as possible for someone that wants to copy this design.

 

[GLyford]

Easiest is solid pins, and drilled bushings. For the cheapest SAE grease fittings, available at any auto parts store, the drill is 7/32, and the tap is 1/4-28. You can drill with a corded or cordless hand drill. You will need a tap handle, but you can get those at hardware stores or HF. Try to find a HSS tap instead of HC (carbon steel) which break easier.

There are metric thread grease fittings which should be just as easy, but I don't know the tap and drill sizes off the top of my head. There is a lso a size fitting that uses 1/8" pipe thread, but a straight thread is probably easier to find. And lastly, there is a type of grease fitting that you just pound in a drilled hole, but I have never used them...my local stores carry the threaded ones.

 

[texasranger556]

The drive in fittings are ok until they pop out or you need to replace one, then they won't stay in as well and you end up threading the hole anyway.

For pins and bushings I buy that kind of stuff at tractor supply in the 3 point hitch/drawbar section. Between the different categories of hitches they have a decent selection from 5/8" or so through 1-1/4" diameter.

 

[polemidis]

The drive in fittings are ok until they pop out or you need to replace one, then they won't stay in as well and you end up threading the hole anyway.

For pins and bushings I buy that kind of stuff at tractor supply in the 3 point hitch/drawbar section. Between the different categories of hitches they have a decent selection from 5/8" or so through 1-1/4" diameter.

Nothing 19" long though. How about to use rod?

 

[texasranger556]

Wow that is long. Getting pins that long in and out might get challenging especially if anything gets tweaked.

 

[polemidis]

Wow that is long. Getting pins that long in and out might get challenging especially if anything gets tweaked.

You are right. I will do the simple approach then, with one pin/bolt for each side instead of one big one. Maybe The lid sides are 18" apart.

 

[Drewintoledo]

Polemidis - just curious if you've browsed the patent library for ideas also?

For example, here's the first hit I found when googling: Patent US4285628 - Grapple system - Google Patents

This is a fun exercize. I once created a design for a wind turbine which consisted of winding coils and potting magnets around plasma cut hardened steel hubs and such. Parts included bearings, magnets, copper wire, DIY jigs, bolts, etc. Since I don't own the tools to cut the CRS/HRS, I had a machine shop cut out the parts for me. I created a "kit" that included all of the parts from different suppliers. Before ordering, I placeed a feeler for a group buy out on a forum and had extremely positive feedback. I negotiated with the shop and the various suppliers and was able to reduce the kit price down dramatically. It'd be fun to see something similar evolve here. As others stated shipping ins't easy on the wallet but in my case the project was a financial success.

 

[Zebrafive]

Nothing 19" long though. How about to use rod?

Mine uses a rod. One end has large, thick washer welded on the other is cross drilled for lynch pins. Occasionally I would lose a lynch pin (I think brush would unlatch it) so I bought the HD "black" lynch pins from TSC and have not lost any since.
The tube for the claw is drilled in the middle and has grease fitting.

 

[polemidis]

Got you. I am wondering if it makes the lid more stiff, and if that worths the extra weight. Anyway, I just used the simple approach with bolts/ nuts instead of a tube with a greasable pin. If that fails soon or needs too much greasing I will upgrade it with the enclosed pin.

I think the design is almost complete. I just need some bracing on the lid, some expanded metal at the back and some protection below the cylinder. But I am tired, I need a break from CADing. I will start working on the BoM. What I am missing is a easy way to do the nesting for the CNC. Freecad's nesting tool is in development and does not work well yet.

Here is the step file.
Here are the original Freecad files if someone wants to edit them (needs Freecad v0.17)

With these 2.5" cylinders I get 2130lbs at the closed position
or 1360lbs with the 2" cylinders
And thats the geometry. The cylinder at the closed position is not 100% extended, it has a little travel yet thats why the lids look like they are overlaping the tines.


I love the colors! hahaha


I have no opinion on SAE vs NPTF ports. Other than the SAE uses a o-ring that seals easier, but the NPT has more fittings available??? What are the fittings on the 3rd function of a tractor does anyone know plz?, I found similar cylinders with SAE ports I can replace them

 

[LD1]

Need to gusset the lower tines

 

[texasranger556]

IMO go with SAE/ORB fittings. They seal better and are much nicer to work with especially if you have to take then apart in the future. Generally I like ORB male to JIC male 90 (or 45) degree fittings on cylinders then get female JIC hoses which come with swivels.

There is also ORFS (o-ring face seal) which is about the best for sealing and serviceability, but they aren't as common and more expensive.

Also JIC and ORB use the same thread pitch so in a pinch you can add an o-ring to a JIC male fitting and thread it into an ORB port.

 

[polemidis]

Need to gusset the lower tines

Yes, I forgot it, thank you! But vertical or horizontal? Maybe laminate them to make them thicker too?

IMO go with SAE/ORB fittings. They seal better and are much nicer to work with especially if you have to take then apart in the future. Generally I like ORB male to JIC male 90 (or 45) degree fittings on cylinders then get female JIC hoses which come with swivels.

There is also ORFS (o-ring face seal) which is about the best for sealing and serviceability, but they aren't as common and more expensive.

Also JIC and ORB use the same thread pitch so in a pinch you can add an o-ring to a JIC male fitting and thread it into an ORB port.

Thank you. Is something common usually on the tractor side?

 

[farm boy00]

Yes, I forgot it, thank you! But vertical or horizontal? Maybe laminate them to make them thicker too?


Thank you. Is something common usually on the tractor side?

I think the most common would be npt or sae

 

[polemidis]

Polemidis - just curious if you've browsed the patent library for ideas also?

No, I have never seen that! Thank for the info. Maybe on the next tool, it will save me some time.
Which by the way will be a well rig


Another question came up to my mind. What thickness should the tubings be??

The orange square members are 3"
The purple on the lid is 2".

The blu round tubing on the tines.
The purple on the lids

Do you need me to provide some dimensions/blueprint so you have better understanding without having to download the .step file? Any other suggestions/changes? (gusseting the tines is one noted)
Thank you guys!!!!!!