Grapple project OPEN SOURCE

[GLyford]

Seriously start adding up all the materials you think you would need, find them online, and price them. Add in shipping and tax (finding local to you will probably be the same or more). Seriously, shipping steel can cost the same or more as the steel itself. Now price ALL the hoses and hydraulic fittings. These add up fast. Find actual hydraulic cylinders, with retracted and extended lengths that will work for the range of motion and power you need. Add in the cost of about 10 lbs. of welding rod and a couple 10-packs of grinder cutoff wheels.

Now assume that you are going to break and mis-cut some, order some wrong fittings and a wrong hose here and there...it is seriously not that far out of line to add 50% more to your existing tally.

OK, you are talking about plasma cutting...do you own a plasma cutter yet? Have you priced them yet?

Have you seen what everything attachments has listed for grapples under the attachments forum?

 

[GLyford]

Let me put it another way:
Build what you want, for you. We'll help where we can. Just don't expect everyone here to jump in on your project with your enthusiasm.

Bonus idea for you:
Making something the least expensive way that still works is what manufacturers do, and they have a team of experienced people doing it. The fact they make enough at the end of the day to keep the lights on and buy lunch is simply survival. Thinking you can teach yourself how AND do it for less is not realistic, no matter how hard you want it be.

It can be fun. It can get you something no-one makes for you. It can take you from something you already have closer to what you need. But don't think that beating the pros at their own game will be easy.

 

[/pine]

There is a big difference between producing a single (one time) product and mass producing a similar product...you really can't make a realistic comparison...

 

[polemidis]

Now on the other hand, would a few pics give you some ideas of things that you might do that are similar, without getting too specific?
View attachment 526196View attachment 526198View attachment 526197

I cannot see the attachments for some reason

 

[polemidis]

Let me put it another way:
Build what you want, for you. We'll help where we can. Just don't expect everyone here to jump in on your project with your enthusiasm.

Bonus idea for you:
Making something the least expensive way that still works is what manufacturers do, and they have a team of experienced people doing it. The fact they make enough at the end of the day to keep the lights on and buy lunch is simply survival. Thinking you can teach yourself how AND do it for less is not realistic, no matter how hard you want it be.

It can be fun. It can get you something no-one makes for you. It can take you from something you already have closer to what you need. But don't think that beating the pros at their own game will be easy.

I mentioned before that beating with pros is not in my interests. Neither I believe that they charge too much. They do what they have to do. But if I can save the labor, the business expensess, and the shipping expenses that a commercial model has, and at some point to have a model with BOM and instructions that someone else can replicate, I will be satisfied. For example you can check the CEB PRess we built in Open Source Ecology. Since it was done for a compresses earth block machine, a grapple will be a toy. I really have no expectations from people. There is not much anyway. I am a little confused in some points (like why some designs have pins when some grade 8 bolts can offer similar function) but nothing much really. Last week I had no idea what a grapple was, today I have a 80% done CAD design.
About plasma cutting. Not yet. I see GREAT reviews on the CUT50 models that cost $250, that will suffice on 3/8" steel. I do not calculate it cost because I am going to buy one soon anyway (I have developed a CNC machine that I want to add the Plasma on when I overcome the Torch Height Controll obstacle). I really do not think these are problems.
Similarly when I tryied to finance a tractor few months ago, and FSA rejected my loan application, I end up fabricating a log arch to use with my ATV, and I had never welded before. Seriously I went to HF and bought a flux welder. The log arch still works, (well, it just retired since I got the tractor with a winch).
My "dissapointment" is when simple people -not pros- are not wiling to share a CAD file. Which is what motivates me. When I will finish the CAD, it will be available to whoever wants to jump start. 3 people refused to give me their designs. Whatever, I spent these 2 raining days in front of the computer and I have it almost ready. Take it from there, and improve it.

You say that I will have to add 50% cost to my projected one. MAybe, maybe not. Thats why I research, and thats why I CAD. To avoid mistakes in real life. But still, I may make some mistakes. When I document everything, the next one guy, will not make the same ones. Thats one step forward.

 

[ovrszd]

This is going to be a steep learning curve for you. Many drawings have failed when construction was applied. It's hard for a fabricator to convince a designer that something won't work. So who is going to be the person that spends the money to see if your drawing will work? Anxious to see physical progress.

 

[mike69440]

This could be a very good 3rd Year Mech. Engineering Design project at a 4 year Tech College to design, build, test evaluate and critique.
Involves almost everything but thermodynamics and dynamics, so maybe design a Pilot valve and spool control valve along with the Grapple and integrate it to a tractor.
Develop the BoM, manufacturing routing, purchasing, subcontracting, schedule, a lot to be learned hear.

The reason is this need to be a 3rd year project, is that it will end up being a senior project to finish, that if you don't finish it, you don't graduate.

Welcome to the real world.

 

[texasranger556]

Re bolts vs pins:
You can get tighter tolerances with a pin and you generally want it to stay stationary with one part of the hinge so you can grease the part that moves. To do that they are often pinned at one or both ends. Also want to consider among other things shear load, shock, operating environment (water, salt, dirt, etc), and useful life when selecting the materials, sizes, and design. Mechanical engineers get paid lots of money figuring these things out. Or copy an existing design.

That's the great thing about forums like this. Post up your design and people from varying backgrounds will point out the problems.

As others have said, if your primary goal is cheap, you're better off building the design around the parts you can find cheaply. For example, if you find surplus hydraulic cylinders that are some oddball size you might save 60% vs a common size. That comes with the drawback that you are married to an oddball size cylinder if you ever break it, or you have to modify.

I'll be interested in your BOM when you get it finished. My guess is you'll be well over $500 in raw materials, plus another $50-100 in consumables. Plus some unknown budget for "rework". If you like doing the CAD work, cutting, welding, grinding, adjusting, painting, modifying, then you can write off those 30+ hours as "free". Remember that buying plate you have to fit your design into readily available sizes like 4x4 or 4x8'. You may have to re-design shapes to waste less sheet material. It all takes time.

For me, I use projects like this as justification to buy a new tool or tools, so my projects usually end up costing similar to a commercially available equivalent, but I get a new tool too.

 

[/pine]

The beauty of releasing a design under a GNU General Public License is anyone can improve or add to the original design and re-release it...anyone that understands software release protocol has to love the approach...

 

[polemidis]

This is going to be a steep learning curve for you. Many drawings have failed when construction was applied. It's hard for a fabricator to convince a designer that something won't work. So who is going to be the person that spends the money to see if your drawing will work? Anxious to see physical progress.

Thats me

Re bolts vs pins:
You can get tighter tolerances with a pin and you generally want it to stay stationary with one part of the hinge so you can grease the part that moves. To do that they are often pinned at one or both ends. Also want to consider among other things shear load, shock, operating environment (water, salt, dirt, etc), and useful life when selecting the materials, sizes, and design. Mechanical engineers get paid lots of money figuring these things out. Or copy an existing design.

That's the great thing about forums like this. Post up your design and people from varying backgrounds will point out the problems.

As others have said, if your primary goal is cheap, you're better off building the design around the parts you can find cheaply. For example, if you find surplus hydraulic cylinders that are some oddball size you might save 60% vs a common size. That comes with the drawback that you are married to an oddball size cylinder if you ever break it, or you have to modify.

I'll be interested in your BOM when you get it finished. My guess is you'll be well over $500 in raw materials, plus another $50-100 in consumables. Plus some unknown budget for "rework". If you like doing the CAD work, cutting, welding, grinding, adjusting, painting, modifying, then you can write off those 30+ hours as "free". Remember that buying plate you have to fit your design into readily available sizes like 4x4 or 4x8'. You may have to re-design shapes to waste less sheet material. It all takes time.
For me, I use projects like this as justification to buy a new tool or tools, so my projects usually end up costing similar to a commercially available equivalent, but I get a new tool too.

Your last sentense will serve as a great argument to get my wife's approval! ahahahahah
I will stay awa from any odd part, since it will not be replicable by others.
Your estimation fits my budget! Hopefully you will be right.

The beauty of releasing a design under a GNU General Public License is anyone can improve or add to the original design and re-release it...anyone that understands software release protocol has to love the approach...

Exactly!! I cannot agree more! And I believe it is time to expand the Open Source into Hardware. It will a great thing The revolution in software has increased bu a lot. My CNC runs open source program, my computer runs only opens source, and I would never imagine myself building a CNC or 3D printer without some other people releasing their hardware designs!!