Simple Grapple Design done!

[ktm250rider]

Woild love to see the firewood processor. Keep toying with the idea of building one with my current timberwolf.

 

[rScotty]

SNIP....
But the impressive thing is that today -in contrast with a few years ago-, we have professional and free CAD programs to design it. And also run the Finite Element Analysis. It is that I -yet- do not trust myself. My experience with steel is zero, I have welded less than 2-3 hours total in my life, and i first used a tractor 4 months ago!
And here is the magic of the open source. I have spent about 200hours CADing, and you guys have spent 4hours helping me. I have the design open to anyone. When I build mine, whatever feedback with be posted on my webpage. The next guy who will build it will have all that for free. And every "next" guy will have a larget pool of feedback. Can we design all the major implements that way?? I think we can.

I think we can design things that way. It is fun to do, but still requires that there be people who will actually build and use them so that everyone learns from the mistakes.

For instance, I think that the "heel" of the lower part of the design is too thin. There is 1/8" steel being used at a sharp corner right where it is bound to get a lot of wear. While doing back-dragging for example. That is something that FE Analysis cannot predict. Most solid buckets solve that problem by making the back of the bucket curved. But bending heavy steel into a radius is just not appropriate for a home-built design.
And maybe I am wrong to be concerned about that steel being too thin. All I have is an opinion.

So the question is this: Do we try to design everything so that it won't ever wear or break and suffer needless expense and weight? Or do we deliberately make it as simple and light as possible and allow the design to evolve as needed?
rScotty

 

[KB7722]

I just downloaded it and opened it just to check it. It looks fine. What exactly is the problem? You can use Freecad v0.16 to open it, but it is made with Freecad v0.17 so ideally use that daily version. If you use solidworkds or some other CAD let me know so I can export it to .step format. And if you want to edit it the individual parts I will upload later these too. I will put some instructions on my wiki page.

Working file now. Thanks!

 

[polemidis]

Woild love to see the firewood processor. Keep toying with the idea of building one with my current timberwolf.

Its here. But I paused developing it for now as the plow and the grapple are a priority. I will start working on that right after. (in a 2-3 weeks)

rScotty I also think that welding the 3/8" tines(or 5/16") to the 1/8" square tube will not give the better results. I will upgrade it to 1/4". Opinions is what I am looking for anyway! If I wanted sure solution I would go to an engineer!
As for me so far I only design what I need. And thats the grapple, the snow plow, the well rig, the firewood processor, maybe a backhoe and then the CEB press (compressed plinths out of dirt, the machine is already made in Opensourceecology.org, i just have to upgrade it). As soon as it makes economical sense. For example I will now waste my time into a tiller or bush hog. There are so many used ones out there.

The other difficult part is how to get organized. In order a design to be fun, a collaboration of some people is needed. Look at my firewood processor above. Its a hugee project. After a while it get boring. And it could be easily split. The splitter, the conveyor, the chainsaw and the feeding system. And someone else can do the hydrauylic components which for me is a pain! I will do it, but its drains my energy.