Grapple Design Ideas

WhiteRock · Apr 21, 2005

That right! Just think, if cutting and tacking it together is fun, you may actually enjoy making a mistake! After you grind and cut it apart, you can weld pieces back together before you restart!

I never thought it could be this much fun! Screw this drawing and paper doll stuff! /forums/images/graemlins/grin.gif /forums/images/graemlins/cool.gif /forums/images/graemlins/grin.gif

DanR67 · Apr 21, 2005

( It won't work. As soon as it rains the cardboard will get mushy and you'll loose your load. /forums/images/graemlins/wink.gif )

LOL! /forums/images/graemlins/grin.gif

But seriously - I know what you mean about "just do it" with steel - and for sure I plan on improvising "on the fly" when construction actually begins. Much of this also has to do with the materials I have on hand - I have a (very) general idea of what I think this will look like - but I may see a piece of angle iron that "fits" part of the puzzle - but only after having completed some of the assembly...

This happened when I was designing my 3PH fork frame - I started off with one thing in mind - then "bingo" - I saw how I could assemble things differently (and in this case - fewer cuts) - and the whole design crystalized in a matter if minutes! /forums/images/graemlins/cool.gif

But of course...I'll be here beggin' for advice here when (not if!) I've screwed something up.... /forums/images/graemlins/blush.gif /forums/images/graemlins/grin.gif

Dan

WhiteRock · Apr 21, 2005

I really think you should consider making a design assumption to limit the 3" cylinder force. Remember you always want to break the grapple before your bucket or loader frame.

If you analyze KubotaBilly's design (of course his FEL was a lot stronger) it is quite interesting how it works. He also used some pretty strong steel. But in the last few degrees before closure, his force on the buck is down to a few hundred pounds, the rest is trying to pull the steel bar apart. This way there are no damaging forces on the loader. As the loader open it gets stronger quick with the max strength at full open.

I you don't you this technique, consider a relief valve.

WhiteRock · Apr 28, 2005

Well.... Did you take PineRidge's advice? Are you cutting steel?

I seem to have hit a hay bale... I am having trouble with my grapple arms. I drew the attached grapple arm in CAD and sent it out for a quote. I specified 1/2" X 28" X 32" with a 1" hole. It came in at $306 per arm. So that's not going to work. I could almost buy a grapple for that. I am a little spoiled I guess, I have been paying $0.15/lb for my steel. But this is a complex cut. I sure need that plasma cutter.

Actually at the above price, I could buy my plasma cutter, and do it myself and have the machine left over.

I am starting to think about a way to weld a bunch of angle iron together to make my arms. It wouldn't be pretty. I don't mind the welding. I just have to make it strong enough. I am just not sure what to do at the moment.

I still have some calls into folks for quotes to see what they come up with. I may try PineRidge's man, Andy I believe.

notamustang · Apr 28, 2005

WhiteRock 1/2" is pretty thick, what I was thinking on mine is to use a skill saw with many abrasive blades. Of course I was looking at 5/16 for mine. Mine will have little to no rock use though. Maybe a ROP program at a high school, you could supply them with that 15 cents a pound steel and have them cut it.

WhiteRock · Apr 28, 2005

1/2" is pretty thick 

I agree. My grapple is pretty big though and I am going to move some big and long stuff. I have no idea whether 1/2" is necessary or not. I have looked at some other heavy duty grapples and they use 1/2". I probably could get by with 3/8" and make sure I get gussets in the right places.

If I were smarter about the correct strength, I could keep my weight down and improve my grapple performance. I guess that is what you get with amateur built. It will still be a lot of fun and a lot of satisfaction from building it myself.

notamustang · Apr 28, 2005

It will still be a lot of fun and a lot of satisfaction from building it myself.


Oh no doubt about that /forums/images/graemlins/grin.gif /forums/images/graemlins/grin.gif /forums/images/graemlins/grin.gif

 If I were smarter about the correct strength, I could keep my weight down and improve my grapple performance.

 You and me both!!!! /forums/images/graemlins/grin.gif /forums/images/graemlins/grin.gif /forums/images/graemlins/grin.gif

On my BX with a tooth bar I am thinking of adding a flow reducer to the dump function because of the noticable added weight giving a really quick dump. I need to save weight were ever I can on my lil toy /forums/images/graemlins/grin.gif

DanR67 · Apr 28, 2005

( Well.... Did you take PineRidge's advice? Are you cutting steel? )

WR -

No - I wish, though. Still doing some "honey-do" projects - the power for my welder is in an out-building - so unless I'm up for a *shocking* experience - I won't be welding outside unless the weather is OK....which means "honey-do" tasks at the moment... /forums/images/graemlins/frown.gif

Having said that - I swung by my local metal recycler last Saturday and picked up some additional stock - some 1/4" and 3/8" plate stock that looks like it should work nicely for reinforcements / gussets etc. I have also brought all the intended steel stock into the garage - so at least I can cut some pieces if the "mood" strikes me.... /forums/images/graemlins/cool.gif

**************

BTW - the 1/2" for your jaws sounds like the right thickness - but hoo! that's pricey! Although it won't give you the nice edge - what about oxy-acetylene cutting them? I can't imagine using a jig- / sabre-saw to cut 1/2" plate - those will take quite a while and use LOTS of blades....

I like the idea of buying your plate - and then contacting a local trade school to do the plasma cutting - I'd bet that would be much more reasonable!

Slow going here too... /forums/images/graemlins/frown.gif

Dan

WhiteRock · Apr 28, 2005

I have another question....

I want to put bushings on my grapple arm pivots. Any ideas on how to make these? I was planning to use 1" pins. It looks like one could use 1" schedule 80 pipe and drill it to one 1".

I noticed that Kubotabilly said he used schedule 40. I think that has a wall of .133. Is that to thin for me? I have been looking for schedule 80 which I think has a .179 wall. Is that thick enough?

Any ideas on a source for Schedule 80? or other material to make them?

I checked a hardware store that claimed they sold all their schedule 80 black pipe (gas pipe I think) that day. I will try to check back with them, but it sounded like an item they didn't sell a lot of.

jmc · Apr 28, 2005

Whiterock,

Sch 40 1 inch has a ID of 1.049. After you true up the ID it might be a little sloppy for a 1 inch shaft, especially if you want to put a grease zerk in it.

Sch 80 1 inch ID is .957 and about perfect to clean up for a nice fit with a 1 inch shaft. If you're welding it, distortion may require that you drill or bore it after welding, unless you make the ID enough oversize to handle the distortion.

I found 1 inch schedule 80 in the local pipe distributor's cutoff box. They still charged 2 or $3/ft.

John