Building a ripper claw for KX41 mini-excavator.

[Sodo]

First things first, I was inspired by this thread Giant Metal Claw, or the Little Excavator Ripper That Could.

Little excavator weighs only 3900 lbs. Sometimes the ground is too hard to dig, so I need a ripper to tear it up first. Or to pick the rocks, loosen them. Also for digging out stumps. Can break more of the roots with a narrow claw - I think. And another use is for trenching. I have this notion that I can bury a waterline kind of like a subsoiler, but not "continuously". I've been planning this thing for more than a year, finally just gonna START!

This is TBN member iointerrupt's KX41 and claw. He wrote that if he were to do it again it would have "more curve". I will take that advice. More pics by iointerrupt: Pic1 Pic2

Gonna start by building the Quick-Attach.

Cardboard template

1/2" thick would be preferable but 3/8" thick is what I have. Have to think about this, using it with the the thumb to pick stuff up will be hard to resist. Pretty sure The thumb will bend that 3/8".

Ready for the holesaw.

 

[Sodo]

After lunch, gettin' after it.:thumbsup::thumbsup:

Drilling large holes with holesaw.

Quick-Attach plates done.

Plates clamped onto boom head.

Ripper claw template.

Ripper claw cut out. I 'plunged' the saw to do those segments.
Then cut the corners out with a sawzall.

Drilling the separation plate so the claw can unbolt from the Quick-attach unit.
Using a 3/4" holesaw.

Parts ready for action tomorrow morning.
Those are doublers for the point.

 

[downsizingnow48]

Looking forward to how it turns out!

 

[Sodo]

Thanks Pat. Dang if you're watchin' now does this mean I have to paint it and do it up good like the stuff you make? I can never really "paint" something. How can I know if I'm actually done welding on it....:laughing:

Here's the quick-attach part. I can unbolt it and use it for other devices.

Nasty claw! Current job is to rip out some large gangly bushes that are taking over a wet area, choking out all the other plants. It's a beautiful area, except for being clogged by heavy brush. Wildlife cannot pass thru. I want to reach far out into the quagmire, cut their roots, and pluck them.

 

[downsizingnow48]

Yep pint of rustoleum gloss black will make that thing look like a million bucks!

 

[Code54]

Looks good. Have some quick attach plates laying in my shop right now to build one for my KX9.
What thickness steel did you decide to use and do you feel it was adequate?

 

[iointerrupt]

Sodo - Nice! Time to get digging. I use mine with my thumb sometimes, it can take it, it just doesn't work as well as thumb+bucket for the things I pick up though (logs, rocks).

Code54 - I used 1/2" for the shank on my ripper, and it has been fine, no flex at all. But the KX41 isn't a high power machine, so might want to step it up for a KX91.

 

[Sodo]

Thanks IO!!

Almost done. I took it out for some digging, but it got dark. As usual. I took out a huge bush, as big as a box truck, with ease. Just root around in it's bidness, break all the roots on the left, then on the right, and it just pulls right out, without leaving such a big disturbed ground as with the bucket. This thing is going to cause some mayhem.

It's all made of 3/8" steel. My bucket is 3/8". Code54 you might use whatever thickness your bucket is. This claw is 24 inches long, a little longer than the bucket. It can touch the boom, just barely. It will collide with the dozer blade.

Pretty sure it needs a doubler here. This is 3/8" steel, the bucket is 3/4" here. This thing can't possibly see the abuse bucket gets, but a doubler is easy.

Thinking of putting an angle here, so it pulls easier thru soil. See Pat, I can't ever paint !!!

 

[Sodo]

Much faster for ripping bushes out. I don't have to dig such a big hole, just break the roots left & right, then go in the middle under the rootball & pull the clump out.

I doubled the quick-attach part to be 3/8 + 3/8 = 3/4" thick. This thing is much stronger than necessary for a KX41, not a chance in heck that this little machine can bend it, EVER. Note that some of the 'increased power' you get is from "rolling" the tooth back against its spine, so a big curve shape on the backside might help. I filled that corner with flat stock (2 x 1/8") at 45deg so the spine doesn't 'hook' on stuff. And also it's hella stronger boxed in like that. Code54 this 3/8" thick unit is strong enough for a 7,000 lb machine for sure.

It's more important to "clamp" than I expected. You pull put a bunch of bushes and pile them then clamp the pile in one bite and travel to the burnpile. Big heavy rootballs shake & pull bushes out of your big bite while travelling, then they are difficult to pick up single. You want to clamp a large bunch tight, one time, and travel.

I'll have to cut away some of the claw to get further clamping. My PECK thumb shape is not ideal for this claw. A thick branch in that 'pinch point' will reduce how far the thumb can close on the clump.

 

[Code54]

THANKS - I have a buddy that thinks he has a piece of ¾ laying around that would be big enough and he said I can have it so that maybe what I use due to the "cost". I like your boxed design and may do something very similar. Do you have an angle or curve you feel would be better now that you are using it?
Your 41 looks like it is doing a good job cleaning up for ya! nice work!