This place is deader than disco, so

[PHPaul]

I'll bore you with some model-building pictures.

I have this International 4300 tractor hooked to a log trailer that I built a year or so ago:

binder2.jpg (16.82 KiB) Viewed 39733 times

At the time, I wanted to mount a knuckle-boom crane behind the cab but couldn't figure out how to get it to fold as compactly as the real thing. A couple of weeks ago, my neighbor/pal Dan had one parked by his shop to fix some hydraulic leaks so I was able to see one up close and get some pictures.

Once I saw how they do it, it was obvious (duh...) and I 3D printed the parts to retrofit my first attempt:

kb1.jpg (15.88 KiB) Viewed 39733 times

Here it is in the stowed position. The trick was the offset "knuckle" and the dogbone links to maximize the travel with a short-stroke cylinder (haven't built the cylinder yet).

kb2.jpg (18.74 KiB) Viewed 39733 times

Here it is unfolded. I have to prop it up for pictures until I get the joints snugged up enough to support itself.

kb3.jpg (13.62 KiB) Viewed 39733 times

Fully extended with a 3 part telescoping boom. Now that I have the construction figured out, I'll probably build a whole new one. This one looks a little small, I'll set it on the back of the truck and see what I think. Probably go a little bigger if I start from scratch.

[Jim @ Jawa]

Bravo to you Paul for breaking the ice.
I'll take your lead in post a little something about the Philippines.

[GeneMO]

OK, saw where you might build another one. I was wondering about your comment on snugging up the joints, and wondered how you would do this.

Looking fine !!

Gene

[GeneMO]

Your Disco comment. Wow. Bunch of my buddies and their gals went to one in Quincy Il. in the fall of about 1977. maybe 78. A group of us were walking up the sidewalk, some couples, a few strays. I had fallen back a bit, my new wifey was about 4 paces ahead. I looked up just as she reached up and grabbed one of my friends brothers hand. Now he was real, quiet, almost unusually shy. He said nothing, just kept marching. About then she figured it out and we all laughed our asses off.

Then we had fun listening to KC and the Sunshine band do Shake, shake, shake; shake yer booty .

Good times. We still tell that story.

Gene

[GeneMO]

Paul, how does this work, I was looking at the posts, and I see where many are viewed thousands of times, but just a handful of comments. Is it spam?

Thanks, Gene

[PHPaul]

OK, saw where you might build another one. I was wondering about your comment on snugging up the joints, and wondered how you would do this.

Looking fine !!

Gene

An excellent question Gene. Haven't quite figured that out myself and I'm about to head down to the "lab" and assemble my fourth iteration of this project. The 3D printer is getting a workout as I try something, am not satisfied with the results, tweak the design, try something else, rinse, repeat...

I'll post pictures when I get it figured out.

[PHPaul]

Paul, how does this work, I was looking at the posts, and I see where many are viewed thousands of times, but just a handful of comments. Is it spam?

Thanks, Gene

Again, excellent question. There's no mandatory registration to see posts here so I imagine a lot of it is Bots/Web Crawlers, but there's also a lot of looky-lous. I wish folks would post, even if to say "That sucks..."

[PHPaul]

kb4.jpg (10.42 KiB) Viewed 39667 times

kb5.jpg (12.12 KiB) Viewed 39667 times

Final version of the knuckleboom. Re-designed and re-printed the main boom 3 times before I got the overall length and the pivot points for the "cylinders" right. Works slick now.

I think I can get the action right by stiffening up the cylinders. The rods slide freely in the barrels now, hoping a sloppy coat of paint will provide enough stiction to hold it in any given position.

[GeneMO]

That is quite a brain teaser !