Articulated arm by Jerry

[Jerry Marcantel]

Yesterday I pretty much finished up working on an Articulated arm for myself.. It's made from 1 1/2" solid round stock. Fortunately I have a friend who has a welding shop that also has a lathe and mill with pretty much all the stuff necessary to call it a mini Machine Shop. Another plus is he let's me use it for no charge and also no charge for the metal I use. He will also weld up anything I need welded in the process of my endeavors...
So, for the last 2 weeks, I've spent a total of about 50 hours there building an articulated arm system ..... What is left to do is build the laser stand and the tools needed, tap the holes in the tool holder, and tighten all the bearing points., .. After that, I'll either paint it or just for grins, I might get it chromed..... Jerry (in Tucson)
180246180247

[Bernie Weishapl]

That is a good looking unit Jerry. Looks like it will do the job. Let us know how it works for you.

[David E Keller]

Nice and beefy looking! I assume(hope) the height is adjustable.

Why stop at chrome? That thing should be gold plated!

[Richard Madden]

Looks good, Jerry. I think this is the first I've seen using solid round stock. Should be nice and stout! I too was wondering if the height is adjustable. Keep us posted on the laser set-up.

[Jerry Marcantel]

Richard and David, Yes, the height is adjustable. I just haven't tapped the hole yet. It goes up to 7 3/4" to center..... My lathe is only 12" so no problem there... When you're using someone's equipment and material, you use what's available. I was lucky to find a piece long enough to use for the post hole. It's only 3 1/4", but beefy enough to support the rest of the arm.... The dog bones are 1 3/16" diameter, and where the bearing pockets are , it is 1 7'16", and each dog bone is 12"....

[Jim Laumann]

And this gets used for?

Thks

Jim

[Jerry Marcantel]

Hollowing!!...... Jerry (in Tucson)

[James Combs]

Extra nice set of arms Jerry. Just curious what did you use for the the pivot bearings?

[Scott Hubl]

Nice one Jerry, and a Nice 1460 too.

Tell me more about your pully and belt system please.
Thanks.

[Jerry Marcantel]

Nice one Jerry, and a Nice 1460 too.

Tell me more about your pully and belt system please.
Thanks.
Scott, thanks for the comment on my lathe. I purchased it for 50 bucks. The tailstock isn't the real one and the pulley cover is missing.
As soon as I got it, I removed the spindle, threw out the bearings and step pulley, and headed to my friends mini machine shop, and proceeded to make a J series 2" x 4" stepped spindle pulley. It was machined from a piece of 4x4" solid round steel stock. Each step has 10 grooves to match up to a J8 belt. That's a serpentine belt with 8 grooves. The 2 extra grooves help with belt alignment.
The motor is from my dust collector I had when I was seriously persuing a woodworking livelyhood. It's a 3 phase 2 hp end mount motor that I had to make mounts for. I also made the 2" drive pulley that has 20 grooves.
I bought a 3hp 10 amp Hitachi VFD to run the lathe.. The instruction book is about a half inch thick, and so far I haven't been able to decifer the terminology used for programing... It works, but I don't think I have all my low end torque or hp.... Each time I use it, I feel better and attempt to program it, but I get lost in the instructions....
The tailstock isn't part of the original lathe. Don't have a clue what it is, but I had to build a base to bring up the center to match the headstock. It works, but probably not as good as the real one... If I can't find the right one, I think one of these days I'll get back over to my friends shop, and build my own tailstock...
The lathe has a 12" swing and between centers before I added the chuck was 37", I think..... Jerry (in Tucson)

[Baxter Smith]

Nice looking arm! Lucky to be able to use his shop. I like to play with metal sometimes but can only do crude stuff.

[Jerry Marcantel]

Extra nice set of arms Jerry. Just curious what did you use for the the pivot bearings?
James, I used bearings that have a 3/8"ID, and a 7/8" od. They have .280" thickness, and that is where I messed up. I thought they were 5/16' (.312"), and bored the holes 5/16" deep. I now need to make some shims thick enough to bring them up to .280 deep. Each joint has 2 bearings for a total of 6 bearings.... After seeing the Clark system, I've decided I'm going to make one, but with a couple of improvements that would make it's operation smoother than it already is.... Jerry (in Tucson)

[Steve Schlumpf]

Looks like you have a pretty good start on your system Jerry! Looking forward to seeing it finished and also to see what you think of it after using it for a bit!

Have fun!

[charlie knighton]

enjoy........

[Richard Coers]

Jerry,
I too have made an articulated system. One comment on your design and what I have found on mine. That final link to the boring bar will add some torque into your body. All your forces will be in front of the pivot. That will make your arms and body the pivot and the force. I torqued my neck and shoulder on a long session. I now overcome that by keeping my legs spread wider and my knees slightly bent. The Kobra system has a great design. They have basically a "T" at the final joint with a handle behind it and the boring bar in front. That lets a better mechanical advantage get set up with forces on both sides of the pivot. I think you may find your links are too long when trying to work on a back cut under the rim. I think my shortest link is 3", and I still find myself stopping and repositioning some of the links to get a smoother flowing cut. Good luck on your first tests. Remember not to transfer the torque to your back! Good luck.