Articulated Tooling

[Mark Mandell]

I'm working on a necked hollowform, and it appears that I'm going to have to make either an articulated tool or a bunch of fixed-shafted tools that are only slightly different in the curves in order to reach the base of the neck plus the "roof" of the vessel out to about the transition to vertical. The neck opening is about 3/4" and I'll be using 3/8" O-1 drill rod with an M-2 HSS cutter inserted with CA.

Anyone here have experience making such (similar to the Serious and Munro jointed shafts) and care to share pitfalls or tips, etc?

Since I don't have access to a mill to make those nice "tongue & fork" joints, I'll be grinding the 1/2 diameter flats on the round rod ends. I plan to use a 10/24 hex-cap screw as the position lock, but am open to suggestions.

Thanks for any input.

Mark Mandell

 

[Jeff Jilg]

I haven't made one of those Mark. And from your work I've seen that you have hollowed a lot. I have forged a couple of custom curved hollowers. And the most successful ones for me - have a curve which brings the cutting tip back to a point where it intersects the original imaginary line extending from the straight part of the shaft. I've seen a couple of pics of curved hollowers where it appears the cutting tip is to the left of that straight line. That has got to create a lot of torque especially during a catch.

If I was going to do it, I would probably mockup a pseudo wooden version and have machinist take the metal parts flat. But just an opinion without any real experience behind it.

 

[Hugh]

Question - If you make an articulated tool, how are you going to move it after you get the tool down the neck of the vessel? Hugh McKay (?) from Oregon made an articulated tool that he was able to move the tip after he had the tool inside the vessel. If you can not move the tip of the tool after it has been inserted into the vessel neck, what is the advantage of an articulated tool over a number of fixed tools with different curves and/or angles? I make fixed curved tools with the drill rod and cutting tip with CA glue and they seem to work well but not with long necks on the vessel. Good luck. Let us know what you end up making.

 

[Mark Mandell]

Economy

Hugh,

Hadn't considered the Sigmoidascopic option, but will leave that to the proctologist.

I'm basically looking to save space in the tool rack. The Serious Tool Hollower, with it's shaped bar and dedicated 'gate', is (for me) overkill. Rolly Munro's stainless steel casting solution is beyond what I can do in my garage or even wish to spend the time on. I've set myself a "learning goal" of solving the neck (and"small" opening) for a hollowform without going to collars which are nice, and in many cases present the opportunity for design contrast, but I would like to "confront" the piece of wood as a unity. Thus, if the grain and base form concept say "spout", I need to find a way to do it without add-ons.

Further, my Scotch ancesters [not to mention SWMBO] demand I do it with the least possible expendature of funds. [Yeah, ma Grreat, grrreat, grrrreat grrran-sire werrre a cheepskate, boot ee'll be no makit fun o' economy]

When I do it, I'll for sure let you know.

Mark Mandell

 

[Andrew]

Anyone here have experience making such (similar to the Serious and Munro jointed shafts) and care to share pitfalls or tips, etc?

I hope you don't mind me piggybacking onto your thread but it's a related question.

Anybody that can do it themselves or know of a (good!) machinist or even a tool company that could put an idea of mine into physical form? It's a hollowing tool that's not been created before and is way beyond my capabilities to create it. It's going to require some non-disclosure and exclusivity paperwork, by the way.


- Andrew

 

[Mark Mandell]

Thread-jacking welcome, Andrew!

Don't know about machinists, but I seem to remember from others who handle such things that a patent is the first step. Except . . you may have to have a working model as part of the application which means you're back to your search for machinst who has enough savy to help you complete the details, but not enough greed to swipe it.

Good Luck

Mark

 

[Andrew]

Mark,

Yep, a patent is the way to go but, unfortunately, the reality of it is that it's just not worth it these days for such a thing as I'm proposing. I own (actually, "owned" is more accurate) 2 of them. Got the first when I was 14 and the second in college. Far too much hassle, money and headaches for a small-timer such as myself to deal with patents. Copyrights and other intellectual property rights are a different matter altogether.

A working example isn't necessary from what I was told several years ago. I had them, though, that I gave to a drafter to make the drawings from. But my patent attorney said the examples weren't necessary. Just the drawings and descriptions, etc. etc. etc. etc. ....................... and the filing fees. <g>

So, I'm still on the hunt for a machinist or company wanting to work on this. You never know, it might actually be useful. <g>

- Andrew

 

[Mark Mandell]

Usefull

I'll ask 'round my area as there are a few shops and 2 T&D guys not far away. Just so I've got the basics . . . This widgit is primarily used for hollowforming wood jars (and bowls?), but also chills beer and keeps all flying insects out of a 125 foot radius, right?

Mark

 

[Andrew]

I'll ask 'round my area as there are a few shops and 2 T&D guys not far away. Just so I've got the basics . . . This widgit is primarily used for hollowforming wood jars (and bowls?), but also chills beer and keeps all flying insects out of a 125 foot radius, right?

Mark

Oh, don't get me started on the chilled drinks! That was another one during the highschool years that I missed by just a matter of about a year. Kind of impractical, in a manufacturing sense, as it turns out. The company that beat me to it hasn't been able to make it happen except as just small test runs. Too bad, too. It was a neat idea and that "frozen water mafia" (ie the international ice conglomerate) would have been put into a pinch. <g>

Completely missed the CO2 + suction = no mosquitoes thing. I just swatted them.

Anyway, yes, I'm talking about a tool to do hollowforms. Not as useful on bowls although there's no reason it won't work. It's not your grandpas' (or your internationally known woodturners', for that matter) bend-a-piece-of-steel-and-call-it-a-new-hollower type of tool either. It's going to take some machining and parts manufacture. Nothing a good, experienced machinist can't do.

Thanks,

- Andrew

 

[phil joines]

Articulated tool

I've made 1. Used a portaband saw to cut flats of 1/2 the rod diameter (5/8") on two pieces. Drilled a #10 hole in one peice and used a thin center punch to transfer the location to the second. Drilled that one with a #24 bit and tapped for 10/24. Rounded the ends on the grinder so they couls pivot. Drilled a 1/4" hole in the cutter piece, tapered the end and polished the whole thing. The other piece is the shank and is used with a torque arrestor.

I found an external tooth star washer between the two pieces helped to keep the end from vibrating loose.

I wouldn't do it again. 5/8" cold rolled is about $16 for a 20' stick and one will make a bunch of tools. The 1/4" x 8" M2 bits from Enco are about $2 and make 5 tips. If you want hand held tools use a shaft coupler and a short piece of rod in the handle so you can swap the shafts. Doesn't take much space to store them.

BTW don't use "tool steel" to make bent tools. It tends to split when bent and isn't any more stable than cold rolled.

 

[Hugh]

Question for Phil - When you say "tool steel" - do you mean drill rod that one gets from Enco or MSC? I have been told cold rolled steel is as good as drill rod. But, I like the drill rod and have not had it "crack" when I bend it. But I heat it up with a torch before bending it. I like the drill rod as it cleans up nicely after you have worked it. Mostly this is a question about the "cracking".
Hugh

 

[john lucas]

Hugh
Cold roll and drill rod or tool steel are two different animals. tool steel is designed to be shaped and then hardened. Cold roll doesn't have enough carbon to get very hard. Your right about heating. Drill rod or Tool steel can easily be bent without problems if you heat it properly. Many steels will crack and split if bent without heat. On my tool making demo I break a needle and then show how it can be bent safely after annealing it. Then I harden it and break it again.
I use cold roll steel for all big tools and put a tool steel, or HSS bit in the business end for the actual cutting. For small hollowing tools and small round skews I use drill rod.

 

[The Spin Doctor]

Machinist

ANDREW I might be the guy you are looking for to help you creating your tooling idea! I have a machine shop in the garage with computerized milling machine, 22x72 inch 12,000 pound manual Monarch metal lathe, Plasma cutter, sand blaster etc... I manufacture a deep hollowing system and steady rest that I have a patent application in on. I am also prototyping an ornamental milling attachment for woodturning lathes as well. Check out my website and give me a call or email. I would be proud to help you if I can. This is one of the reasons I made the investment in the tools and trained myself in precision metalworking!

 

[Thomas Stegall]

Articulated hollowing tool

The best thing I have ever seen or used was the Hugh McKay designed hollowing tool. I believe another turner/machinist has bought the rights to it. The articulated arm at the end can turn at 90 degree angles extending out to 3 inches. The articulation angle can be adjusted while the tool is in the hollow form making it possible to put it in straight and then adjust it to turn the shoulder of a narrow necked form. As a fellow Scotsman I can tell you the only downside of this tool is that the price used to be in the neighborhood of $2000.

 

[waltben]

Just looked through my old bookmarks and can't find it, but several years back there were DIY plans for making your own 'Elbo' style articulated tool from commonly found hardware. I can't recall what the person that posted it called the tool, but it looked feasible. I toyed with making one but decided I really didn't need it (I've a Stubby).

 

[john lucas]

go back through the old issues of the Journal. there was an article about Hugh McKay's system. One day I'll build one. I'm still a learning machinist and that looks like a doable project.

 

[KellyDunn]

John, years ago some of us got 5/16ths drill rod and cut them up and made Berger tool tips. A turner here wants to make his own and if I recall we got oil hardened versus air hardened. But its been so long I forget which one we got. Which one is the best for making your own cutter tips? We all bought one of his tips and did not use it so we would know how to do the grinding. But we all got together at once and we made so many I still have three left unused. But for the right application his tips are great. When Soren called me not long back he said, you know, a lot of turners make their own tips. I said not a word. Anyway this turner has one of Sorens tips on order and I told him we would get an order together from enco. It comes in 3 foot lengths I think. Thanks in advance.

 

[Larry Marley]

Mark,
I know some people who will hollow a narrow opening hollow form from the bottom. Then replace the bottom and hide the glue joint in detail.

 

[Dale Jablonski]

why is this flagged with a thumbs down symbol?

 

[Mark Mandell]

Mark,
I know some people who will hollow a narrow opening hollow form from the bottom. Then replace the bottom and hide the glue joint in detail.

Me Too. The guy lives in my bathroom mirror.