Articulated Hollowing - material question

[Jon Prouty]

Quick question - I've been looking at all the articulated hollowing systems out there (including the Monster which seems to be a rockstar) and I cannot tell what the materials are that are used in the arms and boring bars. Looks like stainless steel boring arms and aluminum articulating portions. Am I correct? Also, the Monster system has multiple holes in the first arm.... are those there you so you can change the pivot locations?

Full Disclosure - I am contemplating building my own system and the material question has my stumped. If it is all stainless steel - I ain't looking to start machining that in my garage.

Thanks all
Jon

[Alan Trout]

No it pretty much is all mild steel used. the holes are just lightening holes in the arm. I am in the process of making new bars out of hardened drill rod as it seems to be a tad stiffer than the mild steel. I will see if it makes any real difference.

Alan

[Randy Privett]

Alan

Your boring bar is made from tool steel.

Randy

[Nate Davey]

The ones he is making are fit to hollow granite.

[Chris Stolicky]

I made my own version, and it is very ugly and less precise than Randy's rig. However, it works quite accurately, I had fun doing it, and it was cheaper. I did buy an adjustable cutter from Randy that makes life much easier.

Oh, I used mostly cold and hot rolled steel. Grade 8 (probably overkill) bolts.

If you have the money and don't want to mess around with making your own, I would recommend the Monster. Otherwise, enjoy the rewarding effort of making your own tools - it does take time away from turning though...

[Bill Blasic]

It may be rewarding to make your own but from the second that I touched that Monster Articulating System it was just a few more seconds till my hand was taking out my wallet. The fluid ease that was required to move that arm around made the price point disappear and I haven't looked back. Going on a couple of years now and it is still as smooth as the day I got it. Would I buy it again, you betcha!
Bill

[Thom Sturgill]

I had a chance to look at the Hollowfast system and the arm seems to be aluminum. The boring bar is steel, but mild steel is fine. That's how I made mine, but I have not used it enough to stand the test of time. I like the clevis pin hollowfast added. I used rollerblade bearings instead of buying the bushings, but that's because I already had them.

[Jeff Nicol]

Un-treated tool steel (O-1, M-2 etc) that are not hardened are not that much stiffer or harder than cold rolled steel. The difference is most of it is stable and has more carbon in it and has been milled or polished to look nice and be a consistent size. You can bend O-1 tool steel into any shape you want before it has been heat treated and hardened. Once you harden it it becomes more brittle and stiff, but must be annealed back to a workable hardess in the upper 50's to mid 60's on the Rockwell scale. So what causes most problems with chatter, vibration or catching is because the shaft is hanging over the tool rest a greater distance, so thicker rod will most likely be the only way to get rid of it not stiffer which may be worse as a large catch could fracture a hardened rod.

My 2 cents,

Jeff

[Alan Trout]

Randy,

What kind of tool steel. It just seems way softer than my water quenched drill rod that I have used. I am assuming it is in O condition. Just curious

Thanks,

Alan

[Jon Prouty]

I had a chance to look at the Hollowfast system and the arm seems to be aluminum. The boring bar is steel, but mild steel is fine. That's how I made mine, but I have not used it enough to stand the test of time. I like the clevis pin hollowfast added. I used rollerblade bearings instead of buying the bushings, but that's because I already had them.

Thom,

This is awesome... I didn't even find the Hollow Fast system when I was looking at different systems. I found a youtube video on it that gives more info as well as a pretty good drawing on their site. I really appreciate the way the tools tips are held into the boring bar with this version - simple, simple, simple. This is how I am going to do mine.

I'm going to use thrust bearings just to make life easier and leave them proud of the surface so it simplifies the drilling operations. This looks perfect.

I can't find the Hollow Fast system for sale anywhere - yet. They must be fairly new to the market with theirs. I own their HoldFast vaccum system and it rocks. I have a feeling this new comer will find its way to a lot of hobbiests if they price it right.

Thanks again Thom!!!

Jon

[Jon Prouty]

It may be rewarding to make your own but from the second that I touched that Monster Articulating System it was just a few more seconds till my hand was taking out my wallet. The fluid ease that was required to move that arm around made the price point disappear and I haven't looked back. Going on a couple of years now and it is still as smooth as the day I got it. Would I buy it again, you betcha!
Bill

Hi Bill - I would buy but I already spent most of my play money on other stuff. I need a few months to recuperate. Building my own gives me something new to work on.

Jon