Boring Bar Cutters

[Edward Weingarden]

I'm getting ready to build an articulated arm hollowing system. Can anyone give me some feedback/direction on how to construct the cutting end of the boring bar. What is the large disc that holds the cutting tool? Where do you get it? Can the end of the bar be altered so that both straight cutters/scrapers and round carbide scrapers can be used on the same bar? Any other input on this topic is most appreciated. Thanks.

[Tom Giacomo]

B.jpg

This is one I built, put about $50 into it. You can get free plans from Capt. Eddie.

[Kyle Iwamoto]

Being incapable of making my own, I bought one from Monster Lathe Tools. They sell just the cutter bits. They sell the holders too. This may be against the "make your own" rules, but you can get parts from them. I like their rig. I hollow without a steady rest.

[Thom Sturgill]

The *easiest* route is to make multiple bars. If you are using mild steel from the BORG it is relatively easy to shape/grind - just don't do it on a CBN wheel. The alternative is to make a series of interchangeable tool holders that mount on the end of the bar.

Either way you need to be able to drill fairly straight into the end of the boring bar. The boring bar is the least expensive part of the system and there are several vendors around. Packard sells these from Hollow Fast I'm sure other probably do too. If you can drill a half inch diameter hole in a 3/4" or 1" bar, the tool holder would then mount in the end of the bar and either hold a HSS cutter or scraper or a small bar with a carbide cutter. If you have a steady rest and long enough bed, you should be able to drill an accurate hole right on your lathe.

As mentioned, Monster sells parts as well as full systems. Their 4-Piece tool set gives you four cutters and a bar/handle while the deluxe adds the swivel tip, extension and side grip but really starts to get pricey at about $175..

[Edward Weingarden]

Tom:
Thanks for the info. I have a few questions-

1. What is the BORG?
2. When making interchangeable holders, are holes for the set screws drilled and tapped into the tool holder bar (set screw through boring bar and into tool holder), or is the bar held by friction from the set screws screwed through the main boring bar?

Thanks
3. Are the scrapers welded or epoxied into the interchangeable holders.

[Thom Sturgill]

Tom:
Thanks for the info. I have a few questions-

1. What is the BORG?
2. When making interchangeable holders, are holes for the set screws drilled and tapped into the tool holder bar (set screw through boring bar and into tool holder), or is the bar held by friction from the set screws screwed through the main boring bar?

Thanks
3. Are the scrapers welded or epoxied into the interchangeable holders.

1 BORG common internet name for Large Box Stores, AKA Home Depot, Lowes, etc.
2 Set screw is through bar only. Friction on tool holder. Same for the boring bar socketing into the handle or rig.
3 Scrapers are generally held on with screws though I have seen some that were brazed or silver soldered.

I have a holder similar to the holdfast unit that Packard sells, but without the indents for the set screws. I can use the square HSS cutters, or a square bar with a carbide cutter on it, or a HHS teardrop scraper which screws on in place of the round holder. I also have a number of dedicated bars (most with the square bits that have been ground to shape) of different lengths and diameters for hollowing different sizes forms. All have been adapted to fit into the same boring bar holder whether it is a long handle or an articulated arm.

[Edward Weingarden]

Excellent info. Thanks again.

[John Keeton]

BORG - big old retail giant.

[Jeffrey J Smith]

Another good source for quality cutters at reasonable prices - and bars, too - is Lyle jamieson's online store. You can get just the cutter holders, straight or bent, the swivel holder, HSS cutters to fit, even the Hunter cutter holder angled for both standard or reverse hollowing. If you're interested in building your own captured bar system, he offers information on copying his...
www.lylejamieson.com

[robert baccus]

Also investigate the Mercedes of cutters. The pro -form woodcut boring tips. The mounted cutters are expensive but the complete powerhead can be bought for $89.95. These are the fastest cutter heads and are catch proof. Important when 20" deep.