• Beware of Counterfeit Woodturning Tools (click here for details)
  • Johnathan Silwones is starting a new AAW chapter, Southern Alleghenies Woodturners, in Johnstown, PA. (click here for details)
  • Congratulations to Paul May for "Checkerboard (ver 3.0)" being selected as Turning of the Week for March 25, 2024 (click here for details)
  • Welcome new registering member. Your username must be your real First and Last name (for example: John Doe). "Screen names" and "handles" are not allowed and your registration will be deleted if you don't use your real name. Also, do not use all caps nor all lower case.

small hollowing tools

Joined
May 3, 2010
Messages
2
Likes
0
Location
Oklahoma
Hi folks, I am new to this site and thought I'd ask for some advice. I am new to turning and have a Jet 1014VS that I am working with, I love the lathe since I am mostly interested in turning small objects such as twig pots, candle holders, boxes, etc. The tools I am using are hand-me-downs from my dad and they are probably the cheapest Chinese made tools he could find, they are working so-so for turning so far but need sharpening on a very regular basis with the woods I am using.

Due to financial restrictions I am currently using some hickory and oak limbs that came down in the Oklahoma ice storm of 2007. I have had good luck with the wood so far, I even have some nice spalted wood to work with eventually. And with the recent tornado that passed over my house on Monday I should have more wood...I needed more wood but sure didn't want it delivered like that!!!

I am needing some hollowing tools and am considering making my own since I don't see how anyone can ask up to and over $100 for a hollowing tool, I don't care if it has a carbide cutter or not it is ridiculous. I am thinking carbide will be best for me since the hickory is like a rock but my question is this...for initial and finish hollowing would it be best to get the flat (like the Easy Wood Tools) or "cupped" (like the Hunter) bits to make my own tools?
I have found a possible source for some carbide inserts, CarbideDepot.com, and they have some flat and some "cupped". I am wanting to make a set of 1/4" and 3/8" tools, straight and "swan neck" for the different shapes I will be turning. Any help on the hollowing bits will be greatly appreciated.
 

john lucas

AAW Forum Expert
Joined
Apr 26, 2004
Messages
8,321
Likes
3,576
Location
Cookeville, TN
It's much easier to build the tools that use the HSS metal turning cutters. They last really well in hard woods and are cheap. With the Carbide cutters you have to tap a pretty small metric hole to handle the cutters. That means buying a tap of that size and having enough skill to drill and tap the holes without breaking that small tap. You also have to be careful not to stack these with other tools because the carbide is very brittle and can be damaged easily.
With the HSS cutters all you have to do is drill a hole. I use 3/16" square cutters and drill a 1/4" hole. For small projects a 1/2" bar is big enough. I usually just glue the cutters in place with CA glue. They are quick to sharpen and easily replaced when they get too short.
 
Joined
May 3, 2010
Messages
2
Likes
0
Location
Oklahoma
I have already learned about drilling and tapping those small holes; I got one done with no problems :D then on the second one the tap broke :mad: when all seemed okay.

Do you know of any place to get small diameter round HSS cutters, something in the 1/4" range? I am doing small hollowing work and some openings are in the range of 1/2" and I don't have room to get much inside so I think a small diameter rod with a small round cutter would be best. I guess I could grind some 3/8" or 1/2" disks down but I'd prefer not to if I don't have to.

Thanks for the info, it is appreciated.
 

john lucas

AAW Forum Expert
Joined
Apr 26, 2004
Messages
8,321
Likes
3,576
Location
Cookeville, TN
Mike Hunter sells what he calls a #1 cutter. It is very tiny, about 1/4" but I would have to measure it to tell you for sure. He also sells the tapered screw to go with them. http://www.hunterwoodturningtool.com/products/
I make my small hollowing tools out of Drill rod. I bend and grind it the way I want and then harden it myself. They work great. Not carbide but you can harden them anyway you want if you order the instructions. I use the water hardening variety and harden them between 58 and 62 rockwell which seems to be about right for edge holding and easy sharpening.
Here is a sample of the tools I've made. The first 2 have the Hunter #1 tips. They can be grabby at certain points inside an ornament. you have to learn how to use them.
The middle one is how most of my tools are made with Drill rod. They can be easily re-bent to any shape needed and easily sharpened.
The bottom one is a HSS cutter silver soldered to a cold steel rod.
 

Attachments

  • Bent-ornament-hollowing-too.jpg
    Bent-ornament-hollowing-too.jpg
    32.6 KB · Views: 97
Joined
Jun 22, 2009
Messages
11
Likes
0
John's suggestion is a good one but If you can face it I'd encourage you to persevere with the tapped holes. Instead of carbide tips though use Robert Sorby hollowing tool cutters which are easily sharpened with a diamond hone and can last a long time.

http://www.stilesandbates.co.uk/CMS/prods.asp?strID=Guest&strCategoryID=BKIXVA649637767288632328507107A&strCategoryName=Woodturning%20Woodworking%20and%20Carving%20Tools&strSubCategoryID=JDVJUE193476262379727333586758E&strSubCategoryName=Robert%20Sorby%20Replaceable%20Cutting%20Tips%20and%20Brass%20Ferrules&strProductID=LWWMOO920328671042904859628933O&strProductName=Robert%20Sorby%20Replaceable%20Cutting%20tips

Although these are very expensive for tiny pieces of HSS they all have a 5mm hole in them so any of 2BA, 3/16UNC/UNF/BSW/BSF or M5 screw will hold them in-place and so you can soon build up a nice range of hollowers and scrapers which have interchangeable cutters. Sorby even sell M5 socket-head screw replacements.

There are three main rules to tapping - drill a straight hole with the right size tapping drill (outer diameter minus the thread pitch i.e. for M5x0.8 use 4.2mm) and then keep the tap straight and lubricated (tapping lubricant or light oil or WD40). For this type of through tapped hole, you only need to buy a taper-tap although you will have to go as deep as it will go to fully form the thread. A second-tap will also work although for very hard metals this may put a lot of stress on the tap.

If you can, use your lathe for drilling and tapping without moving the setup when changing from drill to tap in your Jacobs chuck, but only tap using hand rotation (no power!) and unlock the tailstock and use light hand pressure to encourage the tap to follow the drilled hole. If you feel that tap binding, don't be afraid the back-up and remove the tap and the swarf before continuing. Doing this on the lathe is easy without losing alingment.

Either clamp the bar you wish to drill/tap across your chuck, against the face of the chuck and hold the drill/tap in the tailstock or, if you don't have the capacity over-the-bed, make a small wooden vee block (for round stock) on a wooden stub morse taper (see how to make stub morse taper here... http://www.davidreedsmith.com/Articles/AllWoodColletChuck/AllWoodColletChuck.htm) to support the rod in your tailstock and mount the drill/tap in the headstock. Either way use a centre punch to locate the screwhole position before drilling or use a machinists centre-drill before drilling the tapping hole.

I hope this helps
 

john lucas

AAW Forum Expert
Joined
Apr 26, 2004
Messages
8,321
Likes
3,576
Location
Cookeville, TN
When tapping holes be sure and reverse the tap rotation about every 1/4 to half turn. This breaks up the chips and removes a lot of stress on the cutter. Taps are very hard, and consequently brittle. If you force a small one too hard it will snap and if you twist them side to side they will easily break.
 
Joined
Jun 22, 2009
Messages
11
Likes
0
Thanks for the reminder John. At least on this side of the pond, one reverse 1/4 turn every full rotation is recommended to break up the swarf coming off the cutting edge.

- But to be honest, I've sometimes noticed that the reverse turn to break the swarf free can put almost as much stress on a tap as just going for it :confused:
 
Joined
Oct 29, 2005
Messages
886
Likes
10
Location
wetter washington
Website
www.ralphandellen.us
Have you considered an Allen Wrench?

Available in many sizes, "extras" often come with tools you buy. I have a bag-o-them that I keep for various "re-purpose" applications

TTFN
Ralph
 

Steve Worcester

Admin Emeritus
Joined
Apr 9, 2004
Messages
2,690
Likes
93
Location
Plano, Texas
Website
www.turningwood.com
The other option is to make a jig to round the ends of HSS square cutting bits and drill the ond of the ros and use CA glue. When you need to change the bit, you heat it with a torch and it pops right out.
 
Joined
Jan 24, 2010
Messages
3,058
Likes
900
Location
Cleveland, Tennessee
Hollow tools

When tapping, I always use a couple drops of oil. My observation of machining processes in manufacturing is that they use lots of lubricant. Gallons, to be exact.
 

john lucas

AAW Forum Expert
Joined
Apr 26, 2004
Messages
8,321
Likes
3,576
Location
Cookeville, TN
John Good suggestion. Oil helps tremendously. I use a mix of oil and kerosene. I also have a can of cutting fluid that my dad gave me that works great but it's sticky and messy to clean up.
If you find that the tap binds up when reversing it, take shorter forward cuts. I have actually broken a tap when reversing it. For small taps I do short turns forward. Maybe even less than 1/4 turn until I get a feel for how they cut. For some reason I always break the 6/32 taps. I almost never break any others and I have taps down to a #1.
 
Back
Top