help with turning (or otherwise shaping) a small dome

Yes I do turn on a wood lathe.
How would you compare the safety / level of control and dexterity needed to use safely ?
Wood is fairly forgiving considering the big difference between it and the metal tool being used, and also the turning tools tend to be very large levers/handles in relation to the cuts/depth being taken - I guess what I am saying is that this seems a bit scary of a proposition at first blush to me.

It is a very interesting idea I would like to learn more about though...

Actually, it is very safe except that you are often working near the chuck. I try to use an ER chuck so there are no spinning jaws to whack my knuckles with. The tool rest is only 1/8" away from the work so although gravers are somewhat short, their length is huge compared to the gap that exists between the work and tool. Graver rarely dig in if used properly. Brass can grab if you don't keep your approach angle flat but that isn't hard to do. I haven't had a dig in for many years.

If you can turn wood, you can turn metal. The process is identical to what you already know how to do. I have turned all kinds of metals and plastics, including hardened steel and stainless - no problem for a graver.

I think gravers are the most unappreciated tools out there. Most don't know what they are and very few have even used them. We need to change that.
 
Actually, it is very safe except that you are often working near the chuck. I try to use an ER chuck so there are no spinning jaws to whack my knuckles with. The tool rest is only 1/8" away from the work so although gravers are somewhat short, their length is huge compared to the gap that exists between the work and tool. Graver rarely dig in if used properly. Brass can grab if you don't keep your approach angle flat but that isn't hard to do. I haven't had a dig in for many years.

If you can turn wood, you can turn metal. The process is identical to what you already know how to do. I have turned all kinds of metals and plastics, including hardened steel and stainless - no problem for a graver.

I think gravers are the most unappreciated tools out there. Most don't know what they are and very few have even used them. We need to change that.

ok - so now I have to try it...
one of the things we always try to keep very close tabs on on the lathe is cutting height/tool edge on center of part (usually)
is that just a matter of "feel"? meaning, as in wood I am guessing you can tell when the work likes your angle of attack with the cutter (whereas in the tool holder you pretty much get your feedback by chatter, noise, heat, chip shape, etc)
 
I keep meaning to try gravers. One thing that's held me up is lack of a tool rest. Would hanging a HSS bit out to act as a rest work? I could probably mill up something as well...
 
ok - so now I have to try it...
one of the things we always try to keep very close tabs on on the lathe is cutting height/tool edge on center of part (usually)
is that just a matter of "feel"? meaning, as in wood I am guessing you can tell when the work likes your angle of attack with the cutter (whereas in the tool holder you pretty much get your feedback by chatter, noise, heat, chip shape, etc)

When turning brass, the top of the tool is always horizontal and roughly on center height. You adjust the tool rest height for that. When turning all other materials, the tool rest is lowered so that the tool is at about a 10-15 degree angle. As you say, its a feel thing but when its right, the tool cuts. I mean it really cuts, not scrapes. You will be amazed at how fast you can remove material with a graver.

In that thread I linked to there is some info on making gravers by WR Smith. Have a look.
 
I keep meaning to try gravers. One thing that's held me up is lack of a tool rest. Would hanging a HSS bit out to act as a rest work? I could probably mill up something as well...

Now that you have a plinth, why not make something up? I should talk; I need to make one for my larger lathe, too. Basically, you need a smooth, hardened surface upon which the graver can slide. It should be very solid so there is no give; this helps avoid chatter. It has to be able to turn to parallel the work and it has to be height adjustable. I need to work on a final design and I'll share it. Maybe you can do the same, Trav.
 
I'll have a think on it. I'm sure I can figure something out. The hardened bit throws me off as I don't have a forge or oven I can heat treat things with. Suppose I could torch it and go by color. :)
 
Got a Mapp gas torch? Even a butane torch might do it. If you use O-1 and the part is small, a butane torch will do it but Mapp gas is better. You can also use two butane torches and it will work. Heat the part until it is non-magnetic and then swirl it around in a can of ATF (trans fluid) or used motor oil or peanut oil. Then temper it in your toaster oven until amber. Not hard to do in the home shop.
 
Put in the lathe and use a file. short work if one offs.

Which brings up another thing I need, to buy some new, decent files (or even some very good ones).
Someday, I'll have somewhere near the same quantity and quality of metalworking tools as I have for woodworking, but I'll need a good lottery plan or a new way to keep my wife from seeing where the other $200k went...
 
I'll have a think on it. I'm sure I can figure something out. The hardened bit throws me off as I don't have a forge or oven I can heat treat things with. Suppose I could torch it and go by color. :)

Off topic but....

No man should ever go without a forge! even a tiny one.
here you go;

 
Which brings up another thing I need, to buy some new, decent files (or even some very good ones).

Brands to consider: Pferd, Glardon Vallorbe (used to be Grobet Vallorbe; Glardon V is Swiss-made, Grobet is no longer Swiss-made), US-made Nicholson (excellent long pattern lathe files). Buy good ones. Junk files are ... junk.
 
Back
Top