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June 22, 2010 at 6:51 pm #47970tokeiParticipant
I’m trying to think of some topic that could start us all on this forum to interact some more.
Is it my impression or is it awfully quiet on here?
There should be enough things to talk about to keep us all busy for a good while but it’s not really happening yet.
If this one doesn’t do it let’s all put an idea, question or experience on the board and see if it takes off.
What are the favorite types, shapes, sizes and material of your gravers.
Do you use handles or not.
I’m pretty much beginning in watch repair (watchmaking is way too big a name for what I’m doing) and one of the gray areas is the shapes of gravers I need(diamond shape) what angles, materials, etc.
Your thoughts are most welcome.
CornelioJune 24, 2010 at 2:20 pm #50300
Yes VERY quiet.
Thanks for the infusion!
I don’t know what my favorite type would be but I know that I use square much more than lozenge (diamond shape) gravers. Having both types is a must for me though. I find that the lozenge shape allows for an easy undercut for things like rivets etc. A trick that works well is to make or use a second t-rest and put a 90% notch in it. This will allow you to turn a square graver and use the underside (the diamond shape) whenever you need it. You won’t be able to move along the surface of the t-rest as the notch will prevent that but it works great for plunge cuts like making an undercut.
As for handles…yes you should use them. I don’t use them much but that’s a bad and dangerious habit I have. My reasoning is that I believe I have better control over them without handles. I’ve also had handles come loose on me in the past. If I would have put the handles on correctly that probably wouldn’t have been a problem. One good way to put a wooden lathe handle on is to “burn it in”.(high carbon tool steels only..not carbide!) You do this by heating the end tang of the graver to a cherry red and then drive the handle with several lite taps rather then one or two hard hammer blows. Once on they tend to stay rigid. If you do burn it in here are few words of caution. It’s important not to allow the graver to get too hot much beyond the tang as this can draw the temper (soften) out of the rest of the graver. You can do this by grabbing the graver in a large vise with the tang sticking out of the top. The vise jaws will absorb most of the heat beyond the tang and no annealing will take place in the working area of the graver.
For watch work the common gravers are about 2 1/2 to 3 mm square and about 5 1/2 to 6 inches long. I also have lot’s of gravers that are smaller than that for doing unusual jobs. I use high carbon tool steel gravers almost exclusively. Carbide gravers can be VERY brittle and a real pain to sharpen if you get a decent sized chip in them. It takes a LONG time to grind a chip out of carbide as you don’t want to get them too hot while grinding. One way to grind them is to have a cup of water sitting next to the grinder and every few seconds dip THE OTHER END of the graver into the cup to cool it down. Never dip the end that you’re grinding as they can shatter. Of course I do use carbide gravers occasionally if the steel being machined is just too hard. They will often cut like butter when the tool steel graver can’t even make a dent! When sharpening Carbide remember to use a wheel especially made for carbide.
I love the subject of lathes and anything to do with them. I’ll try to think of some more stuff tonight and add more to the discussion if I can.
BobJune 25, 2010 at 5:59 am #50301tokeiParticipant
Bob thanks for the feedback.
It would be nice if this forum could be a second (smaller) NAWCC style board.
Interesting info on the gravers.
I started out using carbide gravers (1/8″ square).
The first one I ground to a pretty sharp angle a second one had a larger angle.
I feel the second one cuts much nicer than the first. I guess because the cutting edge is not so aggresive.
Recently I took an old carbon steel square needle file, annealed it, filed away the grooves and hardened the tip.
I must say it really cuts smooth. Btw I hardened about 1/2″ at the tip and didn’t temper it at all. It hasen’t broken yet so I guess I’ll leave it that way.
It is smaller, about 2 mm square.
There is one nice little development though. I just received a couple of 3M diamond honing sheets. WOW!!!
They are 6, 3 and 0.1 micron. I haven’t even tried the last two yet. The 6 leaves a MIRROR finish on the carbide gravers. It cuts fingernails like butter.
I’ll test the edge on the lathe tonight.
I’ve seen most square gravers ground with a diamond shape but I’ve also seen some square ones ground at an angle but at 90°to one of the sides. It resembles a wood chisel tip. When would you need that type?
Where do you get your graver blanks?
Yes the lathe is addictive!!! One problem is the chip production and cleanup after that. I clean and lightly grease after every session.
Anyway those are some of the things I’ve come across. Hope more people add their thoughts.
CornelioJune 29, 2010 at 8:20 am #50302
I’m going to have to do a little hunting around for a supplier of tool steel blanks. It’s been many years since I purchased them new. 1/16″ to 1/8″ 01-Oil hardening Tool steel blanks would be good to use for gravers. I’ll check online to see what I can find. You can get Carbide blanks that size at Travers and at MacMasters but not too sure about Tool Steel. Eternal Tools also has a great set of Carbide gravers as well as Escapement files, burnishers etc. Used gravers used to be very easy to find at the local nawcc marts so most members would stock up on them.
Also making them out of old files and high speed steel needles (not the chrome or stainless ones) works really well.
Those honing sheets sound great. Where did you get them? I use to buy something like that but not sure it’s the same product. I would glue them onto a disk (the face) and then spin it in the lathe to sharpen gravers and other tools. What you’re talking about sounds like something new though. Would like to know more about them.
I’m having a hard time visualizing what that graver looks like that you mentioned in your previous post…the one that looks like a wood chisel. Any chance you can post a pic of it?
BobJuly 4, 2010 at 8:59 pm #50304
Links are great..by all means put them up here whenever you have a good one.
I’m gonna order some of those sheets to try them out. I’ll have my son send them down here to us when they get to him. Thanks for the recommendation.
That sketch helps a bunch. The chisel-like graver is a standard graver used for making a linear cut along the stock surface. You can tilt it a bit and draw it along the t-rest surface to make a long cut. I usually grind the end cutting surface back on one side or the other to give it a little relief. You’ll then have 2 angles. The angle that you already have from the top face down and another angle from Right to Left or Left to Right. The nice thing about using hand gravers is that you can often tilt or change cutting angles immediately just by moving your hand. You’ll find that as you do more and more lathe work you’ll end up grinding all kinds of shapes on your gravers and will quickly learn what works for you and what doesn’t. That’s one of the advantages of using tool steel gravers over carbide. They are MUCH easier to grind to different shapes. If you don’t like the shape you have you can change it again and again and again until you run out of graver!
As far as using Diamond paste to polish pivots…not really a good idea as the microscopic diamond pieces will impregnate the steel pivots while polishing. This actually turns the pivot into a very effective cutter which can cut into the brass hole that the pivot rides in. This will wear the hole into an oblong shape…just the opposite effect we were shooting for by polishing the pivot.
BobApril 26, 2013 at 10:26 am #50305derekasParticipant
I am new to lathe work. I am a bit confused as to what angle I should sharpen the graver and secondly what shape should the tip of the graver be. I have researched and it seems an angle of 45 deg. is the norm but on the vids it looks a lot steeper angle.
Should the tip be a diamond shape or should it be just a straight edge.April 26, 2013 at 12:27 pm #50306willofiamModerator
Hey derekas, Your gravers can be all shapes and sizes, the idea of the diamond tip is to get the trailing edge of the graver away from the work, some will be pointier than others depending on what type of cut you are trying to accomplish, if turning a balance staff for instance a longer tip can help cut the grove for the riveting of the balance, a graver can be rounded a bit at the nose to aid in cutting the slope to the pivot, yet you have to make sure the nose also is beveled away from the work. my opinion is that the angle does not have to be at an exact measurement but to little and cutting can be more difficult and to much will weaken the graver. Hope this helps some, if you can try some different ideas and shapes of gravers for practice, as Bob would say, “just try it” use brass or aluminum for easier cutting and you will be an expert in a short period of time, keep on keepin on, William
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