Step 3: Making tool bits

Now you need to make your tool bits for the lathe work.  Grab some High Speed Steel, a smaller piece (I had a 3/8 HSS tool holder, so I used 3/8 HSS. It was a good size) and a bigger piece, 1/2 is a good size for the bigger piece.

To make the tools, there are some terms we need to know first.  I'll go over them quick here, you can find more information by googling about lathe tools.  Here is a nice little video: http://www.youtube.com/watch?v=Mn9jpqI8rao

Side rake: On top of the tool, the angle that the chips slide down after they have passed over the cutting edge.  You want it smaller, because if it is too big an angle, the cutting edge gets too sharp and will break.  8-12 degrees is good for this.

Back rake: Is similar to side rake, except it goes back towards the body of the tool, instead of off to the side.  Again, 8-12 degrees is good.

End relief angle:  This is the angle under the cutting tip, and it is there to make sure the front face of the tool doesn't rub along your cutting surface. 10-15 degrees is good

Side relief angle:  Is the angle that is on the side of the cutting tip, which makes sure the side of the tool doesn't rub as the tool is feeding into the material.  10-15 degrees is good.

End cutting edge angle:   The end angle that makes the point of your tool.

Side cutting edge angle:  The side angle that makes the point of your tool

Nose radius:  The nose radius determines how nice of a finish is left behind.  It is the blend between the side relief and the end relief.

Now, take a look at picture number 1.  It shows the 90 degree chamfering tool, and the boring tool.  The boring tool is not the prettiest, I know, but it works.  You can see in the paint drawings what it would look like if it was perfect (or as perfect as paint drawings can get....)

When grinding HSS bits, rough grind all the angles first, then finish them up on a finishing wheel.  You don't want any metal discoloration, and theoretically you shouldn't if you are using the grinding wheel correctly, but just in case, rough grind everything, then finish grind the last little bits to remove the discoloration (if there is any) at the end.  It's also good to use a finishing wheel, and maybe even a honing stone at the end. 

First, we'll go through the chamfering tool.  It is quite simple.  Take your HSS, and place it on a 45 degree.  Tilt the backside down, so the tip is lifted.  This will create your side relief, end relief, and side cutting edge angle, all at once.  Look at picture 2, you can see how the HSS should be tilted.  Grind the 2 45 degrees (the black lines on the red HSS) to get your 90 degrees.  And that tool is finished!  It has no back rake, nor side rake, nor any nose radius.  Keep the tip sharp!

Second, we'll make the boring tool.  This tool needs end relief, side relief, end cutting edge angle, side cutting edge angle, back rake, side rake, and a nose radius! But don't fret, we'll get it done.  For this, it would be nice to set your tool rest on the grinder to about 10 degrees, it makes making the nose radius a lot easier.  The paint drawing may not look exactly like the tool in real life, that's because my tool is a little funky looking. Just follow the pictures, understand the concepts, and you should be fine.  Honestly,  since this shouldn't be your first lathe project, you should know about tools already, so what I'm telling you should be stuff you already know.

Any ways, on we go.  Check out picture #3.  Here we are grinding the end relief angle, and the end cutting edge angle.  Hold the tool off to your right, and rest it on the tool rest.

Picture #4 shows how to cut the side cutting edge angle, and the side relief angle.  Place the tool on the tool rest to cut the side relief, and tilt it to the left, to cut the side cutting edge angle.

Now, to cut the nose radius, simply do a quick sweep from the angle in picture 3 to picture 4 (top view) to round off the tip.  This is where it is nice when the tool rest is set on an angle, because you can rest the tool there (who woulda thunk it?!) and get a smooth radius.  It's hard to make a smooth nose radius when you are holding the tool in the air, and trying to keep it steady.

Last but not least, the back and side rake angles.   See picture #4 again.  The position that you hold the tool in is very similar, but you rotate the tool 90 degrees,  tipping it towards the wheel, so you are working with the right side facing you, and the top facing the wheel, as opposed to the left side facing the wheel, and the top facing you.

Finally, see picture #5 to see the front, side, and top views of the completed tool.  The black curves would be good to grind off, because we're working on cutting a circle, and we don't want the bottom rubbing.  It will shrink the tool a little bit, and make it weaker, but we are cutting aluminium, so it should be fine.  If you are making a cube out of steel, then just don't go nuts and make super heavy cuts.  Up to 0.015 (0.030 on the diameter) cuts should be fine.

In picture #6, we can see the tool in real life, with all its grinder marks and dings on it.

The last tool we need is the undercutting tool.  It looks like picture #7.  It's basically a parting off tool, on the end of a stick.  So the first step, is take the 1/2 HSS, and grind a thin section in the middle, so there is a big fat section on one side, and a small fat section on the other.  Let's get some specs on this, so we know how big to make it.  From the tip of the tool to the big fat bit, it needs to be at least as long as your deepest bore (6).  My tool is really long, it's a bit excessive.  The amount that the tool sticks out should be at least as big as half the diameter of your biggest undercut (5) (for example, the deepest undercut on this cube is 0.300, so the tool needs to stick out at least 0.150.  Mine is about 0.250, so plenty of room.)  And, the entire end has to be small enough to fit inside your smallest bore (this shouldn't be a problem unless you make a really small bore.)  Check picture #9

Instead of repeating everything I wrote for the boring tool, I'll just tell you what to grind, and hopefully you learned how when you made the boring tool.

1) Start by grinding the very front of the tool, grind the end relief and end cutting edge angle.  (2)

2) Next, grind the back rake (4)

3) Grind the end relief angle (3)

4) Grind the relief angle opposite the first one (near 5 in top view, the 2 on the right in side view)  Between grinding this and the first step,  get your tool width (1)

5)  Grind the radius on the bottom (7)

6) Grind a tiny tiny nose radius on the tip.  You just want a little one, because how big this is affects how deep you need to undercut.  If its a perfectly sharp corner, then you need to undercut just a few thousandths of an inch bigger then your corner to corner distance, but if you have a radius that is say, 0.050, then you need to cut more then 0.050 when you're undercutting, which means the undercut needs to be 0.100 bigger on the diameter.  If you check our calculations, the undercuts are about 0.070-0.090 bigger then the corner to corner distance, so we can afford a 0.030 radius (~1/32 on an inch).  But even still, smaller is better. Try for a 1/64 radius.

And voila!  This was a huge long step, but now you have your three tools.  We can proceed with the cube!
How much width for under cutting tool?
<p>Approx 1/8 in.</p>
<p>if you were to make this from steel rather than alloy, you could be really cheeky with the center ball by using physics. if the finished cube set was evenly heated the metal would expand enough to be able to trap a ball bearing in the center,. best option would be to heat in a brine, that way you would get even expansion. just find the right size bearing and chill it before fitting. the brine would also colour the metal as it is how firearms are blued. just a suggestion from an engineer with a nerdy side.</p>
<p>the heating process would also remove any hot glue used to secure the cubes for finishing.</p>
<p>i want to download the attached file i don't want to go with pro registration any way to get it????</p>
<p>This is great reading! I don't have a lathe but if I did, I'd certainly be spinning up some aluminum in short order. There's another YouTube video out there somewhere in which the machinist filled the first five bores and undercuts with hot glue. You can see the care he used, as the metal certainly absorbed a good bit of the heat, making the cube a bit more challenging to handle while he filled the remaining bores. It allowed him to perform normal speed cuts on the sixth side.</p>
Hello. It is very inspiring work. but i dont have any talent for it. Can i order a turners cube from you to turkey? :)
<p>Really Nice instructable, can you please explain what a PLANAR Bar is , I haven't heard of it before.</p><p>thanks.</p>
Planar bar is basicallt a round bar with one edge ground flat.<br><br>The flat end rests on the vice, the round end touches your piece, and makes sure that there is only one point of contact, forcing the other side of your work to be parallel with the other side of the vice
You can also make a set of step-cylinders which nest into the bores. These hold everything in place as you do the final undercuts, and generally reduce the risk of damage from clamping forces.
You can make a sphere in a cube... Using an inverse ball endmill plunged from all six sides.
I was wondering how to do that... We saw an example of that, but it was made on a CNC. I imagined it was just a small endmill (&lt;1/4 in) and some fancy programming to get the angles required for the circle. But inverse ball endmill would be perfect! <br> <br>It would still be a bit tricky though, because you'd have to make the hole smaller the the diameter of the ball, and that would make it tricky to get the endmill in. <br> <br>I may be getting some more time in a machine shop.... Perhaps I should try it to see how it works out.
The endmill dictates the hole diameter.<br><br>When I was in machining school (Warren Occupational/Technical Center in Lakewood, CO), we learned to grind the radius into the endmill. The trick, for this part, is to cut a larger radius than the cutter. The resulting ball will be larger than the hole when plunged through from six sides. But will remain attached to small support surfaces at the corners.... This is serendipitous, as you wouldn't want the aluminum ball coming free and bouncing into your fragile cutter anyway.<br><br>Once the manual machining is complete, Go back in with a jeweler's saw and free the ball.
Ahhh.... But then you'd have rough saw marks on the ball... <br> <br>If you did plunge in fully on 5 of the sides, on side 6 you could stop, and do similar to what I did in Step 7, for the final side. Just stop the mill, and turn it by hand, so the ball falls off nicely and you dont have to deal with it spinning at upwards of 1000 RPMs :D
If you plunged it completely on 5 sides, you'd have a sphere that isn't very spherical.<br><br>You clean the jewelry saw marks up by hand with your trusty needle files and maybe sandpaper. A machinist worth his salt can turn file marks into replica machine-tool marks. I do it often... And polishing the whole assembly to a bright finish is even easier.
VERRY GOOD! <br>i use to do this by hand in Wood.
Do you have and pictures of wooden ones you could share?
these are my Uncles. My mother has mine <br>i have done copies of all of these Except the 3-interlocking rings on the left <br> <br>
Pretty wicked! Should try making some of these out of metal
it MAY be possible. I'd love to see it if it is. <br> <br>however, the wooden models are only possible because of the ability to use a knife and the sheering properties of woodgrain. <br> <br>One whittles down most of the joint, SNAPS the remaining web, then uses the knife and sandpaper to smooth out the roughness. <br> <br>To achieve the same results in a machine operation, using metal, would probably require an EXTREMELY delicate bit, a very high rpm machine spindle, and a 5-6 axis machine. The very fine, fiddly work your hands do naturally with a knife blade are impossible to replicate in a 4 axis machine. And nearly impossible in a 6-axis. <br> <br>Check out the 5:30 mark on this youtube video for the sort of fiddly maneuvers needed by a machine tool to replicate a fairly simple hand-tool woodworking process. http://www.youtube.com/watch?v=GU32Q6QXtWQ <br> <br> <br> <br> <br>You COULD replicate these in metal, fairly easily, but it would involve casting, not machining.
here are some better photos of the plier joints
Looking at this actually makes me giddy. I love it.
This is really cool, I took a manual lathe class as a pre-req for a bunch of engineering classes a few months ago, I think I'll try this.
Do it!
now I know what I'm making when I gain access to the lathe at my college (and learn to use it). I remember the first time I saw one of these, I just thought and thought and thought until I figured out how it was made. it's shockingly simple, you just need good spatial sense.
Most things are a lot simpler then we think they are. Just take it one step at a time, and before you know it, you're done!
Little typo: &quot;Male it Real&quot; challenge. Thought that I was reading Cosmopolitan for a minute...
Oh my! Thank's for pointing that out. Fixed!
WONDERFUL!<br><br>You beat me to it, but glad to finally see a REAL turners cube!<br>Not saying the &quot;attached nested cubes&quot; aren't fun to look at, but this requires a great deal more skill. And make better playthings for when you have grandkids.<br>Also glad to see you did the double nested version(so much more impressive than a one-in-one)<br><br><br>As I understand it, this was an apprentice job way back in the day.<br>And it was done entirely on a lathe(this being WELL before computers, heck most shops at the time didn't even have electricity!)<br>It was a testament to the young man's skill, to be able to make the 6 facing cuts, to get a cube. Ok, it was a REQUIRED BASIC SKILL. :-)<br><br><br>Step 11, on the final side cutting... that's an interesting technique!<br> Sure would have been quicker than how I did it.<br> I ended up making 5 stepped plugs, with 1-2 thou clearance.(4 jaw chuck, plus a backing plug). Obviously, all 5 plugs were turned on the same lathe.<br>The main advantage to having plugs is, you can have the machine running the whole time. You don't have to turn the chuck by hand for the last bit. Also eliminated the need for using your shims :-)<br>
I'm just finishing up my final project at school, then I'm going to make the &quot;attached nested cubes&quot; (4 cubes) and a free floating one like this, but with 5 cubes instead of 3 :D I'll be sure to add them to this Instructable!
@Xyver; tweeted! Love the arcane vocabulary (is not a miller) Cheers! : ) Site
Thanks for sharing a very detailed and well presented instructable. though it's rarely done now, it certainly USED to be a very common way for a turner to show his skills. When you talk about using a &quot;manual&quot; machine you are of course only adjusting the machine manually,consider doing the same kind of thing with a &quot;Pole Lathe&quot; or &quot;Treadle Lathe&quot;, it HAS been done, but not my me.
I'm mainly talking about manual vs CNC, where we control the machine as opposed to robots controlling the machine.<br><br>I can only imagine how tiring a treadle lathe could be.....
you might be surprised how NOT tiring it can be ;-)
I made one of these when I was training. They are quite impressive and I'm still pretty proud of it :) <br>Thanks for sharing, I hope it inspires people to make one.
Nice and detailed instructable, thanks for sharing.
Glad you liked it :D

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Bio: I like working with all mediums, but so far my speciality is machining and electronics. I try to make all my Instructables from a "design ... More »
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