Step 1: Different Types of Tooling
HSS Tooling can be very versatile and economical, especially if you don't plan on using the lathe very much, or you don't know what kind of parts you will be making. HSS square blanks are around 4$-7$ depending on size (From KBC. Tools), and pre-ground tools can be found for around 20$-30$ (From Mcmaster-Carr).
However, while HSS tooling can be very cheap initially, it can have drawbacks. Mainly, if you're not a professional, chances are grinding tools will take you significant time, and your tools will not always the same. HSS tooling also has a significantly shorter lifespan than other types of tooling, especially in hard materials.
Step 2: Different Types of Tooling (Cont.)
Brazed carbide toolbits can be similar in cost to regular HSS toolbits, or three to four times more expensive. While I don't recommend it, if you do want to go with brazed carbide toolbits, you can see extended tool life over HSS, especially in hard materials.
Step 3: Different Types of Tools (Cont.)
The primary drawback of indexable carbide tools is the initial cost. Most common tools start around 30$ for import tools, and can run up to 200$ for high performance on brand tools. The inserts themselves are typically around 5$-10$ depending on geometry and grade. Additionally, if you need a special tool, you must buy an additional tool, rather than grind it yourself. However, if you don't like grinding your own tools, and just want to make a lot of parts, indexable carbide is my favorite way to go. The inserts cut very well in a wide range of materials, and require little to no time after setting the height once.
Step 4: Choosing Indexable Carbide Tools
Once you have tools, you will need inserts. Most tool stores that sell indexable carbide tools, will also sell the inserts. KBC, Shars, MSC all sell carbide inserts and tools. Each tool you chose should recommend an insert type to use, and you should then be able to find the same inserts in a catalog/webstore. If you have trouble finding the inserts, you may want to look into a different tool, one with more common inserts, as this will save you time and money later. Again, the KBC Catalog has a great section describing almost all common inserts, and breakdown of the naming conventions. I bought my inserts from maritool.com, one of my favorite carbide sources. All of the inserts I chose are CCMT 32.52, which have a .031" nose radius. Large nose radiuses (.031") can increase surface, but will leave a radius on your parts. I chose a selection of inserts, positive rake, Kennametal K68 inserts for aluminum, and neutral rake CeraTip CA6515 inserts for steel and stainless. Positive rake inserts will reduce horsepower requirements in soft metals, but can break off in hard materials. Neutral or negative rakes are much stronger in hard materials, but require more horsepower to push through the cut.
Step 5: Choosing a Holder
Quickchange toolposts have standard sizes, 100 series (AXA), 200 series (BXA), 300 series (CXA), etc. If you just got your lathe, the toolpost should say which series it is. Techshop lathes use a 250-222 toolpost, which is a 200 series/BXA toolpost. All 200 series toolholders will fit the 200 series toolpost, and similarly, for 300 series holders and posts. However, a 200 series toolholder would not fit on a 300 series toolpost.
The toolholders themselves are also standardized. Different varieties typically come in all common toolpost sizes. Again, most tool supplies should have a wide selection, KBC, MSC, SHARS, etc. For most turning and facing tools, a #1 or #2 toolholder will be the best choice. For boring bars, a #2 or #4 holder will be best. Keep in mind, the toolholders have a maximum tool size, for 200 Series/BXA toolholders #1 and #2, a 5/8ths tool will be the largest you can hold. You have to choose smaller tools based on your toolpost.
Here, I chose a single BXA #2 toolholder. This holder accepts the SCLC tool, and has a v-groove for the S-SCLC boring bar, meaning only one holder is necessary.
Step 6: Setting Up the Tooling
Next, install a tool into your toolholder. You can choose whatever tool you want to start with, but I usually start with the turning/facing tools as they are a little easier than the boring bars. Again, be sure to clean both the tool, and the toolholder, as even small chips will cause inconsistencies. Place the tool in the slot, and tighten the set screws as shown. You will want to get these set screws decently tight, if they are loose they can vibrate free.
Now that your tool has inserts installed, and is in a toolholder, you are ready to install it on the lathe. It is again recommended to clean all the surfaces on the toolholder, and toolpost. To install your toolholder, rotate the large handle on top of the toolpost counterclockwise, until the small gibs raises up. Then slide you toolholder onto the approiate dovetail slot. If you have a turning/facing tool, install it perpendicular to the spindle axis, if you have a boring bar, install it in the slot parallel to the spindle axis. Push the tool all the way down, and rotate the handle clockwise until tight.
Step 7: Setting the Tool Height (rough)
To set the height you will want something long, and relatively flat, with two parallel edges. A steel rule, works great for this. You will also want a piece of round of decent diameter. This method will in theory work with any diameter, but it will be more difficult as the diameter goes down. I used a piece of 2" 7075 aluminum round I had leftover.
With the machine off, chuck the round stock in the chuck, and tighten. You will be cutting with it, so don't skimp on the chucking.
Next, move the tool until the cutting edge is in a position to contact the outer diameter of the work piece. Back the tool along the X axis until there is about 1/4" between the tool and the stock. Take your rule, or other object, and hold it so it so the cutting edge of the tool is roughly centered on the length of the rule. Then, advance the X axis until the cutting edge just contacts the rule. Be careful, to much pressure will break the carbide.
You should now be able to let go of the rule, and it should stay in place. If not, keep putting light pressure on the axis until it stays. Now, postion yourself so you can get a good look directly at the front of the spindle. If the tool was perfectly level, you would see the rule perfectly vertical, however, unless you are extremely lucky, it is most likely angled. If the rule is angled such that top is closer to the spindle center, the tool is too high. Similarily, if the rule is angled such that the bottom is the closer to the spindle center, the tool is too low.
Take note of the angle of the rule, and decide which way to move the tool. Then, remove the tool from the toolpost. Loosen the locking nut on top the thumbscrew, and rotate the thumbscrew so it moves either up or down. There is no direct science on how much to move the thumbscrew at this point, so you should use your best judgement, if it is wrong, there will be no harm. Once you have moved the thumbscrew, tighten the locking nut, and re-install the tool.
Repeat the rule test, and thumbscrew adjustment until the rule is too your best judgement, vertical. It does not have to be dead nuts perfect at this point, as you will continue to dial it in.
Step 8: Setting the Tool Height (Fine)
You'll want to take facing cuts, at a D.O.C. as large or larger than the nose radius of the tool. My inserts have a .031" nose radius, so i started with 40 mil (.040") D.O.C. . Take one facing cut, all the way to the center of the stock, and then stop to look at it. *Be sure the lathe can't start while your looking at it*. If the tool is perfectly centered, you will see a smooth finish all the way to the center. If the tool is beneath the spindle axis, you will see a small stub of material that was above the tool and wasnt cut. If the tool is above the axis, the same stub would have been present, however, it is likely that you pushed it off with the non cutting surfaces of the tool. You should still be able to see some marring on the workpiece, but mainly, you will be able to tell because it should take more force to cut the last little bit.
Just as before, you will have to take the tool out and adjust the nuts. Be aware, that you are dealing with much smaller distances this time, so smaller adjustments should be made. Keep taking cuts and observing, until you feel a smooth cut all the way through, with no stub. The tool is now perfectly centered.
Step 9: Setting Heights for Multiple Tools
If you have multiple tools, and only one holder, don't fret, you still can do this only once. Once you have set the height for a tool, get out a set of calipers, and measure the distance between the top of the toolholder body, and the thumbscrew. Write this number down somewhere obvious, on the tool itself is great place. Whenever you need to set the tool height again, you can simply adjust the thumbscrew until you see the same distance. You can repeat the process for as many tool as you like.
Hope this helps you set up your tooling,