Myford lathe/Operation

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There are many operations that can be done on the lathe, I've listed most of the basics bellow and tried to include important pointers for each, some of these are taught as part of the induction.
Some are a more complex and it's advisable to ask for help and advise if you plan on doing these for the first time.

What follows is a guide and usefully reminder.

General advice

Remember the safety points!
Rotate your workpiece by hand to make sure it clears the toolrest and bed before turning the lathe “on”. Do this after mounting new work or tools.
Always double check everything.
Measure twice, cut once.

Micrometer Dials

The cross slide dial is marked in .001" graduations.
The top slide dial is marked in .002" graduations.
These graduations represent how much the slide is advanced, remember that for the cross slide this will reduce the work diameter by twice that!

Inch/mm conversion cross slide
1 graduation = .001" movement = .0254mm
10 graduations = .010" movement = .254mm
1full turn = .100" movement = 2.54mm

.1mm = .0039" = 3.9 graduations
1m = 25.4 graduations


Turning speeds & Feedrates

The RPM and feed rate needs to be calculated based on the work material and diameter. For the various work materials and tool materials there are recommended cutting speeds, these are in Feet per minute.
Most of the cutting tools we have are HSS so there the only ones listed here.

TABLE

RPM = (Cutting Speed x 4)/Diameter

RPM = Spindle Speed
Cutting Speed = Cutting Speed for the material being cut/worked.
Diameter = The Diameter of whatever is turning.

When calculating spindle speed(RPM), round down to the slower speed option offered. Operations like Threading, Knurling, or Parting-off, require much slower speeds (Generally 1/3 to 1/4 Calculated RPM for Threading, Knurling & Parting-off).

The above table also includes suggested feedrates (feed per rev.) for cutting these can be setup via the change wheels on the leadscrew or with practice hand feed.

http://www.southbaymachine.com/setups/cuttingspeeds.htm

Tool shapes

Sharpening tools

Mounting work

Most round jobs can be mounted in the 3-jaw self centring chuck.
If super high accuracy is need use one of the 4-jaw independent chuck and the dial test indicator.
When tightening 3-jaw chucks snug the work first then nip with a moderate force, do not apply excessive force by extending the chuck keys with hollow bar. It is possible to obtain more gripping power with the 4-jaw chuck due to the design however this is not needed for most work.

The jaws in the 4-jaw chuck's are reversible for use as both internal and external holding.
There is a separate set for the 3-jaw. When swapping sets back out all the way then insert the jaws in the order stamped.

Aim to project the minimum amount of work needed out from the chuck jaws, if in doubt use the live centre or fixed steady to support the work.
Rule of thumb is do not extend more than 2-3 times the diameter from the chuck jaws with out a centre or steady.

Errors in the use of self-centring chuck to be copied from the Myford Series 7 manual

It's also possible to mount work between centres or on the faceplate; for details on this check the Series 7 Manual

Facing

This is usually the first operation for most work, producing a flat face on the end of the work.
Facing should always be done before any drilling!
The work face be should very close to the jaws or supported by the fixed steady.
Lock the saddle.
For facing operations its is necessary to feed the cross slide hand, remember your rate of feed can be increased as the diameter is reduced.

Routing cut can be taken at .010"-.020" and finishing cut at .002"

Facing operations leave a rather sharp edge on the end of the workpiece. It's a good idea to smooth this edge down with a file to give it a nice champfer and to avoid cutting yourself on it. With the lathe running at fairly low speed, bring a smooth cut file up to the end of the workpiece at a 45 degree angle and apply a little pressure to the file.


Turning

Drilling

Taper turing

Boring

Threading

Although it is possible to cut both metric and imperial threads on the lathe using the correct cutting tools, metric threads are more complicated as you can not disengage the half nut and so have to stop the machine and throw everything into reverse to get back to the zero position.

When cutting thread on the lathe depth is calculated as 0.614 x pitch. Also known as the minor diameter.
It is advisable to add a slight chamfer to the right end of the work, to just under the thread minor diameter using the left edge of the cutting tool.

Change Gears

http://metal.duncanamps.com/software.php