# Lathe Order Of Operations?



## mzvarner (Apr 20, 2016)

I am new to the mini lathe (machining in general). I have a few basic books, but have not seen this addressed yet. Is there an order of operations when making a part? I think facing is always step one, but after that is it best to drill, bore, turn, angle? I have run into a few issues with some intro projects where I turned an angle to early then did not know how to hold the part (luckily it was threaded so I chucked it with a bolt holding it).


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## JimDawson (Apr 20, 2016)

Order of operation is one of the most critical considerations in machining.  As far as I know there is not much in writing on this subject because no two setups are the same.  As you gain experience, you will ''see'' the order of operations.  Unless it's a very simple part with only one setup I always machine the entire project in my head before I ever make a chip.  Spend the time to just sit and think about how you are going to hang on to, and machine the part during each operation.  Many times on complex parts I spend more time thinking about how to do it than the actual machining time.


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## Bob Korves (Apr 20, 2016)

JimDawson said:


> Order of operation is one of the most critical considerations in machining.  As far as I know there is not much in writing on this subject because no two setups are the same.  As you gain experience, you will ''see'' the order of operations.  Unless it's a very simple part with only one setup I always machine the entire project in my head before I ever make a chip.  Spend the time to just sit and think about how you are going to hang on to, and machine the part during each operation.  Many times on complex parts I spend more time thinking about how to do it than the actual machining time.


Welcome to the forum.
+1 to what Jim said.  Also think about reducing or eliminating additional setups to the greatest extent possible.  If you will have to take the part out and reinstall it, think about how reference surfaces can be picked up quickly and accurately again.  It is very easy to get mostly done with a part and then have no good choice for continuing the work.  Don't work yourself into a corner.  Every project you do is training for future work flow planning.
The six "P"s:  Prior Planning Prevents Pi$$ Poor Performance.


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## Bob Korves (Apr 20, 2016)

Another concept is thinking outside the box.  You can leave additional stock on the work specifically for work locating and holding later on in the job.  You can machine features strictly for indexing the work for a later operation, saving time and effort.  At the end, cut the workholding and layout bits off if desired.  Saves time and gains accuracy.


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## Grumpy Gator (Apr 20, 2016)

_Like Jim said think the whole project through before you even chuck it up. _
_I was taught to plan my steps so as to get as much done with out removing the work from the chuck._
_Check your stock first.Face and put a center in it then run it out past where you need it and move up the tail stock with a lubed dead center and spin it to check for  out of round or bends. Make sure it's large enough to hold plus extra for  cutting off._
_  If you have to remove it from the chuck mark the jaw on the work so you can put it back in the same place._
_ Once you are ready to machine stop and think it through again._
_ A 20 minute machine job can take 3 times as long to plan then to do._
_ If you run into a problem ask us. Take a picture as that will help us give you the right advice._
_*G*_


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## Baithog (Apr 20, 2016)

I try to figure out just how the project is going to go. Maybe its because I'm still green at this, but there always seems to be something that I didn't anticipate. The more complex the part, the more likely that it will not go as I planned. One of the things that I had to come to terms with was being willing to change the setup or just chuck it and start over when that 'oops' moment occurs. Trying to force something is a great way to make little pieces of scrap out of perfectly good metal. Two things will make life with your mini lathe a lot happier. One is a decent indicator and holder, and the other is a 4-jaw chuck. Getting stock to run true after taking it out of an import 3-jaw is really hard without switching to a 4-jaw.


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## chips&more (Apr 20, 2016)

Leave about 0.010” on all the dimensions, then finish everything.


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## stupoty (Apr 20, 2016)

The order of operations depends upon the parts requirements mostly.  An example might be two surfaces that need concentricity are most easily done in one set up, if you have to remove and reinsert the part to a three jaw chuck you will have some run out but may preserve paralism.  But for certain operations this may be fine like clearence holes etc.

Stuart


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## Grumpy Gator (Apr 20, 2016)

_Another tip is after you cut off your work face and center drill the remaining stock in the lathe. Saves time for your next project._
_   *G*_


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## Bill Gruby (Apr 20, 2016)

Quite frankly the operation order is up to the operator (YOU). The very first step is to orient yourself to the print or prints. You need to know the part before you can machine it. After time goes by it will become quite obvious where to begin. Time and practice, over and over again. Dig in for the long haul, the learning never ends.

"Billy G"


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## owl (Apr 20, 2016)

Consider all of your machinery as well.  Sometimes a part can be made simpler and stronger by machining in two parts, then welding or brazing together, or sometimes a difficult lathe operation is easy on a mill.  Sometimes a slot can be filed faster than workholding to machine it, etc. I sometimes find myself fixated on the machine in front of me, when the simple solution is off to one side.


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## eeler1 (Apr 20, 2016)

Agree with the above. Main thing on the lathe is to do all your stuff to your workpiece while it is still in the chuck, i.e., don't be taking it out, doing something else to the work, then putting it back in.  Unless you have to, for some reason, and accuracy isn't too important for that project.  Then it's ok.  As mentioned, it's hard to get it back in the exact same spot if you take it out of the chuck, or even loosen and then re-tighten it.  So plan your operations so you leave it in place until finished with that end of the work, if you can.


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## silence dogood (Apr 20, 2016)

If you are not sure of the order of machine operations, try making the item out a cheaper material.  It may take longer, because you will have to do it again.  However, its better than having to order some more expensive material.


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## CraigB1960 (Apr 20, 2016)

All excellent comments.  I cannot add, except to say that when I first started machining, tool changes, material handling, etc were wearing me out.  A lot of needless steps.   You start to learn fairly quickly what you should of done after you have done it the hard way a couple of times.  I like to plan out the part I need to make and visualize how I will machine it.  Since adding my mill to my shop, it has changed how I tackle certain jobs and certainly what I do on my lathe.


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## LucknowKen (Apr 20, 2016)

CraigB1960 said:


> All excellent comments.


Totally agree


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## Wreck™Wreck (Apr 20, 2016)

It will come with experience, the more times that you do it the easier it becomes.
I did 4 identical parts last week, 9 1/4" OD X 1" wall steel tubing 56" long.

1 Rough turn OD to 9.100 held internally in a 3 jaw and the tail stock end held with a plug, 4 each 300+ LB parts.
2 Put steady rest on lathe and face one end and bore to 8.00 diameter .5 deep, turn part 180° face other end and bore to 7.825 X 1.25 deep, turn a 20° included angle taper on this end 1/2" long, once again on 4 parts.
3 An end cap with a rough bore is then welded in one end, then it goes back into the lathe and the end cap is finish bored and the part faced to finished length.

4 It then goes into a milling machine on a spacer where a 3" Dia. hole is milled 180° apart one having a 2" wide X 3 1/2 long slot for another weldment to fit through.
5 After the cross tube is welded in it goes back in the lathe for the finish OD turning. 8.992-8.995 diameter, a 6" portion of the center where the crosstube is welded in is undercut by .010 because you can never get a decent platable finish turnining over the holes and welds.
6 Back into the mill and the cross tube bores are finished and some 1/4 NPT tapped holes are added
7 Off to the plater for hard chrome where the OD finishes at 8.998" +0-.002

This takes roughly 60-70 hours between my lathe work and someones mill work, you will notice that the parts have to be put in a lathe 4 times, end for
ended once, welded twice then set up in a mill twice. Also they cannot be scratched near the end as they are hard chromed last.

Roughly like this


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## brino (Apr 22, 2016)

Agree with above, but I'll add one tip:

In my early days I would do simple little sketches of all operation steps showing how it was held....even for simple parts.
Eventually you'll find you can just walk it thru in your mind.
For more complex parts I may still do some sketches.

-brino


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## Wreck™Wreck (May 7, 2016)

Today's mistake, made 2 of these parts, 2 3/8 OD X .885 wide with a .190 Rad. groove with a minor Dia. of 2.125 and a .063 X 45 Deg. chamfer on one end, the other end has no chamfer. I put the chamfer on the wrong end and had to make them a second time, order of operations brain fade. 
Small aluminum parts so no great loss. Took about 1 1/2 hours to make the first 2 wrong and less then 1 hour to make 2 correctly as the set up and programming was already done (-:


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