Member postings for Vapeur89

In fact these machines are not for the absolute beginner as they need a lot of tweaking and care. Even if they are sold under “professional mill” or “expert lathe” labels they are only light duty machines. But in my opinion they performs well enough for the average model engineer.

Finally I’m satisfied, I can achieve my goals for a “modest” investment. Surely I won’t buy a second hand chinese lathe nor mill.

I’m on the metric side of the hobby and I use either metric or imperial drawings or kits.  I have no problems with that. It does’nt take very long to convert from imperial to metric. The reverse is not true if you have to work with imperial fractional. You can download a free professional unit converter at http://www.katmarsoftware.com/uconeer.htm

 As to what represents a distance... it’s not easier to figure 1 53/64’’ than 46,434 mm.

 Many times I order stock bars from bristish suppliers as it is a cheaper than in France.

To deal with imperial drawings I use exclusively metric holes and metric thread and I convert distances in mm with three decimals.

In fact before making chips we have to  study and dig into the drawing to understand or to adapt the stock bar we have on hand or to deal with a limited set of tools. So converting is a good starter.

The strengh of SI unit system clearly appears when you have to work with complex physics formulas, but as long as only length is concerned why worry about that?

Hi,>>

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Sometimes the problem comes from the compound slide after  hard work or a dig in. The axis of the compound slide have to be dead parallel to the headstock axis. An error of 0,12° is enough to produce a taper cutting like your’s on a 50mm travel.>>

 Don’t trust the 0° setting of the angular dial of your compound slide. >>

To check it’s easy. It’s almost the same as checking general alignement. Loosen sligthly the nuts that lock the rotation of the compound slide. That’s to ease it for further light adjustment. You need to remove the tool post and place  a lever indicator with a magnetic base on the compound slide. Then chuck a ground  round bar of says ½’’ diameter. Wind the hand wheel to move the compound slide and  place the indicator on to the bar as close as possible to the chuck.>>

Lock the longitudinal movement and the transverse movement (cross slide). Set the indicator dial at zero. Now move away at a maximum distance  from the chuck with the crossslide handwheel. Note the reading on the indicator.>>

Rewind to go as close as possible to the chuck. Move the chuck by hand to find the maximum deviation of the indicator. Note it. Move away and note the reading>>

Then calculate A= (Near chuck1+Near chuck2)/2- (Awaychuck1-Awaychuck2)/2. >>

With a soft hammer and ligth blows -on the tail of the compound slide reduce or augment the reading on the indicator  the reading by A/2. Then check again doing  same procedure. >>

After two or three adjustements the total variation will be reduced to a minimum and  won’t vary. Tighten the nuts. Check again