Lathe Hand wheel Reference Chart Inch to Metric

[duke851]

I made the attached chart to try and help get my mind around thinking in metric and using an inch lathe.

My lathe is a Prazi MD300 and has the following the hand wheels as follows

Cross slide

Increments - one revolution = 50 x .001" = .050"

Marked 0 - 9 every .005" and also marked every .001"

Lead screw, Tailstock and Compound

Increments - one revolution = 25 x .001" = .025"

Marked 0 - 4 every .005" and also marked every .001"

The attached PDF converts everything into mm and in the final column gives the total stock removed.

I checked it with a dial indicator on my lathe and it showed that in is very close with the actual carriage movement being fractionally less than the chart (on the safe side). For one complete revolution of the Cross slide the chart shows 1.270mm movement and the dial indicator read 1.265mm.
An actual cut of some scrap showed cuts to be within +/- .04mm of the chart.
I have to add though that I am not a machinist and would welcome any feedback. (like if I have this totally wrong)

Colin

 

[mredburn]

I find it easier to use a metric/imperial digital calipers and convert the mm into inches on the caliper and then I can cut to that. If I slide the calipers to 13mm as a finished diameter I then push the mm/in button and it tells me I need .512 much easier to keep track of that on my lathe.

 

[BigShed]

I guess I'm spoiled, I have a 2 axis DRO on my lathe and can instantly switch between mm and inches.

 

[rherrell]

I don't use metric for anything and never will, something about an old dog and new tricks.:biggrin:

If I have to fit something to metric I convert it to imperial before I start.

 

[PaulDoug]

Well, the more I work with metric the more I like it. It's frustrating to have to do both and go back and forth. I use metric as much as possible.