As a "quick and nasty", baked bean tins seem to be made from tin plate which is about 0.010" thick.
It might be worth trying different types of tin, such as sardine tins, in case they are any thinner, or thicker.
Cooking foil is probably only about 0.001" thick, and is probably not going to be long lasting, but might do as a short term fine tune.
Do make a centre height gauge. We are not on piece work, but it will save time and frustration in setting tools.
Glad to see that you are up and running, and climbing the learning curve. Nothing succeeds like success. Every job that you do will increase your confidence and experience..
If you can find a couple more 20T changewheels, get them. To get the finest feed, you need three.
One from a ML7 will be OK, once you have drilled a 3/32 hole into one side of it for the driving pin. The bore and width are the same; as are the DP and Pressure Angle
Not long ago, I did this with an ex ML7 60T gear, so that a chap could set up a 20:60/20:65/20:60 gear train.
This gave a feed of 0.0043"/rev as a fine feed, using the Leadscrew. The 65T needed to be on the middle stud to avoid a clash between the two 20:60 meshes..
One other job for the "Round Tuit" might be to make a mandrel handle. This will be handy when you come to cut threads, even with Taps or Dies. It will allow you to turn the Chuck slowly (Ideal when cutting up to a shoulder )
Making it will involve some plain turning, a couple of short tapers, and two external, and two internal screw threads. These need only be 1/4 BSF, 1/4 UNF or M6. 1/4 BSF would be ideal to keep in with the rest of the Whit form threads on the lathe.
A bit of hacksawing and filing will be required, but nothing too complicated.
PM me with an E mail address, and I'll send a picture of the one that I made for a ML4
Howard
Edited By Howard Lewis on 12/12/2019 20:36:00 Fat Fingers!
Edited By Howard Lewis on 12/12/2019 20:37:00