rotary table adaptor myford mikes-models

My model engineering experience has only been seriously sought since this time last year.
In the most part it has been a steep learning curve and very much one foot forward and
ten back!

However, this particular project worked very much as all steps forward. So no doubt
that around the corner soon is a ton of bricks!

I have put off making this particular tool since last year, mainly because of making the
MT2 taper and the screw threads for the Myford Lathe. Making the Mills 1.3cc diesel
engine has required a range of skills which were new to me. Thread cutting on the lathe
perhaps the most demanding. The day before making this project I had just finished the
ER25 collet chuck backplate adaptor. I 'mucked up' two attempts before getting it right.
In the process I made an aide memiore which can be found on the download's page.
However, I seem to have finally 'go it'.

As you will see in the gallery I started by cutting the 12tpi whitworth threads on a 1.5"
diameter bar turned to size when supported by a reveolving centre.

Trial fitting took place using a spare backplate and once a nice fit was achieved with a
suitable shoulder, it was parted off. I used the method of making wider cuts as I went
deeper, this seems to works well and little problems were encountered in what is a
reasonable thickness bar.

After protecting the threads the blank was reversed in the chuck and was centre drilled.
Using various size drills, the hole was increased sufficiently to allow a boring bar to be
used to bring the hole to allow the taper plug to be inserted as a tight fit.

Initially I was going to screw through the chuck holding part to secure the taper bar, but
found it was hardened, therefore tapping was not going to be an easy option. So a
change of plan was required. I decided to secure the two parts together by using a grub
screw coming in from the side against a flat ground into the morse taper. To cross drill
accuratele,y a slice of the same diameter bar was removed and used as a guide. After
tapping 6mm, the grub screw was fitted and a trial fit took place.

Much to my surprise the whole process went without a hitch and the fit of parts was very
good. When taking the fixture and chuck were then offered up to the rotary table
everything again fitted well and quite secure.

Using a dial indicator the accuracy and central location was checked with pleasing
results. Initially I was going to secure the taper fixture with a draw bar, but again as it
was hardened this was left.

There seems little movement when secured together so the taper seems to be doing its
job. I can, now at last, continue on with the building of my Mills! At least this tool will be
used to good effect, hopefully for years to come.