BUILDING THE HEMINGWAY SPHERICAL TURNING TOOL

[Kim]

Bummer of a deal Don

One thing someone recently suggested on the Taig list, quite similar to what krv3000 mentioned, is to spray the broken tap with freeze spray till it gets frosty, then hit it with a pin punch or an automatic center punch (what he recommended) and the tap should just shatter.  I've never tried it myself but it sounds reasonable.  And certainly seems worth a try before redoing the whole part!

Good luck Don!
Kim

[Jo]

Don,

It is not as if it is a large difficult part that you have invested lots of time in  so I would make a new one, it is probably quicker than trying to get that tap out  .

Jo

[ths]

If the polar vortex had come down as far as you, it could have been left outside for the freezing to occur. If you can't get it out without damaging the plate, then given the standard of your work I can see a remake happening. Bad luck!

Hugh.

[Don1966]

Thanks Dave, Bob, Bob, Kim, Jo, Hugh for looking in and your kind suggestions. I guess Hugh and Jo knows me quiet well because I decided to remake the head.

I had some time today will awaiting job to restart. So I did manage to make the base without breaking a tap this time. I did buy a new tap to use even though I had some.
The first photo is the head all drilled and tapped ready to start the dovetails pieces.


After drilling the holes and counter bores I mounted the pieces to be dovetailed to the head with some packing to evulate them for cutting the dovetail without fouling the head.


With a sign of relief that it went well, this is the head all ready for the slide to be made.


Thanks for looking and I will continue If I get more time tomorrow.

Don

[Don1966]

I have more progress to report today. I managed to cut the dovetails into the slide.
I started by milling both sides to a depth of .3125" and cutting on each side till the middle tab was .71875". then flipped it over rised it with parallel to be able to pass the 60 degree dovetail on each side. I cut the dovetails till it was a sliding fit to the head.
Here I am cutting the top to width.

Flipped it over and cut the dovetails to a sliding fit.

This photo is the head and dovetail together.


Thats all I managed to get done for today and thanks for looking.

Don

[Jo]

It is a very nice fit but I hate to be a kill joy  have you not forgot the gap for the gib strip?

Jo

[Tennessee Whiskey]

Hey Bud, I'm looking and learning. I had to go to YouTube and watch one in action to wrap my head around the way it works. That's one sweet piece Steady as she goes and I'm watching from under the shade tree

Y'all come see us,
Whiskey

[Don1966]

It is a very nice fit but I hate to be a kill joy  have you not forgot the gap for the gib strip?

Jo

Hi Jo, yes I had thought about that but the drawing don't show any.

Eric thanks my brother for watching.

Don

[sco]

Weird - my drawing definitely showed a gib strip.  Without it the slide will get damaged as you need to lock the tool in use.

Simon.

[steamer]

if you put a brass pad on the clamp screw, it will work alright and not bugger anything up.
As the dovetail doesn't move under a cut, the lack of a gib shouldn't be an issue.   Keep it lubed...and a brass pad, and all is well.


Dave

[Don1966]

Thanks Dave, the locking pad screw is brass.

Don

[Don1966]

Today I started by boring the .5" hole in the head and inserted the shaft and loctite and pinned it in place. I then assembled the shaft and head to the base securing it with boss and washer. I then mounted it to the lathe with the slide secured inside the head ready for boring.
I start by using the DTI to set the cross side true.

Using the square to set the side square to the drill bit.

Using the laser to find the split between the slide and base.

I secured the slide and shaft with brass screws and started drilling with .25" drill and increase to .3125" and drilled all the way through using the tailstock for support.

Continue with a .5" drill to depth and then used the slot drill to finish. Sorry about the fuzzy photo.
\

A look at the results after boring and not to bad I can take that.

When I had the head mounted to the lathe cross slide I scribed a line to find center of the slide. I then mounted it to the mill vise and drill the hole for the tool holder.

The tool assembled as is for now. I have to make the feedscrew and tool holders. Sorry this photo is kind of crappy.

thats it for now and thanks for looking.

Don

[b.lindsey]

You are making great progress Don. It's a nice looking tool and will make a nice addition in turning capability I am sure. Nice work my friend!!

Bill

[Dave Otto]

Nice work Don!


Dave

[Jo]

  I had to go and have a look at my one:  It also does not have a gib strip but it works ok - so long as you set it up correctly and sharpen the tool right 

Jo