My new friend

[sco]

Steve,

I can see the sense of making a second bracket, thanks for the sleeve and spacer dimensions too.

For a quick trial I just made a simple sleeve 8mm bore and 3/8ths od to allow me to use one of the compound gear bosses to mount one of the screw cutting gears.  Couple of videos showing hot screw-cutting action below - note I ignored the engage back gear and leave the clutch engaged sugestions.

<a href="https://www.youtube.com/watch?v=3C7kbz7rpY4" target="_blank">http://www.youtube.com/watch?v=3C7kbz7rpY4</a>

<a href="https://www.youtube.com/watch?v=NXkbagFqco4" target="_blank">http://www.youtube.com/watch?v=NXkbagFqco4</a>

Liking the automatic cut-off - works just like a Hardinge 

Simon.

[steve-de24]

Simon,

Seeing your video of screw cutting at speed reminds me of the line from Kipling :-

"You're a better man than I am, Gunga Din."

I'll keep engaging the 60 RPM backgear even if it makes me look a wimp! In fact I'm thinking of slowing it right down by making a headstock spindle handle for when I want to cut short internal threads (something I haven't yet tried).

Regards, Steve

[sco]

Probably not better just more foolhardy.  Did take a bit of care to make sure the automatic trip cut in before anything hit the chuck.

Jo recommended making a mandrel handle so that's something else to add to the list.

Simon.

[Jo]

You are doing well learning all about C1 Simon  Sorry I hadn't commented earlier I have been preoccupied 

Dan drew up the extra shafts etc for cutting the left hand threads here: http://www.modelenginemaker.com/index.php/topic,1020.msg12601.html#msg12601

I still have to set up C2  but my new friend is well settled in 

Jo

[sco]

No worries Jo.

If you do come across a set of sh screwcutting gears I'd be interested though.

Simon.

[steve-de24]

Simon,

I don't know what gears you've got but for info the full set supplied by Cowells is

20, 25, 2x30, 32, 35, 40, 50 and 64 as well as the two compound gears  56/20 and 32/16.

Steve

[sco]

Steve,

Whilst picking up the lathe from Jo we cut a complete set of gears including a 37T and 47T for cutting BA thread however looking closely at the tooth form something was not quite right (I think arbor not central on the dividing head) as the teeth are the same depth / shape.

As well as the lathe I got a box of goodies including indexing unit, dividing head and vertical slide.  Also in the box were some curios shown in the pictures below - there are two oddities in the first and second picture that I have no idea what they are, then there are loads of different length and styles of arbor all with a taper to suit head or tail stock.  There where also two faceplates one of which has this arrangement of screws, lastly is this possibly home made boring head.

Simon.

[sco]

Boring head;

[Jasonb]

The V shaped one on the left is likely to be for cross drilling round shafts and fits the tailstock

[sco]

It could be for that but why the thread on the end of the taper?  The taper is horrible also - very scored up.  The boss on the side of the vee looks like in might fit the dividing head?

Simon.

[Allen Smithee]

Simon - surely you'll soon be making the Cowells a quick-change gearbox with e-shifts and ERS motor option?

 

AS

[Stuart]

Looks like a repurposed bolt


Stuart

[sco]

Stuart - The grooves are regular so yes it could have once been a bolt. 

Is it really a cross drilling fixture though, and if it is whats the boss on the side for?

Any guesses for the thing on the LHS?

Simon.

[steve-de24]

Simon,

I'm envious that you've got the Cowells dividing head.

Before dismissing your homemade gears remember that they are used for timing purposes and are not transmitting any great power, so they could be ok for intended use. I suggest you try a test and machine the following metric threads: 
2 x 0.4      3 x 0.5      4 x 0.7      5 x 0.8     6 x 1.0     8 x 1.25
Use commercial nuts as your gauges - you will probably find the cut screw threads are quite serviceable - even if not up to Hardinge standard.

Is the thread on the second from the left arbour a 3/8" x 24 ?  In which case it is for a Jacobs drill chuck for the tailstock.

Steve

[sco]

Steve,

Yeah I'm hoping to use the dividing head on my main mill - not sure about the quality of some of the Cowells machining though - the bore on the head is as rough as a bear's arse even if the spindle is a good fit.

You could be right about the gears but I was worried that long term meshing with the stock gears might damage them.

That arbor is indeed 3/8" x 24 - good spot!

Simon.