# Titanium machining and the results....(picture heavy)



## Anglepoise (Jul 21, 2006)

Well I finally got it finished. My first Grade 5 Ti homebuilt.
And it was allot of fun mixed in with many hours standing in front of the lathe.







Titanium is the perfect material for amateur use. I would never have believed this until I tried it. Following is what I learnt.

Amongst professionals,Titanium has got a well deserved bad reputation because the people discussing it are having to machine it as a money making proposition. And Ti does not like to be hurried.
In my research for this project, an old timer gave me the following advice. "Watch the chip colour and if it changes from silver to blue or brown.....STOP..."

So I took my time. I purchased 3 new cobalt HSS drills and used these to core out a 1/2inch hole to get my boring bar into. I used a water based coolant /lube call "Ancorlube" ( horrible messy stuff )and applied this green stuff with a brush. When heated it made no smoke but boiled and made crackling noises that also acted as an indicated of overheating.






My reason to try and avoid overheating was not necessarily to protect the tooling but to prevent a fire. When finishing, the turnings are very fine like cobwebs and burn with a white hot intensity. I have seen this first hand and did not want to burn a hole right through the chip tray etc.

The cobalt drills did a great job and showed little wear. Drilling speed was approx 350 rpm ( 80 sfpm ).

Boring beyond 1/2inch was handled by a TP** carbide insert and one of these inserts ( 3 sided ) did the whole job.

Parting off and grooving are not my favourite chores, but Ti is fantastic in this regard. At about 80 sfpm, a HSS parting tool produced no chatter and cut like a warm knife through butter. In point of fact, Ti is a very clean material to machine and produced almost no dust and nice chips.






Internal and external threading was handled once again by HSS , single point , modified flank infeed. This stuff is like a big spring and each cutting pass was repeated 3 times with no 'infeed' to work out the spring.






RPM for threading went down to 50 rpm and one set of threads I cut entirely by hand revolving the headstock. Like parting off, the surface finish was fantastic due entirely to the slow speed and very sharp tools.

Except for my boring bar, all tools edges were positive rake and very very sharp. If you linger for a few seconds, Ti work hardens and this caused me some problems when I was taking very small finishing cuts.
Things improved when I was more decisive and trusted the accuracy of the setup.

My best external surface finish was achieved with a round nose carbide insert
run fast ( approx 780 rpm, 200sfpm) . Scothbrite pads smoothed out this finish to a nice sheen.


This photo below shows the LED being aligned ( spring loaded device in tailstock) for epoxying . It also clearly shows the aluminium inner core that will aid in getting rid of the heat.








All told, the project took about 30 hours, but it was worth it to have an addition to my small collection.


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## Kiessling (Jul 21, 2006)

Nice !! :thumbsup:

A little "off-topic" ... but can you say more about the light itself? Seems worthy of discussion ... 

bernie


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## ouchmyfinger (Jul 21, 2006)

Wow, very very nice!

I really like the straight knurls, wonder why we don't see those on more lights. And thanks for all the info on the machining, great stuff.


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## McGizmo (Jul 21, 2006)

:thumbsup: Good job!


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## [email protected] (Jul 21, 2006)

:huh: :goodjob:


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## TranquillityBase (Jul 21, 2006)

Awesome job! Great photos too.

TB


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## Manzerick (Jul 21, 2006)

AWESOME JOB!!!!!!!


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## Anglepoise (Jul 21, 2006)

Kiessling said:


> Nice !! :thumbsup:
> 
> A little "off-topic" ... but can you say more about the light itself? Seems worthy of discussion ...
> 
> bernie



I am not much good at the 'electrical' and have had help from George Scolaro
at http://www.taskled.com. He makes a variety of drivers, direct and controlled, that have the side micro switch.

So the middle section has its driver/switch combination as below






These micro switches are good for 10,000 activations. Dimming is set by an on board computer and the user sets it up as they want.

The rest of the light is pretty basic. 22mm UCL window. 20mm reflector
UYOK Lux III, and a single R-cr123 re chargeable, unprotected battery.

Driver has its cut out set at 2.7 volts so in this case I see no need to use fully protected cells.


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## TranquillityBase (Jul 21, 2006)

Love the led centering device.

I see you're using a self tightening chuck in your tailstock...I'm too chicken to use mine, I had one bad experience, and found out, just how tight those chucks can clamp down on a bit. 

Your design is beautiful, what's next?

TB


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## Anglepoise (Jul 21, 2006)

TranquillityBase said:


> Love the led centering device.
> 
> I see you're using a self tightening chuck in your tailstock...I'm too chicken to use mine, I had one bad experience, and found out, just how tight those chucks can clamp down on a bit.
> 
> ...



Yes...the centering devise is a super time saver and keeps a constant spring pressure on the LED while the epoxy sets.

So far no problems with the key less chuck.

Next project. Well I am very impressed with the performance of these 5 mm
SMJLED's. I think a very small keychain style light with that LED would be worth investigating. Now just have to get some 1/2" dia Ti. Am not going to waste that lovely 1, 1/8th bar.

Thanks again for all your help TB.


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