My Beaut Aussie Cent

[Stephen White]

Thanks Mike. In which case both those tanks were at Binh Ba and took part in Op HAMMERSLEY. What are the chances of both surviving? The AWM write up for 110 includes:

This tank, with Army Registration Number (ARN) 169110, was issued to 2 Troop, B Squadron, 1 Armoured Regiment in South Vietnam at the beginning of June 1969, and took part in the Battle for Binh Ba on 6 June, under the command of 39036 Second Lieutenant David Barry Ritchie.

In 1970, it continued on operational duties in Vietnam with 2 Troop, A Squadron 1 Armoured Regiment. On 18 February 1970 the tank, commanded by 235339 Lieutenant John Harry Brennan, was hit by 3 rocket propelled grenades (RPG) during Operation Hammersley, and received damage to the right hand exhaust shroud, right hand rear track bin and left hand track guard. The tank remained battle worthy throughout the action, and after repairs continued to serve until it was transported back to Australia in December 1970. On its return to Australia, it was rebuilt and then used for training purposes until retired in 1977.


This photo has now been identified as being taken at the end of Op HAMMERSLEY and may show ARN169110 on the left, although I can't see any of the damage mentioned above:

Regards

Stephen

[Michael Cecil]

Yes, Stephen, the chances were slim, but fortunately both have survived - one in a public collection (169110) and the other in private hands (169064).

And talking of slim chances, the AWM also has 169108, the only Centurion to survive with all its in-theatre modifications. When I interviewed driver Greg Harris several years ago ( https://www.awm.gov.au/collection/S02684/) it turned out he had driven both 169110 (2 Troop) and 169108 (4 Troop) while serving in South Vietnam. Quite a coincidence.

Mike

[Stephen White]

The commander's cupola is finally finished, at last, eventually, ....... Last bit was to fit the MG transit arm:





Now back to some straightforward machining tasks with the loader's hatches. First the hatch surround in the turret roof was recessed and had a raised inner lip with some unusual scalloping on the bottom. The purpose of the lip was to stop water flowing from the roof into the turret and it also served as a seal. I machined a separate insert and lined it with a brass lip. The brass was formed using a dapping block:







It will help with the hatches themselves not to fix the insert at this stage.

Regards

Stephen

[Stephen White]

Trial fit of the insert:



Machining the hatches. The top armour and hatches were 1.18 inches/30mm thick, 5mm at scale. I couldn't think of an easy way to mill the corners of the channels on the inside and so resorted to doing it by hand using a Proxxon:







Stages in making the hinges:



Comparison of the scale hinges with the kit ones:





A neat little lamp for detailed work. Available in UK from Rutlands in a job lot of three. The stem is fully flexible:



Regards

Stephen

[Phil Woollard]

Superb work ...puts me to shame !

[davidwilkins]

Stephen,

Stunning work as usual, I am always interested in the tools that are on display in your updates and I always make notes of these with the intention of adding to my own subject to the minster of finance approval.

The one thing that I totally missed on mine was the loaders hatch where recessed this is something that I could change as my hatches are slightly to big, another job to go back to.

As regards cutting the corners of the channel on the underside of the hatch I cut mine out on the rotary table.

Regards

David

[Stephen White]

Thanks. David, I thought about using the rotary table to cut the curved parts of the channels but decided the setup would be too much trouble for something I could do quicker by hand. Not sure it was a good decision. How did you do the work holding in the rotary table?

Brief update,mounting the recessed plate, with its characteristic scalloped bits and fixing the hinges for which I used M3 studs, tapped into the turret roof with the hinges expoxied to them:









I use a metallic colour fabric paint for the welds, which I find gives much finer results on the smaller welds:



Regards

Stephen

[davidwilkins]

Hi Stephen,

I just used the step clamps supplied with the rotary table, the time consuming part was lining up the radius centre with the centre of the curve with X axis of the milling machine. Looking at what you have achieved by doing this job by hand I would be well please with the result.

Looking forward to your next update.

David

[Stephen White]

Sorry this is nothing more exciting than a routine build update......

To continue with the loader's hatch, added the sealing strip and padlock hasps:



The most difficult geometry to establish was the locking mechanisms which hold the hatches open to prevent them clogging the operator on the head on rough terrain. I managed to establish that the open hatch sits at 25deg to horizontal but working out the shape of the catch was tricky and required several goes:





I decided I could make functioning spring loaded door locks. The real ones have a lever to open them. Without that, my version could lock the hatch open but there was no way of releasing the lock to shut the hatch. Oh well, Plan B was a slight change to the profile of the lock to allow it to act in both directions. I made the custom spring to size with piano wire on a mandrel on the lathe:







Finally for today, I turned up two simulated brass springs for the hatches. They don't need to be functional and are of a particular flat section material so were easy to simulate with a thread cutting tool:





Thank for reading, apologies if it's a bit dull after photos, gear changes and rusty track pins....

Stephen

[simon_manning]

real or fake, cannot decide, great work regards simon.

[Adrian Harris]

Great to see more progress on the Cent.

I like the idea of using the threading tool to make the springs. I might have to steal that idea if I ever get around to making the bellows on the 222

I would be interested to know how much of the shaping you do by hand and how much on the mill. I have just enough saved up for a Warco WM16B but haven't pulled the trigger yet due to a lack of space, but there are more and more things I can think would be simple tasks with a mill that would be a pain to do by hand.

Adrian.

[Phil Woollard]

Do I detect sarcasm simon ref our lovely new thread?

[Stephen White]

Adrian, hi. "A pain to do by hand" sums it up. There isn't much I do which couldn't be done with a Proxxon and some milling cutters and a lot of patience. I still prefer to use those for shaping irregular forms such as the towing bollards but for everything else, the mill wins. The WM16 is perfect for our needs and Warco service is excellent.

After the mill itself, the best investment I made was a two axis DRO. The Warco simple one is perfect, unless you need to calculate PCDs or understand COS, SIN and all that stuff. Fitting requires some drilling and tapping and I also machined a couple of supports to mount the Y axis scale. I can give you dimensions if you go ahead. The DRO gives you accuracy and repeatability, which saves a lot of time.

For aluminium. I'd recommend using roughing cutters for the majority of work. The DH-1 vice is a must and thereafter, it's a choice of tilting vice or rotary table. If one of the tilting rotary tables, you pretty much cracked the basics. You'll need a 4 or 6" rotary table - I bought smaller to start with and regretted it.

Happy to help further if needed.

All the best.

Stephen

[davidwilkins]

Hi Adrian,

Thought I would add my 2 pence worth. Totally agree with Stephen the Warco wm16 is brilliant machine and Warco has excellent backup service. I have however changed mine to Axminster Siege x3 this was only to make it more comfortable to operate with my bad back.

The extra money spent on DRO, DH1 vise and I would definitely recommend going for a 6" rotary table over the 4" if you don't I think you might regret it later.

Regards

David

[Stephen White]

Next the bullet splash guards for the hatch springs, formed out of annealed aluminium:









I then followed a tip from Dave Dibb, Armorpax, to apply the stencil to the M19A1 .300 ammunition liner. Thanks Dave. I'm not entirely happy with the application, using MIG acrylics mixed to the correct colour. It might have been too thin, allowing the pooling. It's a bit tricky because you don't want it looking too perfect, as a stencil:



Regards

Stephen