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Re: My Beaut Aussie Cent

Posted: Fri Jun 23, 2017 12:32 pm
by Dennis Jones
Outstanding Stephen. Look forward to seeing it at Tankfest. Regarding the weathering just drive it through a muddy field and then a dusty one, then leave it out in the rain !!!

Dennis.

Re: My Beaut Aussie Cent

Posted: Fri Jun 23, 2017 5:37 pm
by Phil Woollard
Looking excellent Stephen, you will have your work cut out weathering the ol girl, just remember to use a different thinner based system, one that won't remove the lovely British green (as if you didn't know lol ) :D , please send the new release photos from Bovi just as soon as you can for those that can't get there regards Phil.

Re: My Beaut Aussie Cent

Posted: Fri Jun 23, 2017 11:07 pm
by Steve Stuart
I agree with Dennis's suggestion as a good way forward, especially as you have had, hopefully, five years of family and friends going on holiday to Vietnam to have brought genuine, correct, mud back on their shoes for you to use 8)
As children now say, one more sleep until we find out, and if you are driving down tomorrow morning it is not going to be a long one.
Safe journey, see you tomorrow!
Steve

Re: My Beaut Aussie Cent

Posted: Tue Jun 27, 2017 11:46 am
by Stephen White
Thanks guys, appreciate your kind comments. It's been an intense couple of weeks to get her ready for TankFest but the sun shone, the battery lasted two days and she even acquired a coat of Bovvy dust - the wrong colour of course......

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Not much left to do now, searchlight, mantlet cover, fire extinguishers and weathering...

Stephen

Re: My Beaut Aussie Cent

Posted: Tue Jun 27, 2017 3:48 pm
by Phil Woollard
And tighten the tracks! :) She does look lovely, just the running ground detritus in the running gear looks the part.....very nice.......Phil.

Re: My Beaut Aussie Cent

Posted: Tue Jun 27, 2017 7:45 pm
by Andreas Walter
Perfect Centuron, I have not yet seen a more beautiful tank.
Greetings Andreas

Re: My Beaut Aussie Cent

Posted: Wed Jun 28, 2017 12:18 pm
by Dennis Jones
The bridge looks pretty good as well !!!

Dennis.

Re: My Beaut Aussie Cent

Posted: Wed Jun 28, 2017 9:19 pm
by Christoffer Ahlfors
Thank you Stephen for a fantastic build story! :D

Beyond being more exciting than any TV series, you have been very generous with sharing your experiences, knowledge and methods in detail. Documenting the build to this extent probably makes it take twice the time. In fact, it should be possible to copy your build, but I will bet that there are not too many around, who can possibly manage. :roll:

Words like stunning, deeply impressive, fantastic etc sound kind of thin after the eons of hours and episodes we have all followed, but what can I say - I am out of words... :shock:

Excellent leadership - thanks!

Re: My Beaut Aussie Cent

Posted: Sat Jul 22, 2017 10:20 pm
by Stephen White
Thanks, very much appreciated, especially Andreas and Christopher. I hope it encourages more build logs and posts with substance on the Forum.
On with final details. I described the three types of AFV fire extinguisher used by the Australian Cents on page 20, here:

http://www.armortek.co.uk/Forum3b/viewt ... &start=285

In the period I'm portraying, 064 had three BCF type extinguishers.

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I did consider casting the extinguishers in resin but they're enjoyable to turn up, using a ball cutter on the lathe and the detail is relatively easy to make with brass.

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I then turned to the mounting brackets.

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For the cup which sits at the top, I used a dapping set. Dapping is simply a way of turning flat metal into a dome shape using special dies and punches. The dapping block has a series of concave depressions, each matched by a dapping die. The metal is annealed to soften it and placed over the block and the die is then tapped lightly with a soft hammer to form the depression. To form the draw (ie depth), the metal is cut oversize and successively smaller dies are used until the required shape is achieved. I also had to form two flanges, which were done by forming with a repousse hammer. YouTube inevitably has instructional videos on dapping but it isn't rocket science.

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I got the first flange a bit off centre to start with but it's easy to go back a step and re-form it accurately;

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Thanks for looking.

Stephen

Re: My Beaut Aussie Cent

Posted: Sun Jul 23, 2017 9:22 am
by simon_manning
that was genuinely interesting, i did not know about a ball cutter for the lathe, and also that kit for making "dishes", metal bashing is not my strong point but superb information, regards simon.

Re: My Beaut Aussie Cent

Posted: Sun Jul 23, 2017 9:37 am
by Phil Woollard
Stephen
It looks to me like you could do with a "fly-press" .
It's possible to use a good pillar drill to do the same job, so long as its of the heavy duty variety. A fly-press is a wonderful tool for cutting, broaching, bending, forming, extruding and I dont have one! Nice work ....Phil.

Re: My Beaut Aussie Cent

Posted: Sun Jul 23, 2017 9:52 am
by Stephen White
Thanks guys, glad to share knowledge acquired by trial and error.

Phil, I have a half ton fly press, which doesn't get much use. I'm not sure which bit of the process you thought could be done on a pillar drill?

The secret of dapping is to have a large selection of punches and dies, each incrementally smaller than the last, so that the metal can be formed in small stages, to achieve the required draw. My set for example has 36 punches, ranging from 24.5mm to 3.5mm. You can do with a much smaller set but chances are, it won't have just the size you need. I also find that it's trial and error to gauge how much oversize to cut the blank for a given diameter and depth. There must be engineer's tables to calculate the answer but life's too short.....

Stephen

Re: My Beaut Aussie Cent

Posted: Sun Jul 23, 2017 10:18 am
by Stephen White
Simon, ball cutter vids (posh name is "radius cutting attachment").

Proxxon, the one I have:



Cutting demo (health warning about the muzak):



Regards

Stephen

Re: My Beaut Aussie Cent

Posted: Sun Jul 23, 2017 10:22 am
by Fabrice Le Roux
Hi,
Lovely job Stephen. Dapping will rapidly work-harden the annealed blank, so worth annealing at each stage to reduce risk of splitting the edge.
Simon, disc-cutters and dapping/doming sets can be found at jewelry suppliers rather than from the usual model engineering bods.
cheers
Fabrice

Re: My Beaut Aussie Cent

Posted: Sun Jul 23, 2017 11:11 am
by Phil Woollard
Extrusion tables, tricky stuff,you can use a pillar drill to press down true and straight, it does not need to be turning, I suppose that's why they are called a drill press, I will shut up now lol :D