From: Think Tank Subject: Think Tank Vol. 00 10/06/2001 Think.tank@tesco.net ------------------------------------------------------------------------------- MODELLERS' INDEX 1: Casting large tank turrets 2: Casting large tank turrets 3: Fire Power 4: Wanted - Magazines from the 'Golden Age' of Military Model Magazines 5: 1/76 card model MkIV 6: Websites 7: Humber LRCs in NW Europe -------------------------------------------------------------------------------- TRADERS, ANNOUNCEMENTS & NOTICEBOARD INDEX 1: Tankette indices to Vol.36 No.3 -------------------------------------------------------------------------------- MODELLERS -------------------------------------------------------------------------------- 1) From: Bradford Chaucer [bradford.chaucer@snet.net] Subject: Casting large tank turrets >I was looking through an article about casting T-34/85 turrets this week >and several references were made to the process. However, it occurred to >me that I have never read an 'idiot's guide' to how one goes about the >casting of large metal objects such as tank hulls and turrets. I am aware >that sand moulds are used and that the masters are often carved (and >subsequently modified) from wood but how is the actual mould constructed >and made hollow, how is the sand held together, how is the master >extracted etc.? I suspect that when handling that much iron, the last thing one would want about is an idiot!!! :-) I am familiar with the basics of sand casting. I would presume that's how they are cast from the surface appearance of the hulls and turrets. Basically, they would be cast the same way a bell is. A master is made with the inside and outside surfaces as they are to be in the final casting. I doubt that all that much machining can be done as a tank hull would be a bit tricky to throw onto the old milling machine!! I would also assume that the sand would contain some sort of binder, which is a common process. In smaller castings, cores and critical parts are cast in sand that contains phenolic. After the mold is rammed up and the master removed, the mold (or core) is baked to set the phenolic and make the mold or core more rigid and able to be handled without crumbling. The mold is then assembled and the metal is poured. The mold would be a split mold, so after the sand is rammed up (to compact it), the halves are separated and the master extracted. It would have been coated with some sort of mold release compound to lessen adhesion. A turret or tank hull, aside from the size, would generally be an easy mold because there are no real overhangs and there are generous curves and slopes to the sides. Regards, Bradford Chaucer -------------------------------------------------------------------------------- 2) From: PSmith6328@aol.com Subject: Casting large tank turrets Hi, At last a subject on the Think Tank that I am an expert on. I used to work in a foundry as a Moulder/Coremaker and among the many jobs we made were the first batch of Challenger turrets. I could write for England on this subject, in fact come to think of it I may do an article for Tankette/Think Tank. Basically as you said you have a wooden pattern which basically represents the outside shape of the turret, the internal cavities are made using what are called cores; these are again made of sand. The metal thickness is gauged using studs (they look like large metal cotton bobbins) and they are wedged between the mould side and any cores to stop them moving about during casting. The studs melt and fuse into the casting and then it is left to cool before fettling or cleaning up. I will write that article now but if anybody wishes to know more details just get in touch direct to my home e-mail. Regards Phill Smith -------------------------------------------------------------------------------- 3) From: Geoff Cooke [Geoff.Cooke@tesco.net] Subject: Fire Power It was interesting to see some that George has set up a web site on the artillery. I also spoke to a chap at Salisbury club, whose theme was artillery. For all you Gunner-philes out there, the Royal Artillery has just opened its new museum at Woolwich, called Fire Power. I have visited and there are things of interest to occupy most of us. It is open seven days a week, 10 - 5 and is at Woolwich Arsenal. There are plans to have a ferry from central London to attract visitors, but it is a bit out the way. Hall one is open and there is a lot of archive material held there, what access there is I am unsure. Geoff Cooke -------------------------------------------------------------------------------- 4) From: Anthony Dent [Anthony.Dent@sd-partners.com] Subject: Wanted - Magazines from the 'Golden Age' of Military Model Magazines I am keen to obtain copies of magazines - including Military Modelling and Airfix Magazine but there could be others - from the days when every issue seemed to have a 1/76 scale conversion article. This is in my memory around 1970 to 1974. I am particularly interested in the early 1970s MM articles by Geoffrey Futter on 'the Funnies' and Gerald Scarborough's many contributions to Airfix Magazine, but I am sure there are others. I would like either original magazines or I'd be very happy with good quality copies. All reasonable prices paid and other charges covered of course, and for what it's worth I'd be extremely grateful! Please contact me on a-dent@tcp.co.uk, 0797 318 8467 or 54 King Edward Drive, Grays, Essex RM16 4AQ. Anthony Dent (5463) -------------------------------------------------------------------------------- 5) From: Clifton W. McCullough [mccullou@hal-pc.org] Subject: 1/76 card model MkIV I have my first card model on my website: http://www.hal-pc.org/~mccullou/MkIVB28.html It's a British WWI MkIV in 1/76 scale. The capitalization in the URL seems to be important. The files are large, so it takes time to load. If I figure out how to display thumbnails and link them to the full-size files for downloading, it will come up a lot faster. The native format files are even larger. I would appreciate any comments/recommendations. Wayne McCullough -------------------------------------------------------------------------------- 6) From: Steven Guy [sgne13354@blueyonder.co.uk] Subject: Websites I have a website dedicated to Australian armour which I would be happy for you to plug. It is at www.thunderandsteel.co.uk I hope you can add this to the Think Tank newsletter. Best Wishes, Steven Guy. www.thunderandsteel.co.uk -------------------------------------------------------------------------------- 7) From: Listmaster Subject: Humber LRCs in NW Europe In the course of unpacking my books last night, I fond a photo of a Humber LRC in a Dutch book on the liberation of West Veluwe in 1944-45. It belonged to the recce regiment of 49 Div and carried the AoS number 41. It seems from the caption to have been between Ede and Ederveen but my Dutch is non-existent so I may have read it wrongly. Robert -------------------------------------------------------------------------------- -------------------------------------------------------------------------------- TRADERS, ANNOUNCEMENTS & NOTICEBOARD -------------------------------------------------------------------------------- 1) From: Listmaster Subject: Tankette indices to Vol.36 No.3 The latest update has just gone out. Due to the inability of the ISP Freeserve (which several recipients use) to receive executable files (those with an .exe extension), they now go in unzipped form. The two formats I use are MS Excel 5 and Lotus 123 and they incorporate a series of filters to make it easier to run to ground a particular article or drawing. If you would like to be added to the list, please email to rlockie@platosoftware.com and request to be included. Please specify which version you want – the default is the Excel version. Robert -------------------------------------------------------------------------------- Robert Lockie (Think Tank Listmaster) Back issues of Think Tank can be found at: http://www.tac.com.au/~sljenkins/thinktank/thinktank.htm -------------------------------------------------------------------------------- End of Volume