So here's the deal: I am not entirely happy with any of the available M50 turrets. DEF comes closest, but the bustle is too short and I'm not convinced that the contour at the end of the bustle is right. Everyone else have bustles that are too small overall, and have shape issues at the back. The others also have detail problems around the trunnion box, and DEF and Dragon don't have either cast-in cheek armor or applique. So I'm building my own, using the images and drawings in Dr. Manasherob's books, and this is what it looks like so far:
As you can see, there is much yet to be done. The mantlet is just down to texturing and adding the straps & bolts for the dust cover, but the trunnion box isn't even completely roughed in yet. There is a lot of epoxy putty work and shaping to be done yet, to say nothing of adding all the necessary details, weld seams, and casting symbols. The turret will represent a General Steel low-bustle with cast cheek, and a pistol port added from steel stock by the IDF during the conversion. The oval hatch will sit proud of the turret roof, as many of the retrofitted ones do. The hatch coaming is only partially complete here. The oval hatch and the pistol port door are separate parts. The bustle is coming along; the shape is beginning to come in to where I want it. More filing & sanding, more Mr. Surfacer, more comparisons, repeat until happy. And if I find my way to happy with this, it just might become a master pattern. Let me know what you think!
Greg
"You could probably use some armor. A Sherman can give you a very nice...edge!"
That's the problem, Jeff...none of the kit (Dragon/Cyberhobby & MP) or aftermarket (Tank Workshop, Formations, DEF Models) turrets are quite right dimensionally or in overall shape. This becomes more clear if you spend time staring at the drawings & images in Dr. Manasherob's books, especially Lioness & Lion of the Line vol. 2. That one has dozens of close-up images of the turret. So I started with a Tasca shell, one without cheek or applique because that's what I had on hand. I've added the cast cheek, built the bustle up from laminated layers of styrene, and cut .040" strip stock to get started on the trunnion box. The mantlet is all strip stock, sleeved tubing, quarter-round stock, and epoxy putty. I've got a Tasca M4A4 kit that has been sacrificed as an engineering mule; the upper & lower hull parts went to make master patterns for my Chilean 60mm HMGS kits that will be released next month. The turret was spare, and suitable for conversion.
"You could probably use some armor. A Sherman can give you a very nice...edge!"
Yep. Neither cast cheek nor applique on it; should have one or the other. Bustle is too small and too square. The oval hatch is flush, which means either a very late and very rare low-bustle turret was used for the conversion or a high-bustle one was. In either case, the turret would need cast-in cheek armor, but the bottom of the original bustle (where the IDF bustle casting sits) is rather too low for a high-bustle or howitzer turret. Raise the hatch a bit and add a coaming around it and either cast-cheek or applique would be right for an earlier turret with a retrofitted oval hatch. The pistol port is also suspect, being of the it-was-there-originally type. That's OK for a converted high bustle or howitzer turret (which this turret doesn't accurately represent), but wrong for other types unless certain features are added: With applique on the cheek, you're fine for an early low bustle. Otherwise, the shapes of the pistol port structure should be different because the IDF cut out sections from those turrets that had welded-shut pistol ports or none at all and added pistol ports scavenged from other scrap/wrecked turrets or fabricated from scratch. The trunnion box doesn't have correct detail for the sheetmetal surround welded to the front face of the turret, either. Compared to drawings, it's also slightly small in width. And that stepped contour at the base of the turret all the way around is simply wrong; any machining or grinding needed to trim the casting wouldn't have removed a strip of material that tall evenly all the way around the circumference. The outer surface of the turret shell wasn't that critical dimensionally; it just had to clear the splash rails all the way around.
How important this all is to you is dependent on your level of obsessiveness and AMS. I have both pretty bad, and it leads me down such dark paths as this...
"You could probably use some armor. A Sherman can give you a very nice...edge!"
Looking good. Myself just started down the path of correcting a DML turret. I have a couple I'm going to play with. Now I've figured out what is wrong, not sure if I want to live with them as they are. I also got a MP M50 in the mail yesterday, so maybe I will be working it too.
How so? Are you finding those turrets more difficult to work with than the Tasca? Tamiya is also pretty good; I did an M50 turret some years ago (and inaccurately, based on current research) on one of those. Both MP and DML use softer plastic, and DML is also rather thin. Are they flexing too much as you work with them?
"You could probably use some armor. A Sherman can give you a very nice...edge!"
Just what I like to see around here. Even though the IDF Sherman's are not my thing, it's great to see some serious scratch and conversion work going on.
How so? Are you finding those turrets more difficult to work with than the Tasca? Tamiya is also pretty good; I did an M50 turret some years ago (and inaccurately, based on current research) on one of those. Both MP and DML use softer plastic, and DML is also rather thin. Are they flexing too much as you work with them?
I started out thinking I could just lengthen the counter weight on both the MP and DML, then reshape the end, add this and that and be off to the races.
Yes the DML one is thin and both the MP and DML being soft. Yes the DML is flexing a lot even when cutting. I found the DML also to be to narrow. I have quartered the DML counter weight, which works good for the top half but not so well for the bottom half. I'm now using a Tamiya turret, from M4A3 kit, as the base for the MP parts and an old DML turret, from a M4A1 or M4A4 kit, now as a base for the DML parts. I'm thinking now it would have been wiser to scratch the counter weight, as it would be two fold. Faster and easier to carve on. Still might go that route. At this point I'm no where happy with my results.
Do you have Lioness & Lion of the Line vols. 1 & 2? Especially vol. 2? They are an absolute Godsend when tackling something like this. Volume Two has about two dozen pages of close-up images of the turret from every angle, from two different tanks...and they aren't identical. With those and copies of the scale drawings you'll get there doing the bustle and trunnion box from scratch. The bustle is pretty straightforward to rough in as a separate piece; just use a square to keep the front, bottom and sides trued up at the spot where the turret join happens. Build it up with thick styrene, start grinding away with a Dremel and 180/100 grit nail sanding sticks (get em all, 100 down through 600, at Sally Beauty for cheap), and work it in. Compare to the drawings in the book, and slowly the shape will come in. Once you like it, glue it to the turret shell and keep refining it.
The trunnion box is more challenging. First, I put in anybody's gun rotor part in the opening in the front face of the turret. Doesn't matter whose or what bolt pattern, it will never be seen and it's only there for support. I've done this a couple of times now, and I prefer to start with the top panel. Cut it to shape, and leave it a little long at the front. Glue it to the front face of the turret, and make sure it sits at the right angle when viewed from the side. What I did was tack it in, set it on the desk, and use my calipers to measure the height of the panel at the front when I had the down angle I wanted. I then cut & square up shims with my Chopper 2 and True sander, and stick them under the front of the box roof panel at the outer edges for support. Then use a little bubble level (a couple of bucks at Harbor Freight) to make sure the top panel is level side to side. Apply more glue to the turret joint, and LEAVE IT ALONE...I mean walk away, don't even look at it, for about four hours while it cures. It's tempting to leave it for an hour or so, then pick it up and want to keep working, but don't do it. That panel is cantilevered out in space at this time, and it WILL move on you. Don't ask me how I know this...
Once the panel is good and dry, I use thin sheet stock to shim it to the gun rotor face for additional support, and do the same exterior shim thing for the bottom panel of the box. Leave that alone too!! Once both top and bottom are set and level you can rough in the side plates, and the structure will begin to firm up. Once the plastic glue was dried, I shoved in a bunch of epoxy putty to fill in and add support, both around the outside of the rotor panel and inside it to make it solid.
At this point, you may be ready to add a mantlet & dust cover, and other details. For me, I just ground out most of the rotor and epoxy putty with a Dremel so that I can fit a slice of .438" diameter tubing inside, sectioned and installed sideways. This will provide a rotating surface so that I can add my 60mm parts and set the angle of the gun as desired. The dust cover will be added later using epoxy putty.
"You could probably use some armor. A Sherman can give you a very nice...edge!"
So, more progress on this. The shape of the trunnion box is now pretty well dialed in, and detail work has begun. The cast-cheek armor has had a little more strip stock added at the bottom and a layer of finishing putty added, then sanded to smooth the contour. I think it looks better now. The trunnion box front will be left pretty much as seen here; no sculpted dust cover will be added. Either the 75mm or 60mm Chilean mantlet assemblies will fit, and any desired elevation can be set. That leaves sculpting the dust cover to the end user, but I wanted the flexibility of allowing for a choice of gun elevation. The last couple of images show a trial assembly of the 60mm mantlet tacked in with Elmer's glue. I am liking how this pattern is shaping up right now. Your commentary is most welcome...
Greg
"You could probably use some armor. A Sherman can give you a very nice...edge!"
Glad to hear that you guys like it. I'll have more images in a couple of days. Right now the cheek has been slathered in Mr. Surfacer 500 and textured, and it's looking good. I've got the sheetmetal surround in place around the trunnion box where it meets the turret, and tomorrow there's a little more sanding work to do on the rounded corners. The perimeter strip for the dust cover is in place too, though I haven't started on the little strips & bolts that secure the dust cover. I've tweaked the back of the bustle, and that looks better with each iteration of sanding, Mr. Surfacer texturing, and examination of the whole. I wasn't happy with how the coaming for the oval hatch looked, so I've started over on that. With any luck I'll add this to the product line later this year.
"You could probably use some armor. A Sherman can give you a very nice...edge!"
We're creeping closer! I'm still working on the oval hatch coaming, a little more strip to add there. Then I can work on the hatch hinge itself. The cast-cheek armor looks good now, and I'm pretty happy with the back end of the bustle. There is a decided kink both inwards and downwards to the front of the bustle where it meets the turret shell, and I am still dialing that in. The trunnion box is well along, and I have the sheetmetal strips done around the perimeter and most of the weld seam added. There's a short stretch under the box overhang that isn't done, and it isn't seen in any of these shots. It will barely be visible when finished, for that matter. I've finished off the retrofitted pistol port, and added casting marks to the turret. They are for a General Steel casting, and if you have Son of Sherman you'll know that the part numbers are accurate and the serial number within the proper range. The General Steel shield is a little large, but you work with what you have and I think it looks great. On top, I have the base for the bustle ventilator installed with it's three bolt heads. The ventilator cap will be separate, and for that matter so too will the the pistol port door and the oval hatch.
Great progress on this turret Greg and as I said before these pixs will come in handy in the near future! Any special plans for this turret??
Honestly? I hope that this will become a master pattern. It will prove challenging for my caster; that undercut on the trunnion box is a b&*ch of a feature to deal with and probably really hard on molds. But I've got some irons in the fire that might result in this eventually coming to market with a resin muzzle brake and an aluminum barrel.
"You could probably use some armor. A Sherman can give you a very nice...edge!"
So, this week I've had some other matters to deal with and not so much bench time, but this one's been fighting me this week. The previous photos don't really show it, but with Mr. Surfacer priming the bustle I wasn't entirely happy with what I saw. The angle at the back wasn't quite symmetrical to my eyes, and a check with the caliper revealed that it was a little short. Adding material solved that, but left the ventilator too far forward so off it came. It will get replaced tomorrow. The sides seemed to bulge out a bit when viewed from dead aft, so more work with 180-grit sanding sticks to get them more vertical. And the contours at the front of the bustle didn't quite seem to be coming in, either. It finally dawned on me that I needed to get something else done before I finalized the contours at the joint: I had to get the weld seam laid in, and use that as a reference for further tweaking. So the images below show the weld seams laid in, and I'm happier now with what I see. I've got the antenna bases roughed in, too. Sharp-eyed viewers will note a change in the serial number and slightly different placement of the "SER", "E", and General Steel shield. Despite an overcoat of Future, they didn't survive the handling that has gotten the shapes to where they are now. That hatch coaming still isn't done, and the hinge not installed and the base built up, either. I can work on those again now
It is certainly going slowly, but gradually and bit by bit I am dialing it in. At least I think so...
"You could probably use some armor. A Sherman can give you a very nice...edge!"
Post by Allied-Eric on Jan 12, 2014 10:26:30 GMT -5
Great Progress on the turret Greg! The shape of the over turret does L@@k better then the DEF, not that the DEF turret is bad just a bit short. Needless to say you can put me down for one when you get to the casting phase!
Great Progress on the turret Greg! The shape of the over turret does L@@k better then the DEF, not that the DEF turret is bad just a bit short. Needless to say you can put me down for one when you get to the casting phase!
There are three issues with the DEF product that need to be addressed: Lack of applique or cast-cheek armor, the bustle being too short by about .160", and that kink in the bustle at the extreme rear when viewed from above. I just don't see it when staring at the multitude of images in Dr. Manasherob's Lioness & Lion vol. 2. His drawings don't show that feature, either. I will freely admit that there was probably some variation in the shape of the castings, just as there are with the Sherman turrets originally. But I am not convinced that the kink is really there.
I'm using Archer's surface detail weld seams for that, two or three strips of them laid side by side. They don't stick spectacularly well, even with an overcoat of Future. I think that when all is said and done I'll have to seal them in with a coat of Tamiya fine surface primer over the entire turret.
Greg
"You could probably use some armor. A Sherman can give you a very nice...edge!"
Here's a few more. Not a lot of progress, though the hatch hinge is fitted now. Other things are mocked up, and there was a contour issue on the right side that's been puttied up. These do show the thing in what approximates it's natural habitat, and so far so good...
"You could probably use some armor. A Sherman can give you a very nice...edge!"