Sherman ARV Mk.1 South Alberta Regiment

[JCON]

More nice work brother, I would make my own lumber and straps with some sort of cinch clamp to release them easily...

[Beekster]

That's what I'm leaning towards. I've trolled through my vast library of Sherman books and found several images of these tanks, though none specifically from the South Albertas. One thing that is clear is that the resin plank racks aren't quite right. The side section that goes down to the sponson top is centered on the resin parts, but photos clearly show it further aft. I think I will handle the access issue this way: The two vertical straps that are forward will get hinges at the top and a flat tab on the engine deck with a bolt head. Unscrew the bolt, flip the strap up and over the top, and pull the planks out forward. Stowed this way, the angle of the hull top ensures that gravity wants to keep the planks in place anyway on level ground, and the bolts keep them from pushing the front straps and escaping when the tank is pointed down-slope.

It is also clear that crews did a lot of their own alterations to stow various spares, and that a few of the fittings included with the kit aren't really necessary. There's a fiddly standoff for the front tow lugs to position the tow cable higher up; none of the images I have seem to show it in place. Crews simply used the lug with a shackle to hold the cable end like any other Sherman.

[JCON]

Sounds really good!!!

[BUCKY]

I have no doubt that what you come up with will be better than what was supplied! Looks like you have on yer thinkin' hat!!

[dogfish7 (R.I.P.)]

Some excellent upgrades on this build Beek!

[Beekster]

I've finally got the back end pretty much squared away. The various boxes and bits are in place, and I have retention pins for the blanket bin installed along with their chains. That's .016" brass rod with some Aber chain soldered to the top, then suitably draped and the other end glued to the rear plate:





I went to my LHS and got some basswood strip to make a new stack of planks for the engine deck. The stack is fractionally taller than the resin, but that won't make any difference visually when all is said and done. I will stain them with watercolors to give them an aged look then seal them with Dullcote. When that's done I can get started on the frames for the stack. When it comes time to paint I will try to mask this off so that the wood tones remain:


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And finally, here's that snatch block for the front; it rests across the bolt flanges for the differential covers. On the left, a hook on the diff cover goes through that vertical loop and on the right that horizontal loop rests over a post on that differential cover. This thing is an inch and a quarter long, and made up of five pieces: Top, bottom, sheave, and the two loop ends:




That's where this gets a little interesting. Both loops are labeled part #12 on the instructions. But they actually aren't the same. The one on the left has two little nubbins which fit into depressions on the top and bottom, and thus it (theoretically) can pivot. All well and good. But the other one has no such nubbins, so it isn't really identical, nor are there corresponding depressions in the top & bottom parts. What's more, you can see plenty of daylight when you fit it. I had to punch two discs out of styrene, glue them to the loop end, and sand them to fit in order to assemble this little widget. Not really a big deal but pretty much part & parcel of dealing with resin conversions like this. Mostly I am just glad that I got the top & bottom pieces removed from the pour plugs without breaking them.

[JCON]

Moving forward is a good thing, work looks fine!!!

[BUCKY]

All these additions are making it pop!!

[reserve]

I have Legend's M-9 dozer blade set, been on the shelf for a year now as most of the parts are so badly warped. It'll be an ambitious day with the pot of hot water when it comes out...

Fine beginnings on an interesting and unusual subject

Regards,
Mark

[Beekster]

Jan 16, 2018 9:03:15 GMT -6 reserve said:

I have Legend's M-9 dozer blade set, been on the shelf for a year now as most of the parts are so badly warped. It'll be an ambitious day with the pot of hot water when it comes out...

Fine beginnings on an interesting and unusual subject

Regards,
Mark

Mark, it might be worth measuring the warped pieces and using them as templates to build the thing from scratch.  Having mentioned that stack of planks, I would add that this is hardly the first time I have had to use resin castings as templates to make something myself.  The fault doesn't lie with the master pattern maker, rather with the method of casting and sometimes storage.  Parts pulled from the mold too soon can warp since they are still cooling down (the catalytic reaction that hardens the resin creates a fair amount of heat).  Storage of finished castings in a warm place can also lead to warping. That can happen at any place along the supply chain from manufacturer through transport to retailer to you.  I've got an attic space off my War Room where I will store kits, but not resin conversions. It can get pretty darn warm there, even in drippy northwest Oregon, but styrene tolerates that far better than resin does.

[JCON]

I had a kit in my garage that warped from the heat in the summer here in Eastern Washington... of course we do have an occasional week over 100 degrees and the metal shop gets even hotter if I don't leave the windows and vents open...

[JEFF]

Outstanding stuff, Beeks.

[Beekster]

This morning's lesson is entitled "Trust your references, not the instructions". Take a look at the Legends instructions for the ARV Mk. 1, the highlighted area down at the bottom right:

Look at where that Hollebone drawbar is fitted. It's attached, more or less, to the thin strap material for the wood planks. This is stupid for several reasons. One, the drawbar is bulky and rather heavy so no one in their right mind would want it stowed up that high. Two, the structure it is supposed to be attached to is not strong enough to hold it. Three, the loop that the bar ends go through isn't attached to anything at all! OK, maybe it's welded to the hull top but the other two reasons make this a ridiculous place for it. Now, stowage arrangements varied on these tanks but this location is more typical:



I could probably get the kit part to fit there, but it suffers from a couple of problems. One is that there are bubbles marring the clevises at the ends of the bars, and that would be tough to fix. Second, cleaning up the flash in the seam between the bars would also be a pain in the butt. You know what's coming, don't you? Yep...I'm making a replacement, seen below in process, and will make my own hanger and clamp for it:



And because I think I can, I will try to make the pivot point functional.

[BUCKY]

Looks like it's gonna be a nice fix!!!

[Beekster]

Jan 18, 2018 11:56:27 GMT -6 BUCKY said:

Looks like it's gonna be a nice fix!!!

Yeah, Bucky, I'm happy with it so far.  So much so that I'm building the other one too, the shorter version that is stowed on the left side.  The only tricky part of making these is to ensure that the clevis ends are parallel, and that both sets on the short bar are in the same plane.  That is easily solved by making an assembly jig which keeps the parts aligned while the glue sets up

[JCON]

Looks good brother!!!

[BUCKY]

Certainly looks more realistic!!

[Beekster]

I've mentioned jigs and fixtures on this thread and others. These are nothing more than home-made tools that hold parts together and make assembly easier. When doing scratch work, is isn't always convenient to use conventional clamps, vises, or other such fixtures, so I build what I need when I need it. For example:


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At the top of the image is a fixture I made to hold the hull of this M4A4-based ARV. The crossbeams on the hull bottom rest on the long rails. Why did I do this? Because the radiator hump on this hull is lower than the lowest points of the suspension pads or the crossbeams, so it rocks side to side on the bench. That makes it awkward to attach fiddly bits. So far this works fine using gravity, but if I need to I can use Elmer's to glue the hull to the fixture temporarily. Below that on the left is a fixture I made to assemble the rods for the Hollebone draw bars, and one is in place to illustrate the function. To the right is one I made this morning. It will be used to make the oval loop that secures the drawbar rods together, as shown on the resin part. All it is is rod stock the same size as the drawbar parts with a .040" spacer to account for the gap. Later I will reinforce the joints with superglue and lightly sand things smooth, and then I am ready to start building up strip stock to make the loops. I will use a little tape on one side of the fixture to keep the loop I'm building from sticking to the fixture. Finally, at the bottom, is a fixture I made for the Madill 071. This brass rod stuck vertically in a solid styrene block was used to assemble the 60-odd pieces that went into each of the six Wichita brakes and clutches, holding them plumb and level as each layer was built up. Most fixtures like this are discarded after use, but this one I will keep...there might be another yarder to be built someday.

Back to the model itself. I've had a bit of a setback with the planks on the deck. They are fine, but I can't do what I would like which is to leave the rack structure partially complete so that I can remove the planks to paint the model. The structures are just too fragile. So what I will have to do is tape down the plank stack again and build the racks, permanently enclosing the wood. I will have to mask off the whole area to keep from painting the wood, and paint the racks by hand afterwards. That will now have to wait until my airbrush station is back in business, since I want to seal the wood stack before locking it down.

Otherwise, I've started on bits at the front:



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The track tensioning wrench and a pair of handles are on the turret ring cover, the snatch block is on the diff cover, and the vise is glued to the skate rail on the left side diff cover. The snatch block just sits there by gravity, which is nice since it can be removed to get paint underneath. I might revisit my previous decision not to add casting marks to the center section, since the just might be visible now. The skate rail worries me, as it is rather fragile. It's secured with Kneadatite epoxy putty, which is a bit rubbery and has some give to it so that this assembly can tolerate a few bumps. One piece that you won't see until the model is done is the tiny resin handle for the vise, which wouldn't last five minutes at this stage.

[dogfish7 (R.I.P.)]

Nice work Beek!

[JCON]

Jigs are always helpful no matter the hobby!!! Good job on fashioning them...