Cromwell Mk 4 1:16 scratch build Ludwig kit

[43rdRecceReg]

Just to be absolutely clear, when you buy the Tk6.0/6.0s, you get a bundle of cables (if you buy from the right person- eg. Forgebear). The cable that connects the MFU board to the small interface for the 'IR receiver 'mushroom', commonly to be found beneath the commander's or loader's hatch, plugs in the Ch16 socket on the 6.0 and 6.1 series boards.
The same IR receiver cable is supplied for ALL board versions. However, if you look at the diags. Below, you'll see that the 3-pin JST XH (?) female connector fits the tk.6.0 snuggly. Getting terminal and connector terminology right can be a challenge, given the range involved.
However, it won't fit the 6.1/6.1s units. For that, you will need the flat-3-pin JST female type. You will also have to alter the stock pinout on 3-pin servo unit cables, should you use one, to match the pinout in the mushroom base interface. That's it, I think.

Meantime, I'm making an attachment bracket for the T34 Spotlamp, which will be used as an ersatz turret spotlamp on the Cromwell. There's no immediate way of bonding the lamp bracket to the turret wall, without making an angled support bracket.

TK series CH 16 connections compared

T34 spotlamp for Cromwell turret

Once the spotlamp/spotlight has been fixed in place, and a two-pin connector fitted, it will go into the LED 3 array-Tail lights (LED 4 is for the headlights LED 5 for MG flashes). After that, I can connect everything up, and test it out. I"d like to put some sort of flash in the barrel, but the bore is small. That'll be a later add-on, when all else is okay.

[43rdRecceReg]

I've just cobbled together an attachment bracket for the Turret Spotlight. Fabricating one out of thin bits of brass would look more impressive, on a closer inspection, but this model is not going to be sitting in a museum display case. I will add a couple of 'bolt heads', perhaps; I may even add a real bolt to the bottom of the bracket to ensure it remains attached to the turret. Then, I'll paint it up and disguise the wires. All that remains to be done for the light is to fit a two-pin flat JST, and plug it into LED 3 on the board.
One thing I've noticed since spraying the model, and adding lacquer, is that the surface seems to be a magnet for every passing particle, and mote, of atmospheric detritus. Could be some sort of static phenomenon; but whatever the cause, it's annoying.
Also, the gunsight has broken during the recent re-wiring- just as it did on the Comet.
As attractive and detailed as the Cromwell 3D printed stuff was I bought from Shapeways, it's just way too fragile. That's why I've not added the printed locks to the storage bins. (Jürgen has those neat details on his Cromwell, I see- but maybe they were printed with a superior robust plastic.).

Cromwell spotlight-pic A

Cromwell spotlight-pic B

[43rdRecceReg]

Can anyone recommend a (preferably prewired) 3mm high-intensity LED?
A 5mm LED will not fit in the Cromwell barrel.
If I can find a suitable candidate, I might fit the same to the Comet, which is currently only lacking a barrel flash effect- for a full range of effects. Now, I suppose, some will include the recent barrel smoking effect from Heng Long; but that's not an option I want to go with.

[jhamm]

Grind off the rear edge of the LED, then it fits into the barrel.
On my Ludwig Cromwell it fits.

[tankme]

The Taigen High Intensity LED is slightly smaller than 5mm. It fits in the barrel of my T34/76 barrel.

[43rdRecceReg]

Thanks, Jürgen and Tankme for the tips!.

[43rdRecceReg]

One thing you'll need if you put the TK 6.1s in one of your models, is a jumper for ch 6 'Trigger'. The recoil won't work without a jumper here. I have a lot of breadboard connectors, and two single female types make a good jumper, after soldering and with insulation added.

I just received some 5mm pre-wired LEDs today. Handily, the rubber bands' colours match the tints of the bulbs. The packet above contains more breadboard connectors. I use a lot of them; they're very cheap and easy to use.

I picked a red one for the gun 'flash'.

Testing it in situ

Next thing is to bury it a tad deeper in the muzzle.
I also made a holder for the emitter unit. It's resting on the mudgaurd to the right; but destined to be active through the Driver's portal.

Here it is peeking through the Driver's portal. When not in use, it can be concealed. That will be all the time, in practice, as I don't use IR.

[43rdRecceReg]

The re-wiring and MFU heart transplant are pretty much complete now. I'm just waiting for a compact (but powerful) NiMH battery to arrive- one that will fit the allocated space.
Having looked recently at Jürgen's tastefully kitted out Cromwell, I should say, perhaps, that I've had some Shapeways printed add- ons for quite a while; but haven't added them.
The reason? Well, they break all too easily. Just look at the gunsight below.
It's my estimation that while the bits are beautifully formed and printed, and to scale, they're so fragile that even a sneeze could break them.
If your Cromwell, or other scratch-built model's going to perform well out of doors, in mixed scenery (including long grass) you're going to either:
1. Have detailed extras made out of tough material
or,
2. Expect your pride and joy to return with an abused look.

Cromwell-broken gunsight and extras

I had exactly the same problem with the Comet. I think what this says is that if you want a built with museum looks, don't expect it to defy nature unscathed
Thus, I won't be adding catches to the storage bins, unless I can find some made out of metal or nylon. In some instances, I made the hinges and engine deck hatch locks (they look like Dairylea/Kraft cheese triangles!) myself, out of styrene and fitted them instead. I will fit the fire extinguisher and some tools, however. One will be the large track tool that resembles a hockey stick.

[PainlessWolf]

Good afternoon, Roy!
Still following along on this one. ( I hope to have my own piece of rolling British armor one of these fine days ) The work is excellent and yes, there is always a fine line to be walked between Shelf Queen details and a Running vehicle. You seem to be walking that wire quite well, my friend.
regards,
Painless

[Jimster]

Great build thread! I haven’t been commenting but following along in amazement.