AA Combat Engineer Tractor (Frog)

Jacko464,

Yes, an excellent kit from Badger 3D!
As you can see, I depicted it as a vehicle at BATUS.

Paul

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That idea that the different sides are offset therefore they must be different lengths is an old wives tale that tracked vehicle crewmen still believe to this day; but it is untrue. IN order to track/drive straight, the tracks on both sides must be the same length.
The reality is that while some vehicles with torsion bars DO have their ROADWHEELS offset, one side slightly forward and one side slightly back, the idlers, sprockets, and overall length remain the same. Some vehicles (German Tiger tanks for example), offset the torsion bars so that the roadwheels remain lined up from side to side with no offset. And vehicles using other types of suspension: VVSS, HVSS, Christie, leaf springs, etc. have no offset.
Adding an extra track block to one side of the vehicle will throw the tracking off, causing the vehicle to steer to the side, needing constant correction.
Ken

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Now this is an interesting discussion… So how does that pulling to one side work - the sprockets on both sides rotate with equal speed, right? So the linear speed at the “teeth” of the sprockets is same - and then the teeth of the sprockets are pretty rigidly connected to the track touching the ground. If it’s really so - maybe I’m wrong - then what causes the imbalance?

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Very nice work with those tracks matey … When I did my AA CVRT Striker, the resin (horrendous) tracks went straight in the bin.

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The tracks. Compared to a wheeled vehicle, the sprockets are like the hub/wheel and the tracks are like the tire. If you have the same hub/wheel on each end of a drive axle, but put different size tires on the wheels, the vehicle will pull to one side.

It gets more complicated with tracks because tracks stretch and have to be constantly adjusted, but starting off with two different size tracks just makes it worse.
Ken

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Trust me mate if there was an alternative it WOULD have been used​:joy::+1:

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I can assure you it is not.

One of the first serials in the Commander’s Functional Test (CFT) for this vehicle was to count the track links. 74 left, 75 right (with a new track). I commanded one for four years, I ought to know.

I’m sure Royal Ordnance wiould be only too happy to confirm this to you should you wish to doubt it, since the vehicle is no longer in service.

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Now we have the track issues sorted​:crossed_fingers::grinning:
A bit of etch work done and the exhaust and air intake on,
One of the anchor launch posts is on but the mounting block for the second one is awol so I’ll have to make one.

That’s it for now,
Jacko

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Ivan, this is taking me back, and i’m enjoying your work.

You need to drill out the anchor mounting points, the steel flukes of the anchor were tapered to a point and sat with one point in each mount when the vehicle was configured to swim… not that clear from this picture, but you see the idea.

Are you going to clean out the Fairlead rollers too?

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Glad it’s bringing memories back👍
There are holes in the mounting blocks but could be drilled a bit more,the rollers and flip over pulley will be cleaned out and drilled.
I won’t be having the anchor on the front as the attachment plates on the swim board were broke beyond repair! TBF I can’t remember ours having them on anyway!

Cheers
Jacko

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IIRC, new washboards didn’t have the brackets for the broken down anchors fitted, those had to be taken off the ‘old’ washboard and attached to the new.

Since swimming was a quite rare activity anyway, we rarely attached the broken down anchors to the washboard (especially in BATUS). A more practical solution was to assemble all the anchors and as and when they were required, they were brought up by the G10 wagon. goodness, they were heavy.

The DS staff used to get really cheesed off with Frog crews in BATUS because we would routinely cross the notional rivers on the exercise area to get from A to B. The notional rivers were supposed to be (simulated) around 1.5 meters deep as I remember and were supposed to act as insurmountable barriers to vehicle movement. We would point out that the Frog could wade to 2m without preparation and that their rivers were not a credible obstacle. That never went down well really.

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Great isn’t it getting one over the DS👍
I remember coming across a ‘destroyed’ bridge on exercise the DS said we couldn’t cross it so being in a Scammell with a No9 on the trailer we said we have our own bridge and carried on😉

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Well, I suppose it is important to remember its just a game and you’re supposed to play it. In reality, you’d use whatever means available to achieve your goal.

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All the credit in the world for those that can tackle these resin kits. I was pulling my hair out just doing a couple M60 door guns. More than anything I think it’s working with that darn super glue. So difficult compared to Tamiya super thin with the brush.

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Always have a sharp chisel blade and razor saw handy :slight_smile:

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Ok not a lot to report,
One bank of smoke discharges were missing so had to make them,anchor stand,flip over pulley on and a few more bits on the front.
The wash board is not fixed just a test fit as it won’t go on till after painting.


Thanks for looking
Jacko

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Looks good.

Just in case you are inclined, these bosses should be drilled out. They are the mounting points for the steel rods that are inserted in order to coil the SWR around when using the RPA.

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Some work done on the ‘rear’ end mostly etch parts🙁not my favourite but hay ho!


I looked at drilling out the rod points on the front as Roly suggested but they were a bit delicate so I left well alone
The instructions would have you putting the water jets the wrong way round but thanks to the walkaround I’m using that was spotted.
.
Cheers
Jacko

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Point of order. They’re not water jets. Propulsion is achieved via an impellor Duplex drive off the engine. The intake is circled. Between the intake and the outlet is the prop shaft and propellor. The ‘outlet’ is called a Dowty Cowl and steering is achieved by moving these either together or individually to direct the flow of propelled water in the desired direction. Two levers inside the crew compartment are used for this purpose.

N.B. The rear mud guards and top of the Dowty Cowls were ttreated with non slip paint.

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