00 FD 96 John's Main Contender

[John Clarke]

Hi Steve, Glad you like it, easy enough to do. I wanted ask, did you just file the horrible crease off on the turret top left hand side or did you fill or both.
Cracking job you made of it. (Pictured)
Elevation servo.
One of the aims of the idea was not to change the "Armortek" option too much, so that a return to the original supplied mechanism would be easy to adapt back. A bag of original parts already in the spares box. Plan B, if everything goes Pete Tong.
The gun barrel is not just heavy, but very long too as you know, and I felt thinning it to reduce weight could only weaken it. I don't have a lathe either . The lead counter weight is an extra 1.2kg to the original setup, it's a necessity to take the load off the servo. But then the fat servo itself has a lot less weight than the original mechanism and motor, so you could say it's probably only half the extra weight (600g) that's been added to the original set up.

I remember a discussion years back where some builders wanted to slim down the weight of their Armortek models, I wholly agree to disagree.
Why do we buy these monsters in the first place and not buy an alternative manufactures 3mm fibre glass model.
Up to 90mm of frontal turret armor, that's why. ( I do anyway)

I'm must emphasize I'm not expecting much from the new system, But I've had experience of the screw jack system in Centurion, Comet, KT and watched others, the whirring sound of the robust screw jack and slow speed mimics the hand operation of WW2 tanks very well but it doesn't compare to the actual powered action of an MBT gun elevation. this is my take on it.
The servo system I've fitted is not a very sophisticated system and should only work on the 90' frontal arc. I'm not going for accurate angles of gun elevation or depression, enough to show it works should be enough for most of it's time in use. The manual override control should allow clearance over the rear deck.

At the end of the day the main thing is not to damage anything with that bloody big gun.

[Steve Norris]

Hi John
The crease was removed by a combination of a big file and filler, not to difficult to do but quite messy.
I don’t have access to a lathe to modify the barrel but I was thinking about replacing it with something lighter like a carbon fibre or fibreglass rod . Getting the right size may be a problem but I will see if I can find anything that will do the job.
With the weight of the turret as it is, adding or removing weight may not really make much of an overall difference so I will go the easiest route.
Working on the rear deck at the moment so the turret will have to wait before I do anything further with it.
Regards
Steve

[John Clarke]

Hi Steve, thanks for the info on the turret crease, it is the next job. Hopefully I can do the job as well as yours
The servo reverser arrived today, so I'll be trying that later on the recoil unit.

[John Clarke]

The crease has now gone, Just as Steve said, a bit of filing, a dollop of filler and and a little bit of shaping. Looks so much better and well worth the time spent on it to get those curves back. Next up, the turret roof and turret bustle.

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[John Clarke]

Armed with the best of the 80's on the boom box, I began to put the bustle together and then move onto the turret roof. Even making sure I'd got the corner brackets the right way round, the fit was not as good as expected with a few big gaps to deal with. Holes in the rear side cheeks needed realigning and it became apparent that the turret roof would be offset by about 1.5mm to the left when fitted looking forward. I made up some spacers to shift the side cheeks outwards and reposition the Bustle floor pan. I like to say I centered it all up but the Chieftain turret is anything but symmetrical, the original is the same too. The roof was "centered" by slitting a thin section off the casting recess edge. I'm happy to say the side cheeks line up nicely angled with the cast armor now. Though closing the gaps (well within British Leyland standard spec) between the bustle cheek sides, left another problem, the turret roof didn't fit anymore. And will have to be trimmed to fit.

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[Steve Norris]

Hi John.
I do recall having similar issues when assembling my turret, nothing that was a major problem but plenty of hole pulling and filler.
Regards
Steve

[John Clarke]

The chop shop continues, I wanted the turret roof removable using magnets, and have cut the turret roof across the bustle line to make it easier to fit on the angled section and allowing the alignment with the rear edge of the bustle. I was also trying to get a little "step" in the armor plate as with the original on all the bustle edges. Once cut the roof was glued together (JB weld) with an added strengthener underneath, and a line of epoxy representing the weld line on the original across the upper turret roof.
Because the turret roof used to be part of the structure supporting the bustle, floor pan and sides have been glued with JB weld.
It may sound pointless extra work, but to me it's future proofing, I can paint and fill retaining points with easy access to the mechanicals in the turret.

The turret roof is held in place with magnets. Magnets were glued into the turret casting and steel countersunk M3 set screws were placed up side down on turret roof plate to give them a good surface area on the magnets below. Recessing the nuts holding in the countersunk setscrews on the upper side.
I've made some alignment blocks to keep the turret roof aligned from old dummy periscopes from Centurion that were supplied with the model in a "spares box".
"Never throw your spares away, keep em for a rainy day!"

[John Clarke]

With the turret roof jointed and now in position, I can start adding parts supplied with the kit. I'll be doing a lot mods to some of the parts supplied, the rest of super detailing bits will have to be made.
Starting with the two hatch covers at the back of the bustle. The battery hatch cover just needed the lifting handles trimming, I'll add more detail later.
But the Metadynes hatch cover needed replacing with a much thicker piece of material, the full size hatch is actually thicker than the battery hatch cover, so the thin steel plate had to go in the spares bin.
I didn't have any thick aluminum big enough to cut out a new Metadynes hatch, so I glued two pieces of 3mm plate together and worked with that. Using the supplied hatch plate as a basic template to get the general shape then filed the new hatch piece to shape. Once cut out and filed up I could then fit the handles in the correct position. Sadly the supplied thin hatch doesn't have this capability.

What an odd name "Metadyne". so I looked it up:
"The Metadyne is an intriguing type of electrical machine, akin to a rotating amplifier, and is particularly suited to heavy duty operation where constant voltage input needs to be converted into a constant current (but adjustable) output. The contrived name comes from the Greek 'Dynamis', meaning power. The machine had was found to be useful for certain types of drive mechanism, including gun turrets and cranes, and to a lesser extent, traction; under this name it was developed in the 1930s and 40s by Metropolitan Vickers and was a development of the earlier Amplidyne machine developed in America." Hummm And I was expecting Gyro's to be mentioned.
Clear as mud.

[John Clarke]

Works progressing on the NBC pack. The model comes with just a basic steel box, an intake and hinges. So loads of scope to super detailing it
The intake needed some filing work, taking out the curves, filing off the corners and adding more slots. I've slightly repositioning the mounting position (thanks for the heads up Charles) and ordered some m1.4 hex set screws from China for those finer details.
Still got to make the lifting lugs and door fittings and that tiny switch knob thing between the handle. And some other things I've probably missed.
On the turret bustle I've made the lifting guides from scraps and have come up with away to mount them still look like they are connected to the easily removed magnetically held turret roof.

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The original NBC intake.

[David Battson]

Hi John,
Some very fine detail there. Those 1.4mm hex heads are a great find.
I'm interested in the lifting guides, do you have any pictures of them in use, I can't work out what they are for.
David

[John Clarke]

I have not seen the guides being used either I'm afraid. I'm guessing it's a lifting guide. Goodness knows how they used to sling them, and they may have only been used when the gun dismounted or vice versa.
Their odd angle in this original picture shows paint rubbed off like a steel rope caused it as opposed to some sort of frame support. Although this one does have add on's probably for that reason.

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One of many items welded to the turret of probable unknown use. Other than a tripping hazard of course.
The NBC box on the model seems smaller than the original, not as wide or as deep as it should be, so my lifting guides are mounted inwards to reduce to obvious mistake. No doubt yours will find its way into your spares bin.
Being smaller also makes scaling down stuff like the trunking plate awkward on the side NBC pack. Which took too many go's to get it to look right-ish.

The original tank

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[David Battson]

Hi John,

The purpose of the guides occurred to me after posting the question - unfortunately I can't find any reproduceable photos. They are used to control the cable rubbing on the turret when the tank is being lifted by crane with the turret is facing backwards - such as when being loaded onto a ship.

I haven't measured up the NBC, but as it happens my one is going spare if you need any parts - reason is of course that the MK3 had a much more basic clean air filter in a small bee hive shaped box on the right hand side of the bustle. Predictably I have spent some time measuring the one in the photo now that it's back at Bovington.
David

[John Clarke]

Now that you mention the lifting direction it occurred to me I had seen a picture of the Chieftain being loaded at Liverpool docks in William Suttie's book The Tank Factory. Great book I might add too.

Thank you for the offer on the NBC box, but I have enough with the one I have. Looking forward to seeing the "Bee Hive" version. To be honest not the prettiest looking thing was it. I think it looks "Steam Punk" in some ways.

[Charles A Stewart]

Now that answers a lot and makes sense. I now need to make them, yet more Chieftain add ons.

Will it ever end

Thank you John
Cheers Charles

[John Clarke]

Glad to be of service Charles, not just add on's, screw and glue on's
So I'm becoming a basket case, After aligning the bustle armor plates, the turret baskets top forward bracket on both sides needed some attention (don't reach anymore). Also trying choose the best looking basket grill insert from original tanks for the Mk5. There are a lot of bespoke versions tall, short and lots of cut outs for somethings lost in time. Time to find the extra projectiles box too. The little box bolted to the basket on some tanks.

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Starting with adding an extra loop at the base of the Commanders basket. This added another little job of fitting an extra spar that I hadn't seen before until making these detailing changes. It helped out nicely adding strength to the short extension that needed making it a bit more realistic.

The four millimeter brass tube was brought from B&Q and I ran some soft alloy wire down the center so that while bending by hand it didn't crease.
Heating the brass tube on the gas hob to soften it up before hand bending.
The extra hoop and other pieces where glued on with JB Weld which takes a lot longer to cure in this cold weather. but worth it squaring the bottom of the basket nicely along the bottom edge.

Just trying to make up my mind how to finish off the basket insert upper edge. Probably with some thin aluminum sheet bent over.