Chieftain No. 34

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Charles A Stewart
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Re: Chieftain No. 34

Post by Charles A Stewart »

Good evening all.

Today's sunny morning thought was, "I could paint a bit more Bailey Bridge". :D

Unfortunately that thought was interrupted by a big wet cloud, bo....cks :cry: So to the workshop. I thought I would look at the Bazooka plates, so here we go; fit, paint, put to one side: Simples said Sergei!

It is my choice to use the slotless c/sunk screw and I think it will work, as long as care is used with the counter sink, hence the replacement rear plate :roll: .
Baz plates1.jpg
Baz plates 2.jpg
That aside we ran the model this week, taking Stephens advice regarding the trimming. There still seems to be more input from the left track than the right hand track.

So we lifted the tank onto blocks to see what's afoot( or atrack), both sides operated absolutely fine, as per the trim adjustments. We are operating on a solid surface for now, any thoughts?

Cheers all, take and have a good week.

Charles

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Re: Chieftain No. 34

Post by Stephen White »

Charles, it's not obvious why there might be a difference between running tracks on ground and running tracks elevated. You say the trim is set so that both tracks accelerate together when jacked up. I guess it's possible that you might have some exponential set on one of your motion channels. That would cause one track to accelerate at a faster rate initially than the other, although the "slower" track will eventually catch up at full chat. With a channel mix to give you steering, that effect will be masked. Check for Expo (Roller bar press, Function List, D/R and Expo). Check the two channels you've got motion set to. Expo at the bottom should be set to zero in both directions (zero and zero). To look at each channel, highlight the channel in the channel window with the scroll bar, press the scroll bar to select and then scroll to the next channel).

If there is no expo, then the problem is probably something to do with the physical condition of the running gear and tracks. Is it possible that you've got some interaction or binding between the track horns and the road wheels? I've not fitted tracks but gather the clearance is minimal and any misalignment of road wheels might lead to binding. (To check the roadwheeels are aligned, you would need to split the track and run a long straight edge or piece of string between the centres of the idler and sprocket wheels).

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Charles A Stewart
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Re: Chieftain No. 34

Post by Charles A Stewart »

Cheers Stephen, thank you for your prompt reply.

It might take me awhile to get my head around the first paragraph of your reply, but thank you, my lad may see it differently, as the youth of today do.

The alinement of the road wheels, sprocket and idler: I love that great minds think alike. I used a plumb bob & string and I am happy with the set up. This is one of the curious things, the model actually runs in a straight line, given the above.

Again many thanks

Charles

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Re: Chieftain No. 34

Post by Charles A Stewart »

Evening all.
Had a good day, in my books anyway, working on the bazooka plates (you'll enjoy these). I have posted a previous photo here, apologies for repetition.
Baz plates1.jpg
baz 1 (2).jpg
baz 2 (2).jpg
I have seen in publications, Chieftains in various states of dress; no bazooka plates, i.e. as oppo. forces, makes sense or in other illustrations a mixture of missing plates, was this deliberate or due to breakages?

I will admit I like the idea of partial "plates off" as it shows the working running gear.

As ever comments welcome.

Hope all had a good time at the open day, I am just too far away. Any Chieftain road wheel/tyres left?

Take care.

Charles

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Re: Chieftain No. 34

Post by John Clarke »

Nice work Charles.
Deliberation of fitting the Bazooka skirts, to have and to have not, it is a question.
I'll be going all in and fit them all.
Reasons, I've got a few. but I have to be careful they may not have an accurate history.
But, in the British Army first parade was strict and I'm guessing you'd have to have a pretty good reason not to be wearing your skirts.
Oh Man, I only ride em I don't know what makes them work,
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Re: Chieftain No. 34

Post by Charles A Stewart »

Hi Folks.

Totally forgot about the live stream from Tankfest today, we'll watch it later. Nice turn out of models though, didn't see a Chieftain, perhaps its out of shot :roll: .
PT plates.jpg
Continued with the work on the "plates" today and finished construction of the PT/nearside. I turned the tank around too, a first as I usually can get access to both sides, however the light is better on one side than the other. So to do the plates on the ST'BD/off side it seemed a sensible thing to do, ahh but :shock: .

John Clarke has highlighted in another post on this forum, an issue of inner road wheels scuffing on the bolts of the plate supports: I have this issue too :( .
InkedWheel scuffing 1_LI.jpg
Inkedtyre scuffing 2_LI.jpg

I suspect it is recent as No.34 never really ran long enough(gear box failures) for this to be a factor before last October(the mud run :x ). No34 spent all winter and spring with the suspension dismantled. Once reassembled, electrics fitted (very recently) and tested without tracks and jacked up, no issues. All subsequent runs have been videoed, this may help, but I am not sure, feel free to look and comment.

Stephen, I believe your analysis of the issue that something mechanical is at the root of the neutral turn problem is correct, if done very slowly the turn works, albeit on a shiny surface(garage floor). However if there is snagging, this is possibly acting as a brake on rougher surfaces :oops: .

Presently I am committed to completing the Bazooka plates, as once "done" they can be stored, oh you'll love them, the holes don't match, but that could just be me :cry:

Happy Chieftains all

Charles

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Re: Chieftain No. 34

Post by Mark Russell »

Charles A Stewart wrote:
Sun Sep 19, 2021 8:33 pm
Hi Folks.

Totally forgot about the live stream from Tankfest today, we'll watch it later. Nice turn out of models though, didn't see a Chieftain, perhaps its out of shot :roll: .

PT plates.jpg

Continued with the work on the "plates" today and finished construction of the PT/nearside. I turned the tank around too, a first as I usually can get access to both sides, however the light is better on one side than the other. So to do the plates on the ST'BD/off side it seemed a sensible thing to do, ahh but :shock: .

John Clarke has highlighted in another post on this forum, an issue of inner road wheels scuffing on the bolts of the plate supports: I have this issue too :( .
InkedWheel scuffing 1_LI.jpg

Inkedtyre scuffing 2_LI.jpg


I suspect it is recent as No.34 never really ran long enough(gear box failures) for this to be a factor before last October(the mud run :x ). No34 spent all winter and spring with the suspension dismantled. Once reassembled, electrics fitted (very recently) and tested without tracks and jacked up, no issues. All subsequent runs have been videoed, this may help, but I am not sure, feel free to look and comment.

Stephen, I believe your analysis of the issue that something mechanical is at the root of the neutral turn problem is correct, if done very slowly the turn works, albeit on a shiny surface(garage floor). However if there is snagging, this is possibly acting as a brake on rougher surfaces :oops: .

Presently I am committed to completing the Bazooka plates, as once "done" they can be stored, oh you'll love them, the holes don't match, but that could just be me :cry:

Happy Chieftains all

Charles
I countersunk all of mine 😀😀😀
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Charles A Stewart
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Re: Chieftain No. 34

Post by Charles A Stewart »

Mark.

That has too be the most easiest & sensible solution, I will follow your lead, after all they aren't too structural.

Cheers Charles

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Re: Chieftain No. 34

Post by John Clarke »

It's always good to shed light on these abnomalies and air solutions.
I've got a few of those skinny head m3's.
I thought I'd flatten the heads off then they'd still look like bolts.
That's of course if you could actually see them once the skirts go on.
Time to polish up the mirror Richard :D
Oh Man, I only ride em I don't know what makes them work,
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Re: Chieftain No. 34

Post by Charles A Stewart »

Hi folks.

Another week (I don't spent all week on the model, but!).
fender 1.jpg
fender 2.jpg
Skirt 1.JPG


I give in, who measured this :roll:

Charles.

PS watch the next build :D

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Re: Chieftain No. 34

Post by John Clarke »

They look pretty good to me Charles.
I'm told the bracket mounts should be rectangular. I'll file some off the top when I get round to them :lol:
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Re: Chieftain No. 34

Post by Mark Heaps »

Charles A Stewart wrote:
Sun Sep 12, 2021 7:03 pm
I have seen in publications, Chieftains in various states of dress; no bazooka plates, i.e. as oppo. forces, makes sense or in other illustrations a mixture of missing plates, was this deliberate or due to breakages?
If the inner circlip on a trackpin broke, the pin would drift outwards initially clanging against the inside of the skirts to give you some warning. If it drifted too far outwards, it could and did hit the skirts with enough force to shear the retaining bolts.
Also theoretically possible that if the crew had not tightened the bolts sufficiently they could vibrate out whilst moving causing the loss of a skirt plate but I never experienced that.
One of our tasks as the ARV or ARRV crew on any road move was to keep our eyes open for any skirts in the middle of or at the side of the road, stop, pick them up and put them on the rear decks.

When & if they got replaced during the exercise would depend on various factors. Such as did we spot it, also when would we next encounter that tank, due to being "distracted" by other repairs & recovery taskings, time available and difficulty of extracting the sheared bolt, and immediate availabilty of replacement bolts / square retaining nut if required.

Not sure about OPFOR deploying without skirts, Stephen White would know best there, but I am fairly certain that "friendlies" deployed with all skirt plates fitted. Whether they were all fitted at ENDEX was a different matter so do what visually appeals to you, it will not be historically incorrect.

I never saw a skirt plate so damaged that it could not be re-fitted and it would require a replacement.

Mark

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Re: Chieftain No. 34

Post by Charles A Stewart »

Good evening Mark.

Thank you for the insight, I will use your observations as do like to see the suspension, track movements.

Will I get away with "Sorry guv a track pin must of knocked it off, never heard a thing". Although I am sure it would have made a hell of a clatter.

Thanks and cheers for your input.

Charles

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Re: Chieftain No. 34

Post by andymusgrove »

Hi Charles

She is coming along very nicely and thanks for the updates.

Can I ask what have you used for the decking 1/2 round strips?

Cheers

Andy

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Re: Chieftain No. 34

Post by Charles A Stewart »

Evening Andy.

Plastruct MRH125 from Expotools or a ye olde local model shop(if you are lucky enough to have one). Expo seems to want trade customers as recently I have not been able to buy stuff unless I am trade.

However e-bay works but watch the prices.

Strips glued down with Loctite 480(black).

Cheers Charles

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