A34 Comet Mk I Type A - New Build

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phil fitzpatrick
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Re: A34 Comet Mk I Type A - New Build

Post by phil fitzpatrick » Wed Oct 19, 2011 10:02 am

Thanks for the Info RE Erasor Stephen,I will be having a try out on some test peices to
see if I can get the Cast texture something close to Bodo's exsamples.
Cheers
Phil

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Re: A34 Comet Mk I Type A - New Build

Post by Bodo Langbehn » Wed Oct 19, 2011 11:35 am

I just have seen the advance to get the cast surface. The eraser you have used is not powerful enough to get a satisfying effect. I have taken a normal sandblasterpistol and the pressure was about 6 - 8 bar (think it`s arround 60 - 100 PSI ).
The small eraser I only use to clean soldered components as seen on the picture. That is the abutment of the 2 cm gun.

Bodo
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Stephen White
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Re: A34 Comet Mk I Type A - New Build

Post by Stephen White » Wed Oct 19, 2011 6:11 pm

Bodo, I agree, although it does produce a very fine pattern which is useful and I did find it worked when the spachtel was still uncured and soft.

Did you mean something like this for the bigger gun? This one operates at 90-100 psi

http://www.justoffbase.co.uk/Sandblasti ... ealey-SSG8

Regards

Stephen

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Re: A34 Comet Mk I Type A - New Build

Post by Bodo Langbehn » Wed Oct 19, 2011 6:32 pm

Hi Stephen,

yes that is the size of the pistol I use to get the results I want to have. I let the spachtel dry complete to get sharp edges, where I blast it away. I have attached the turret picture again, where you can see the difference between the surface from the steel plate turret and the casted gunmount.
The turret was only thin coated twice and blastered with low pressure and the gunmount several times thick and blastered with higher pressure.

Bodo
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Re: A34 Comet Mk I Type A - New Build

Post by Stephen White » Sat Oct 29, 2011 6:51 pm

Time for the belly plates:

Image


Image


Image

There are more circular ones to come.

Regards

Stephen

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Re: A34 Comet Mk I Type A - New Build

Post by Stephen White » Sun Oct 30, 2011 9:08 pm

There are 82 bolts on the belly plates, yes I counted them.

The PM said: "they should be recessed so the head is nearly flat with the top of the plate, so it real terms the heads would not be damaged if the tank was to run its belly on something hard, a lot of work but i know how detailed your models are.....".

So you can look at a photo several times and not see what's there:

Image

It's not just the belly plates. Here are the bolts for the outer hull side plates:

Image

It might well be a Leyland design standard common to British AFVs.

So, out with the mill and 82 bolts later:

Image

Image

So a genuine thanks to someone who took the trouble to offer constructive criticism (and whose models I admire). It's one of the things that makes this forum. I'm now going to turn off the computer.

Regards

Stephen

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Re: A34 Comet Mk I Type A - New Build

Post by phil fitzpatrick » Sun Oct 30, 2011 9:29 pm

Very nice work Stephen,well worth the extra effort with the milling :)
Cheers
Phil

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Re: A34 Comet Mk I Type A - New Build

Post by Derek Attree » Mon Oct 31, 2011 2:51 pm

hi Stephen
Nice looking belly plates what thickness are they ?
The screws look like m3 so you could use a counter bore for the rebateing if no mill. :D

I have just found the manual in the big box so I am having a read getting ready to unpack...
That is almost a year after delivery which was on the 16th Nov last year mine is number 36.

Looking good

Derek
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Re: A34 Comet Mk I Type A - New Build

Post by Stephen White » Mon Oct 31, 2011 4:20 pm

Hi Derek, glad you're alongside as the Navy say.

The belly plates are 10 SWG in old money, 3.2mm which is pretty close to scale. The hex bolts are deceptive, they're actually 10BA. I'm just turning the seven circular covers, another labour of love.

I've looked at the fixing for the suspensions bars to the hull floor, for which Mark is using the usual M4 hex. The hull ought to be smooth in those areas but I don't fancy using a countersink given the depth of material available. Probably have to live with the hex but I may rebate them a bit in keeping with the "Leyland style".

I've got stacks of photos if you're ever stuck.

Best regards

Stephen

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Adrian Harris
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Re: A34 Comet Mk I Type A - New Build

Post by Adrian Harris » Mon Oct 31, 2011 4:39 pm

> I don't fancy using a countersink given the depth of material available.

Are these the holes along the edges of the hull floor ?

On the Tiger, these are also M4 but countersinking seems to work a treat - though probably against official Armortek advice...

Is the comet hull floor 2mm or 3mm, and steel or aluminium ?

Adrian.
R.I.P Margaret I.L.Y

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Re: A34 Comet Mk I Type A - New Build

Post by chris fry » Mon Oct 31, 2011 7:24 pm

hello Stephen,

countersinking the bolts for the floor to the suspension bars i think is fine, because the load is being spread between the floor and suspension bars, just don't go to deep with the countersinking,

cheers, Chris.

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Re: A34 Comet Mk I Type A - New Build

Post by Derek Attree » Mon Oct 31, 2011 7:41 pm

Hi Stephen
Thanks for the reply, I spent the commute home looking at the manual and
its not obvious when you fit the bushes in the suspension bars and how they are retained.
I suppose its like the German kits and you use a loctite.
I dont think I will start putting mine together till after the Warwick model boat show on the 11,12 ,13th as I am displaying
there for the 3 days.

Derek
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Re: A34 Comet Mk I Type A - New Build

Post by Stephen White » Mon Oct 31, 2011 11:01 pm

Thanks Adrian, Chris and Derek.

I'm reassured about countersinking and I'll go that way.

Derek, unlike the German vehicles, it's the suspension arms that are bushed using retainer loctite as usual.

Regards

Stephen

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Re: A34 Comet Mk I Type A - New Build

Post by Stephen White » Sun Nov 06, 2011 6:42 pm

Turned and fitted the oil and fuel tank drain covers and the gearbox and sump drain covers:

Image

Fitted the bottom plate to the suspension bars with countersunk M4 x 10 rather than the M4 x 8 hex which would have stood proud:

Image

The kit bottom plate bends to form the lower front and rear angle plates in one piece. In reality these were three seperate sheets of armour and so grooves were millled to provide a sharp join and weld:

Image

The kit lower front plate and tow plate form a flush join:

Image

In reality the toe plate was a much thicker piece of armour and formed a lip which creates a very noticeable shadow:

Image

So a milled fillet to be added next.

Regards and thanks for looking.

Stephen

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Re: A34 Comet Mk I Type A - New Build

Post by Pete Mallett » Sun Jan 08, 2012 12:16 am

Have any of you chaps got the Comet Plans Pack from the Library at Bovington? Or obtained any of the re-printed Wartime Comet Manuals from MLRS? I think everything you're looking for will be covered in those references!

http://www.mlrsbooks.co.uk/bookstore/in ... &qry=Comet
If you can enlarge direct from 1/35th, the increase should be 583%. If the enlarger can only go to 400% max, then do one englargement at 400% and then enlarge that one a further 145%.

The maths beats me but the figures do work.
The maths is not really all that complicated. If you take a measurement at 1/35th scale and it comes out at, say, 5mm. Then that's 100% of that measurment. If you times it by 2 then you're increasing the size by 200%. Times it by 5 and you're increasing it by 500%. Therefore 583 % is times-ing it by a ratio of 5.83. And your next question will be "but how do you work out that ratio in the first place?"

...Easier than you think! The scales 1/35 and 1/6 are really only fractions. So if you divide the denominators of these fractions you get your ratio with which you'll do your multiplying from one scale to another. E.G. to scale up from 1/35 to 1/6 you simply divide the denominators, 35 by 6 to get 5.8333r, which is essentially the 583% you'll punch into the photocopier.

And it works for all scales too, scaling up from 1/45 to 1/6 simply divide 45 by 6 and get 7.5 (or 750%). Scaling up from 1/72 to 1/6 then divide 72 by 6 to get 12, or 1200%. As easy as 123!
1/6th in the UK come visit us at http://www.onesixth.co.uk

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