Armortek

Thanks John Looks like i've got the same 10BA bolts as you btw

ok so cutting the exhaust holes with the router is up next, Now the problem here is two fold. The first is I don't have the ability to get an accurate centre which is critical given the proximity to the edge and secondly, any drill is likely to go off centre because of the resin being softer than the aluminium and the drill will take the path of least resistance......hence the use of the router to cut the holes. So first of all, on the side that has the Gue and Main exhausts, I positioned the bushes where I wanted them and drew round the outside of them. That side was then set into the jig ensuring the use of double sided tape.

So now how to do the alignment; first using a blank piece of paper, draw a cross hair using a ruler and protractor to ensure 90 degree angles between the planes. Measure the diameter of the main exhaust bush which was approx 40mm which means the radius is approximately 20mm. Measuring from the centre of the cross hair, put a pencil mark at 20mm on each line then position the bush between the marks and draw round the bush...... Cut the circle out ensuring that no pencil line remains. Place the template into position on the work piece.... Mark the positions of the cross hair on the work piece then draw lines through them to form another cross hair........ Keep hold of the paper template. Now we need to make a template to guide the router and since we are cutting a hole of 15mm diameter, we need a template with a hole in but not just any size hole! To calculate the size of the template hole the following formulae is used.....
Template hole diameter = (Work piece hole diameter reqd - cutter diameter) + guide bush diameter.......so for me that works out as follows.....
Template hole diameter = (15 - 5.6) + 16 = 25.4mm.

I used 6mm mdf for the template which was cut slightly larger than the router base. Onto this I again drew a cross hair using the technique previously described then using a 25mm Starrett cutter in a pillar drill (thats all I had in this diameter), I cut out the hole using the cross hair centre as the centre..... A test cut was then conducted on the jig surround to confirm the hole cut was 15mm diameter..... The template cross hairs were then aligned with the work piece cross hairs where upon the template was secured into position and the cutting begun..... Because there is very little aluminium being taken away here the depth of cut can be increased to 0.4mm per pass without any undue impact on the cutter.... When the cut is finished, note the orientation and position of the template before removing and insert the other side panel with double sided tape into the jig. No need to mark this up now providing the template is replaced in the same position and orientation as before.

With the main exhaust cut in both sides in exactly the same position, time to move onto the Gue exhaust. Using the paper template from the main exhausts, mark the radius of the gue bush on the cross hairs, position the bush centrally between the marks and draw around its circumference. Cut out the circle and position on the appropriate side panel. I used a piece of 15mm copper pipe to hold the main exhaust in position whilst I positioned the Gue template.... Mark the centre with a centre punch and gradually drill out to the required diameter using a pillar drill........that's all there is too it!

I have a feeling that this is not the last time the router is going to be used on this tank....I can feel it in me water

I have been busy tapping out the numerous 10BA holes in the exhaust box. Taps keep snapping much to my frustration and not even at a convenient place where you can grab old of the broken part to extract it Of course, its never the tools fault, just the operator driving it

So whilst waiting for a replacement set, I've turned my attention to the gun clutch... So started off by reducing the width of the screw blocks to facilitate greater movement, in addition, I also removed the internal radii to add to that increase. I also bevelled the inside edges of the side walls that make contact with the swivel arms which allows the clutch to close up further. Then made my own Tommy bar complete with ends...... Final assembly in accordance with the instructions gave this..... The original looks like this however..... More tweaks required methinks ........M4 pivot pins replaced with M2 Hex heads and the lower grab bolts replaced with M2 cap heads. In addition, 2 additional M2 cap heads were added........ That's better.........you could also reduce the width of the body sides but I chose not too.

Like it.

Great attention to detail Richard, and just when I thought it was safe to spend some time on the front end.

I'm beginning to have a love hate relationship with Chieftain. (Beginning?)

Re-phrase, I love to hate it

Thanks John. Mine started ages ago

Idlers today... Made up the shafts first; assembled with Loctite Blue and a little gentle persuasion get get them tight in..... The bearings were installed in a similar manner to the road wheels with the shafts being held in a vice whilst the wheels were spun.... The wheels were then etch primed after cleaning then it was time for the awkward bit, the dreaded letters! 3mm letters were used in the main with some 2mm letters. I found the easiest way to do them was to lay them out where I wanted them to go, then used tweezers for the 3mm or a stab with the scalpel to dip them in superglue, wipe of the excess and then position appropriately. I didn't have any issues with the letters fixing straight away; perhaps because i may have used a different etch primer?? Repeat for the remaining letters.... Finish with a little paint and varnish....idler wheels done..... Idler blocks to follow

I know I was going to be doing the idler blocks but decided to deviate to look at colours and in particular, urban camo colours of the Berlin Brigade.

There are plenty of pics out showing Chieftains dressed in there urban camo; the problem is, can you use pictures to determine what colours you should use. In addition, should you trust any model paint suppliers who say these are definitely the Berlin Camo colours? So, I thought I'd experiment! I purchased several colours as identified from Reference books, model paint suppliers and authoritative sources all purporting to be the colours used on Berlin Chieftains.

After marking out equal squares on a piece of ali, etch priming then two coats of white undercoat, I sprayed each of the colours. I then took a photo on my CoolPix SLR and one on my iPhone10, in the same light and at the same time of day. This is what they looked like when compared together.... Quite a difference, particularly in the brighter colours ie the white and the lightest grey. When compared to the original, would you be surprised to know that neither have represented the lightest grey correctly; it actually sits somewhere between the two!

So with the above in mind, should we trust the colours in pictures to be accurate and true? I think the above categorically says NO.

So which of the above colour sets was correct for Urban Camo? Have an educated guess if you can't find an authoritative source and trust me when I say, they are hard to come by! At the end of the day, I would expect the urban camo colours matched the surroundings of the city; white for buildings with a brown matching the soil colour and a grey resembling worn tarmac.....now how hard can that be.........

It's almost as if we're living in a parallel world.....

Richard, you might wish to read posts of the last couple of days about colour where there are specific answers which may help you. All you've proved is that photos and printed sources are not reliable guides to colour. The only objective way to assess colour is to find the original paint specification, translate that into one of the established colour standard systems and then compare with a sample of your paint using one of the accepted colour spaces. I show how to do this in the new Knowledge Base Topic. (And I deal specifically with the Berlin colours).

Stephen White wrote: ↑

Fri Jun 12, 2020 8:32 pm

All you've proved is that photos and printed sources are not reliable guides to colour..

Spot on Stephen which was what I was trying to demonstrate; admittedly, the last sentence was a little tongue in cheek The only things you can use on the pictures are the details and the positioning of the various blocks of colour.

Looking forward to the knowledge base article

So after reading the excellent knowledge base article written by Stephen White, I decided to experiment and do my own mixing with the iModelKit App. Apart from the full white, Stephen has kindly identified the other Urban Camo colours as BS499 (Service Brown) and BS632 (Dark Admiralty Grey) from the British Standard 381C.

Using various paints from the Tamiya and Vallejo ranges (but not mixing the two manufacturer's together), I came up with a delta for each of the paint mixes of less than 0.4 using the Vallejo Air range which if I understand correctly, means there is no discernible difference to the naked eye between the mix and the actual colour.

The mixes are as follows: Lets get these Berlin Chieftains looking all the same and have a parade!

Of course, you could always buy it ready mixed! Does anybody know of a source that would mix acrylics in small volumes?
Idler blocks next honest

I went to purchase the above paints online and it appears that 71.253 is no longer available! A quick recalculation and we have an alternative.... which is available! The delta has increased but only to 0.4

Richard, good that you've been able to make use of the Knowledge Base Topic. For the post-graduate course, you can always fall back on Dunkelgelb. Everyone knows what Dunkelgelb looks like, until it's apparent that not even the Wehrmacht could make their mind up, with four official iterations, one version without an accepted RAL standard and some so-called colour experts who have original colour chips but are too selfish or commercial to make them available publicly.

How many shades of Ferrari red are there? and for that matter how many shades of JCB yellow?
Looking at the Batus Chieftain, there's so many shades of "Nato" green it's enough to pickle your brain. and as for pebble dash sand yellow or gawd knows what light stone.
Your probably better off going to Halfords and choosing Sierra baby nappy brown and Moggy Minor green, then use a quality matt varnish.
Once the paint tricks start though, weathering, scuffing, 3d shading, chipping, rubbing, dirtying, streaking, aging, rusting, the original base coat disappears. Every body knows matt paint ages fast in the sun light, A quality Varnish will slow it down but how many original vehicles were given a quality varnish?
A friend of mine ordered Olive drab from reputable military paint supplier, the supplier took three goes to get it reasonably right even though he had been given RAL number, Mind boggling.
I say go with what you like. Eye sight fades with age and there's not many of us under forty, no one can say for sure what colour is correct on that basis
Being the worst painter in the world, I use what's on the shelf usually, like I'm guessing a lot of crews did too. I just hope I've got something like the right colour.
My wife say's I exaggerate too much, I think she's wrong, Fortunately, I'm a million miles from painting the final coat on the Chieftain.
This is how I feel about painting, any resemblance between Richard with his favorite tipple is purely coincidental.

I know that I was due to finish off the idler bolcks but something else caught my eye over the weekend!

Having filed my casting lugs down to fit into the lower hull then ground the sides down of the casting to match the hull sides, things were proceeding nicely. A trial fit of the mudguards showed a little panel beating was required to make them fit. The front lugs on the casting were fitted now whilst I had the opportunity for easy access having first ground out a recess for the front fixings in the casting. It was then I noticed I had a similar issue regarding fixing of the front towing lugs in that, the top fixing holes would not be accessible once the front plate was secured into position as you can probably guess from the picture below...... As a consequence of this, I started to look at the positioning of all the towing eyes on the front. Why, because the Berlin Camo is a very distinctive and repetitive block pattern of a specific size which will clearly show errors in either scale or position of components on a model when compared to historic photo's! There is unfortunately no artistic freedom with this pattern so things must be relatively accurate if you are to stand a chance of replicating it. The next photo shows the positioning of components in the standard model build...... Now compare this to the following two pictures..... The lugs are far too far apart in terms of relative position; the eyes of the left and right lugs should be level with the top of the inside cap of the idler blocks which then gives you space for the registration number. The middle eye is too low and need s to come up such that the top of it is almost level with the bottom of the left and right lugs. This would then give a relatively accurate split for the paint centre line across which is level with the top of the middle lug. so onward to some experimentation!!

Shifting the left and right lugs down such that the lower hole on the front plate is used to secure the top part of the lug reveals this picture...... Drawing a line across shows the relative position of the bottom of the left and right lugs in relation to the middle lug. Shifting the middle lug upwards gave the following....... Now whilst the lugs appear to be in a better position, the gap between the top of the left and right lugs in relation to the bottom of the casting is too big and at the same time, i think the middle lug is sitting too high so, how do I get around this....hmmmmmm.

Time to redraw the lugs methinks! Using the method I previously used on the rear lugs, I started to modify the supplied lug. The shape around the eye of the lug was extended to push the hooks out forward and upward just like the rears had been. This in effect increased the downward length by some 10mm. Next I increased the angle on top of the lug which increased the upward height of the lugs. When compared against the original, you can see the differences...... Once manufactured, the new lugs were installed complete with hooks. The middle eye was installed in its original position..... A second line was drawn across the lugs to show the difference.
The middle lug was then re positioned and a further comparison made... and looking from the side...... Now I must stress, I've done all this using the Mk1 eyeball which in my case isn't very good; I have no drawings to refer to so I could be wrong here! All I know is it looks a little better and should better allow me to match in the urban camp pattern correctly; on the front at least

That's a radical mod for a radical paint job you've got there Richard.
But sometimes things have to be made to fit and it will only get more radical when the Stillbrew gets attached.
This Chieftain model is effectively a blank canvas, you'll be shifting stuff around to suit the Berlin camo for months.
Gawd, just look at the positioning of the boxes on the rear mud guards
That's a physical photo shop spray job worthy of E'Harmony.
If the guy that painted this model did blokes belly's, he'd make fortune.

Who says the Camera don't lie

Though I do think your model's gonna need a "fat lip" like my Chiefy Mctank face!
Every Chieftain should have one.
Still you could always do a Goonie! "Hey you guy's"
Cover the good eye and your good to go.

One Eye'd Willy