Armortek

Thanks for the encouragement, much appreciated particularly Per with your fantastic eye for detail and knowledge.

Not much new to report this week, working on the second final drive casing. Thought a couple of comments on tools might be helpful. Another low cost but really useful tool for transferring measurements is the surface scribing block:



Simple to use, set the scribe to the measured dimension, find a true, flat surface and transfer to the new material with a scribed line:





I've also been testing the roughing cutter and WD40 method Paul Scott recommended and it is very effective, producing very small chip size, less galling and much less aggressive, particularly with a difficult cut on the rotary table:



Almost finished, but for a couple of details:





Regards

Stephen

Fitting the running gear into the final drive casings. The outer seal and driven gears first.



Mark recommends dry fitting ie no greases or oils, in order to avoid picking up material which could erode the gears. An alternative is to use a dry lubricant such as Rocol Oxylube, described as:

Inorganic, resin bonded dry film of molybdenum disulphide in aerosol. Developed to lubricate sliding mechanisms such as plain bearings, pins, cams and slides particularly in vacuum environments.
•Designed for applications where contamination by aggressive chemicals or petroleum based solvents; oils and greases would destroy conventional lubricants
•Fast curing time
•Dry film lubrication – resists pick up of contaminants
•Prevents galling, pick up and seizure
•Suitable for fine threaded components
•Approved to Rolls Royce, Naval and NATO Standards. Also approved for Submarine Clearance
•Temperature range of -200ºC to +450ºC

Really useful that it's approved for use in Royal Navy submarines.........



Finally, Loctite High Strength 270 to lock the bearings in place:



Then the bushes and shafts for the jockey wheel, again lubricated with a dry film of Oxylube. I always find fitting bushes a challenge. The difference between a good clearance fit and an interference fit is so small. I used a scraper to hand fit the bushes. It's also essential to fit both bushes with the shaft to get good alignment.

Regards

Stephen

Some detailing of the track guide rollers. On the rear side, a notional bit of machining to remove the flat face:



On the front side, a bull nosed cutter to deepen the curvature:



The hub caps given a more rounded profile using a Proxxon radius turning attachment:





Final results mounted:





This more or less finishes the final drive cases, a long haul but lots of detail to see. Now to bolt up, spray with the base coat of Olive Drab Lustreless and mount.

Regards

Stephen

Hi Stephen.

Just brilliant my friend watching every post as they come up very well done the engineering class continues .
Next tank you get you should just go the whole hog and only buy the tracks.

Cheers Paul.

Hello Stephen,

just looking for words I can't find Outstanding work, wow

cheers,

Uwe

Hi Stephen
Very impressive work.

Derek

> Also approved for Submarine Clearance

I read that in conjunction with your comment on clearance fit and interference fit, and wondered if they used Oxylube for sliding submarines through things. I obviously need another holiday

Loving the detail going into this Cent.

Adrian.

On a slightly more serious note, will you put 270 on the gear shaft as well, to prevent lateral movement of the gears

That lateral movement is what seems to cause the witness marks seen when you remove the gear casings from tanks which have been used for a while.

Adrian.

"nice" REGARDS SIMON.

Kind comments, much appreciated, especially from such esteemed Armortek old hands (Simon, that's old as in well established....... BTW, have you seen the blurb on the SW Model Show in May?)

Adrian, eyes of needles, submarines, the mind boggles. Mind you, after the benefit of some British Airways festive plonk in T5, I'll believe anything.

Serious answer to serious question is yes to Loctite on the shaft to prevent lateral movement. I recall Mark recommends it in the build instructions. The driven gear has a slight protuberance on the side opposite the shaft and in a fit of enthusiasm with my new scrapers, I almost committed the schoolboy error of removing it, before realising it would prevent direct contact between the two surfaces if the gear moved laterally. So far from thinking Mark had not set a facing tool to centre, i now realise it's a very clever piece of design. Sorry Mark for doubting you. Oh well, back to more BA fizz.

Seasons greetings to all.

Stephen

Hi Stephan,

It seems such a pity to paint this gem in Olive Drab (not my favourite colour) but I guess there are few alternatives.

About lateral movement, there were no protuberances on the opposite side of the shafts on my Tiger II driveshafts and I didn´t want to use loctite instead a circlip did the trick;







Mark out were you want it, put the shaft in the chuck. Go slowly - work you way from the inside(gearside) towards the outside, test it and adjust until you get a tight fit.

/Per

I can't add much to what has already been said Stephen. Just amazing detailing!

best regard
Tim

Happy Christmas to one and all. Before the festivities descend and interrupt important tank building activities, one last post.

Joined the final drive cases, using a liquid gasket of Loctite 5296, then bolted them up with high tensile hex heads and replicated the bulges on the rear faces where the bolts sit:







Then for some colour. My friends at 355 Restorations weren't completely happy with the colour match they'd done for the Australian Olive Drab Lustreless, which is a very distinctive and unique colour. Using Paul Scott's colour sample, they did a re-mix for me in two part paint. It's the first time I've used a two part paint and it does involve a lot more careful mixing and thinning. The resultant match on the hull front and rear is stunningly accurate:







I hit a problem however with the final drive cases where the paint took a long time the dry, remained shiny rather than satin and after 24 hours was not hardened off. I might have waited another 24 hours but decided the problem was spraying too many coats at once. I elected to strip the cases and start again, which was a pain but allowed some more texturing and tidying up:



Per - I know what you mean about Olive Drab but I'm enjoying two aspects - the research into Olive Drab is if anything more complex and involved than the German wartime colours which have been studied to death. Secondly, if you look at what modellers like Michael Rinaldi achieve (see Tank Art Vol 2 - Allied tanks), there is a satisfying challenge in painting and weathering a monochrome tank and I'm looking forward to getting to grips with filters and pinwashes and all the good stuff Simon does so well.

Happy Christmas, or Winter, Non-Denominational Holiday as it's known in some parts.

Thanks for looking and happy tank building

Stephen

Hi Stephen
its great following your,very impressive detail and quality.
Colour mix looks good in your photo,have a nice Christmas,
Regards
Phil

Normal service resumed.....

At the second attempt, base colour on the final drives and started the weathering with dark brown and a Vietnamese red Earth pin washes and some filters. I find filters tricky, you don't really know what the effect is going to be until they dry. The alternative of using oil paint rendering is much more immediate and controllable, so I'll be using oils next to bring out the shapes. Before and after:







The inner half of the final drive casings was welded to the hull at manufacture and featured a very prominent flange on the upper surface, so that's next:









Happy building if you're fortunate to have some holiday.

Stephen