7mm Mickoo's Commercial Workbench

mickoo

mickoo

Western Thunderer
Lancastrian said:
Dave,

The tender story is a little convoluted as there are the three "Stanier" modified high straight sided 3500 gallon Fowler tenders, or "modified old standard", one of which, as you mention, ran behind 48600. Additional to this are the Stanier 3500 gallon tenders, which are basically a 4000 gallon tender type but on a 6'6" + 6'6" wheelbase. These latter type were paired with Jubilees from new and then of course moved around. However, I have also seen mention of 10 high sided flush tenders, but don't have access to my reference material to check this out.

Here's a photo of 45660 with a Stanier 3500G tender:
https://flic.kr/p/5v5rKT
Click to expand...
Correct, a little is skimming it a bit though :D, one of the ten Fowler high sided tenders was fitted to 4F 44604 which forms next months (or as soon as Princess Royal is finished) build project, so some new etched sides or scratch built and punched rivets.....etches I think :)).

The problem I have with the three specials (9000-9002) is the brake rigging. On the Royal Scots the rigging follows Fowlers compensated linkage style rigging but (and I haven't checked the tomes) my understanding is that the chassis were retained from the old Fowler tenders and new Stanier bodies fitted.

However, Staniers Pacific tenders have a more streamlined single rod each side front to rear, looking at the frame drawings they match closely to the later Pacific tenders and 9000-9002 were rebuilt with the standard Stanier 4000G tanks.

It's a logical leap of faith to assume the first three had the same linkages as the following examples and were precursors to that lineage, despite having bodies that look like Fowler tenders. Either way I'll hang fire on that detail as the elves carry on searching for proof.
 
C

Clarence3815

Western Thunderer
Rob has been building a production series Princess, this one is the original machine. There were a lot of differences between 6200/1 and 6203/12 based on experience. The motion and reach rods are particular examples.
 
mickoo

mickoo

Western Thunderer
dibateg said:
Very nice Mick... I'm trying not to want one!

Tony
Click to expand...
My advice.....don't unless you want to do some extra work, there's a few bits wrong with it, the resin boiler assembly is wrong resulting in an incorrect pitch and relationship with the firebox; I think the original metal one might have suffered the same as well. That means the rest of the model is then compromised around that; I binned mine and used the remaining etches in the kit to make a more accurate metal one and then undo the alterations made to make the resin one fit.

The valve gear is wrong as are the motion brackets, you need to hack it the valve gear about and make some new parts to get it reasonably close to the real engine, the motion brackets I lived with. If you're not careful, your piston thrust line can end up way too low so the whole lot looks like it's dragging it's sorry butt along.

Having said all that, it is the best place to start if you want a Crab; it is also an old kit so most of the issues are likely down to lack of access to accurate information at the time of design.
 
Dan Randall

Dan Randall

Western Thunderer
I don’t think I imagined it, but I was chatting to Dave Sharp yesterday and I’m pretty sure he said the Crab was next?…

(But huge apologies, if I’m wrong!).


Regards

Dan
 
dibateg

dibateg

Western Thunderer
It would be the Gladiator one I'd get.... the JLTRT one would be too much work...

Still, I might have built all the locos in the cupboard by the time an MOK one comes out...
 
mickoo

mickoo

Western Thunderer
dibateg said:
It would be the Gladiator one I'd get.... the JLTRT one would be too much work...

Still, I might have built all the locos in the cupboard by the time an MOK one comes out...
Click to expand...
Good point.

I'd forgotten about the new Gladiator one; that would be a better starting point these days.
 
mickoo

mickoo

Western Thunderer
Back to the day job and little more work on the Princess Royal tender. After much sleuthing I found the brake rigging is the single bar type, not the later compensated rigging on nine and ten ton tenders. For some odd reason the works drawings for Coronations and Scots all show compensated linkage yet many photos clearly show single bar type. I'll have to dig further but suspect there's a difference in build orders somewhere.

I was going to use the kit white metal axle boxes but got a bit wayward with the hot stick and was forced to 3D replacements. That was fortunate as the kit ones are not correct, they use the later larger snubbers which butt up against the anchor bracket. On these three tenders the snubber is spaced away from the anchor bracket by a lobe to allow it to rock.

It also looks like the springs are shorter as the tie rods have a distinctive cant inward toward the top when viewed side on. The current ones are only fixed with double sided tape to gauge proportions and positions (no drawings found yet) I won't fix them permanently as the lining around the arched holes passes under the anchor brackets.

This leads to another problem, the 3D tie rod will almost certainly get broken at/during/after paint so I'll redesign the units to take NS wire, it's a bit more fiddly but stronger I hope. I can fix the axle box and spring with wire tie rod before paint and then just slide the anchor bracket and snubber afterward.

My axle box is too shallow and needs to be pulled outward by about 1.5 mm, that'll get done with the other reworks tomorrow.

Other than that, everything else fitted tickety boo.

Img_2633.jpeg

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Img_2635.jpeg

Hopefully have the tender all wrapped up tomorrow or early Friday.
 
Overseer

Overseer

Western Thunderer
mickoo said:
It also looks like the springs are shorter
Click to expand...
I haven't looked at LMS tenders in any detail but have been looking at springs on some earlier tenders that had different length springs on the different axles. Some had longer springs on the centre axle, presumably to reduce the load carried on this axle to keep the outer axles on the track, and one had longer springs at the leading axle probably on the basis that the coal weighs less than water. Were all the springs on these tender the same length? Would be an easy tweak with 3d printed springs. Whether it would be noticed is another matter.
 
mickoo

mickoo

Western Thunderer
These particular springs were all the same length but the ROD tender has longer (by 6") in the middle.

To expand, the anchor points are also the same distance apart but I suspect the later and larger tenders which used basically the same frames had slightly longer springs so the tie rods were vertical.

There also appears to be distinct engineering to keep the tie rod at 90° to the spring plates (Aberdare is an extreme example) but over time the rods became vertical with a translation plate that ensured forces were 90° to each component.

Close up of a Stanier 10T axle box and spring, the translator plate is the domed like washer that sits on top of the spring plate and ensures the thrust washer (above) always sits at 90° above the domed surface.

6201_21.JPG

Img_2576.jpeg

On the first three tenders (9000 - 9002) the top of the snubber also has a domed rib and thrust washer underneath the anchor point so the snubber is shorter and has a gap to the anchor plate. A poor crop from a larger picture.

Image2.jpg

Note also nine leaves instead of ten on later tenders and the resultant extra gap between the spring and safety brackets.

When these tenders were rebuilt to the larger ten ton capacity I expect the springs and snubbers were all changed for the later types.
 
mickoo

mickoo

Western Thunderer
End of the week update, not finished but close now, to be fair it's been a four day week...that's my excuse anyway ;)

The whole interior, front bulkhead, footplate and scoop/handbrake stand covers are all still loose (hence gaps between side sheets and bulkheads/brackets), just in case I need to get in there before sealing it all up.

As a rule I never fix the footplate down until the engine is on it's wheels and the cab fitted, frequently you'll find it's the wrong height, especially on tenders that fit across several classes.

The tank vents are replaced with 3D (in the machine and ready tomorrow) to get the right heights and shapes and the locker doors are a bit of a mystery right now. The kit ones are too small anyway so new ones will be needed, the drawings shown side hinges next to the coal space tunnel, some photos show lower edge hinges.

I still need to get back to the chassis and scratch build the brake cylinder area and brake weight shaft etc, but that can be done later once the upper works are all complete.

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