7mm Loose Ends

28ten

Guv'nor
That should do it :) the spring wire needs to be trimmed, but it should work

render.JPG
From underneath. The U ends are not structural, and not needed for Commonwealth bogies​
underside.JPG
To make ride height adjustment a little easier, a couple of notches indicate midpoint, helping set the ride height and an extra hole will give a little pre load, but i need to calculate the exact amount needed​
features.JPG
 

Dog Star

Western Thunderer
When you prepare the layout for the photo-tool you might wish to consider using the space between the solebars for some washers and rings to:-

(a) fix under the bolster to increase the bearing area of the bogie pivot bolt.
(b) increase the bearing area between bolster and underframe... washers on top of bogie and under floor for bearing surface.
(c) ring on top of bolster to provide lateral stablility to corresponding washer on floor ( or put another way, to transmit thrust between bogie and floor over a larger area than pivot bolt).

If the above does not make sense, consider how NQLTRT bogies are attached to the resin floor.... the threaded bolt wears the bearing hole in the etch frame / whitemetal bolster... the small surface area on the bolster in contact with the floor (hence does not minimise rocking of the body on the bogie).

Mr. Penn-Sayers has turned some shouldered bolts for me to minimise the wear of the whitemetal (from the thread of the supplied set screw)... and I have increased the bearing area on the bolster to circa 15mm diameter to reduce the tendency of the coaches to rock in motion.

regards, Graham
 

Dog Star

Western Thunderer
Don't worry Graham, I had spotted that! I shall also be bushing the pivot :)
I do not know how the JLTRT or Easybuild MK.1 BR1 bogies fit to the floor... in the case of the Gresley coaches the bogie has a w/m bolster with a hole for a 4mm set-screw, the set-screw goes into a nut-sert in the floor moulding.

The shouldered screws which have been made for me, thank you Paul, are 4mm x 1mm thread, with a shoulder of 5mm diameter and a head of 8mm diameter, hence there is a need to enlarge the hole in the bolster. The shoulder of the screw is long enough that the bolster can rotate free when the screw has tightended into the nut-sert.

The floor moulding has a flat area of around 1cm x 1cm surrounding the nut-sert, the corresponding area of the bolster is a ring, about 10mm ID and 13mm OD. I have put a 15mm diameter circle of styrene on the floor moulding to increase the contact area between bolster and floor - the thickness of the disk is that which is required to set the buffer height at the required dimension. As yet I have not been able to complete the job because I am not sure how to produce the necessary part in the required quantity. The ring on the top of the bolster is about 3mm deep and I intend to fit a styrene washer, of diameter to fit inside the bolster ring, to the underneath of the floor moulding. This disk shall not be thick enough to take any vertical load, the purpose of the washer is to act as a constraint on horizontal loads along the carriage centre line. Why? To limit any tendency for the bogie pivot bolt to rock for and aft when running.

regards, Graham
 

Dog Star

Western Thunderer
To make ride height adjustment a little easier, a couple of notches indicate midpoint, helping set the ride height...

Now that is a nice touch and one which I hope other kit designers will plagarise.

Thank you for that idea.
 

Dog Star

Western Thunderer
Just checked with your photos under the heading Bogies in Wonderland... the bolster of the Commonwealth bogie is very, very, similar to the Gresley bogie bolster. The photo of the CW parts shows the ring, on top of the bolster, which is the only contact point between bolster and floor moulding. What a pity that NQLTRT has not produced a representation of a prototype bogie pivot casting (bolted to the underneath of the transoms of the underframe).

regards, Graham
 

28ten

Guv'nor
Slightly frustrating day today looking after sickly kids :( anyway thinking time is never bad and I thought to hedge my bets I would etch two lots of horn guides with different wire spacing. There will also be a second set of 'sidepods' and ends to fit easybuild MK1 sides should anybody wish to attempt fitting them.
guides.JPG
 

28ten

Guv'nor
Just checked with your photos under the heading Bogies in Wonderland... the bolster of the Commonwealth bogie is very, very, similar to the Gresley bogie bolster. The photo of the CW parts shows the ring, on top of the bolster, which is the only contact point between bolster and floor moulding. What a pity that NQLTRT has not produced a representation of a prototype bogie pivot casting (bolted to the underneath of the transoms of the underframe).

regards, Graham
The bolster fitting to the resin floor, obviously once you start looking at sprung bogies the thought of reducing rock n roll needed for rigid bogies comes to mind. iirc easybuild supply an aluminum space which the bolster acts upon, but there isnt much contact area.
 

28ten

Guv'nor
I wasnt in the mood for bolsters :)) so I thought I would try and get to first base with the Wessie cabs, there is quite a bit still to do, like getting the drivers hands on the controls:) and it all needs blending, but its going in the right direction.

IMG_0767.jpg
 

28ten

Guv'nor
Its been a rubbish week for getting anything done, but i managed to solder the brake rods to one bogie :rolleyes: I know Dan is horrified by this but I use a milled brass strip soldered across all the brake gear. Two reasons for this - the rod is gives a nice straight line, and secondly it is much stronger. Once the bolster is on and its painted nobody has ever noticed;)
Its always a big challenge to make a model sufficiently robust for regular handling, and the bogie is one of the places that does tend to suffer and broken/missing/crooked bits look terrible. if im feeling really belt and braces I attach a cross piece between the outer brake hangers, its invisible once the bogie is in place, but it adds a lot of strength.



IMG_0784.jpg

IMG_0785.jpg
 

Phill Dyson

Western Thunderer
I know Dan is horrified by this but I use a milled brass strip soldered across all the brake gear. Two reasons for this - the rod is gives a nice straight line, and secondly it is much stronger.

While I admire the superfine detail of some modelers :bowdown: I also very much like usable working models with the inevitable compromises that they need to work well IMO :):thumbs::thumbs::thumbs:
 

28ten

Guv'nor
While I admire the superfine detail of some modelers :bowdown: I also very much like usable working models with the inevitable compromises that they need to work well IMO :):thumbs::thumbs::thumbs:
Having built several, i can safely say the thin etch does not stand up to a lot of abuse, and its even harder to get them all to line up.
As i said its been a crap week and i have noticed something else that needs doing ( sorry about the shaky phone shot)
all the seats have moulding marks and i need to find a way to fill them that wont require sanding every damn seat, as there is over 100 seats to do...... it might be xmas 2015 finishing them at this rate
IMG_0786.jpg
 

mickoo

Western Thunderer
Stick a piece of 5thou plasticard, the same width of the seat between the armrests, over the holes and blend with the seat where it folds into the headrest? Tedious but not as much as filling and sanding
 

Dog Star

Western Thunderer
Stick a piece of 5thou plasticard, the same width of the seat between the armrests, over the holes and blend with the seat where it folds into the headrest?
There is a tendency for thin plastikard sheet - and that means five and ten thou - to "sink" into hollows over time. So if going this route then smear Milliput into the depression before fixing the plastic sheet.
 

Phill Dyson

Western Thunderer
First I make sure you can see them through the glazed windows of the trial assembled coach (Preferably with fully painted interior as this will help darken the interior). If they do show I would be tempted to glue paper over the effected cushions with PVA & paint once dry :)
 

Alan

Western Thunderer
I agree with Phill, check that it will be seen when in the coach. Also I don't know if you are going to put passengers into your coaches, if you are that will take the need away from doing some of them.
 

28ten

Guv'nor
I agree with Phill, check that it will be seen when in the coach. Also I don't know if you are going to put passengers into your coaches, if you are that will take the need away from doing some of them.
Passengers? no way am i painting that many :))

I think i shall try some of this http://www.creativemodels.co.uk/perfect_plastic_putty-p-28808.html its water soluble so I should be able to smooth it easily.
Paper soaked in pva is a good idea Phill :thumbs:
 

djparkins

Western Thunderer
Its a fairly common problem that you also get in some etched kits unless the designer has used an inner skin for the partition

Ah Well Cynric - not all designers are the same! Can I ask why the seat cushioning seems to slope downwards towards the front of the seat? - it would be quite dodgy travelling on those, especially with your back to the loco! The central arm/headrests seem to be the wrong shape for Mk.1 stock of that era.

Regards,

DJP
 
Top