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by Russ Elliott
Tue Nov 29, 2016 8:01 pm
Forum: Steam Locomotives
Topic: recommended sideplay on loco wheels
Replies: 43
Views: 10207

Re: recommended sideplay on loco wheels

I assume by the 0.4mm "natural sideplay" at this radius you mean the P4 slop plus the track gauge widening? Yes. My "about" attempts to convey that we're only looking for approximate values, to get a feel of what might be needed in a chassis. (In that respect, I'm actually sympa...
by Russ Elliott
Mon Nov 28, 2016 10:28 pm
Forum: Steam Locomotives
Topic: recommended sideplay on loco wheels
Replies: 43
Views: 10207

Re: recommended sideplay on loco wheels

[2-10-0 Austerity] So what is it on the 5th? - I imagine it will have the same sideplay requirement as the others as the gap is the same. Yes. [72xx] But how to work out the 4th axle sideplay? It's about the same as that on the 2nd axle, i.e. about 0.4mm. Don't forget the natural sideplay of wheels...
by Russ Elliott
Sun Nov 27, 2016 10:25 pm
Forum: Steam Locomotives
Topic: recommended sideplay on loco wheels
Replies: 43
Views: 10207

Re: recommended sideplay on loco wheels

Julian Roberts wrote:So the second and fourth drivers will each come half way between the points c and v. So that will be the sideplay we need, but what is it? Is it half v? I doubt it, as between c and v it is, as it were, a curve sided triangle.

At an intermediate point:

versine-aleatory.gif
versine-aleatory.gif (1.64 KiB) Viewed 4300 times
by Russ Elliott
Fri Nov 25, 2016 8:15 pm
Forum: Steam Locomotives
Topic: recommended sideplay on loco wheels
Replies: 43
Views: 10207

Re: recommended sideplay on loco wheels

SIdeplay is only critical if you haven't got enough. Ah, there's the rub. No one is criticising an empirical washers method, Philip. The sums are there in case anyone wants to know what might be entailed in the difference between "a little bit" and "a little bit more". Some kits...
by Russ Elliott
Thu Nov 24, 2016 2:25 am
Forum: Steam Locomotives
Topic: recommended sideplay on loco wheels
Replies: 43
Views: 10207

Re: recommended sideplay on loco wheels

Just for once I would beg to differ Russ. Given the angle of the flange face (see your diagram), the flange doesn't enter into this until a significantly sharp curve is met. Yes, accepted, Will, and I was being over-safe, because in many cases (although not in this one), people who ask the 'sidepla...
by Russ Elliott
Tue Nov 22, 2016 6:22 pm
Forum: David B
Topic: On the Cushions
Replies: 12
Views: 4351

Re: On the Cushions

Back to the 'quick tack but don't melt the bluetack', David?
by Russ Elliott
Tue Nov 22, 2016 6:18 pm
Forum: Steam Locomotives
Topic: recommended sideplay on loco wheels
Replies: 43
Views: 10207

Re: recommended sideplay on loco wheels

jon price wrote:I have two but I just measured them and one appears to be 17.8mm which is no good.

17.8 is fine, Jon. Use it for the outer axles, and use the 17.7 one on the middle axle.

Double-plus good...
by Russ Elliott
Tue Nov 22, 2016 6:14 pm
Forum: Steam Locomotives
Topic: recommended sideplay on loco wheels
Replies: 43
Views: 10207

Re: recommended sideplay on loco wheels

Winander wrote:The chord is the wheelbase, or is a little added to account for the wheel flanges?

It's sensible to add a little to account for the wheel flanges.

flange-on-rail.png
flange-on-rail.png (7.82 KiB) Viewed 5651 times

(snaffled from the redrawn Malcolm Cross original)
by Russ Elliott
Tue Nov 22, 2016 12:26 pm
Forum: Steam Locomotives
Topic: recommended sideplay on loco wheels
Replies: 43
Views: 10207

Re: recommended sideplay on loco wheels

versine.gif
versine.gif (1.63 KiB) Viewed 5734 times
by Russ Elliott
Sun Nov 20, 2016 6:37 pm
Forum: David B
Topic: On the Cushions
Replies: 12
Views: 4351

Re: On the Cushions

Little bits of bluetack on the front, in the middle of the sides. Tack solder on the back, top and bottom. Check the front view. Remove bluetack. Can then seam up on the back if you want, but really, there's not much point because there's no need for a strong joint.
by Russ Elliott
Sat Nov 19, 2016 2:32 pm
Forum: Starting in P4
Topic: Making a Start - The Peak District Midland / Monsal Dale pre 1903
Replies: 1215
Views: 207381

Re: Making a Start - The Peak District Midland pre 1905

Le Corbusier wrote:Why P4? Well firstly because I have no layout, no stock and no loyalties, so why not

A useful theme for Society PR, methinks.
by Russ Elliott
Fri Nov 18, 2016 11:35 am
Forum: Tools and Techniques
Topic: Correct wire for CSB and chassis springs
Replies: 24
Views: 5973

Re: Correct wire for CSB and chassis springs

Is it a case of finding the most suitable plot for your wheel base and then adding additional ballast locally to ensure a proportional distribution? Yes. Would this be done by eye by assessing both ride height in relation to wire thickness and horizontality in relation to distribution - or is this ...
by Russ Elliott
Thu Nov 17, 2016 1:28 pm
Forum: Tools and Techniques
Topic: Correct wire for CSB and chassis springs
Replies: 24
Views: 5973

Re: Correct wire for CSB and chassis springs

0.010", 0.011", 0.012" and 0.013" diameters are the most common CSB usages in 4mm scale. (Guitar string retailers call these '10 gauge', '11 gauge', '12 gauge' etc.)

Cantilever (non-CSB) springs will usually need to be considerably thicker.
by Russ Elliott
Wed Nov 16, 2016 8:48 pm
Forum: Track and Turnouts
Topic: Point blades opening amount
Replies: 27
Views: 7417

Re: Point blades opening amount

Tony - your gap looks about right to me, as well. I'm surprised you should think there could be an interference between wheel back and blade back, though. Even if entering the switch from a curve, i.e. with wheelsets not perpendicular to the track axis, there should still be adequate clearance even ...
by Russ Elliott
Thu Nov 03, 2016 3:26 pm
Forum: Track and Turnouts
Topic: Point blades opening amount
Replies: 27
Views: 7417

Re: Point blades opening amount

Is the "residual switch opening" the distance between the movable blade somewhere between the end of planing and the beginning of the first 'fixed' (i.e. non-switchblade) chair?
by Russ Elliott
Thu Nov 03, 2016 3:07 pm
Forum: Steam Locomotives
Topic: Is the CSB Doctor in?
Replies: 10
Views: 3198

Re: Is the CSB Doctor in?

Jon - give yourself some decent room:

Try a = 12mm, b = 11mm, c = 13mm and d = 9mm, with 0.23mm (0.009") wire.
by Russ Elliott
Wed Nov 02, 2016 10:03 pm
Forum: Layouts and Operations
Topic: Drybrook Road in the beautiful Forest of Dean
Replies: 6
Views: 3249

Re: Drybrook Road in the beautiful Forest of Dean

One of my favourite stations.

A large signal box amid 5000 trees.

drybrook-road.png
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by Russ Elliott
Tue Oct 25, 2016 10:23 pm
Forum: Railway Buildings
Topic: Meldon Viaduct
Replies: 21
Views: 4997

Re: Meldon Viaduct

I reckon doing Meldon in etches would be many hundreds of pounds.
by Russ Elliott
Sun Oct 23, 2016 8:38 pm
Forum: Layouts and Operations
Topic: Finally Made A Start in P4!
Replies: 215
Views: 55306

Re: Finally Made A Start in P4!

Knuckles wrote:All the pics on this page have some of the best and most convincing scenic modelling I have seen in a long time.

Yes indeed. A real bit of landscape that 'happens' to have a railway line going through it.
by Russ Elliott
Sun Oct 23, 2016 8:21 pm
Forum: Track and Turnouts
Topic: Greyboard for trackbase?
Replies: 4
Views: 1659

Re: Greyboard for trackbase?

If you do shellac (and I can't see a great need for it), do it on both sides, otherwise the card will bend like crazy,
by Russ Elliott
Mon Sep 26, 2016 7:30 pm
Forum: Will L
Topic: Track Gauge Widening, All You’ll Ever Need to Know
Replies: 77
Views: 22630

Re: Track Gauge Widening, All You’ll Ever Need to Know

Russ, is your 500 Kg the weight of one wheel or that of both wheels and the axle? It should be the latter at least, I think. Also, is no component of the weight of the remainder of the vehicle involved? Noel, I took 500kg as a guesstimated weight of a single 'solid' wheel (like a 3-hole disc), beca...
by Russ Elliott
Mon Sep 26, 2016 4:58 pm
Forum: Will L
Topic: Track Gauge Widening, All You’ll Ever Need to Know
Replies: 77
Views: 22630

Re: Track Gauge Widening, All You’ll Ever Need to Know

How are you calculating the sideways force on the flange? I promised earlier to dig out some sums, so here we go. Imagine a typical prototype 3' wheel (weight 500kg, say) striking an 'immovable object' like a check or a wing knuckle at a sedate 15mph. If the the impact takes place over a duration o...
by Russ Elliott
Mon Sep 26, 2016 4:11 pm
Forum: Exhibitions
Topic: Scaleforum 2016
Replies: 115
Views: 29304

Re: Scaleforum 2016

Tony Wilkins gave me some video of the tippler to upload on the CLAG site in due course.
by Russ Elliott
Mon Sep 26, 2016 4:07 pm
Forum: Track and Turnouts
Topic: Building a Double Slip
Replies: 53
Views: 15089

Re: Building a Double Slip

Nice.
Enigma wrote:Now all I've got to do is lay it, wire it and fit tie bars.

Suggest fit the tie bars and the dropper wires first, while you can get at the undersides.

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