The Great 3F build off

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grovenor-2685
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Re: The Great 3F build off

Postby grovenor-2685 » Mon Aug 27, 2012 8:58 pm

Please let me finish:
You had your chance :)
Keith
Regards
Keith
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David Knight
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Re: The Great 3F build off

Postby David Knight » Tue Aug 28, 2012 1:36 am

The other jig. Very simple this, all it consists of is a scrap piece of brass, end faced both ends, and drilled part way through 1/8". In use it gives a larger, more stable base for pressing axles into wheels. I have a number of these to suit different sized axles. Once the first wheel is mounted the second one is (comparatively) simple to set up. I chamfer the ends of the axles slightly and lightly countersink the inside of the axle hole just to help things centre themselves. The pictures should explain most things.
the gear.jpg
the gear.jpg (89.9 KiB) Viewed 8860 times

in use.jpg
in use.jpg (81.46 KiB) Viewed 8860 times

half done.jpg
half done.jpg (78.73 KiB) Viewed 8860 times

The vice is not a commercial product but any decent vice (oxymoron?) that has parallel jaws and closes smoothly will do. After this lot is done the second wheel will go on but not until bearings and spacer washers (if needed) are added in the correct order and the right way around :thumb

Cheers,

David

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Horsetan
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Re: The Great 3F build off

Postby Horsetan » Tue Aug 28, 2012 9:46 am

davknigh wrote:
Horsetan wrote:or a jig with a series of crankpin holes..... :mrgreen:


I fully intend to use mine for more than just the one project.....


Production version for general sale to members :?: ;) ;) ;)
That would be an ecumenical matter.

David Knight
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Re: The Great 3F build off

Postby David Knight » Tue Aug 28, 2012 1:50 pm

A flattering thought but probably not practical given the distances involved. I would cheerfully provide drawings so that those with lathes could churn out their own. I'm sure that anyone with a dividing head for their lathe (I don't have one) could work out a pattern to produce a jig with intervals properly spaced to produce what you're after Ivan but it's also a question of demand as to whether more than a one off would be a practical proposition. Any thoughts out there?

Cheers,

David

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Horsetan
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Re: The Great 3F build off

Postby Horsetan » Tue Aug 28, 2012 9:31 pm

davknigh wrote:..... Any thoughts out there?


My first thought is that I don't actually have a working lathe :shock:

I should have, but it took up residence somewhere in Essex a while back, and I haven't seen it since.....
That would be an ecumenical matter.

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grovenor-2685
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Re: The Great 3F build off

Postby grovenor-2685 » Tue Aug 28, 2012 9:41 pm

There's no need for a dividing head as the only thing that matters about the series of holes is there distance from the centre to get the various crank throws, where they are round the circumference doesn't matter as you only use one for any given wheelset.
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Keith
Regards
Keith
Grovenor Sidings

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Horsetan
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Re: The Great 3F build off

Postby Horsetan » Tue Aug 28, 2012 9:52 pm

grovenor-2685 wrote:There's no need for a dividing head as the only thing that matters about the series of holes is there distance from the centre to get the various crank throws, where they are round the circumference doesn't matter as you only use one for any given wheelset.


Holes, in a sort of spiral arm arrangement arranged off a common centre, in other words....
That would be an ecumenical matter.

David Knight
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Re: The Great 3F build off

Postby David Knight » Wed Aug 29, 2012 2:00 am

grovenor-2685 wrote:There's no need for a dividing head as the only thing that matters about the series of holes is there distance from the centre to get the various crank throws, where they are round the circumference doesn't matter as you only use one for any given wheelset.
Regards
Keith


If you are doing the job for yourself I would agree, if you are doing some sort of production run as Ivan was thinking I think the head would make things a bit easier and more accurate.

Cheers,

David

allanferguson
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Re: The Great 3F build off

Postby allanferguson » Wed Aug 29, 2012 12:27 pm

I think this is an excellent system for ensuring identical crank throws. I'm wondering whether you take the throw from the correct prototype measurement, or whether you take the throw in the available wheels. I don't see it as possible to move a pre drilled, or even a pre dimpled crankpin hole in a wheel, and particularly for those of us who model pre grouping trains the chance of finding a wheel that has the right diameter, the right number of spokes, and the correct crankpin throw may be quite small. With inside cylinders, of course, the crankpin throw in the wheels may be different from the piston stroke, but is very hard to determine from available information. I'm afraid I tend to use the nearest I can find to the correct wheel, and accept the crankpin throw as given.

Allan F

David Knight
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Re: The Great 3F build off

Postby David Knight » Wed Aug 29, 2012 2:11 pm

Allan,

I took mine from the existing wheel in an act of blind faith. As for the correct dimensions I'm sure the collective wisdom of this forum will see you straight.

I was thinking about relocating the hole from a pre drilled or dimpled wheel and to me the solution would be to drill from the back so the drill would be less likely to wander off course. Plugging the pre drilled hole would also help.

Cheers,

David

Lindsay G
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Re: The Great 3F build off

Postby Lindsay G » Thu Aug 30, 2012 9:20 am

I've just latched onto this particular thread but will be following it from now on as I too have a class 812 to build. A couple of observations on this thread and apologies for timing of the second which may be too late in the day for the Class 812 tender (and maybe too much into detail as well).

allanferguson wrote:I don't see it as possible to move a pre drilled, or even a pre dimpled crankpin hole in a wheel.....

Allan F

The area around the present hole or dimple can be drilled out and plugged/glued with plastic rod or brass of the correct diameter. The crankpin hole can then be re-drilled into that plug using a jig similar to the ones shown earlier. I may be wrong, but I think Chris Pendlenton used this method especially when inserting brass bushes for engines that would be heavily used (hope my memory isn't letting me down too badly!).

As regards the handbrake on the Class 812 tender, several of the Caley Coaches kits come with incorrect round handbrake columns. Whilst I can't be 100% certain about the McIntosh 3000 gallon tender (that normally comes with the 812 kit), I think that this was in all probability in a square rather than round housing.

If memory serves me correctly, the 828 restoration book does not have any pictures of this detail, but then again I don't know if 828 is presently linked to a McIntosh tender (there was a lot of mixing and matching around with various tenders on Jumbos and 812's). There are numerous pictures of tenders in The Caledonian Railway Jumbos book which all appear to have square brake housings and the plans of the Drummond 3120 gallon tender in the same book indicates a square profile.

Did McIntosh change this detail on his version of the tender? I don't know, but the McIntosh Caley tank engines of around the same period also had handbrakes in square housings and an image of a class 439 is attached. So everything seems to point to a square housing.

Lindsay
439 029.jpg
Part of cab area of CR419 at Bo'ness

allanferguson
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Re: The Great 3F build off

Postby allanferguson » Thu Aug 30, 2012 3:00 pm

Lindsay G wrote (inter alia) "The area around the present hole or dimple can be drilled out and plugged/glued with plastic rod or brass of the correct diameter. The crankpin hole can then be re-drilled into that plug using a jig similar to the ones shown earlier. I may be wrong, but I think Chris Pendlenton used this method especially when inserting brass bushes for engines that would be heavily used (hope my memory isn't letting me down too badly!)."

Trying to drill a hole partly in one material and partly in another is just an invitation for the drill to wander. Plus if the crankpin isn't central in the boss moulding, isn't it going to look a bit silly?

Allan F

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grovenor-2685
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Re: The Great 3F build off

Postby grovenor-2685 » Thu Aug 30, 2012 4:56 pm

Trying to drill a hole partly in one material and partly in another is just an invitation for the drill to wander
Which is, I think, why he said drill the hole out (oversize) so the new hole is entirely in the plug.
The size off boss is going to limit the extent to which you can move the hole without it looking silly as you suggest. But then even Horsetan's example of standard 2 to standard 9 is only a move of 2 scale inches, most would be less.
regards
Keith
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Keith
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DougN
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Re: The Great 3F build off

Postby DougN » Fri Aug 31, 2012 3:15 am

I think every one is slightly right. I think the article is in 175 MRJ by Chris on building the standard 4MT .... He made an adjusitble jig with 2 arms so that the hole can be drilled vertically. Something about the holes beinig blind if I recall. I am at work and can give the chapter and verse on the Building Code of Australia but not MRJ.... more the pity. :evil:
Doug
Still not doing enough modelling

David Knight
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Re: The Great 3F build off

Postby David Knight » Sat Sep 01, 2012 8:42 pm

A response to Lindsay G's posting on tender hand brake columns first. In reviewing yet again the book on Caley 828 I found a picture on p. 20 and also 22 that show the square column spoken of. Fortunately I'm not modelling 828 ;)

I've started to work on the cab while waiting for some more bits to arrive and it has presented me with another interesting, err, shall we say challenge? If I follow the kit instructions the cab interior is built of a floor, splasher box tops and sides and a boiler backhead. However, when rummaging through the kit box I came upon an etch that was not mentioned in the instructions but when folded up made into a complete cab floor/splasher box combination.
Cab floors.jpg
Cab floors.jpg (89.18 KiB) Viewed 8450 times

When put together with the cab and backhead the stock parts come together to produce the following.
Cab A.jpg
Cab A.jpg (107.61 KiB) Viewed 8450 times

The mystery etch produces, to me, a more pleasing interior except I'll have to build out the bottom of the backhead casting to full width.
Cab B.jpg
Cab B.jpg (98.71 KiB) Viewed 8450 times

The kit was originally designed to be built in 00, EM or P4 thus the stock parts reflect the need for the extra space needed for the 00 wheels. My guess is that Jim Smellie remembered that I was a P4 modeller when I ordered the kit all those years ago and tossed in the extra cab floor, so, very belatedly, Thanks Jim!

A final note; Does anyone have any suggestions as to how they would fit a fall plate 'twixt engine and tender?

Cheers,

David

John Palmer
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Re: The Great 3F build off

Postby John Palmer » Sun Sep 16, 2012 12:58 am

davknigh wrote:
A final note; Does anyone have any suggestions as to how they would fit a fall plate 'twixt engine and tender?



A method I have used successfully is shown on the attached sketch. A U-shaped length of wire is soldered to the underside of the fall plate, and the arms bent downwards at an angle of roughly 45 degrees at a point about a millimetre back from the fall plate’s leading edge. The arms are then fed through holes created in the angle formed by the back edge of the footplate. The protrusion of the fall plate ahead of the point where the wire ‘U’ is cranked downwards rests on the back edge of the footplate. Having the arms of the ‘U’ cranked allows the fall plate to swing without constraint and thus accommodate vertical displacement of the tender relative to the engine.

If you’re using a split axle collection arrangement, make sure the wire arms can’t create a short across both frames!
Attachments
Fall plate.jpg
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Will L
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Re: The Great 3F build off

Postby Will L » Sun Sep 16, 2012 10:49 am

The problem with fall plates, I find, is that they do. So if you watch Knutsford carefully,towards the end of the show you will find the odd engine or two running with a fallen fall plate hanging vertically between engine and tender. How the footplate crew mange I don't know.

It happens when the loco is handled in the fiddle yard. We do our bet to avoid such handling but, Knutsford having a fiddleyard at both ends, what with the occasional operator error and a wish to ring the changes, we still keep on finding occasions when it handling becomes necessary. The next tender loco I finish, (note how carefully I worded that), is going to be designed so the fall plate can't fall much below vertical. Then, if it jams between loco and tender, it will at last prevent the fiddle yard operator from running it like that.

Will

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grovenor-2685
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Re: The Great 3F build off

Postby grovenor-2685 » Sun Sep 16, 2012 11:35 am

Design it so it can't fall below about 45 degrees so its impossible to couple engins and tender without lifting the fall plate into place.
Or, perhaps, the fall plate could double as the coupling?
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Keith
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Keith
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Trevor Grout
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Re: The Great 3F build off

Postby Trevor Grout » Sun Sep 16, 2012 10:56 pm

Horsetan wrote:
davknigh wrote:..... Any thoughts out there?


My first thought is that I don't actually have a working lathe :shock:

I should have, but it took up residence somewhere in Essex a while back, and I haven't seen it since.....



Yes :thumb , its sitting on the bench in the shed, exactly where it was when you last visited actually, :shock:

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Horsetan
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Re: The Great 3F build off

Postby Horsetan » Sun Sep 16, 2012 11:03 pm

Should we not, er, warm it up, like?
That would be an ecumenical matter.

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MarkS
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Re: The Great 3F build off

Postby MarkS » Mon Sep 24, 2012 1:58 am

Two steps forward one step back - Some progress here at Chateau Beaufield with #73.
The footplate assembly is coming together, the cab is now attached, toolbox/seats cut down to P4 width and soldered in.
The firebox backhead will need a bit of work, starting with narrowing at the bottom...

The cab with unlikely backhead -
73 cab_firebox back.jpg

The tender is close to being ready for primer, with just a couple of minor bits to attach. - that is a Tablet catcher on the side.
73 Tender.jpg


And finally, any suggestions on how to make the chimney fit the smokebox? Mr Rice suggests using a hammer, the result was one bent chimney... fortunately I have a second.
72 chimney.jpg
Cheers,

Mark.
"In the end, when all is said and done, more will have been said than done..."

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Will L
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Re: The Great 3F build off

Postby Will L » Mon Sep 24, 2012 9:30 am

Oh that's not nice. Did it come with the Kit? Think you need to talk to somebody who knows how to turn one properly. I'm not sure there is enough meat left in the flair at the base do anything with. One wonders if Mr Rice's words about a hammer may have had an edge you didn't appreciate.

Will

John Palmer
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Re: The Great 3F build off

Postby John Palmer » Mon Sep 24, 2012 11:16 am

Here’s a vicious enlargement of the smokebox on my own Maygib Bulldog, showing that it is possible to get reasonable results by bashing the flared chimney base over a former. The picture shows such a former, though I think not the one used for this particular locomotive. Note the spigot let into the former; if this can be made to a close sliding fit within the bore it should prevent any buckling of the chimney when it is hit. The flare at the base needs to be annealed to assist forming it to the shape of the smokebox

Chimney flaring.JPG


Speaking from memory (since this engine is the best part of 30 years old), one fairly critical factor in the chimney’s manufacture was the thickness of the flared portion, since over-enthusiastic bashing of the chimney onto the former could lead to the flare splitting at its point of sharpest deformation along the top centreline of the smokebox. The other problem with this method was that lowest edges of the flare sometimes had a tendency to remain proud of the smokebox. In best bodging tradition I overcame this by peening the lower ‘skirts’ of the flare down onto the former using a hammer and wooden drift. This becomes a practical proposition once the chimney can be accurately held in position by the spigot

This particular chimney was my own turning, as I wasn’t entirely satisfied with the supplied Maygib version for a BR-period engine, but the shape before forming was substantially the same as that shown by the lowest of Mark’s photographs, so the method described is capable of application to the kit-supplied article. For this work I had the big advantage of a lathe with vertical mill/drill attachment, but I assume it should not be too hard to locate suitable size bars for both the former and the spigot. The only problem then is accurate perpendicular drilling of the former to receive the spigot.

The tender bulkhead is looking good. I see there is no grab iron mounted transversely on its top. I have applied such a grab iron to both of my Bulldog tenders, but I am struggling to find positive confirmation of its presence. About the best indication of its presence in BR days that I have seen is the shot of 43216 at Highbridge shown as the 8th photo in the Newman family history site to which I posted a link on the first page of this thread. I’m now also wondering when the S&D Bulldogs received their mechanical lubricators, as I have a shot taken in 1920 of number 66 without one. If I am right in thinking this was a feature peculiar to the S&D engines I would guess it was the product of a decision taken in Joint Committee days.

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MarkS
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Re: The Great 3F build off

Postby MarkS » Mon Sep 24, 2012 4:48 pm

Will - yup it came with the kit, which is 30+ years old. Annealing it and some careful work as suggested by John Palmer could save it, I'll report back.

John - Thanks for the excellent suggestions, I will give it a try on the test chimney first...
As for the tender bulkhead, I have not seen evidence of a grab on the top, but I am looking at photos from the 1920's or earlier (Example - p36 - Picture History of the S&D - Robin Atthill).
Back on page 2 of this thread, Steve "Essdee" says the following -
S&D smokebox door numbers seemed to come a while after the lubricators were fitted, perhaps as late as 1928.

I assume there would a door(s) on the front of the bulkhead for toolboxes, but, in the middle, full width, one on each side???
Cheers,

Mark.
"In the end, when all is said and done, more will have been said than done..."

essdee
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Re: The Great 3F build off

Postby essdee » Mon Sep 24, 2012 7:23 pm

Mark,

Hi again; good to see No. 73 coming along steadily - my own 72 is still in round-top form (the last one to be rebuilt to Belpaire form, in 1925).

You have done a very neat job on those tender stanchions, and the fabricated toolbox is looking just the businesss; very characteristic of the S&D Bulldogs until their tenders were replaced piecemeal! There were three doors on the toolbox. I would guess for - tools, driver's and fireman's snap possibly? I enclose pic of my version on No. 63. (Never model another person's model, by the way.....!) I think Wild Swan monographs of either the 3F or the 2P will give actual drawings?

I used the same wheeze as John Palmer to form the chimney flare, using a 1/8th brass rod progressively to ease it to shape without scratching or deforming the thin brass too much. IT can be done.

Sorry I cannot narrow the lubricator appearance on the S&D 3Fs, between 1925 and 1928 I have a feeling.

Look forward to further reports; keep up the good work!

BW

Steve
Attachments
SDJR 63.17 - Copy.JPG
SDJR 63.26.JPG


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