William's Workbench - LBSCR, LC&DR & SER in 4mm, and Gauge 1

[Siberian Snooper]

This is how Martin Finney deals with outside frames.

 

The cosmetic axlebox is a good sliding fit in the hornguides, the axlebox is one piece and half etched at the edges to form the sliding fit, it's folded in half and the resulting slots fettled to give the sliding fit. the centre hole is opened up, to a loose fit on the axle, the fly crank hides the small resulting gap.

 

 

Now ready to quarter the leading fly crank on the other side and test. Then the outside frames can be fitted. Avoid getting Locktite in any of the bearings. Guess who?

 

HTH.

 

[Regularity]

6 hours ago, Lacathedrale said:

I'm still not sure how cosmetic axleboxes will work on the outside frames - with this method I'll have a nice square slot in the outside frames with a round axle going through the middle of the void? If I have something tight fitting/etc

MRJ 46.

Guy Williams fitted a square piece of metal in place to show the front of the axlebox. It was soldered to the outside cosmetic frames, and had an oversize hole in it for the axle (you don’t need much movement for compensation to work, unless your track is awful, in which case fix the track) which was invisible behind the outside crank. Old kits used to have a slot in the outside “axlebox” with the outside frames being attached to the body.

Not what I would do as I prefer to be able to drop all wheel sets out of the frames, so as not to disturb the quartering, but every way of doing this has positives as well as negatives - cross posting: I would do it as per Martin Finney, possibly with those as the working axle boxes and the inside frames being cosmetic (because lining up 4 axleboxes on a single axle would be a pain in the butt, although typically only the driven, crank axle had internal axleboxes, the others being outside only).

Edited June 14, 2022 by Regularity

[Lacathedrale]

Thanks matey, I've got that MRJ so will refer to it in due course.

 

Finally started the loco chassis - it's going well so far!

 

 

I should probably make myself a B2B gauge, shouldn't I?!

[Regularity]

3 hours ago, Lacathedrale said:

Finally started the loco chassis - it's going well so far!

That was quick!

[Lacathedrale]

Well, I had been reading the instructions before bed every night :) I think I'm going to need some extended axles to set up the axleboxes and hornblocks properly, so to set myself up for success i've sent over an order to Poppy's Woodtech for their jig that comes with the axles.

 

Speaking of ordering things I've caved in re: the transfers for the GWR wagon, so it will get some of Fox's finest in due course. I am going to continue working on my hand lettering, but since I also needed transfers for coaches I figured it was silly not to just add it to the order.

 

Still not sure what to do about the LNWR horsebox - the turned bearings needed to be removed in order to swap the wheels out and re-gauge to EM-SF, but they were a washout anyway with so much rolling resistance the wagon would slide down an incline with locked wheels rather than turn them. I think it was due to contamination of the bearing surfaces and/or the fit being slightly too close.

 

With the undercarriage 'complete' everything is a right pig to access, I can't even properly clean the inside faces of the arms that the bearings would need to glue against because it's all half-etched joins and inside corners. For now I've used the original slotted approach and may just use a dab of glue to fix a bar across the top of the slot. Hopefully with the length of train I'm looking at for my layouts the rolling resistance will not be acute - I am definitely going to be avoiding inside bearings going forward though!

[Lacathedrale]

Pains me to say it, but the transfers I think do make this one look a bit nicer:

 

 

It's had quite a few coats of paint and varnish at this point but now it's definitely in the 'good enough' bracket!

 

My afford to represent grease axleboxes are dubious, I sliced off the front latch and side lugs and then added a 45 degree chamfer to the top.

 

The original wagon used the Ratio coupling hook which I didn't drill out, so I snipped that off and slotted the headstock for a Smiths coupling hook and links. Unfortunately the entire underside of the wagon is packed with liquid lead, so sprung couplings were not possible - it's just glued in there.

 

For posterity's sake, I initially coated this in a mixture of Heavy Sienna, Heavy Umber and Pale Sand - but it came out very dark and required too much pale sand added (which then turned it a salmon colour). The colour I eventually settled on was Vallejo 'Red' and Vallejo 'Red Leather', lightened slightly with some pale sand. This is roughly analogous to @Mikkel's recipe, albeit using brighter starting colours and needing less lightening.

 

I would like to use the hybrid livery as shown by Mikkel in his fabulous 'Same but different' blog entry too, but I think this is after my 1899 cutoff. Maybe it'll sneak in for variety's sake at a later date.

Edited June 18, 2022 by Lacathedrale

[Lacathedrale]

Everyone said that the HL kit instructions must be followed to the letter, so when it said "for a compensated chassis, open up the horn slots to the half etched lines" I did so. Except on the first page it also said 'this kit can be sprung on two of the three axles'. I didn't join the dots, and well...

 

 

I'm not sure if this is recoverable as although the horns guides can shift fore and aft to ensure squareness, and the horns themselves in the vertical axis - these plain bearing holes cannot, and now I have no datum to work from at all, so I think this is scrap?

 

Honestly, I'm not even mad, this is 100% my fault - but it does raise the question of what to do? Try to salvage it somehow (how?), use the parts for a similar locomotive build (LCDR T-class: same wheels, smaller wheelbase, inside frames), or just get on with the 2-4-0T build mentioned previously (which will require the purchase of more wheels, extended axles and cranks, etc. etc.)

[Paul Cram]

The MJT horn block allow for one fixed axle. Even if you don't use the sliding one it will be cheaper than a new chassis.

[Lacathedrale]

44 minutes ago, Paul Cram said:

The MJT horn block allow for one fixed axle. Even if you don't use the sliding one it will be cheaper than a new chassis.

 

So, buy another pair of hornblocks and guides and get all three axles sprung? I don't see how I can have a fixed point for the driven axle with any level of accuracy at the moment...

[Regularity]

As I have said, you don’t have to have a fixed axle, and there are some advantages, too, such as being able to drop the axle boxes, wheels, axles and gearbox as single units without disturbing the quartering: useful for maintenance and painting, and also smoother running as the body does not move in accordance with the fixed axle. It can be slightly more fiddly to get the first axle square, but a simple jig made from a block of wood with axle-diameter holes drilled at precisely the correct centres, with axle material inserted, can help here if you don’t wish to buy one of these chassis assembly jigs.

Hate to say it, but I did recommend this path.

Having a fixed axle is useful as a reference for setting the other other axles using the coupling rods as a jig, but only - and only if - the fixed axle is dead square to the longitudinal axis of the frames. 
Mike Sharman recommended fixed axles in his book on flexichas, but did demonstrate how to have a moving axle as well, and as he said, the book was subtitled as a way to build chassis, not the way. Iain Rice popularised the fixed axle, along with (I believe) Rod Nero’s original Perseverance Kits.

[Lacathedrale]

Thank you matey, happy to give that a bash: I've ordered another set of hornblocks and horn guides. I also have ordered a poppy's woodtech jig so that should be arriving soon.

 

Could you please advise how I'd go about setting the location and orientation what would have been the fixed axle?

The kit comes with beam compensation, axial across the front two axles. Presumably, this will need to be amended? I don't know with the motor whether a transverse pivot like our discussion of the 2-4-0T would work, is there an easy alternative?

Edited June 19, 2022 by Lacathedrale

[Regularity]

The pivot for the leading axle can be as simple as a piece of rod fixed to a spacer, but if the axle is running in bearings, it will make sense to have a beam above the axle, parallel to it, transferring the weight to the bearings. You just need twin beams for the other two axles: you should find that you have more than enough material on the edge of the fret. Use the sketch I sent to give you a rough idea of the shape. You will need to drill and tap holes for the screws, then it’s a simple case of screw, washer(s), beam, washer, nut.

[Regularity]

3 hours ago, Lacathedrale said:

The kit comes with beam compensation

BTW, what source is the kit?

[Lacathedrale]

It's a High Level Jinty replacement Chassis - given my 3D shell is designed for a Jinty chassis, I'm hoping it'll be broadly compatilbe with the jinty replacement chassis! The kit comes with beam compensation on the leading/middle and a fixed rear(gearbox) axle.

 

There are springs fixed underneath the horn guide cutouts so I don't think I can 'drop the axles' very easily, though.

 

If I understand you correctly, We are instead going to pivot the front axle so it can roll by itself, and move the beam to the rear two axles pivoted so it can pitch:

 

Seems reasonable to me.

 

The other question is around where to fix them fore and aft - with the original bearing, that's the datum for locating the other two axles in their hornblocks and guides -but with all three moving, I can get them fixed relative to each other, but not sure how to get them in the 'right' place relative to other features on the chassis itself?

Edited June 19, 2022 by Lacathedrale

[Regularity]

27 minutes ago, Lacathedrale said:

 

If I understand you correctly, We are instead going to pivot the front axle so it can roll by itself, and move the beam to the rear two axles pivoted so it can pitch:

Yes.

 

Quote

There are springs fixed underneath the horn guide cutouts so I don't think I can 'drop the axles' very easily, though.

I use the underhung springs as axle-keeps, if the loco has underhung sprints. I cut them, and the hangers, separately from the frames, using thicker material (although I am not 100% sure it is noticeable) and with hole at the top of the hanger, which is a push fit onto a pint fixed into the chassis. It’s only a bit of extra work, but needs to be thought through and planned from the beginning.

 

The position of the side pivots above the horizontal is calculated as half the depth of the axle box, plus or minus the height from the horizontal line connecting the ends of the Dean compared to the pivot point, depending on whether the pivot is above or below that point.

I will run up a sketch.

[Regularity]

It’s mostly common sense, and drawing it out like this puts some people off and leads to unnecessary denigration of compensation as being too complicated.

Personally, I prefer to do this when marking out the frames. If using a kit, I would tack the frames together to make sure that necessary cut outs (for hornblock guides) and holes for pivots were in the right place.

Hope this helps:

 

 

[t-b-g]

It has always seemed a bit odd to me to go for a suspension type mechanism and still have a fixed axle.

 

One of the benefits of suspension is that if any rail joints are not perfect, then the loco rocks as it goes over them if an axle is fixed. Over the years, I have managed to learn to lay flat track and I usually build my locos rigid but I have built a few sprung and/or compensated just to prove to myself that I can and also because they sometimes run on layouts which are not mine and where I didn't lay the track. The smoothest have been the ones with no fixed axle.

 

On a three axle mechanism, whether they are all driving wheels or some are carrying wheels, the twin beam plus a fixed centre pivot on the third axle would be my choice too. Something like a "Poppy" jig will help set up one axle square across the frames and then allow the others to be spaced from it.

 

Without a jig, a block of wood with a 1/8th inch hole drilled with a pillar drill and a steel rod inserted gives you a good base for setting up the first axle nice and square. The others can be done with the coupling roids and 1/8th steel rods with the ends turned down to fit the hole in the coupling rods.

[Regularity]

16 hours ago, t-b-g said:

It has always seemed a bit odd to me to go for a suspension type mechanism and still have a fixed axle.

In Mike Sharman’s case, he used to build some multi-stage gearings, with the various spurs etc running on axles mounted in the frames. A fixed axle was essential for this, but with modern gearboxes and cradles, and indeed with his own wonderful gearboxes he produced back in the day, there is no need.

But Mike suggested it, and Iain Rice promoted it, and therefore it became the way to do things.

Edited June 20, 2022 by Regularity
Autocorrect….

[Lacathedrale]

Hi chum,

 

Make sense to me.  Since the frames are already together, I should be able to use

 

To clarify, the difference between white and peach beam is simply the shape (in order to fit around loco fittings)?

A/E = height of top of hornblock with axles in normal position

C/B are positive/negative offsets of pivot, since the pivot location it must be at least the diameter of the pivot plus some amount of clearance from A/E.

 

[Regularity]

10 hours ago, Lacathedrale said:

To clarify, the difference between white and peach beam is simply the shape (in order to fit around loco fittings)?

A/E = height of top of hornblock with axles in normal position

C/B are positive/negative offsets of pivot, since the pivot location it must be at least the diameter of the pivot plus some amount of clearance from A/E.

Yes: I try to fit beams such that they won’t be seen, but when you have a side tank, then there is less to worry about.

The lines go through the centre of the hole in the axle box, the distances A and E are the dimension from there to the top of the axlebox. (If the axleboxes are accurately machined - with LRM’s are - then that’s half of the height.)

The diameter of the pivot is irrelevant, at least the way I do it. The twin beams are cut from the same material as the frames, and the pivot passes through them, but yes, the offset simply reflects where you might want to put the pivot.

The more accurately you mark out and cut the rubbing points on the beams (where the rest on the axleboxes) and mark out and drill the pivot hole, the less adjustment you will have to make later on. The rest of the shape doesn’t matter a lot!

[Lacathedrale]

Perfect. I checked out the Rothes drawing of the Jinty and overlaid the same type of diagram:

 

 

Taking the datum as the bottom of the frames and assuming a bit of elasticity in the drawing:

 

The centreline of the axles is at 2mm

For the front axle the pivot point bearing on the middle of the axle should be at 3.6mm.

The bearing surface of the beams should be at 4.5mm and the pivot of said beam (with a nominal 4mm width) should be at  6.5mm. The ends are radiused or undercut.

 

I should be able to use a combination of layout fluid, height gauge, scribers and my milling machine to get the various holes in place.

[Regularity]

2 hours ago, Lacathedrale said:

layout fluid

I use a permanent marker pen.

A rub with purple Scotchbrite afterwards and it isn’t so permanent after all!

[Lacathedrale]

Just to put a heartbeat on this topic - I've yet to recieve the other HL hornblock still, apparently it's en route - so not much in the way of progress I'm afraid!

[Lacathedrale]

I bought a built GWR O4(?) wagon for a song on eBay and after trimming the brake shoes, adding a pivot rod, removing the D-shape tension lock coupling, and fitting 3-links, I set about painting it in the red scheme - it's yet to recieve powders and a final super-matt varnish but overall I'm fairy pleased with the evening's work:

 

 

I've another (unbuilt) version of this kit, I may well paint it in the hybrid livery illustrated so well by @Mikkel in his 'same but different' blog entry:

 

 

Edited July 7, 2022 by Lacathedrale

[Mikkel]

Sounds as if the red wagon bug has bitten! 😃

I should probaby warn you that the Mink in the hybrid livery was just a one-off playful experiment on my behalf, based on speculation about a particular photo of a particular van. I don't think there was a hybrid livery as such, just maybe a few freaks that ended up looking like this.

 

A suggestion regarding your 4-plank 75089: In my view, you'll want as a minimum to paint the solebars red. There is also growing support on here that the entire underframe should be red. For me the jury is still out on that one but you may be better off going with the majority opinion.