Atlantic's works: Portable layout update - test run troubles

[Mersey508138]

Seems like my idea of using markits wheels is not a good idea if I am understanding what I have read correctly but just to add some further information onto my idea, the thought was to also use the original shouldered screws that hold the connecting rods in place but the hiccup woukd have been working out slthe size of the stepped hornby crank pin.

[Atlantic 3279]

Well if the Hornby shouldered screws fit the holes in the Markits wheels, you're half-way there - IF that is, the shouldered screws themselves fully accommodate the thickness of the rods. If half of the rod thickness is accommodated by a shoulder/step on the pin/boss of the Hornby wheel, you'd need to find a way to emulate that provision.

And welcome everybody to page 400...

[Mersey508138]

Many thanks for that Graeme, your advice and that of all the members and staff ( mods ) is always appreciated and welcome

[Mercator II]

Congrats on 400 pages

Soo much useful and inspiring modelling, thank you for sharing

[Atlantic 3279]

Dismal weather last weekend making outdoor work or leisure unappealing, I moved some furniture and borrowed our lounge again for few days so that I could set up and test the whole of the track and electrical system of my new portable layout, all together, for the first time.

To my great relief, all round board-to-board connection of the electrics did not reveal any problems, but some annoying snags arose with the running of a deliberately large selection of stock through the Peco code 100 points that I've used for the continuously curved approaches to the fiddle yard. I had previously tested the points one or two at a time, and found that locos and rolling stock with fine RP25-esque wheel flanges, and BTB dimensions set to suit my finer code 75 track in the scenic parts of the layout, would cope with the points perfectly well providing that I closed-up the check rail gaps by adding 0.010" plastic strips to the faces of the check rails, so I had prepared/modified all of the facing code 100 points accordingly. I was now finding however that with 5 facing points in uninterrupted succession on a continuous 3 foot radius equivalent curve, things didn't work so well with some stock! In the case of one loco with fine bogie wheels for instance, despite carrying weight on that leading bogie, when directed to an inner curved road, the wheels were beginning to climb the curved "outside" switch/closure rail before even reaching the start of Peco's remarkably short check rails, with consequent derailment at the crossing gap. That led to me having to devise a method to allow me to extend the "leading" ends of the curved check rails in several points so as to start two or three timbers closer to the toe. That took care of the trouble with leading bogies. The gremlins did not surrender at that stage, of course. I found trouble with at least one tender with fine wheels, set up so that only the rear axle bore weight and both the leading and middle axles simply floated as the nose of the tender rode on the loco rear drawbar. There was no fault with the tender, but at one particular crossing gap a rear wheel repeatedly plunged into the void, tilting the tender and leading to derailment. Whilst I knew from past events that it was possible with care to also successfully narrow the crossing gaps by soldering additional nickel silver strip to the wing rail extensions, I did not consider that an easy thing to do. Fortunately, an alternative plan that I tried, more in hope than in any belief that it would work, did in fact solve the problem. I extended the tail-end of the curved check rail on that point all the way to tip of the blade of the next point around the curve...

[Atlantic 3279]

The slings and arrows hadn't finished with me at that stage either.
I had noted a couple of weeks previously, derailment of my modified Heljan 02 on a curve of my loft layout. Busy with other things at the time, I had not investigated, but that evidence, added to the fact that the O2 had in the past repeatedly derailed on a combined curve and slight crest on the "Grantham" layout, simply made me place more blame on the fine flanges - perhaps unfairly as it turns out.
Notwithstanding my additional check rails on the new layout, the leading coupled wheels of the very naughty O2 kept wanting to climb over the outside rail of the fiddle yard approach curves wherever there was the slightest discontinuity in the smooth rail head. I expressed my sentiments, then investigated the loco. I noticed that when placed on a flat surface, there was almost no clearance between the tops of the pony wheel flanges and the solid cast underside of the main chassis block in that area, and that such little clearance as there was disappeared completely if I applied only a little extra downforce to the front of the loco. I wondered whether, on non-ideal track, the pony wheels were actually contacting and lifting the front of the main block, so that the leading coupled wheels were robbed of any tracking forces. On taking off the pony truck and running the loco, nothing was improved, so that theory was wrong. What I did then also notice, was that I felt there was just the very slightest freedom for the 8-coupled portion of the chassis alone to see-saw, because the leading coupled wheels sat just a shade higher than the other six. If I could measure the discrepancy at all by sliding thin material under the leading wheels I thought it was no more than about 0.005", but given that, if anything, the middle coupled wheelsets in a rigid chassis ought to be the ones that sit slightly high, I wondered if I had found the root cause of the trouble, so I had a look at the possibility of doing something about it.

With the loco inverted in a makeshift padded cradle, I first removed the three screws that in turn allow the lower cosmetic cover plate to be removed from the chassis, taking with it the brake gear.

Release of the two further screws that were now revealed allowed the functional keeper plate, with its pick-up strips a delicate wiring, to be folded back to reveal the axles in their round-bottomed channels in the chassis block.

Without stripping down the outside motion too, there was fortunately just enough free movement available to allow the leading axle to be lifted out of its channel and nudged slightly to the rear.
I was hoping to test the effect of inserting and simply trapping a curved shim in the channel for the front axle, to push the axle down by say 0.010", and then to re-assemble and test the loco before doing anything to make the modification "permanent". I failed in my attempts to curve a small piece of thin brass shim to the required shape, so I then tried working from a brass tube starting point.

Even after the projecting portion began to bend, I was able to further taper the edges after sliding another piece of 2mm OD tube inside to provide support. I could then cut off the projection, producing a something like a quarter-cylinder packing piece that would lie neatly in the bottom of the slot for the leading axle. The axle appeared to fill the width of the slot fully enough to prevent the packing piece from turning with the axle.
Reassembled and re-tested, the loco was completely free of its former derailing habits, and at low speeds ran very smoothly. Signs of a problem did appear though when I wound the loco up to high speed and let it run several circuits. It began to audibly and rhythmically pound the track, making me suspect the development of a tight spot in the rotation of the coupled wheels. When I again took off the lower plates and lifted out the leading axle I could see that the packing piece had been dragged round away from the deepest part of the slot. I have therefore thoroughly de-greased and abraded both the outside face of the packing piece, and the slot in the chassis, prior to using a smear of epoxy to bond the packing piece in place, nice and centrally. Re-lubricated, re-assembled, and tested again, the loco seems fine - so far anyway.

[Atlantic 3279]

I even ran into trouble with my Gresley 4-8-2 streamlined neverwazzer. Enjoying a moment of silliness, I allowed it to storm around the layout at full tilt, over the de-bugged track, quite ignoring the fact that I had heard a slight click when it first set off. Suddenly, on dead straight track in the fiddle yard, it stopped dead, with a clunk, and hurled itself and tender over onto one side, revealing this:

I suspected that either the leading crankpin had snagged on the con-rod, or (and?) I hadn't noticed that the joint between the combination lever and union link of the vale gear had flipped over the wrong way (which easily happens on this sort of "fine" Hornby vlave gear if the loco is ever run or mis-handled while inverted). Either way, the con-rod and radius rod were bent, the piston rod, slidebars and so-called valve rod were pulled out from the back of the cylinder, and the crosshead out of its slot in the slidebars.
With the body removed, cylinders released from the chassis, and the rods carefully straightened, I was able to re-insert the relevant rods into the cylinders, screw the cylinders firmly back in place, and then tweak the various rods as necessary to make sure that the con-rod couldn't possibly catch on the crankpin again, unless squashed out of shape by poor handling of the loco. I would have left matters there, but the more I looked at the matter, the more convinced I was that with the con-rod on either side at the extreme rearward point of its travel, there was hardly ANY piston rod still inside the cylinder. Maybe that sudden stop had actually been due to the piston rod dropping down slightly and then jamming against the back of the cylinder?
It is probably my fault that such a possibility existed, as I had made the model by altering a Railroad A4 model and then substituting the finer-scale version of the vale gear for the original chunky Railroad stuff, but I had merely adapted the original Railroad cylinders (minimally) to accept the new valve gear, thinking that as they are almost totally hidden, there was no point in buying/fitting a nicer-looking set instead. I think the finer scale Hornby cylinders perhaps feature something that the Railroad ones do not - enough of a representation of the gland on the back of the cylinder to support the end of the piston rod even when pulled all the way back.
I've now done what I possibly should have done in the first place. I've drilled enough clearance in the cylinders to accept a long piece of brass tube, glued in place, to act both as a piston rod guide within the cylinder and slightly to the rear of it too, where it crudely represents the gland.

[Atlantic 3279]

Another piece of rolling stock to fail its layout test was my Mousa Models 3D printed D.303 GNR six wheeled luggage brake. An end wheelset simply fell out while it was running, causing another derailment. As with the third class coach from the same stable a few months ago, the cause was warping/splaying of the W-irons, exposing the end of the pin-point axle.

Unlike that earlier case though, the W-irons here were not so brittle as to fracture when pushed back towards the proper position. These were more like rubber. In this case, the outer wheelsets are supported by W-irons that are printed totally separate from the stepboards, so bracing the stepboards as I did on the third class coach wasn't going to help. After some head-scratching and careful test-drilling, I found that I could drill horizontally through the axleboxes where there was a reasonable amount of solid material, missing the wheel bearings in the process, so that I could insert some 0.7mm brass wire in a goalpost shape, tucked almost invisibly under the inner edges of the bottom stepboards and alongside one of the brake yokes. Painted black, it should be fairly discreet.

I thought this a better approach than trying to glue the inside face of the W-irons to vertical pins inserted into holes drilled in the coach floor, as the holes for those would have to be drilled vey close to the springy wire for the suspension system. I can just imagine that getting snagged in the process.

On checking the third coach of this Mousa trio, a D.154 luggage composite, it looked to me as if its middle wheelset wasn't far off being in trouble too, so I've given that a bit of support as well. In this case, I was able to recruit the footboards to help once again, as they are sufficiently "joined up" with the structure of the W-irons and axleboxes.

Curiously enough, the outer W-irons on this one have more structural connection with the footboards too, unlike those on the luggage brake, so the print designs do not appear wholly consistent.

[mick b]

I am not surprised to read re the O2 saga . The one I had was a real pain from day one .

It didnt like any curves at all, at which point ebay beckoned and good riddance.

I am amazed that Heljan are trying?, to sell another O2 issue soon.

Re the six wheel coaches , Brass W irons or a Clemison etch or both ?

[Atlantic 3279]

Would you believe that I also found trouble with my Hornby J15, which has done very little work since new, other than shuffling 'twixt station and fiddle yard a small number of times on some of "Grantham's" show days. It was okay at low speed, but if run at higher speed it started screeching! I suspected a dry bearing somewhere, so I've had the body off and re-lubricated anything that could not already be seen to be amply lubricated. In the process I had to ask WHY Hornby chose to fit a non-removable motor retainer around the armature shaft between the motor (brush end) and one of the flywheels, making it almost impossible to inspect or re-lubricate the bearing at that end of the motor casing.

The final quirks to report refer to two kit built locos. I've now noticed, for the first time, that my own-build mainly whitemetal-bodied Kingdom Kits L1 Robinson 2-6-4T, with D13 open-frame motor, and which runs perfectly (as it always has) on an H&M Clipper / Duette, a Gaugemaster hand-held, or a now rare H&M walkabout flexible controller, is hopeless when run from a genuine Kentroller, even with its feedback switch in the off position. It begins to make the Kentroller overload LED glow from the moment it sets off, and runs more and more feebly until coming to a stand with the overload light glowing brightly if you try to persist in driving it. I've checked for any obvious shorts and found none, and as it runs very willingly on the other controllers I am not inclined to try to puzzle this one out. The other non-compliant kit loco is a Millholme B5 that I acquired already built. It has been fine on other layouts so far, but on my new one it really doesn't go happily around the innermost curve into one end of the fiddle yard. It audibly grinds its way around the series of curved points, where the curve is no tighter than many others it has happily traversed. There's less sideplay in the coupled wheelsets than I would have aimed for had I built it. Am I going to do anything about it? Nah....Am I bovvered?

[Atlantic 3279]

Re the six wheel coaches , Brass W irons or a Clemison etch or both ?

I'm trying to put off or avoid the evil day Mick...

[mick b]

[Atlantic 3279]

A bit too busy with the layout to get involved with more thorough revisions to existing pieces of stock just at present, and if I had more time I would prefer to turn into reality more of the stock that is still just an intention, before I have to tackle "less interesting" re-build work.

[Atlantic 3279]

The portable layout is now packed away again safely, and I've been re-testing some of the stock, this time on my loft layout.

The O2 now behaves very well, as do the Mousa GNR six wheelers, and the 4-8-2. I do however have a couple of puzzles for those with suitable knowledge and experience, or with a mighty and deductive brain:

The Hornby J15, freshly re-lubricated everywhere that appeared to show the slightest possible need for lubrication, seemed initially to run quietly, even at its rather limited maximum speed, when going forwards. I did however find that max speed in reverse still tended to provoke the odd screech, and that once provoked again there were hints of the same when running forwards at full tilt, or when slowing down from speed. It will probably only ever be used at fairly sedate speeds, but it would be nice to know what's amiss at higher speeds anyway.

The Kingdom Kits L1 which was quite definitely running very reluctantly from one of my two Kentroller hand-helds on the portable layout, which then ran perfectly normally on switching to my Gaugemaster plugged into the very same control socket, and which has always run normally on my other various controllers, showed no sign of trouble today when using the very same Kentroller in the loft. It ran perfectly well on another Kentroller too. I cannot therefore confidently point the finger of suspicion at either layout, at the loco, or at the Kentroller which was objecting to the struggling loco yesterday.

All answers to these mysteries to me please, preferably lightly pencilled on the back of a £20 note...

[nzpaul]

The Hornby J15, freshly re-lubricated everywhere that appeared to show the slightest possible need for lubrication, seemed initially to run quietly, even at its rather limited maximum speed, when going forwards. I did however find that max speed in reverse still tended to provoke the odd screech, and that once provoked again there were hints of the same when running forwards at full tilt, or when slowing down from speed. It will probably only ever be used at fairly sedate speeds, but it would be nice to know what's amiss at higher speeds anyway.

The Kingdom Kits L1 which was quite definitely running very reluctantly from one of my two Kentroller hand-helds on the portable layout, which then ran perfectly normally on switching to my Gaugemaster plugged into the very same control socket, and which has always run normally on my other various controllers, showed no sign of trouble today when using the very same Kentroller in the loft. It ran perfectly well on another Kentroller too. I cannot therefore confidently point the finger of suspicion at either layout, at the loco, or at the Kentroller which was objecting to the struggling loco yesterday.

All answers to these mysteries to me please, preferably lightly pencilled on the back of a £20 note...

In my experience, a screech as opposed to a squeak is almost always caused by a motor bearing. Ringfield motors are notorious for generating a very disturbing noise from the loaded bearing behind the gear. I would be suspicious of the commutator end bearing on the type of motor in the J15, although it could be either end. I know you've already had the motor out but it's the only thing that spins fast enough to generate squeals and screeches.
Re the L1, any sign of a build up of carbon in the commutator slots? In combination with feedback controllers, that can lead to some interesting performance issues.
Apologies, I don't appear to have a £20 note to scribble on.

Paul