97xx

This is something of a prototype comment, but posting here for interest. In May 1950 The Railway Magazine, an article "From Tunbridge Wells to Eastbourne via Heathfield" containing: "Just before Hellingley, one of two principle streams forming the Cuckmere River is crossed. This station, in contrast to all the others, has no passing loop or signals although there are interchange sidings with an overhead electrified line leading to the metal hospital, the tower of which can be seen about half a mile away on the left." (My highlight). A non-electrified line with an overhead electrified siding?

Saw that Key Publishing are still selling these for £36 or so, versus the whopping £130 I saw somewhere! Anyway, fancied doing some heavy weathering... Sorry about the desk as backdrop - not the most 'railway' of environments! It's surprising how under photography the green still looks so green - in the flesh it's a good deal darker and more subdued.

I'd be interested to see how true AG wheelsets run versus Romfords/Markits. I absolutely cannot stand wobble/nodding donkeys. I have only tried AG drivers once on a large-overhang 2-4-2T but the wobble was 'down' to the standard of many current RTR models! I rewheeled it with Markits and it's as true as one can expect. At the risk of embarrassing myself, link below - it is a pretty rough fully scratchbuilt model I made in my teens in the 1970s, chassis two strips of 1/16" brass hand-drilled in my Dad's garage and so yes there is a little wobble but that may well be down to the chassis... https://app.box.com/s/2uu04sei5qiuxwkjw90igdialirdqx8b (Sorry it's on Box, but I do not have a YT account).

Sorry, yes, useful to see the GA - thank you. Still no idea why a UJ - except to accommodate sloppy design and manufacture, so perhaps I've answered my own question! Unless there is some reason the (original) motor cannot be mounted tight up to the gearbox?

Helping a friend re-motor a S/H Adams Radial which came mint aside no motor/mount/flywheel. AFAIK this originally has a 5-pole skew wound open pole motor, a flywheel and a UJ between motor and worm/gearbox. Can anyone help with all of any of: Source of suitable double-ended motor to allow for flywheel Source, or dimensions of, worm required to mesh with gearbox (which is present) Explain why a UJ is necessary when the gearbox/wheelset does not move? Point to any open-source 3D files for printing mounts or other relevant parts. My preference would be to source a decent quality DE motor, fit a flywheel, and fab a motor mount (with a little adjustment to set the mesh). Would value any thoughts. Thanks!

FWIW, the blanking plate does the following: 1. Rectifies the incoming loco feeds (which very obviously can be of either polarity DC) to feed the elements of the loco circuitry that require DC of a specific polarity no matter what direction the loco is commanded (these are the four largish black diodes marked A7 - four in 'bridge' configuration I expect). 2. Provides protected DC of track polarity to devices requiring directional control - e.g. to drive marker lights or cab lights. This may be direct to device, or simply a signal to some of the more complex on-board circuitry to work it out (looks to be the case here) 3. Applies some interference suppression - to limit noise generated by the motor and other switching devices being sent back down the track (one or more of the 330 marked devices which are 'chokes' or inductors - coils of fine wire on a ferromagnetic former- plus a resistor/capacitor network) 4. Applies some interference rejection - to limit potential disturbance to loco electronic circuits from track-borne noise (ditto). Others may know - are there any 'standards' for blanking plate circuits?

You should indeed get a constant reading at any particular point - accepting that it's a 3-pole motor you may at certain points catch two windings instead of one - meaning you can get different readings but not ones that fluctuate. I recall changing an Airfix 14xx from plunger to scraper as the small springs had lost their temper due to current draw and were useless. Plungers are good in theory but seem difficult to get reliable in practice, especially with the large side-play in RTR models.

What a shame, albeit predictable. Little consolation, but a really excellent exercise in weathering.

@rapidoandy You've been very open and your team on here have been communicative and responsive. Problems afar set aside, I'm sure we'd all agree that this sets a welcome and high bar in terms of customer engagement which is an increasingly rare commodity in this age. Good luck resolving the fundamentals - here's to getting that smile back!

Thank you @RapidoCorbs for such a swift, understanding, and courteous reply, plus the PM. To reiterate, you at Rapido HQ designed a potentially truly outstanding model, and I am sure we all feel your pain at the issues you've experienced.

Er, this was a warranty return to, and 'repair' by, Rapido, from whom I bought the original direct.

Please do not be offensive - if you consider I was raising my voice, that does not constitute me being offensive.

@RapidoCorbs I'm now very annoyed. Having returned my badly-running 15xx for a refund, my request has been ignored and I've been sent an even worse one. It has a hopeless eccentricity - see videos attached. Plus it's blindingly obvious that the rear axle (which was OK on the original one) has a wheel with indeed the centre not in the centre. I don't care how 'detailed' it is if it basically runs like a dog. If you'd done what I explicitly asked for, this post would not be here to show yet another hopeless chassis. https://app.box.com/s/9pm1zx5cq2xn188lkfazrxxmexxj6sck https://app.box.com/s/9o7pgw34nk52zxwiq2ycv8x87jp021a7 For good measure here is a chassis I made in 1975 in my Dad's garage with a drill and two bits of brass strip held together in a vice. If the 15xx was half as good as this (which isn;t brilliant I admit) I'd be fairly happy although bemused why holes and right angles are not possible in modern china. https://app.box.com/s/gvm3brxufwsp3j3fdagp2rh65xtgjd5o @RapidoCorbs What do I now need to do to GET MY MONEY BACK?

An/the issue that we have now is that there's 'stuff' between the track and the motor - and if you use low rent components (which they will be - see other threads about I think it was APT and burning out of components) then you can and will get problems with less than perfect controllers. There are often references to old H&M type controllers - the issue is that they put out potentially higher maximum voltages and also have zero 'smoothing'. So, although they are 'DC' in the strictest sense of the definition, they are actually fluctuating DC. They basically take the sine wave and just rectify it - which means the 'negative' lobe gets flipped to the positive side - thus all the voltage out is positive, but it is varying from zero volts to the set volts at 100 times per second. Also, the H&M type was deigned to put out enough beans to drive big HD Ringfield and Triang XO4 type motors - which easily took up to 500mA - meaning that if you apply this to some tiddly chinese coreless motor which draws 100mA then the voltage can rise too high - because the power draw normally pulls an output voltage down. Let me add that this should NOT affect any well-designed electronics. But if you stick a inadequately rated component in such a circuit then something may go pop.

It's an interesting area - DCC by definition provides motors with ca. 12V pulses, which the decoder produces from the continuous full voltage provided to the track. What get's varied is the 'on' time. So whatever motor you have gets what is called Pulse Width Modulated (PWM) power in DCC mode. I would say PWM, per se, is not really an issue (although I can see LF would be less than ideal but this would need to be very LF but can't see anyone would deliberately design that way). AFAIK feedback controllers sense the back EMF produced and as this rises when the motor is under duress more power is applied to keep a constant speed etc. Obviously if the motor is straining to move the load, and is thus heating up (partly due to current draw under load and partly due to the back EMF causing additional heating), then giving it more beans will only heat it further. A weak/crap motor won't be able to handle it. Hence why FB controllers are not 'recommended' by some. You can appreciate this in N gauge where everything is so small and getting heat out even more of an issue. Coreless motors will be less tolerant of it for all the reasons we've stated as they are much less tolerant of heat build up. I very much doubt an XO4 would struggle with 'feedback' controllers...

I have a pair of 1505 Fox etched and painted brass cabside plates. No longer required as have returned my wobbler for a refund. Free to anyone who wants them... Please PM... EDIT: NOW GONE.

The significant difference is that: 1. A conventional motor has a 'rotor' consisting of a laminated iron 'core' (with the three to five lobes we refer to as 'poles') over which are wound the windings, sitting INSIDE stationary permanent magnets, 2. A 'coreless' motor has a rotor with a very fine set of cylindrical windings with a hollow 'core' INSIDE which is a stationary permanent magnet. (So it's like a one-ended can suspended on a shaft) So a coreless is sort of inside out, and has no 'poles'. In theory a coreless motor should have no cogging: as there are no poles (and just a continuous winding in a continuous a magnetic field) we don't get the effect of the rotor 'handing off' from one pole to the next inside the magnetic fields. (The winding is helical and layered which gives the effect of an infinite number of 'poles'). Without getting too carried away, the reason coreless motors struggle with certain types of controller is that you have very high peak currents which cause significant heat generation, and you don't have the laminated iron core to help dissipate heat. I will no doubt be shouted at, but a really bad idea unless you have very high standards of components and manufacture (where they are excellent).

I'm afraid I must be missing something here - bits missing, items bent or broken, chimneys at odd angles, glue across the model, detrietus in the paint, chassis that are fundamentally out of true, and wheels with the centres bored off centre! Yet an excellent model??? What Rapido aspired to and designed was/is indeed truly outstanding, But what their chinese supplier has delivered is way, way, short of what we, and Rapido, paid for. Most/many of these defects are blindingly obvious when these models go in the box - we are told how much hand finishing is required so someone actually saw these defects and quite deliberately and consciously packed it up and shipped it hoping they'd get away with it. And this very point makes any comments about "it's only a small proportion" null and void. We are surely not helping Rapido by basically saying that we'll settle for the major defects, try to fix them ourselves, straighten out wheelsets, or just live with them? The supplier will be laughing all the way to the bank!

They are links to a publicly accessible set of files - annoyingly you do need to download them as 'visitors' to Box cannot watch them online. If you have a Box account you should be able to view them in a browser. Sorry it's all a bit of a kludge!

Really kind - thank you! Soldered brass sheet with plastikard boiler, and tank fillers and vents turned in Dad's drill. I nearly kept the 15xx as it is an astoundingly good model in many ways, but the running will only get worse given the eccentricity and call me old-fashioned (which you can given the 36xx!) but 'running' is Priority No.1 for me. I've spent some time more recently making compensated chassis and it is a joy to see a six-coupled loco crawling flawlessly through complex pointwork but I have to say that I avoid plastic wheels as I simply cannot get flawless concentricity and parallelism with them. Even the Markits/Romfords take some fettling in the mill vise to get precise alignment. The merit of the all-metal is that they don't take any sort of permanent 'set' once assembled which precludes later adjustment. I find that if I try to true (or correct) plastic ones using my usual techniques, they might be OK immediately afterwards, but will usually re-assume their original misaligned set the next day. FWIW the procedure I use, making use of a heavy duty mill vise, is: Measure the B2B and decide on what you will work to Measure across the outside of flanges (assuming tyres are fitted correctly) Make up a precision spacer for that dimension Put some support in the bottom of the vise for the loco Place the loco wheels JUST into the vise - and it is 'just' given sanding pipes, wheel weights and so on Do up the vise onto the spacer - this trues all axle wheelsets to the same B2B Rotate wheels 180deg, repeat Rotate 90deg, repeat and 180 again If you are lucky you'll end up with a pretty (a) accurate and (b) parallel and (c) wheel perpendicular to axle wheelset. With metal this works well, but as I say the plastic tends to spring back. Very much wanting the 15xx, I *did* try correcting it, and it was briefly pretty reasonable - even dropped the Rapido Warranty team a note to say I'd hang on to it after all and see. But next morning it was back to the wobbles.

I've done a comparison of my 15xx on the DCC RR with my 1970s scratchbuilt 36xx 2-4-2T on same, and from what RapidoCorbs has said of others I'm correct to want to return it. Yes, I know the 36xx is not a pretty sight at all, and although having a little bit of a 'nod', it's not a bad runner given the rudimentary chassis, and I felt a reasonable benchmark given and equally challenging wheel layout. I'm assuming those with good running 15xxs are similarly stable? 15xx: https://app.box.com/s/n04kntigt1yeg1iqoz85hqnw662l1ybz 36xx: https://app.box.com/s/2uu04sei5qiuxwkjw90igdialirdqx8b I would add that Rapido's prompt returns replies have been very professional I really do feel for them: very very good potential let down by dubious behaviour at the manufacturer.

Deleted post - wrong forum!

Very useful video and reply - sets a clear benchmark of what is unacceptable. I managed to improve mine somewhat, but it's at least as bad as that AFTERWARDS. Will return. I would absolutely love to see a video of one that runs properly on a RR posted.

All this discussion has catalysed me to get mine back out of the box, and inspect/measure. 1. B2B vary between 14.1 and 14.5mm on a wheelset. The driven axle is good at 14.5±0.05, middle 14.3±0.2, front 14.4±0.1, but see 2. 2. Some wheelsets have wheels not perpendicular to the axle, albethem parallel in places (so B2B measures OK). This makes eccentric running MUCH worse. 3. One of the rear wheels clearly has a poor pickup as it is ineffective at certain points 4. One axle has defective quartering, and with the non-perpendicular wheels (meaning crankpins are't axial to the axle) causing the coupling rods to snap in and out along the crankpin on one side at the centre wheel. This is contributing to the cogging effect. Four of the six brake shoes were not located on the pins on the chassis, although if there was any silver cloud, it meant they weren't touching the tyres... I note also the flywheel has absolutely zero effect - shutting off the power results in a skid to a halt.

Yes centre is sprung - not 'compensated' as this technically refers to multiple axles that are connected in some form to improve track contact over irregular contours. Not on the video but I did look more closely at that middle axle and the wheels are out of true. Driven wheelset is tolerably OK, front wheelset is very poor. Unfortunately, short WB and overhang means the eccentric wheels kick the loco ends from side to side. Having said all of this, my scratch built 36xx of 1970s (a large overhang 2-4-2T!) has a good deal better running quality - made in my Dad's garage with hand tools and brass strip chassis. And if anything will be prone to 'wobble' or hunting that will be the one.