Izzy

Stay-Alive.... or not! Those who believe there is no such thing as coincidence might find the following quite funny considering only yesterday I posted on Doncaster Green's thread about not fitting stay-alives to plastic bodied locos because of issues with odd 16v tantalums..... I wasn't quite so amused.... Today I went to run the Hunslet 05. I would put it on the track and then after a brief interlude my DCC system would say there was a short. ???? After playing this game about half a dozen times I realised there had to be something wrong with it since with any other loco all was fine. Hm. Since locos don't just develop shorts for no reason I came to the conclusion that something on the electrical side had failed. The motor, the decoder, or the stay-alive. Something told me the time it took to register as a short tended to point to the stay-alive, but you never know. Nothing looked amiss once the body was off, but the chassis alone still gave a short when placed on the track confirming my initial diagnosis rather than a breakdown in insulation between the body and chassis. Working backwards from how it was put together it seemed the best way to track down the problem was to disconnect things in reverse order, stay-alive, decoder etc. A process of elimination. Once the stay-alive was removed it all worked. Okay, well that was helpful in that it wasn't the decoder or motor, but, oh bother.... So then I stripped the stay-alive down to the individual parts to test them. Zener, resistor, schottky diode, plus the three 220uf tantalums. I had plenty of bits to make another to replace it but I wanted to first find out why it had apparently failed and what had gone wrong. With my basic old Maplins multimeter I tested all the bits. Another of the D case Tantalums had gone belly up it turned out. Not with a bang as before thankfully in this case but with a wimper just becoming open so current passed straight through. So not a disaster, just annoying Since I had obtained some flat 470uf tantalums which I had used in the J69 and J15 rather than re-build the stay-alive with more 220uf D case ones I chose to produce another using one the advantage being it would be slightly smaller in size in width and height, and 470uf had proved enough. I do hope this doesn't become a regular chore and more of these D case 220uf tantalums fail. That would become really tiresome. Bob

Since one of the 16v tantalums in the 2MT went bang non of my plastic tender locos now have stay-alive (except the re-built Royal Scot where there was the room to use 25v tantalums so way above the track power level) on the grounds I didn't want to end up with a melt damaged body. TBH with six wheel per side collection they shouldn't really need them. Non of my bogie diesels has them either. But I have tried one in the J15 just to see if there is any noticeable difference/advantage since the tender wheels are perhaps a bit iffy. Bob

Hi John, In recent times I have pretty much standardised on the 7x16 size coreless motors as a 'one-size-fits-all solution', having used them in everything from the little Hunslet 05 to the slightly bigger re-built Royal Scot with no power issues at all. These have been both the cheap ones off eBay from past times and those now in shop 3. They seem to cope with whatever is thrown at them, which using DCC just builds on, and the deciding factor on haulage is purely down to weight/mass. Use one of these along with a ratio of 30/40-1 and fill the body with lead and you should have no problems. * Bob * and it goes without saying a Zimo

In which case @Robin C will need to confirm this with say James at DCC Train Automation before going any further. Having to change to another DCC system will I have no doubt help decide what other parts to go with it will be best.

I may be wrong, and perhaps someone can correct me if so, but as a user of a Prodigy Advance 2 system I believe they are not compatible with any form of automation in respect of feedback/block detection since neither Loconet or Railcom is supported.

Yes, it’s really good, but is a significant enlargement on Minories with the multiple carriage sidings etc. which are the key to its operation. In recent years I have come to realise that decent large capacity fiddle yards are a must for single user layouts if you don’t want to spend more time just continually changing stock in them to run the most simple of sequences when the layout track design doesn’t have the capacity. It’s different if two people are involved and one just works the fiddle. Bob

Yes it does, indeed it’s been far more successful in providing the scope for wider operations than I could ever had envisaged. I just like the idea, the challenge, of making an original design folding baseboard Minories that could give a similar level of operations since my first truly worthwhile layout was a small folding baseboard design. Bob

I'm of the opinion that in the early days most layouts placed operational use at the forefront of their designs with just mostly token scenery within the railway boundary unlike today where the opposite often exists with many and the railway side seems almost incidental to the scenic one. To my mind Minories falls into the former category and I still often think I would like to build a minimal size version but get stuck at wanting to expand the range of trains to make it more interesting to operate. How to do so without expanding the track design much or having more platforms. Different types of traffic rather than just more of the same. That would I feel get boring to operate quite quickly for a lone modeller such as myself. Bob

J15 construction resumes It seems it’s over a year since I last wrote anything about the J15 build. This it turns out is because work stopped in early January of last year to await the turning of items and it’s only now that I have eventually got back to it. Despite the fact I was at that time waiting for boiler fittings it is actually the tender that has now been completed first. This in itself would not have been possible without the kindness of fellow 2mm association members @2mm Andy & @queensquare in offering the necessary tender axlebox castings from their stocks which were no longer available in shop 3. Thanks again chaps. Another reason the tender has been finished first relates to the need to tuck the small Zimo decoder and stay-alive pack in it. If I thought fitting such into previous locos such as the Hunslet 05 and J69 were a challenge they have proved comparatively easy by comparison. Part of this revolves around the fact these exGE tenders were quite small in comparison to others and once the 7x16mm coreless motor was inside there wasn’t much room left. Here are size comparisons with a LMS 4F Fowler tender and an Ivatt 2MT. Since it seemed to be of interest I’ll deal again with this aspect in case it helps others facing similar problems. The only space to fit the decoder was behind the motor in the rear, just enough for the tiny 8x6mm Zimo MX615. Goodness knows what I would have done without these being available. As with the J69 the aim was to sit it on top of one of the flat 16v 470uf tantalums I had obtained. But once I added the Zener and diode/resistor into the mix I found it was just too tight a fit into the space vertically, which was just under 6mm deep. So somehow I had to try and reduce the ‘thickness’ of the decoder/stay-alive sandwich. As I had to obtain more bits anyway instead of mini-melfs I found sources of SMD components. SMD100R resistors (which I’d used before) plus SMD schottky diodes and SMD Zeners. Although not massively smaller they were enough to allow the pack to reduce so it would fit. The SMD ones are in the front in this shot. I was able to put the Schottky and resistor on the side to help lower the overall height. A side on view. And one from above with the tender body in place. Although five J15s were fitted with side window cabs and matching tender ones specifically for working the Brightlingsea branch and Colne Valley lines with tender first running, and were thus Colchester based locos, I have instead chosen to keep the loco as a normal one so the tender just has the much more common tarpaulin rail fitted to the tenders for tender first working in poor weather. Now I am satisfied that the loco & tender run okay under DCC on Priory Road, something I was concerned about, finishing off the actual loco can commence. I should add that for this testing with the plain metal bodies tamiya masking tape was used to isolate the bodies from the split frame chassis. This will not be needed once the bodies are painted. I find a couple of coats of paint from the Halfords rattle cans, primer followed by matt black, provides all the insulation required between them. Bob

First off you really need both a resistor and diode in circuit and in addition a Zener will help limit the current to the capacitor. If you look around online several circuit diagrams and component suggestions will be found. I use a 100R SMD resistor combined with a Schottky SMD 40v diode and a 16v Zener. As to decoders well, I now only use Zimo. The MX600 at £25 is still available and will be far better. Bob

J15 with two speakers Well, it's been a while since I last posted on this thread. It isn't that things haven't happened, All Saints East itself has been completely rebuild for a start, and new items in the form of a couple more locos added, but the main focus has been elsewhere with another scale/gauge. However the making of these new locos and fitting them with sound, (a J68 from an etched kit and a Thompson L1 using a Hornby body on an etched chassis), brought to my attention that the only tender loco, the converted Hornby RTR J15, didn't sound right with the sound clearly coming from the tender and not the loco. This wasn't readily apparent when I first fitted sound to it after the conversion to P4 but slowly became apparent over time when run alongside the other locos. The question was, what to do about it? I'm afraid I am one of those people that can't leave things as they are if I find something that's not right and isn't to my liking. There was nothing wrong with the sound, the J15 project from Youchoos, indeed it sounded great (and stills does) with a few tweaks for personal preference for individual sounds levels. Now I'd fitted sound to both these new steam locos by fitting speakers into their smokeboxes and it began to occur to me that this was what I needed to do with the J15. With a speaker already in the tender and having read and posted questions about twin 8ohm speaker set-ups it seemed quite possible to do and especially as I had fitted a Zimo MX645 which can cope with this in either speaker wiring formation of series or parallel, having a 4-8ohms output. Speakers wired in parallel halve the impedence while in series this doubles. So two 8ohm in parallel are 4ohm while in series it becomes 16ohm. It seems the lower the impedance the louder they are and visa versa. The speaker impedance must obviously match or be less than what the decoder can provide. So in parallel is not possible for those that can only provide 8ohms, which is the vast majority of Zimos. ESUs are all 4ohm I believe. The big issue was finding the space. The Hornby J15 has a cast metal footplate and upper body in two halves for weight which is great but what space remains is stuffed with the chassis and motor etc. There is no empty space at all. Eventually after measuring it all up I realised I could, just, squeeze one of the small 15×11mm planar speakers I have used recently into the smokebox standing vertically, but only if I was able to cut out the large chunk of metal that sits there behind the smokebox door. It took me quite some while to pluck up the courage to attempt this, the ever present danger of just wreaking the complete loco not being far from my mind. Because finding a spare body would not be easy (probably impossible) should things go pear-shaped. Trying to work out how to actually cut out this metal section also took some time. If only the smokebox door came out…..and I could get the boiler/cab off the footplate…. In the end one day I just took the plunge, parted the loco and tender, and took the body off the chassis. After removing the screws under the cab floor I managed to slowly lift the cab away and by gently levering the cab/boiler up/down it started coming away from the footplate. It took a long time as I didn’t want to bend/warp/crack the footplate. The front slips under the footplate and this is what the chassis screw goes into. It was the middle part of this tall square pillar I had to remove, well almost all of it actually except the very bottom bit with the screw hole. As there was a gap either side which shows the rear of the smokebox door I decided to push my luck and see if I could force the door out from the rear. I guessed it was glued into place. It’s plastic, one of the few parts that are. Just when I was about to give up it flew out of the front with a crack and ended up on the floor feet away. Given the sound made I thought perhaps I’d smashed it, but no it was intact and undamaged. That was lucky! With it removed there was then easy access to the pillar and so I chain drilled it top and bottom to remove the bulk and cut it out and then spent a long time cleaning it all up with burrs in a mini drill and to get the square corner shape into which the speaker would fit. I had to cut away the pillar below the front of the smokebox which was a tricky task to complete. Once done it proved possible to get the speaker into the space but only a flat piece of plasticard could be added onto it to make a sealed enclosure. After soldering on the wires I wrapped it in Tamiya masking tape for insulation against the body, not wanting electrical shorts of any kind. This tape was also used to hold the wire runs to the inside of the boiler. Initially when all done and wired up I found the larger Zimo speaker in the tender still overwhelmed the other volume wise, so replaced it with another 15×11 planar to get an even sound output. This worked nicely. Now it seems as if the sounds come from the loco itself whichever direction you listen from. So a lot of hard work but worth the effort. Bob

I guess all the magazines are going to miss the annual advertising income Hattons used to provide, the often multiple pages.

Experiments have continued. It seemed just adding the small planar in the smokebox didn't really have the desired effect, the sound volume of the larger Zimo dumbo in the tender overwhelming it. It was better, but still noticeable. So then I removed it and fitted another of the 15x11 planars in it's place, the idea being they would/should match and thus balance out better. This seems to have worked out. The sound now just seems to come from the loco as a whole rather than a specific area of it as before. This might be helped by the fact the one in the tender is right at the rear of it to match/counter the loco one being right in the front. This is good given all the work I had to carry out on the loco body to obtain the space for the speaker. Even in parallel at 4ohms however the volume level output couldn't match that of the single Zimo dumbo at 8ohms. I had it set at 20 (cv266) for my needs in a small room and have had to increase this to 60. Part of this might be because there was no room to add an enclosure to the smokebox one so I didn't with the tender one either so as not to skew too much the balance I was after considering the space in it to act as a soundbox anyway. Bob

Yes, it does, many thanks. Luckily the Zimo concerned is a MX645 which can do 4-8ohms. So it looks like parallel will be what gets wired in. Bob

I've spent this afternoon testing the theory. Joined up in Parallel the speakers worked fine no matter which way around the wires were. In series one way they were both noticeably quieter one way than the other so that must be the way to judge when they are wired correctly. I got the impression that in Parallel they were louder than in series but this might be because it was all done in the open. Now I am trying to carve out enough space in the J15 smokebox area to fit the small planar, an ESU 15x11mm, when I will test both setups again to try and determine which is best, and if the second speaker actually makes much difference. Bob

As there are no markings on any of these speakers and they are both of similar design, flat with sprung contacts, and able to be fitted into different sized enclosures, I guess I could assume that they are given ‘standard’ polarity I.e. the same orientation, and then go from there. Thanks for the helpful replies. Bob

Quite basic question I’m afraid but one I have not been able to find clear answers to with searches although I have tried. Maybe I’m a bit thick. I have a sound fitted tender loco, Hornby J15 with Zimo MX645 + Zimo 8ohm dumbo speaker, that I want to try and add a small 8ohm planar speaker into the smokebox because as it stands the sound is great, but does really seem as if it’s coming from said tender rather than the loco. I’m hoping that this might help balance it a bit better. As I understand it the MX645 is capable of driving two 8ohm speakers in parallel (4-8ohms at 3W) but I can’t seem to discover whether polarity is important or not I.e. if the wiring needs to be the same to both or doesn’t matter. And if it does, how to set it up, to tell what the polarities are etc. without blowing up the decoder amp! Can anybody advise please? Thanks, Bob

Looking on Rail-online I've found D5815 at Wath diesel depot in 1966. D5685 near Audley End. D5677 at Stratford 1967. All SYE & double arrows but most others seem to have FYE. I might have missed a few though. Bob

And I think this came about by the need to come up with a design that used just standard L/R hand points, all that were available for TT at the time. This was the driver from which it all developed IMHO. Everything past that just refined and adjusted it for other scales and needs. To my mind though it wasn't just about the track design, so simple and clever as it is, but the whole concept. A small folding layout that could be used and then packed away in a small space. Maximum usage from minimum hardware in terms of layout size, rolling stock numbers, and thus total outlay. The way housing is going these days, new builds where there are no garages and precious little other spare space of any kind, means ideas like this will become even more important than they have been in the past for many. Witness the growing number of 'shelf/plank' layouts now around. It has always been this way for me.

You’re right, they are PP3. Don’t know where PP9 came from so sorry, they are a larger 9v used in old transistor radios. Both are 9v where I guess the confusion originated. But really any fresh battery from a single AA/AAA up should run a 0-12v motor to see whether it runs at all, for a short while at least. Some really large ones might need 3v. Rechargeables drop around 0.25v so that has to be born in mind but are often good for anywhere between 900 - 1600 mAh or more.

Thanks, that’s good to know.

I’ve had a (BT) phone with Call Guardian for some years now. All cold calling doesn’t get through. Only rings for allowed numbers or announced calls. Just not sure whether the system will work when the line goes digital - if it’s VOIP compatible - or will have to get a new one.

Small N gauge motors like these should draw no more than around 60-100ma. I've had three N gauge going on a circle of track together and the total draw was 160ma. So a single motor should run quite fast on a new/fresh PP9 and still turn on one that's well run down. Can you test the current draw on a MM? I don't have any Dapol N gauge any more to test myself. When I did, a 66, 156, 87, they all had this motor design, ran well, and didn't get more than warm. Perhaps I didn't run them long enough to heat them up. It would be interesting to discover what they consume compared to the figures I gave, which apply to the Farish can motors and newer coreless cans.

Although some older design motors can run fairly hot I would not expect it of present day ones. Or only if they are under extreme loading. Running light/with no load, as in your shot, they should remain cool or barely warm at most. Is the combi a feedback controller. If so that might be having an effect.

If you want to add stay-alive then I would suggest you get 8-pin wired decoders. Easy to cut off the plug and then hardwire by removing all surplus wires. With 6-pin - where there is no common + blue wire connection - they use half wave for the lighting circuit through the black track connection. So then when adding SA you need to locate both the common blue+ and ground connection places, designated solder pads etc. Some have them, many don’t. With 8-pin there is the common + blue so all you have to find is ground for the SA. Much easier by comparison.