Priory Road - North East Essex in BR days

[Clive Mortimore]

On 13/01/2024 at 22:17, Izzy said:

Having soldered the front windows in place I then added the coal bars to the rear ones and fitted them. This was done by cutting the bars (36thou PB wire) over length, placing them in position on the drawing with d/s tape and soldering the window to them. Then trimming to size before also soldering into position. As the windows rotated fairly easily I tack soldered them to ensure they were vertical before final fixing. 

 

 

Bob

Now that is just showing off, not many 4mm modellers could do something that good. 🙂

[Izzy]

21 minutes ago, yaxxbarl said:

Bob,

 

On the rear windows/spectacle plates, how did you cut the rings for them? Was it from a piece of suitably sized tube?

 

Cheers,

 

John

No John, I made them on the lathe out of 1/8” stock when I did all the turnings recently. Kept the outside diameter and drilled them out 2.5mm. It all started out when I made the cab windows in the J15 oversize by mistake - they are the same size - and so got the idea to use inserts and decided to do the same with the J69/1. I guess rings from 1/8” brass tube might be possible to cut. 
 

I am hoping to knock up a simple punch from either 1/8” brass or steel to produce the ‘glass’ eventually.

 

Bob

 

[Izzy]

 

J69/1 details

 

The work of adding the details has slowly progressed over the last week. I started off by trying to work out where all the bits needed to be and the holes required for them and then drilling 0.3mm pilot holes to be enlarged as necessary. In the end I counted 30 holes... so it took a while to do. 

 

 

Doing them in one go I find better than doing them at the time of fitting and then finding a detail already in place prevents the hole being made. It is for this reason that I now leave fitting  chimneys and domes until last, finding they are either in the way or keep getting knocked and damaged in the handling. I also leave adding footsteps until the end for the same reason. 

 

I fitted the whistle first simply because in getting the holes in the right place it 'pinged off' onto the floor so I made sure when I luckily found it that it wouldn't do it again.....

 

Then I made and fitted the clack valves, produced simply from 0.4mm brass rod with slices of 0.8mm & 1.0mm brass tube ( Albion Alloy).  Since I need some for other locos I made a batch of six. I often make bits in batches when I know more will be needed in the future. 

 

 

 

 

All the details except the Westinghouse pump - a 2mm SA stainless steel 3D print - and etched handrails knobs - were made up from wire & tube of suitable sizes. It's all time consuming rather than difficult but does produce reasonable results. 

 

Working out the order in which to add the parts is key I find in not tying yourself in knots and it does tax my simple brain so it was slow going as the loco is 'busy' as regards pipes runs etc.

 

 

I fitted the smokebox door next to enable the handrail fitment.

 

 

The condensing pipework I made up on some paxolin before fitting. 

 

 

Nearly there

 

 

 

The footsteps I always back with a narrower strip for strength before adding the steps themselves as I'm always finding myself bending knocking them in handling If I am not careful.  I think you can just about see them in this shot. The buffers were from a batch I turned when I made the N7/3.

 

 

The steps are small bits of sheet cut and bent up and then soldered into place.

 

 

With the chimney and dome now added it's beginning to look decent. Like the smokebox door these were glued in place with cryno. I have always fitted them this way rather than soldering. It means when whitemetal castings are used and something isn't quite right there is a greater chance of getting them off and re-using/re-seating them. 

 

 

 

Not quite there yet though, there is the pipe runs along the footplate sides for the brakes etc plus the actual bufferbeam pipes. 

 

Bob

 

Edited January 22 by Izzy

[Yorkshire Square]

How did you get on with stainless steel Westinghouse, Bob? They were a bit of an experiment and I was sort of disappointed when they came back from the printers. Having said that, it looks the part on your loco, along with all the other fittings. Nice work!

[Izzy]

9 hours ago, Yorkshire Square said:

How did you get on with stainless steel Westinghouse, Bob? They were a bit of an experiment and I was sort of disappointed when they came back from the printers. Having said that, it looks the part on your loco, along with all the other fittings. Nice work!

 

Thanks Tony. Compared with the 3D plastic versions and the home-made one I eventually made up for the N7/3 when they all fell apart in my hands I think they are quite nice. They do certainly look the part I feel. Here's a quick comp shot with the N7/3.

 

 

I don't know if it would be possible to print them in a slightly softer material because trying to drill 0.3mm to take the pipes was near impossible. I managed to make a dimple to help locate and that was all. But it might be whatever is used. However I do find they take normal soft soldering with no issue so actually adding the pipes - some PB wire - wasn't the problem I expected and a good strong joint resulted.  TBH it's nice such parts exist at all, so thanks.

 

Bob

 

[Izzy]

With regard to the stay-alive aspect and 'just' using a single 470uf tantalum I thought I would try and make a video of the result. It's not that brilliant so you'll have to forgive the shaky and less than wonderful result but I hope it does - just - show the amount of run-on that exists. It's a crude way of doing it but I couldn't come up with any other that actually showed it clearly enough. 

 

 

Obviously more uf would always be better but it works good enough for me.

 

Bob

[queensquare]

19 hours ago, Izzy said:

With regard to the stay-alive aspect and 'just' using a single 470uf tantalum I thought I would try and make a video of the result. It's not that brilliant so you'll have to forgive the shaky and less than wonderful result but I hope it does - just - show the amount of run-on that exists. It's a crude way of doing it but I couldn't come up with any other that actually showed it clearly enough. 

 

 

Obviously more uf would always be better but it works good enough for me.

 

Bob

Brilliant Bob, great results from a single 470 tantalum. Very encouraging re. retro fitting some of my smallest locos with a stay alive.

 

Jerry

[Izzy]

On 24/01/2024 at 07:06, queensquare said:

Brilliant Bob, great results from a single 470 tantalum. Very encouraging re. retro fitting some of my smallest locos with a stay alive.

 

Jerry

 

Glad you found it useful Jerry. This is one of those aspects that is difficult to convey in words and seeing says all that's needed.  I just wish I had the skills to present things better. 

 

As far as the Buck goes it's now finished, or rather should I say that it now joins the queue - it's getting quite long - of those waiting for spring/warmer weather and painting.  The final details of pipework along the footplate sides, injectors under the cab, lamp irons and destination board brackets now added. Any cab interior will wait until painting is complete. These isn't quite as much spare room as I'd hoped so it will be very basic. 

 

Here it is up against the N7/3.

 

 

I am pleased with it's final weight. I have been able to add enough lead in the smokebox, bunker and tank sides that it's now 43gms. This is the same as the larger Farish Jinty.

 

 

One aspect that did worry me for a while when comparing it with my other steam locos was it's size. For a while I wondered if I had produced the drawings size wrongly for these exGE tank locos are generally seen as smallish, yet in reality these last designs, and thus the biggest, weren't. It is smaller than of course the N7/3 but in some respects seems to loom over the Jinty at some angles and quite dwarfs the J15 in height and width. 

 

 

It's nice I now have a selection of scratchbuilt exGE steam locos in 2mm.

 

 

Now I must really get on with the J15, the poor thing was started first of all the current construction and is the last to be got towards the finish line. I've had a few issues arising to solve with it, not the least being finding enough room in the tender to fit more than just the tiny Zimo MX615 i.e. some stay-alive in the form of the flat 470uf. It's going to be difficult.  But also the ex farish 4F tender wheels look as if they won't last the course, the N/S plating on the tyres is wearing off and the copper under layer is showing even though they have hardly had any use.  Current collection was thus pretty poor under plain DC until the loco was hooked up. I may have to replace them with 'proper' mk5/6's. But comparison with the J69/1 has shown up an aspect of the N7/3 that will be dealt with first. The lack of beading around the side and front windows. It looks poor and needs doing. Somehow I missed it when completing the loco and didn't notice it until now. 

 

Anyway I hope my relating some of the J69/1 construction, the making of parts, might help and encourage others to give it a go. 

 

Bob

 

Edited February 3 by Izzy

[Izzy]

 

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

 

[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

[Jan W]

Do you know what track voltage your dcc system gives?

If it is around 16V or maybe more, could it be an idea to try to reduce it to approx. 12V?

Safer for the capacitors. The zener still limits the voltage on the capacitors to the max. value.

 

Jan

[Izzy]

1 hour ago, Jan W said:

Do you know what track voltage your dcc system gives?

If it is around 16V or maybe more, could it be an idea to try to reduce it to approx. 12V?

Safer for the capacitors. The zener still limits the voltage on the capacitors to the max. value.

 

Jan

 

Thanks for the thought Jan. It's 14.9v. As it's a Prodigy PA2 system sadly there are no adjustments I can make. It's a very limited/closed system - expensive for what it is today where the Z21 would be my choice - but as I only want it for loco control I stick with it because the 3.5 amp output gives plenty of overhead for powering the hacked servos etc. through a voltage regulator (plus I have a wi-fi handset).  

 

Bob

 

 

 

[Nigelcliffe]

18 hours ago, Izzy said:

 

Thanks for the thought Jan. It's 14.9v. As it's a Prodigy PA2 system sadly there are no adjustments I can make. It's a very limited/closed system - expensive for what it is today where the Z21 would be my choice - but as I only want it for loco control I stick with it because the 3.5 amp output gives plenty of overhead for powering the hacked servos etc. through a voltage regulator (plus I have a wi-fi handset).  

 

 

You could drop the track voltage with a string of diodes.   One pair of back-to-back diodes in one of the track feed wires will drop about 0.7v.  So, three pairs would drop things to 14.9-2.1=12.8volts.   Fast rectifier diodes, and 4A or 5A rated given your DCC system's output.  

[Izzy]

2 hours ago, Nigelcliffe said:

 

You could drop the track voltage with a string of diodes.   One pair of back-to-back diodes in one of the track feed wires will drop about 0.7v.  So, three pairs would drop things to 14.9-2.1=12.8volts.   Fast rectifier diodes, and 4A or 5A rated given your DCC system's output.  

 

I had thought about doing something like that, Nick Mitchell suggested reducing the track voltage when the first 16v tantalum went bang some time ago, but I wondered if it would have any side-effect on decoder performance in respect of motor control so didn't take it any further. 

 

Thanks for highlighting how I might achieve it. Would you have any code numbers for suitable diodes Nigel?  I presume you mean fast recovery diodes. I've had a look around but as usual the more I look the more confused I get ....

 

Bob

[Nigelcliffe]

2 hours ago, Izzy said:

 

I had thought about doing something like that, Nick Mitchell suggested reducing the track voltage when the first 16v tantalum went bang some time ago, but I wondered if it would have any side-effect on decoder performance in respect of motor control so didn't take it any further. 

 

Thanks for highlighting how I might achieve it. Would you have any code numbers for suitable diodes Nigel?  I presume you mean fast recovery diodes. I've had a look around but as usual the more I look the more confused I get ....

 

Bob

 

UF5404  is readily available (including Rapid on the industrial estates in Colchester if they still have a local sales counter).   

Officially they're 3A rated, but should be OK for the use you're giving them - only going to see full current briefly in a short circuit situation.  

 

I'd also recommend a power district current limiter to reduce the track maximum current;  I run most of my stuff with a MERG cut out built for 0.75A at the track.   We run Burntisland (4mm scale) with them set to 1.5A (there's over half a dozen of them dividing up sections of the layout).     There are some fairly cheap ready to use types,  I think the NCE one is fairly cheap - Kevin at Coastal DCC in Ipswich could say what's available, and their current options.  

 

 

- Nigel

[Izzy]

 

Today I spent most of it trying to reduce the track voltage the Prodigy PA2 puts out. As suggested by @Nigelcliffe I obtained some UF5404 diodes with which to do this. Ultimately this has not been successful. 

 

As diodes generally drop 0.7v I got the idea to use 4 pairs to drop 2.8v so reducing the 14.9v at the track to 12.1v. The plan was to have two pairs on each feed to make it easier to arrange. Here I hit the first problem. The voltage only reduced down to 13.5v. So it seems these diodes are quite efficient and only drop 0.35v. This then meant it needed 8 pairs to get down to that 12.1v. This took some arranging, 4 pairs on each feed in the space I had available since the base station sits in an A4 size really useful box on the floor under a layout. 

 

Once I had finally arranged this and tested the output which did sit at 12.1v I tried the system with my test track and two layouts. The test track is just a plain oval on a piece of hardboard, useful for testing newly acquired locos or running stuff in. I measured 12.1v at the track and the loco used ran, but didn't seem to have any power. Stop the loco from moving and it could barely turn the wheels even at maximum speed. This seemed weird and far from normal.

 

Connecting up to the first layout - Priory Road - the track voltage varied depending if the accessory bus to the voltage regulator was switched on or off. If off it was 11.8v but if on, so the signals and hacked servos could be used, this dropped to 10.5v. Locos again ran but not like normal, while the points struggled to move. With the second layout it was worse. The track power was just 9.5v and points wouldn't throw properly, like the locos they seemed to lack power. 

 

At this point I felt the diode chains were badly affecting the base station output and so then removed them. Although in theory adding them should cause no harm I worried it had. Thankfully with it all reverted back to standard it all worked again as it should. Track power was back to 14.9v and all points threw correctly.

 

So, with a Prodigy system at least, this way of reducing track voltage doesn't work for whatever reason that might be, and I will just have to either accept and allow for the track voltage, or change DCC system to one where the track voltage can be set to choice, as with the Roco Z21. 

 

Bob

[Izzy]

 

A Z21

 

After thinking through all the aspects with regard to the recent posts concerning DCC track power levels, stay-alives with 16v tantalums, and the quite small decoders used in 2mm I decided to take advantage of the special price my nearest local Railway Model Shop sells the Roco Z21 at and paid them a visit and obtained one. This is Scograil and they share a outlet in Ipswich with Coastal DCC and Orwell Models. My Gaugemaster/MRC Prodigy system has thus been withdrawn from use and put into reserve status for the immediate future. It’s served me well for 14 years.

 

I had the Z21 up and running in about 15mins and is being used with a cheap dedicated 6.5” android smartphone, a Redmi A1, as the throttle. This was obtained last year from Currys for £59 and so this new combination has cost about the same as I originally paid for the basic Prodigy PA2 in 2010. Whether I will invest in a Wlanmaus handset as an alternative with rotary control is moot. Apparently it can’t share the same loco database, which is a significant drawback. But it’s an option to consider.

 

So the track power is now set at 12v. I also intend to set the Circuit breaker trip at the best level for 2mm, if I can work out what that should be. At the moment I’m spending the time entering all the locos into the database. This is taking a while but having photos and description to select which one to use is I find very helpful compared to having to remember each locos DCC address. Another advantage of using a phone/pad as the throttle is in having a description of every function assigned to each loco for ease of selection. My iphone and ipad will get the layout/loco databases as both a backup and as alternative throttles when needed. These are easily transferred between devices over wi-fi.

 

Bob

 

 

[Nigelcliffe]

13 hours ago, Izzy said:

 

A Z21

 

After thinking through all the aspects with regard to the recent posts concerning DCC track power levels, stay-alives with 16v tantalums, and the quite small decoders used in 2mm I decided to take advantage of the special price my nearest local Railway Model Shop sells the Roco Z21 at and paid them a visit and obtained one. This is Scograil and they share a outlet in Ipswich with Coastal DCC and Orwell Models. My Gaugemaster/MRC Prodigy system has thus been withdrawn from use and put into reserve status for the immediate future. It’s served me well for 14 years.

...........

 

 

You could pull the Gaugemaster out of the store, connect the Prodigy track output to the "sniffer" port on the Z21, and thus use the Prodigy handsets for control knob control with the Z21 sending instructions to the track.

 

 

There are also ways to add a £20-ish control knob to Android Phones, if using the EngineDriver App for loco control.  That does require running JMRI on another computing device.    I'm not aware of the control knobs working with the Roco App.    

 

- Nigel

 

Edited February 29 by Nigelcliffe

[Izzy]

9 minutes ago, Nigelcliffe said:

You could pull the Gaugemaster out of the store, connect the Prodigy track output to the "sniffer" port on the Z21, and thus use the Prodigy handsets for control knob control with the Z21 sending instructions to the track.

 

Thanks Nigel, that sounds interesting, I did wonder if the handsets alone could connect this way rather than the whole system, which would mean yet another mains plug/supply which I wouldn't want. But the long term intention is probably to sell off all the PA2 bits anyway, the basic system, the wi-fi handset, the wi-fi adapter for tablet/phone, if there are any takers. 

 

At the moment I have just discovered the speed curve adjustment response for the throttle slider  in the Z21 app which is proving interesting to use. 

 

Bob

[Nigelcliffe]

1 hour ago, Izzy said:

 

Thanks Nigel, that sounds interesting, I did wonder if the handsets alone could connect this way rather than the whole system, which would mean yet another mains plug/supply which I wouldn't want. .....

 

No, its whole Prodigy system for the "sniffer" - just an option which is cheaper and available now.   

 

There are a lot of handsets that could connect to the Z21, but not Prodigy ones.  Handset list would include:  Lenz, ZTC (with some wiring faff on connectors),  Roco, Digitrax, Uhlenbrock, Fleischmann,  and others.