The Snapper's DCC Workshop - GW Saddle Tank 2007

[3 LINK]

Hi Tim,

Always enjoy reading these topics of yours, food for thought so they say.

Funnily enough my next loco build will be the jltrt 2251, I notice that you managed to open out the resin firebox, can you tell me how you went about it? I always thought the resin was next to bullet proof, although I have never had any trouble drilling the holes for the hand rails.

Regards,

Martyn.

 

[TheSnapper]

Hi Martyn

Thanks!

Loco was Heather's build though- she may be along soon........

Tim

 

[Heather Kay]

Hello all. Thanks to Tim for showing his workings. Not being all that electronically minded, it's very useful knowing someone who is!

Martyn, I have a build thread on the 2251: clickety-click-linky

The resin JLTRT use is, I believe, impregnated with glass to give it some strength. It does blunt drills eventually. I have had success with a Dremel and grinding disc, or sanding drum, in opening out areas such as fireboxes. It's messy, and potentially nasty, so I try not to do it indoors, or while breathing!

 

[SoundsLoco]

Hi Tim,

many thanks for your reply. I tried wiring the fan in the same manner as the lights, but the voltage was far too great and unfortunately, the 5V option that is on the MX695 is not present on the MX696 so I think that Plan B will come onto play - don't wire up the fan, you cannot see the rotation anyway.

I'll just tidy the wiring up this afternoon and seal the speaker with silicone and call it a day.

regards

Mike

Mike,

There is no 5V option on the MX696S, but it is available on the MX696K and KV. (I know that's not much use in this case, but worth bearing in mind for future, perhaps).

I normally re-use the Heljan fan PCB. It has a small pot which can be used to get to a modest fan speed, then trim if necessay with CV60.

Although, when using Swiss Mapping, it is possible to pre-assign specific 'dimming' values for each individual Function Output. This can avoid the use of CV60 and the consequential need for dimming masks in CVs 114 and 152.



To assign an operating key to FO6 using Swiss Mapping is very straightforward.

Swiss Mapping requires you to first determine an unused SM group. There are 17 groups, each of 6 CVs following in sequence from CV430.
(Group 1 is CV430 to Cv435, Group 2 is CV436 to Cv441, and so on. Each CV in each group has a special function; for your simple on/off switching you will need to use only 3 of the 6 in whichever group you use).


Assuming that SM groups 1 -5 have been used for other functions, the first CV in SM Group 6 will be CV460.

(read your decoder to check that its value is currently 0 (zero) and if not use a different group which is free).

Choose the F key you would like to use and put its number as the new value in CV460 (e.g., if you wish to use F15 as that's the same key as the fan sound, say, then make CV460 = 15)

Then assign the Function Output to that F key:

CV462 = 6 (for FO6 in forward direction)
CV468 = 6 (for FO6 in reverse direction)

That's it.


All wired or harness fitted ZIMO decoders are equipped with shrink wrap insulation. I think they must have tested this system at some point as I've never had a heat related problem with any of the one's I've fitted. LOL.

Kind regards,

Paul

 

[3 LINK]

Hello all. Thanks to Tim for showing his workings. Not being all that electronically minded, it's very useful knowing someone who is!

Martyn, I have a build thread on the 2251: clickety-click-linky

The resin JLTRT use is, I believe, impregnated with glass to give it some strength. It does blunt drills eventually. I have had success with a Dremel and grinding disc, or sanding drum, in opening out areas such as fireboxes. It's messy, and potentially nasty, so I try not to do it indoors, or while breathing!

Good Evening Heather,

Thanks for the heads up, I am already an avid reader of yours when you post further instalments regarding the 2251, especially being that it’s next on my to do list.

Might sound cheeky but is there a chance of a short video clip, once all the electrickery has been done.

Regards,

Martyn.

 

[Heather Kay]

Might sound cheeky but is there a chance of a short video clip, once all the electrickery has been done.

Well, I am reliably informed I can run these models on my strictly DC setup, and some of the sound may kick in. On that basis, I doubt a video would help demonstrate much, sadly.

 

[Ressaldar]

Hi Paul,

many thanks for your reply and explanation. Coincidentally, I had earmarked CV460/462/468 in my mind but it was where the 'power supply' lead should be connected that stopped me from carrying out the installation. Which + terminal should I use?

I had the loco running on the Club layout last night and was very impressed with the noise from the double sized Zimo sugar cube speaker that my friend had supplied.

regards

Mike

 

[SoundsLoco]

Mike,

Use whichever of the +ve pads is most convenient, they are duplicates.

Kind regards,

Paul

 

[Ressaldar]

Hi Paul,

many thanks for that information, I will retrieve the loco next week as I handed it over last night without the fan wired up. My friend was most impressed with everything else.

regards

Mike

 

[TheSnapper]

Request for Help!

Has anyone any ideas what this may have sounded like:



This is a customer commission which was largely scratch-built by David Amias, apart from the cab and firebox.

Cheers

Tim

 

[John K]

I’d stick a City of Truro sound set in it. Nobody will know any better.
John

 

[simond]

Or a Dean Goods.

Similar firebox, similar smokebox, similar motion, valves & cylinders. Adjust the chuff rate to suit the larger wheels.

Lovely looking model.
Best
Simon

 

[TheSnapper]

The GW Theme continues......



Although I prefer to install everything on the loco chassis, sometimes it is not possible.

On this model, there was no room in the frames due to the dummy inside motion etc.




Fortunately, the boiler was hollow enough to accommodate the decoder (Zimo MX645) & stay-alive capacitor (Digitrains “Zimo- SC68 equivalent”).




The capacitor was clear-shrink-wrapped and then wrapped together with the decoder with an oversize piece of black sheathing to form a double insulated package. The idea is to avoid any chance of shorting, as it would be loosely located in the boiler.



For the same reason, I wrapped some Kapton tape around the top of the motor





The only place for the Zimo cube speaker was behind the motor. I had to move the pinion gear temporarily to one side to fit it in. I used Araldite to fix it and it works well.





Final testing could be done with the decoder package resting on the dummy inside motion!

 

[TheSnapper]

Thanks John & Simon for your suggestions

I’d stick a City of Truro sound set in it.......

John - I know you favour Zimo - Digitrains don't seem to have a project -have you used the YouChoos one? If so, is it OK?

Tim

 

[John K]

Hi Tim
I’m afraid I haven’t used the YouChoos sounds. You are correct that I use Zimo wherever possible. I have no Western engines, but a young friend has used the Truro from Olivia’s which comes on an ESU V4. BTW, Olivia’s also have a Dukedog listed which might be a better option Olivia's Steam Sound Functions. | Olivias Trains
Best
John