Thursday, April 24, 2014

Improving a Tank Engine

G'day,

After having spent twelve years in the Royal Australian Navy and now being a civilian, it felt strange not having any ANZAC day commitments. I watched the Canberra services on TV and felt a lot of admiration for those that have seen or have been affected by conflict. I was lucky, being Navy aviation orientated meant that most of my time was spent safe and sound in Nowra. I volunteered to join the Navy, I could not imagine how some people felt being conscripted. It would have been very hard. 

Instead of marching I spent the day finishing off my Trax Z13 for this evenings club meet. As this was my first real DCC conversion a few things needed tidying up. One such thing was the extra driving wheel pick up method. As standard the Trax model is fitted with a plunger type pick up on the non driven driving wheel. Previously I simply added a bronze wiper for current collection on the driven driver. I was not completely happy with this arrangement and wanted to add another plunger pickup in lieu. The positioning of this plunger pickup comes very close to the brass gearbox. With some measurement and purposely built parts it all lined up and fitted quite well. I had a large piece of Teflon type material which I made the shouldered bushes out of on the lathe. The Teflon piece was around 40mm in diameter so unfortunately a fair bit was wasted turning it down to around 3.5mm! NWSL make some nice little shouldered bushes so I may order some of those for the next Z13. Luckily a spare spring is included in the locomotive spares kits. With a turned washer, spring, bushes and pickup rod it was all added to the chassis. So far it has worked very well. I may carry out this mod on future models.


Existing plunger on left, new plunger on right.


Along with this mod, 1311 received a new Mashima motor. I was having some erratic running problems when the loco was first used. As the motor warmed up it tended to come good. I noticed while running the erratic motor on the bench that it did not hold a constant speed. You could hear it sort of hunting whilst running at higher speeds. The commutator was quite dirty and grooved but even after a clean up it didn't really improve things. With the new motor I was able to use two screws for mounting. The old motor was held in by two brass straps, these could be seen quite easily in the cab. Now with the new mounting method the motor takes up less room in the cab. The only issue I have now is that the new motor makes a little more noise than the previous power plant. I am hoping as the brushes bed that this noise decreases.

On other fronts, I took a trip to Canberra last weekend for the ARHS Garratt steaming. I went there with the intention of recording some sound for use in ESU decoders. As this was my first attempt I learnt some valuable lessons. Next time I will be better prepared.

In regards to my track laying mission, I have decided to use the OO-SF standard and have ordered the track gauges from DCC Concepts. These can only really be used with code 70 rail so I may have to take up one of my mates offers to build some code 55 suitable gauges. The OO-SF standard has been used for a long time in the UK. Interestingly the AMRA fine track standard is basically a carbon copy. I like this standard as it enables the use of 1mm flange ways without the need to modify the back to back of wheel sets away from already established standards such as the NMRA standard. This means that models straight of the box should only need minor tweaking to make sure the back to back is within tolerance and also means that I will have no problems running my models on other peoples layouts. Sounds good. Just have to build the track now ha!

Well that about it. Not very interesting I know!

Linton

Friday, April 4, 2014

Three Cylinders are Better Than Two

Hi,

I have been working on a NSWGR D57/58 ESU sound project for a few months. After a few attempts, some bad and some ok I think I have finally come up with something that sounds accurate.
My second attempt used only three chuff sounds in four drive scales. While this was ok it seemed too clean and repetitive. Thanks goes out to Colin Hussey as he pointed this out to me after I sent him a recording of the project playing through the decoder. This made me go back to the drawing board where I decided to use a real recording using all six chuff sounds. A lot of audio modifications were made and I ended up with 24 different chuff sounds which were loaded into their corresponding drive sound slots.

While the 57 and 58 most likely sounded a little different to each other, due to various design reasons, I am at this point happy to live with the models sounding the same. I may modify the sound files again to improve the 57 class project, however at this stage it is not very high on the to do list.

After seeing how DCC can improve the running ability of a model, my Uncle decided to bite the bullet and asked me to install sound into his second run Bergs D57. The 57 is pretty much fully converted now and performed nicely on the Illawarra clubs DCC layout last night.

I still need to come up with an easy method for disconnecting the micro connector so as the tender and loco can be separated. While it is not too bad at the moment, I want to make it more accessible and less fiddly.

Anyway here is a clip of my Uncles 57 on my four meters of track. Still can't get the DSLR to take good video. Sorry about the focus.



Linton