Zorcan

So . . . no one out there understands how the DCC Concepts device performs so much better than a "Conventional" capacitor/diode/resistor device?

Does anyone understand why these devices provide such a long run-time in the absence of the DCC track power? I have opened one up and can see that the circuit is more complex than the "traditional" one I am familiar with - of Capacitor(s), diode and resistor. It contains 6 off 0.47uF 2.7 volt capacitors in series. There also appears to be a resistor ladder, with each capacitor connected in parallel to one of these resistors - I take it that this is to ensure an equal/controlled voltage (and therefore charge) for each capacitor. There are also several other components which I cannot identify - nor is it clear as to how they are interconnected. The most powerful devices I have made contain 3 off 0.47uF 5.5 volt capacitors in series. In principle, therefore, my device should provide twice the endurance of the DCC Concepts device. In fact, I get less than 1 second of running after the track power is lost, whereas the DCC device runs a loco for several seconds. I would appreciate any insight anyone can add.

Very useful Izzy, wish I'd found this post earlier.

That's very helpful, wish I'd found this post earlier!

I have been looking at the possibility and practicability of fitting stay-alive devices to TTS decoders for some time. Attached is an article that describes what I've done and the results. I hope some of you find this interesting and welcome comments. Thanks to Izzy for his post on this topic - his TTS connection point is much easier to attach to than the one I found - I'll be sure to use it in future! TTS Stayalive.pdf

Many thanks to all of you - I've just bought myslef a set.

Apologies if the information I'm seeking is available elsewhere on the site but my searches have found nothing relevant. I need to remove the connecting rods from an 00 gauge loco. They appear to be attached with very small (between 10 and 11 BA) bolts that have very thin heads. I'm looking for suitable tools etc. Thank you

Hi John- I had exactly this happening in my initial devices where the magnets were sitting under the running rails. I have not been able to replicate this problem with the published design. It IS true that if the train is not moving smoothly then couplings can part.

Having decided that Kadee couplings were the optimal way to provide the operating flexibility I wanted on my layout, it only remained to determine the best way to provide the uncoupling function. Kadee make 2 devices: Part code 83 - this sits above the sleepers and between the rails and supports both instant and delayed uncoupling operation. It is, however, visually non-prototypical and each unit costs about £6.50. Part code KD308 - this sits entirely under the track and comes in at only £4.70 or so. As I needed 30 or more uncouplers for my layout, the cost of either was discouraging. I have devised and successfully installed an alternative device that sits entirely under the track (and so is 100% invisible), and provides very reliable operation. At less than 2.5 mm depth, it is easily accommodated inside the ballast layer - i.e. the cork (or in my case closed-cell foam) track bed that many modellers use to reduce noise and help model the ballast bed. It even works on curves - I have used them successfully down to 1000mm radius. These devices are simple and quite quick to make and come in at less than £2 per head. The attached document is a guide as to how to make and install them. Uncoupler Guide.pdf

Yes - it may well be that its not just the motor that may prove short-lived with the Mainline locos

Yes, I've considered all these issues and possibilities. I have a part built manor chassis from a kit (my mainline manor is top of my conversion list) which I plan to finish but I'm not sure if my eyesight and dexterity are still upto doing a good job!. If they are Comet do chassis kits for all my GWR locos. Buying working Bachmann chassis is not a generally acceptable fix - they cost almost as much as a complete loco and their only manor to date has a split chassis - which can often be doctored to take a DCC decoder but I understand that's not a given. I've also got some motorised tenders but tender driven models don't seem to run as realistically as loco driven ones-I am planning to try this as a last resort though Having discovered cheap motors that will drop into Lima models, I was hoping the same option might apply for Mainline. Many thanks for your input.

Has anyone successfully replaced the old Mainline loco motors with something smoother and more durable? There seem to be one or two cheap and easy options for Lima - can these - or others - be used in Mainline models?

Diodes wont work if you want DCC - the back EMF signal will be blocked.

Hi Dave - do you remove all the interference suppression capacitors from your locos when fitting chips to them? - failing to do this can distort the EMF feedback signal to the decoder and so upset speed control. Just a thought . . .

AHHH! That's good to know - I find I usually only find out vital details like this AFTER I've burnt my bridges! Thanks Andi

Yes - I realise I need to remove at least part of it but thought that I should leave some - otherwise why is that raised crescent there in the first place? - I figured it was to stop the gear lifting or dropping out of alignment with the rest of the mechanism.

Yes I think an extra one is the best I could hope for - there is an "interrupted" ring in the geneva gear with the drive pin sitting half way around this "interruption" - I hope that makes sense!. I'll be sure to report back when I've tried

Thanks to all who've responded. I've been googling and have discovered that it is a Geneva drive - I've also found out how it works. The only relatively simple way would to speed things up a bit would be to re-profile the drive wheel to give, say, 3 drive cycles (instead of the standard 1) for every cycle of the geneva drive wheel. It would also require additional spigots at appropriate points around its circumference to engage the turntable. There's spare geneva wheel on ebay just now so maybe . . .

I have modified a Hornby turntable to drive the turntable motor via a DCC loco decoder and fitted additional tracks between the "pre-designated" ones which are provided by the turntable design. This works OK but it is irritating to have the table stop for several seconds at each "pre-designated" track when it would be more realistic to have it continue to rotate (The DCC controller allows rotation speed to be reduced to a crawl in order to align precisely with the required track). Is there a mechanical modification that can be made to the drive mechanism to achieve this?

Thanks guys - the credit card trick worked a treat - I cut one into 4 narrow strips - one for each corner. I couldn't afford the repayments on the card so I've killed two birds with one stone

Can anyone help me here please? The official Bachmann assembly diagram and instructions state the the body just clips to the chassis and can be removed by "carefully prising" it away. I have tried with as much force as I dare but whilst it moves a little, I cant see how to get it off without damaging it. Has anyone mastered this problem?

I should have added that I've not attempted to set any speed curves.

Yes - I've had several similar experiences. They ranged from minor undue speed variation in one model through extremely zealous down-slope acceleration to violent stop-start jerking in others. In all cases, I had not removed all the motor suppression capacitors. In all cases, doing so fixed the problem.

I eventually applied due force and guidance and managed to relocate the drive shaft. The force was such that I'm incredulous as to how ANY mishap that did not also result in cosmetic damage to the loco could have dislodged it in the first place (I was not present when the "event" occurred).

Hi - I have used these both as wired and 8 pin plug varieties. They (all?) feature stay-alive leads (some come with small stay alive devices). They have specs similar to common or garden devices from Bachmann, Hornby etc,