NIK

Hi Ray, The six notches might just something possibly a brush or brush holder catching on the six electrical bonds between the commutator and the armature coils (assuming it is a three pole motor). If so that probably shouldn't happen in a motor. Take care. Nick

Hi, During UK lockdown I decided to practise casting in my back garden with my first fishing rod. I found I couldn't see the metal shot I had as a dummy tackle as I reeled in so I wrapped it in small yellow rubber bands (the narrow type). After the first cast I reeled in the line and while the weight/bands were hanging 3 feet above the ground a Robin flew to it, changed his mind and flew on. Afterwards I realised the weight etc looked like a ball of meal worms. Take care. Nick

Hi, I think we are at cross purposes. That's not AC. AC is a current that flows in one direction and then back the other way and does this repeatedly. I had a selenium rectifier that got overloaded. It took decades for me to forget the smell. Take care. Nick

Hi, Do you mean AC (where the current goes positive and then negative) or DC pulses?. Just out of interest which controllers had an adjustment for AC injection?. Take care. Nick

Hi, I lost money when a small model railway supplier failed to supply a kit and subsequently disappeared off the model railway radar. Many exhibitions are organised years in advance and unless an exhibition manager gets info from trading standards or another official body that an offence has been committed they may be reluctant to disinvite a trader. Take care. Nick

Hi, I've started seeing Starlings appearing to catch insects about 60 foot up. Saw a small hawk being mobbed by two crows (it was smaller than a crow). Too far away to confirm it was a Sparrowhawk. Second time I've seen a bird of that size being mobbed this week. Take care. Nick (in North Hampshire, UK).

Hi, I hope I've got this right but a 6 function DCC decoder may have the following function outputs: F0f (forward light) F0r (reverse light) F1 F2 F3 F4 If that is the case then mapping F2 to F5 would result in what you saw. Take care. Nick

Hi, What do the instructions supplied with the loco say?. Take care. Nick

Hi, I don't know who the photographer was and if I did I wouldn't name him to spare his blushes. I'm guessing he hadn't done model railway photography before. As a teenager I once got paid to do a rush photographic job. The engineering firm my dad worked for needed some photos of part of a mechanism. It may have been part of an automated ticket barrier for the Singapore metro. The photographer they normally contracted was off in the North Sea photographing oil rigs. The mech was tricky to photograph as it was a mixture of black anodised aluminium and polished stainless steel plus it was small but deep. I only had a Zenith SLR and an ancient hand held exposure meter but the print negatives came out ok (I printed the B&W photos via my Zenith enlarger). Take care. Nick

Hi, Photography is sometimes not done by modellers. A mate was having his layout photographed for the Railway Modeller and the photographer wanted to take the photos with minimal depth of field. My mate pointed out this was not how things were done and it would make things look - well, toy like. I can't remember if stern Steve was phoned but sanity was restored. We need another Brian Monahan. Take care. Nick

Hi, It's probably not just DCC decoders (or some decoders) being more sensitive to power interruptions, the design of pickups that may be fitted to modern designs of RTR locos may be a contributing factor (along with track cleanliness and track flatness which have been a factor even when DC was the main option for model railways). The more accurate a model the less space there is between chassis components and tiny debris can get stuck more easily. That debris can bend pickups away and stop wheelsets sliding on their axle bearings. Also the design of models based on a bigger range of prototypes may dilute the knowledge base of the RTR designers with respect to long term reliability in real life conditions. Take care. Nick

Hi, It may have been deleted but I think the history of Pulsed DC controllers and their operation with coreless motors has been covered before as a topic on RMWeb. Just out of interest the only RTR loco I have that came with a coreless motor is a DJ Models Class 71 OO Electric outline loco. It draws 200ma light engine (without lights or sound), top speed of 55mph and can't pull the skin of a rice pudding. I've bought a Faulhaber coreless motor to try as the motor for a kit built OO EMU and hopefully I will have better results. Take care. Nick

Hi, How relevant is this to the OP or to the topic involving DCC?. I think you mean Compspeed but maybe your fingers weren't composed at the time. Take care. Nick

Hi, The topic is about Coreless Motors on DCC so DC controller experience is not so relevant. High frequency PWM drive is becoming very common in DCC but until recently in the UK coreless motors were restricted to non RTR locos so there wont be much practical experience of coreless with DCC. Maybe there are not many instances of problems of coreless motors with DCC on UK locos because folks now buy a modern design of DCC decoder to go with their expensive RTR loco. Maybe the first few UK locos with coreless motors were highlighted by the reviewers in model railway magazines so DCC users has some sort of guidance of what sort of DCC decoder to fit. Now some magazines don't bother to mention if a newly released loco's motor is iron core or coreless. Take care. Nick

Hi, Well done to Andi for an identification. At first I thought a bit was broken off the PCB at the speaker end but I think its a bit of insulating tape hanging over the edge of the PCB - It might be very thin Kapton or aged Sellotape. If it is sticky tape then any tiny debris from the other items in the consignment might collect on that tape and possibly short out any tiny contacts on the components. So maybe carefully look at replacing/removing the tape before applying power for the first time (remembering to identify where the DCC track power should enter the PCB). If you are going to test the PCB I would start out with a standard programming track output as the power source (not one slightly boosted for sound use). If no smoke appears then proceed as per any sound decoder (may need to use programming output tweaked for sound decoder use). That capacitor hanging off the PCB may have been added by the previous owner. Without further research I would recommend removing it with its wires before any testing in case it fails and shorts out. I've had a main track on a loco PCB burn out just due to a derailment. Also the PCB was resting on bubble wrap. That could be a cause of static damage so until the PCB is installed in a loco I would recommend you keep it in an all paper envelope or all card box. Take care. Nick

Hi, At a guess and without knowing what size it is it looks like most of the main PCB for a diesel or electric outline locomotive, possibly US given the age of the chassis it was sold with. It seems to have a digital command control decoder of some type built in to the PCB, could be NMRA DCC and it may be a sound decoder (if the roundish thing at the top is a speaker and not an energy store). In which case its probably nothing to do with the UK Mainline chassis apart maybe for being part of a modeller's project to mate it with the chassis. If you want to test it on NMRA DCC you may need visual confirmation it is NMRA DCC (hopefully someone on here will recognise it or you can look online at DCC decoders for non UK locos - could be from a loco with narrow engine compartment - probably a US 'mainline' diesel loco, not a streamlined loco or a B unit). Take care. Nick

Hi, There may be two aspects to running coreless motors in model locos: 1) Motor damage. 2) Poor slow running. With DCC aspect 1) can be addressed by selecting a DCC decoder that can output a high enough frequency drive to the motor. 2) Poor slow running on DCC - I don't have any practical experience of. If a motor outputs too much torque at low revs and the feedback system in the decoder is not correct then surging could happen. Many DCC decoders have some adjustment of key feedback parameters and some brands have quite sophisticated adjustment. Also DCC systems can respond differently to tiny interruptions in the track/wheel and wheel to pickup interfaces than DC controllers and locos. Coreless motors have less magnetic friction (cogging) so respond quicker to fast changes in the power being applied (such as pulses from DCC decoder motor drives). For the same reason they have more of a flywheel effect than iron cored DC motors so once they have been given a power impulse it takes longer for the motor/output gear to retard back to a lower speed. Take care. Nick

Hi, The Red Kites only reached my part of town about ten years ago. Unfortunately my telephoto lens broke shortly afterwards and I couldn't afford to replace it and carry on snapping the Kites. There is a golf course a pitching wedge away from my house and I'm wondering if its still being mown and sprayed with herbicide. If not its ecology might change fast. I've read that Red Kites don't take live prey larger than worms or beetles there are now probably squashed rodents (first surprised and then flattened by middle aged runners). Before the lockdown I almost trod on a rat when I was crossing a lock gate on a canal. The rat was traversing a beam below the plank the humans use for crossing and I and the rat arrived at the step down from the lock gate at the same time. Take care. Nick

Hi, I've yet to even see a Hen Harrier although a few years ago a neighbour said he saw a pair above a nearby field. I once had a juvenile Peregrine Falcon land in my garden briefly (after 24 hours of continuous rain) and a mate in the same town had the same in similar circumstances. Take care Nick

Hi, Saw a Buzzard flying about 50 feet up the other week. Buzzards had largely been displaced in the last few years by Red Kites over the part of the town I live in which is in North Hampshire. I surmised the Buzzards appearance was due to reduction in roadkill. Also it was flying lower than normal. Of course there may be less dead lambs this year if the weather has been milder. Two days ago I saw a Red Kite go over my garden at about 20 feet high - I've never seen one go that low in my town before. I guess like the Buzzard it was extra hungry or it was a country bird that was searching for food outside of its normal environment. Those people who normally leave food out for kites might be changing their habits and there is probably less discarded takeaways on the streets. Take care. Nick

Hi, Following on from a previous post the Coastal DCC website says the MX636D has 8 function outputs. A pinout of a MTC21 connector I found shows 8 function outputs available labelled F0f, F0r and AUX1 to 6. So maybe there is no need for soldering. I think I tested all eight outputs on a MX634D by just by plugging its 21 pin connector into my ESU decoder tester (two were at logic level). What it doesn't seem to say on the Coastal DCC website is what the current rating is of each function output, what the total is for all eight functions and what the total is for the motor plus functions. Note the MX638D is considerably cheaper but it only has 6 conventional function outputs and two logic level outputs so in that respect it all depends whether the loco you are planning to put it in requires 8 functions or 6 'f' plus 2 logic. Take care. Nick

Hi, A digital SLR with a selection of lenses (plus a tripod). An SLR so you can get an optimum view of what is in focus, a selection of lenses to get optimal optical quality for the distance you want to shoot from and a tripod for maximum stability during long distance shots and or low shutter speeds. The SLR will also allow you smaller apertures which is key if you want 12ft to the inch style depth of field. I don't think anybody does an SLR small enough to sit on a baseboard and photograph an N gauge train let alone a Z gauge one so no one camera type can do everything. Take care. Nick

Hi Nigel, Do the DCC decoder manufacturers make it clear in their online literature what frequency their various decoders PWM run at?. I recall some online decoder manuals (ESU, ZImo, Lenz & ?) do mention the frequency(ies). Do you know of a decoder selector that includes PWM frequency (the Coastal DCC selector doesn't seem to include it)?. Take care. Nick

Hi, Re: operation on DCC: You need a type of DCC decoder that can output high frequency drive to the motor. This is because DCC decoders and most DC feedback controllers send full voltage pulses with a square edge to the motors. Most iron core motors can cope with this but coreless motors require a more sophisticated drive in order to stay reliable. This can be done by driving them with pulses of sufficiently high frequency that the lower inductance windings of the coreless motor can 'resist' enough of the short pulses to avoid motor overheating. If a low inductance winding is given a lower frequency drive the current stays too high for too long. I think DCC decoder drive frequencies from 11khz upwards are ok, 19khz and 22khz are also frequencies I can recall from DCC decoder specs. Take care. Nick

Hi, Wouldn't Shane have heard the loco motor buzzing if it had a DCC track supply connected to the motor outputs?. Take care. Nick