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NIK

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Everything posted by NIK

  1. Hi Mike, Sorry, I didn't spot it was a non DCC topic but carrying on from what DCB said did you buy any of the units second-hand in which case there is a slight chance they may have DCC decoders fitted but running in DC compatibility mode. You said it was not controller specific but were all the controllers tried of the feedback type?. There is just a chance that feedback controllers may struggle with multiple units. Also I find it very difficult to judge slight changes in speed of a model train - maybe coupling together units is showing variations in electrical pickup. Do the units have Kadee buckeye couplers at the cab ends - that may reduce the effect of surging. Regards Nik (EMU and DEMU mad)
  2. Hi, I've not looked into this in detail but I think I remember talk about the back EMF feedback features of decoders reacting with one another when in a consist. I think the solution that was mentioned was to turn off the back EMF feedback feature on all 'locos' except the leading one. I think that's a bit of a challenge for model Southern Region practise in particular where splitting/combining of units can occur quite frequently in stations and fiddle yards. I don't think there are any DCC decoders that offer say the option to automatically turn off the back EMF feedback to all of the advanced consist bar the front unit. Regards Nick
  3. Hi, Perhaps Bachmann sold a larger number of green 4-CEP than Hornby sold 'original' 4 VEPs?. Or some of those who bought original 4 VEPs are too ashamed to reveal that they had by advertising them for sale?. Regards Nik
  4. Just a few minutes to go before opening. Steve Flint is the judge for Best Layout this year. I'm told there are some tempting prices on a second hand stall. Grindley Brook looks like a treat for afficionados of scenic modelling. Regards Nik
  5. Hi, No work on Beggarwood Lane planned this week at the club as we prepare for our annual exhibition at the weekend where this time we hope to raise some money towards the interior of our new club hut so that we can get it signed off by the building inspector and we can move in. Beggarwood is planned to all go up after our show. A lot of third rail has been lowered. In addition to a block of flats a 1960's industrial unit has been started for the right hand end of the scenic section. It looks a lot cleaner than the Victorian warehouse to its left and the 1930's flats to its right but I guess it should do. Scenery was starting to encroach on the site for a shunting signal for the carriage sidings but after consultation with our newly retired signalling engineer its going to be replaced with three ground position light signals. We've started to look at whether the viewing public will be able to see the aspects. Once the layout is up we can put a bit of string on the floor to represent the barriers and then see which if any of the ground signals can be seen straight enough to be seen. Will probably fit all three ground signals with surface mount LEDs plus wires as it will be difficult to retro fit them. Signalling the carriage sidings has brought up the problem of how to signal bidirectional lines. There are understandable route numbers for the three sidings, and for routes that are unidirectional I was going to add clearing a signal to the end of an NCE macro. That's not going to work for bidirectional routes where the signal to be cleared depends on the direction the train is going to go. We may have to look at the NCE macro number allocation to find macros that are both spare and where the number indicates which direction the train is to go. The NCE Power Pro macro numbers go from 0 to 255. 0 to 9 have been allocated to routes in the goods yard in order to speed up shunting (less buttons to press on the hand held cabs etc). Some of 10 to 99 are allocated to routes on the clockwise and anticlockwise mainlines. Some of 100 to 199 are allocated to routes associated with the loop on the anticlockwise mainline. Some of 200 to 255 are allocated to routes associated with the spur with the gradient. Some of 100 to 255 are used linked to other macros to extend them as NCE Power Pro macro can only have up to ten instructions each and some routes involve setting more points than that. So they are reserved but not typed by the operators (hopefully). Regards Nik (on behalf of Basingstoke and North Hants Model Railway Society - still looking for members)
  6. Probably. Depends what you mean by sound. The photo shows a circuit board with a DC blanking plate plugged in. So no DCC sound decoder mentioned or shown. Or a DCC non sound decoder. The spring like thing is an inductor in series with the motor and if its come away at one or both ends the motor will not run. Regards Nik
  7. Hi, There is a commercial kit in HO that use a tiny DC motor to open the hinged jaw of a Kadee coupling. The motor could be controlled I think by a DCC decoder probably one of the types that deals with DC motor/solenoid DCC uncouplers. The DC motor/solenoid approach I think makes it easier to couple up as motor/solenoid only pulls the jaw open and a very light spring returns it while allowing coupling without operating the actuator. A servo tends to stay at the position it was last set to and is difficult to budge when coupling up. I think the friction when coupling has to be less than the static friction of the most free running bit of stock you have. In OO I've measured static frictions down to 0.75g for one type of 4 axle coach (with electrical pickups on the coach). You could do something similar to the kit mechanically 3D printing the coupling parts (apart maybe for the spring)?. Regards Nik
  8. Most of what you said plus JMRI (free computer assistance software for model railways)?. Regards Nik
  9. Hi, Well spotted. My booster is drawing 440ma at the max setting of my DC rolling road. Did you measure the current draw at max speed step/max DC voltage?. Regards Nik
  10. Hi, Some DC motors sold to fit in model loco kits etc have varistors fitted internally which may limit voltage spikes. Whether they help with EMC I don't know as the varistors could be there to protect the commutator. Regards Nik
  11. Thanks Andyman7, I didn't know there had been a batch of Blue Grey Hornby VEPs with improved gearing. I've been comparing the slow running of a SWT Revision 2 4 VEP with a Blue 4 VEP. I will look through my Blue Grey VEPs to see if I have any with revised gearing - will the corridor sections having internal compartment windows modelled be the giveaway?. Regards Nik
  12. Hi, I'm not sure a definition of DCC READY as 'Not fitted with a decoder but any can be used for all functions to work correctly.' quite covers it as there can be locos with more functions than some decoders have. Also the amount of space in the loco and the current requirements limits which decoders can be fitted. Also there are lots of different DCC decoder connectors some of which are incompatible with one another. As to another reply about all DCC decoders being DC compatible is not quite true as some decoders have problems with some PWM controllers, including Hornby HM7000 decoders which can stop working. Also DC layouts with high voltage track cleaners probably damage DCC decoders. Regards Nik
  13. Hi, I've been doing a bit of comparing of running qualities and wheel dimensions between an early Hornby 4 VEP and my revision 2 SWT 4 VEP. Early VEP power car: poor slow running (Zimo MX600R). Approx 1.3mm deep flanges on trailer coach wheels. 130 scale mph top speed. Latest VEP power car: better slow running (ESU Lokpilot 5 after autotune and manual adjustments). 1mm flanges on trailer coach wheels, 0.86?mm flanges on power coach. Both early and latest VEP had 13.33mm wheels on the power coach which equates to 3 foot 4 inch diameter. 13.33mm dia is the same as the Dapol OO Class 73. Power bogie wheelbase is 35mm. Regards Nik
  14. Hi, A ESU Lokpilot 5 DCC decoder arrived and I replaced the Zimo MX634D with the ESU decoder to try and improve the running. I put the revision 2 Hornby 4 VEP power coach on my rolling road and ran the ESU Lokpilot 5 "Autotune" feature. I didn't get the same motor control (Back EMF etc) CV values as a friend who autotuned his 4 VEPs on the flat bits of his layout. I only have a 4 foot test plank to hand at the moment and the autotune runs the powered vehicle at high speed for 1.5 to 2 seconds. As the values on the rolling road were noticeably different I used CV values similar to his: CV51 = 11 CV52 = 4 CV53 = 94 CV54 = 29 CV55 = 16 Slow speed running was then pretty good on the flat but when I made quite a down gradient the VEPs speed was a bit erratic. I lowered CV 55 value to 8 and that made the down speed smoother. Next to try it on Beggarwood Lane with all the VEP coaches, first the EMU on the flat and then down the gradient. Regards Nik
  15. Hi, Did you mean LMR in both instances?. Regards Nik
  16. Hi, Just for a bit more detail, without a suitable current limiting resistor between bridge rectifier a typical DCC decoder bridge rectifier will be damaged by the initial current as the capacitor charges. A diode is needed between the capacitor positive back to the +ve on the bridge rectifier so the charge from the capacitor can be supplied to the appropriate bits of the decoder when contact is lost with the track. Regards Nik
  17. Hi, I had it a number of times recently while creating or editing an RMWeb topic reply. Regards Nik
  18. Hi, I've just had a funny one while evaluating a new (revision 2) Hornby OO 4 VEP in SWT livery. I noticed while trying the DCC slow running of the power car on a test plank that it was jerky in one direction (to the left) but smooth in the other. Turning the power car end for end and it was smooth to the right and jerky to the left. I cleaned the track, added a stay alive and tried adjusting the Zimo MX decoder K and I parameters to no effect. I then noticed the test plank has a slight slope to the left. Levelling the plank and the power car was smooth in both directions. Making the plank lower at the right hand end makes the power car jerky running slowly to the right but not the left. I will check the flatness of the club layout I intend to run the VEP on (at least the bits where the VEP may be running slowly and are also seen by the public). I've got some ESU Lokpilot 5 decoders on order so they may help with slow running on gradients. Regards Nik
  19. Hi, I've just noticed on my SWT new 4 VEP power car the slow running going forward is a lot better when the power bogie is at the 'front' than when it is at the back. Does the great weight over the motor bogie crush dirt on the top of the rails so the pick up on the trailing bogie is better?. Regards Nik
  20. Hi, Re surface mounted point motors I would avoid the micro linear servo type as they tend to have not enough power to reliably operate points. Regarding DCC decoders for locos I try and use Zimo decoders when they are available. Of course selecting a decoder that is small enough and powerful enough is a higher priority than manufacturer. I don't have much experience about consistent stopping and braking especially if you intend using ABC control with distance control. Regards Nik
  21. Hi, According to the Hattons DCC decoder manual and JMRI Decoder Pro definition the Hattons decoders do not have a brake on a function feature. Did you mean a MERG CANCMD2?. Regards Nik
  22. Or the original Hornby 4 VEPs - the mystery being how the two designs got approval. Regards Nik
  23. Hi, Its section 11.1.4 of the Lokpilot 5 manual that deals with 'autotune'. I don't know if this also works on rolling roads as in that case most of the loco has no momentum. Regards Nik
  24. Hi, I've yet to fit a servo in a model railway vehicle but servos typically need a power supply of 5 volts and they draw hundreds of milliamps (more than a 5V logic level output from a small decoder). As far as I know small DCC decoders that can control servos don't come with 5 volt power out. One way is to make a circuit with a fast bridge rectifier to convert the DCC to DC and then a DC to DC converter to drop the rectified voltage of about 12 volts down to 5 volts. I don't know if anyone makes such a circuit, German or USA suppliers would be the most likely to. Regards Nik
  25. Hi, I spoke to a club member who has just bought two SWT 4 VEPs about the slow running problems I had with mine. His VEPs ran badly with ESU Lokpilot 5's until he did the autotune. So I will try a Lokpilot 5 and see if it improves the running on mine. He also said the wheels look rough and sound rough at speed. I've now done a few runs of the VEP on a club DCC layout and it runs smoother with the three trailer coaches. I help with a gradient and curve predictor which predicted the VEP should just go up a 1 in 40 gradient with 36 radius curve given a run up rather than a standing start. The 4 VEP would go up the gradient with curve without signs of spinning. However I haven't measured the static friction of the trailer wheels yet and they have an effect on the prediction. The VEP would not haul any extra coaches up that bit of track although the club coaches to hand were not free running. There was one two inch long stretch on the gradient with curve where the 4 VEP would not start without spinning its wheels but apart from that it was fine (the gradient/curve predictor does not presently deal with starting on an up gradient/curve). Until the whole layout is up I wont try any speed tests - will it exceed the 130 scale mph my original 4 VEP does?. Regards Nik
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