Robin2

I have the Deltang Tx1m transmitter controlled by an Arduino Uno. (This is visible at the rear of my video). The transmitter can transmit 7 channels of data (which would be used for various functions such as ailerons, elevators, rudder, motor speed etc on an aircraft). In my case my receiver only needs one channel to control the speed and direction of the loco. For each receiver you can choose which channel controls the motor. That means that my transmitter can control up to 7 locos operating simultaneously. Of course my brain couldn't manage that - they would all crash - but that's not the fault of the technology. It would also be possible to allocate (say) two (or more) channels to each loco so that lights could be switched on and off. That would obviously reduce the number of locos per transmitter. I'm not aware of any reason why I couldn't add more transmitters to my Arduino Uno to cope with a larger fleet of locos. Because my locos run on a single LiPo cell and don't draw much current I can use the smaller Deltang Rx41-d receivers. I have a demo setup which uses a potentiometer connected to the Arduino to control speed and direction (centre off). You can see the white wire leading to it in my video. The Arduino Uno has connections for a max of 6 potentiometers. However my main intention is to control the trains from my PC using the Arduino as an interface to the transmitter. I am also using the Arduino to control two fiddle-yard turntables, one at each end of my layout. That should be working in the next day or two. I have a Topic about it in the "Computer Control" section. I also plan to add train detection for automated running (hopefully). I will be happy to provide any further details. ...R

Frank ... that's wonderful (but how do we know you are not using electrically conducting glass; have a magnet hidden somewhere or a piece of transparent fishing line - just joking). Kev ... Sorry I have no interest in or knowledge about special batteries. I have no plans to go into production. The batteries I am using measure 7mm diameter x 30mm long and claim 80mAh capacity. None of the other sizes I have seen on a few internet shops will fit. There are thinner ones but they are too wide for N Gauge. In another loco I could fit a battery that's 7x12x30 but I haven't seen any that size. Part of the problem is the cost of mail-ordering a single cell - so I decided to standardize on the ones I have. I was originally thinking of using pairs of cells (7.2v) to avoid having to change the factory fitted 12v motors but I have decided to stick with single cells to make refueling my "fleet" easier. I think you would need a very large production run to justify an unusual shape and I doubt if any model locos sell in sufficient quantities. Phones sell in their millions. It would be interesting to know if the Chinese market has other sizes of small LiPo cell that are not yet on the market here. Stuart ... I like the idea of you being a spokesman for BPR/C. What I object to is your apparent simultaneous role as a spokesman for the "rest of the hobby" (your words) whoever they are. I don't feel any urge to prove that my BPR/C loco is "genuine" - especially to someone whom I had expected to accept my bona-fides and welcome my efforts. I have described the simple features that make my loco work, and people are welcome to copy the idea themselves. If they have specific questions I will try to answer them. If they are not interested, that's a matter for them. ... R

Stuart, I'm rather tired of this. You say "its not me you have to convince, its the rest of the hobby" Let the "rest of the hobby" speak for themselves and stop acting as their unelected spokesperson. You are no help to the BPR/C cause if you insist on sowing doubts about other people's honest and successful work. If you, yourself, think my video is a fake tell me why you think what I have done isn't possible and then I will try to provide a convincing answer. ...R PS it would be quite impossible for me (or you) to produce a video that could not be challenged as a fake.

Stuart, You started this topic so I can't understand why you are so sceptical. I haven't come across anyone else who questions my bona-fides. It's not like I was trying to demonstrate perpetual motion or magnet powered motors. And I am not the only one with a working N-Gauge BPR/C loco - there are also videos on the Deltang website. Take my word for it, the loco runs perfectly well when it lies on its back with its wheels in the air. ...R

Stuart, I'm completely confused now. I put a link to a short YouTube video in Post # 85 in this Topic, and, from your subsequent comment in Post # 86 I presumed you saw it. When I went back to that Post just now the link wouldn't work so I have edited it. To save you going back there this is the link If you saw the video (or view it now) and don't believe it you must be assuming that I am trying to deceive the world - why would I bother? ...R

Stuart, I don't understand where this question has come from The Deltang stuff is already available - how else would I have been able to convert my loco? Or are you the person who remains to be convinced that I already have it working? (And my comment about Acc+Ess was tongue-in-cheek ) ...R

Hi Tony, I hadn't realized your other (incorrect) post had been intended for here so I commented on it where it was. To save people jumping around I said "... it looks like your system is a bit behind the Deltang system?" ...R

Yesterday I removed ALL the wiring from under my baseboards and ordered 2 more Deltang receivers. Soon, and for the first time in 30 years of dabbling with model railways, I will be able to "play" with my trains. ...R

I've been interested in trains planes and automobiles (and boats) all my life - both full size and models. I like making things and fiddling with things. I'm not so good - or so interested - at finishing things, but I love starting. However I have never really been interested in actually driving model trains. And last night I suddenly realized why. I have mentioned earlier in these pages that I have converted my Grafar Large Prairie to BPR/C but I had only run it on a 400mm piece of spare track for testing. Yesterday I decided I really should try it on my "developing" layout. And IT JUST WORKED. I could run up and down the track or go in and out of sidings without any hesitation. And when one of the loco bogies derailed it just kept going until the whole loco derailed. Just like the real thing. Previously with all my track powered locos (both OO and N) I could guarantee that they would get stuck somewhere and need a push start. And that was why "playing trains" was never interesting. Hooray for BPR/C. ...R

The Deltang radio system that I use is complete in itself and doesn't use DCC so I have no advice to offer on that front. You can use the Deltang receivers to operate lights with some of the extra channels. I don't know if it's possible to control sound systems. The Deltang receiver is "bound" to a transmitter so there are no interference issues. ...R

Hi Stuart, The problem (as I see it) is that if you standardize on a motor/battery combination you will limit the range of locos you can convert or you will bring on yourself extra work changing motors that wouldn't need to be changed if you could use batteries that suit them. This would be less of a problem in larger scales where there is more room for a "standard" battery. A battery is easily overcharged if it is fed with a too high voltage. In the case of LiPos I believe fire is a likely consequence. If the battery is fed with a modest voltage the charge current will indeed reduce to a trickle as the battery's internal voltage rises to match the external voltage. But with that modest voltage the overall charge time might be too long - hence the use of complex chargers. I am currently (no pun intended) planning to charge with modest voltages. I'm not sure what you have in mind with your comment about the rectifier. Perhaps are talking about rectifying the output from a mains transformer. However there is another issue - which way round is the loco placed on the track? This doesn't matter when there is no battery inside the loco. As I am planning a couple of fiddle-yard turntables my locos will have to be able to deal with being "the wrong way round" on the charging track - hence the need for a rectifier inside the loco. ...R

I don't want to give the impression I have any expertise in relation to LiPo charging - quite the contrary. The circuit I got from the internet regulates the voltage (I have a digital multimeter - or three). With my single cell setup I have set the voltage high enough to get 4.2v at the battery after allowing for the voltage drop (about 1.3v) across the rectifier diodes. That's measured with direct connection to the pickups. If there is a voltage drop at the track/wheel or wheel/pickup interface it will act to make things safer (and slower to charge, as you say). I have measured the charging current (while sitting on the track) at about 30mA but at the moment I have no idea what state of charge was on the batteries when they were delivered. I could obviously increase the current by increasing the voltage but I am happy to play safe for now. I have yet to experiment with a voltage divider. If it does not work safely I will have to have different charge tracks for the locos with different numbers of batteries - not insurmountable but it is a potential source of error. I also suspect that the charging rate may be more of an issue for the locos that retain their 12v motors as I expect they will consume more power. But maybe I can fiddle with the track voltage to deal with that, and then readjust the voltage divider on the Large Prairie to take account of any changes. I will probably order the receivers for my other two locos in the next few days and then more experiments can follow. ...R

Hi Frank, There is no room for it in the loco so I will use the charging circuit to feed the appropriate voltage to the charging track in my fiddle yard. I am hoping there is room in the small loco for a couple of small resistors to make a voltage divider and that a voltage divider is an appropriate way of charging a single cell from a 2-cell voltage. I haven't experimented with this yet. To stay on the safe side I don't intend to do fast charging. ...R

That's good news. Hopefully he is just going to move this Thread to a more accessible location so that all the info it contains remains available. ...R

This is a link to the web page where I found the circuit I am using for LiPo charging http://shdesigns.dyndns.org/lionchg.html It seems from the "Charge Characteristics" graph that charging is straightforward as long as the batteries aren't severely discharged, the current is limited and the upper voltage limit is reasonable. I don't plan to leave them unattended while charging. If anyone has any alternative information I would be interested. ...R

@Frank - cool videos. @StuartM, @David, I've thought a bit before answering your request (which is unlike me!). I have already unsuccessfully petitioned Andy to have a front-page link to radio control (to this thread and another on the 7mm group about r/c road vehicles) - because I think people will only find this thread by accident. Perhaps you could have another go at him? However I'm not at all convinced that another new thread will be helpful - won't it just leave people even more confused about where to post ideas and questions. Of course I will listen to counter-arguments. Having said that I will be delighted to share my modest experiences with anyone and everyone, including, if anyone wishes, the program that I've written that allows my Arduino to send PPM signals to the Deltang Tx1 transmitter. At one level switching to radio control is easy-peasy. Install a battery and a switch; connect two wires from the receiver to the battery; connect two wires to the motor; switch on transmitter; switch on receiver; drive. The complications are in fitting all the bits inside a small body - which is really a mechanical exercise. There is also the issue of recharging the battery. It's probably not practical to remove the batteries to charge them or to swap a fully charged battery for a depleted one (as the R/C flyers would do). So I am using pickups from the track to charge the battery. My idea is just to have charging power in the fiddle yard. With 3 locos each should spend at least 2/3rds of its time there so I don't expect the battery ever to become depleted - but that's not tested yet. I have installed a small rectifier in the loco (made from 4 diodes) so that it doesn't matter which wheels contact the positive track. The rectifier also has the advantage that the battery energy can't get to the track and short-out with another loco's battery. LiPo batteries need careful charging and I have found a circuit on the internet that allows me to adjust the voltage and limit the current. The interesting bit will be when I convert my bigger locos using 2 batteries each (7.2v as compared to 3.6v for the large prairie). I am hoping I can put a dropper resistor into the Prairie so that it can charge safely from the higher voltage needed for the other locos. But that, is a week or two away. As I think I said in a previous post, my plan is to be able to control my trains from my PC and, if I can get my computer-controlled-fiddle-yard-turntables working, I hope the computer will be able to run an end-to-end service without my intervention - so I can sit back and watch trains just as if I had room for a continuous loop. I think that covers the key issues that I have encountered. It's probably best if people ask questions. ...R PS It's not necessary to use a computer to control the trains. If you have a suitable transmitter (like the R/C flyers or car people use) that will work fine. You can see that in the Video on the Deltang website.

The bits I needed for converting my Grafar Large prairie were: Deltang Rx41d-w5-w receiver -- £29 Deltang Tx1-m transmitter - £12 LiPo Battery £0.76 Servo to donate motor and some gears -- about £8 Arduino Uno microcontroller to generate control signals for transmitter £25. Bits and pieces to make new chassis -- about £3 Bear in mind that the transmitter has 7 channels which can manage 7 locos if you only need movement control. If you wanted lights you might need 2 or 3 channels per loco. So the full cost of the transmitter and the Arduino can be shared over 7 locos. I will also be using the Arduino to control fiddle-yard-turntables and, possibly, points and signals. This is not expensive compared to the cost of a Hornby Elite plus DCC decoders. And then there is all the fun of doing it. Hope this helps.

The model shown in my Video in post #85 is definitely NGauge and entirely self contained. However it doesn't use DCC. The tiny Deltang radio receiver contains an electronic speed control so it just require two wires connected to the battery and two wires to the motor. And switch between the battery and the radio. The battery is an 80mAh LiPo cell giving 3.6volts. It's 30mm long and 7mm in diameter. The motor came from a small servo and measures 8x10x10mm. I am planning to convert a Grafar "Crab" (tender loco) and a Class 101 DMU using the original motor and a pair of batteries giving 7.2v. Space is surprising tight in the Crab but should be ample in the DMU which is more like the size of a diesel loco. ...R

In spite of Stuart's entertaining video link I presume you mean an NGauge battery powered model of a diesel railway locomotive. It should be much easier than my Large Prairie because there should be a lot more space inside the body. ...R

I agree with you but I don't understand your point. If weight is necessary lead could be added. My Grafar large prairie has a die-cast body so I don't think I have lost much weight by switching to an aluminium chassis. (And I've just discovered that Americans spell aluminum they way they pronounce it!) ...R

Thanks Stuart, It runs perfectly well on the table top - but without direction! I doubt if anyone who is seriously interested in converting to radio control will need proof. People who want to believe it's not possible will, of course, demand proof. ...R

Hi all, I have now got my old Graham Farish large prairie 2-6-2 tank working with battery power and radio control. You can see a short video on Youtube Apologies for the background radio sound and the Loco isn't as noisy as it sounded to the camera. I am using a Deltang Rx41d-v5-w receiver, a Deltang Tx1-M transmitter that is controlled by an Arduino microcontroller. I have replaced the Grafar motor with a small motor from a servo. It is all powered by a cylindrical Turnigy Nano 80mah LiPo battery. I had to make a new chassis for the Loco so that I could fit the motor and drive the rear axle rather than the centre axle. I have included a full-wave rectifier (4 small diodes) so I can recharge from some track sections without worrying which way the Loco is oriented. The electronics works very well but I think I need to tinker with the wheel quartering to get it to run smoothly at low speed. It works fine if I omit the centre axle with the motion! I have also posted this on the FreeRails forum. ...R

The Wifi smart phone bit is trivial if you have a phone with a browser. I can already do that with a small web server program that I wrote and which controls the trains through my Hornby Elite. I am in the process of designing a new chassis for my old Grafar Prairie tank so I have room to install the motor from a small relay a Deltang receiver and a LiPo cell. I'm still wondering whether to make the chassis with plastic or brass. I don't foresee any problem controlling a Deltang Tx2 transmitter from my PC (and smartphone) and, apparently, the TX2 can control up to 7 locos - though I only have 3. There should be no problem converting the other 2 to radio control - one is a DMU and one is a tender loco. I might even be able to insert a 2 or 3 cell Lipo so there is no need to change the 12v motors. ...R

Manufacturers could start moving in the direction of battery power if they built all new locos with lower-voltage motors that would run on a single LiPo cell's 3.7v. It would be trivial and very cheap to include a suitable resistor to allow the "out of the box" loco to run on existing 12v DC or DCC systems. I doubt there would be any difference in the price of the motors themselves. Such low voltage motors could pave the way for battery powered DCC systems with control signals and top-up power going through the track but with much greater operational reliability. And the more enlightened could easily use radio control instead of DCC. ...R

In case anyone is interested ... Following Giles' helpful references I have had a long exchange of correspondence on the FreeRails forum http://freerails.com/view_topic.php?id=4451&forum_id=45&page=28 and I am thinking of building a simple computer-controlled radio-controlled system for my 3 n-gauge locos using a Deltang transmitter and receivers. ...R