RBE Posted July 15, 2015 Author Share Posted July 15, 2015 Interesting that stock as you cant run around it there and get to DY152 or DY154 to get you back onto the branch. Link to post Share on other sites More sharing options...
Marcus 37 Posted July 15, 2015 Share Posted July 15, 2015 Could have been a talk through. Not as uncommon as you may think. Done it several times at different places where the move is physical but not signalled. Usually during times of disruption, engineering work or equipment failure. Link to post Share on other sites More sharing options...
RBE Posted July 16, 2015 Author Share Posted July 16, 2015 There are ground signals on the Derby lines protecting trains going south which is the opposite to normal running. A run around move on the coalville branch would mean a light engine run to either platform 1 or the freight loop and then a shunt signal move over the ladder crossing to the branch. Link to post Share on other sites More sharing options...
RBE Posted July 16, 2015 Author Share Posted July 16, 2015 So I got my parcel back from Shapeways. I'm happy with the outcome. I've assembled a quick point motor using a spare SG90 servo I had and some guitar string. I've yet to pick up some more microswitches but you have to imagine one fixed to the right side where the little bracket is. The three photos show the position of the servo arm as it moves full sweep from one side to the other. As you can see the guitar string is formed in such a way as to allow the ball on the servo arm to slide as it makes an arc which prevents the wire from having to move upwards through the point tie bar. The movement is enough to provide a springing action on the point blades when fully over. The ball position on the arm dictates throw so these could be used on OO or even O gauge with thicker wire I should imagine. When swept to the right the servo arm will lower the microswitch arm and change the polarity of the frog above. Simples. I am liking this. When my sleepers finally arrive I will build the rest of the track up and fit one of these with a servo tester to assess movement. Any good? 3 Link to post Share on other sites More sharing options...
Marcus 37 Posted July 16, 2015 Share Posted July 16, 2015 (edited) Very clever indeed mate... Very clever. Looking forward to seeing them installed and working the points. There's certainly no end to you're ingenuity. Edited July 16, 2015 by Marcus 37 Link to post Share on other sites More sharing options...
bigP Posted July 16, 2015 Share Posted July 16, 2015 (edited) -- Edited January 30, 2021 by bigP Deleted Link to post Share on other sites More sharing options...
RBE Posted July 16, 2015 Author Share Posted July 16, 2015 Thanks chaps. It is WSF yes. Not too bad price wise, they work out about £4 each, I could probably add some holes in it to reduce matial costs. Currently with the servo and microswitch the whole thing is about £7 or so. 1 Link to post Share on other sites More sharing options...
bigP Posted July 16, 2015 Share Posted July 16, 2015 (edited) -- Edited January 30, 2021 by bigP Deleted Link to post Share on other sites More sharing options...
RBE Posted July 16, 2015 Author Share Posted July 16, 2015 I thought so. Its considerably cheaper than a tortiose and if you so wished you could rip the gubbins out of the servo and just run it as a motor. It works by full sweep of movement so no precise servo control needed. Link to post Share on other sites More sharing options...
d winpenny Posted July 16, 2015 Share Posted July 16, 2015 (edited) Very clever I like it David Edited July 16, 2015 by d winpenny Link to post Share on other sites More sharing options...
RBE Posted July 16, 2015 Author Share Posted July 16, 2015 (edited) I've got a servo tester and microswitches on order so once they arrive I'll get the pointwork built and hook it up. I will of course need some more servos for the rest of the points. I may revise the design a little to allow the microswitch to clip in rather than use screws but I was going for quick change under the baseboard should it need maintenance during a show. Anyway the class 60 is still wearing all over rail grey but the 47 is looking a bit nearer the finish post! Edited July 16, 2015 by RBE 7 Link to post Share on other sites More sharing options...
branchie Posted July 16, 2015 Share Posted July 16, 2015 Hi Cav. Just stumbled across the thread and I have to say I'm impressed. The standards of your modelling, as ever, is top notch. It's good to see you back in the groove ... The HEAs look good Christian. Link to post Share on other sites More sharing options...
Marcus 37 Posted July 17, 2015 Share Posted July 17, 2015 That 47 looks spot on mate. You're getting quite good at applying this Intercity livery. Should look superb once weathered. Looking forward to seeing the 60 done as well. Been looking at those route maps again. The only way of coming off the branch to run round via DY152 would be to go all the way back up to Wetmore junction to get back over on to the down goods. Rather a long way round. As you say you can get back from the two ground signals on a wrong direction move from Platform 1 or the down goods. That I have done with the S Stock but only to cross back to the down goods from the up goods. 1 Link to post Share on other sites More sharing options...
RBE Posted July 17, 2015 Author Share Posted July 17, 2015 Thanks guys, glad youre on board Christian. The HEAs are superb!! I also now own a rake of 24 HAAs which need some weathering treatment. Following what you have just said Marcus I am now considering modelling the wrong line ground signals (they are just under the other side of Shobnall road bridge in reality but I could use my trusty modellers licence to pull them directly under the scenic side of the bridge to provide interest and maybe do some run around moves or even wrong line moves with possibly a failure in platform 2 meaning passenger trains have to use platform 1 for both directions for a short time until the failure is cleared. So much potential!! Link to post Share on other sites More sharing options...
lyneux Posted July 17, 2015 Share Posted July 17, 2015 Hi Cav, I like your idea for the actuator wire to keep the vertical travel to a minimum - very neat! Here is my attempt at a bracket (I have 40 turnouts on my fiddle yard that needed doing quickly so I thought I'd knock up an etch). They are nice and strong in 20 thou brass and work out at about half the cost of getting them 3D printed. Mounting the servo horizontally makes them very low-profile under the baseboard. I find that you don't need much throw to actuate a OO turnout (less than you have illustrated there) so presumably an N gauge one needs even less. Of course, it depends on how thick your baseboard is too (mine are 6mm ply). They go together pretty fast too: I managed to assemble 12 of these in an hour one evening last week. I am averaging fitting about 4 per evening to the layout. Regarding drivers, if you are using DCC then have a look at the ESU Switch Pilot Servo. For just a bit over £20 it both programs and controls 4 turnouts (and also has connections for switches for non-dcc operation!). It's about the cheapest method I have found for DCC control. All-in with brackets, servos, switches and controller it works out about £11 per point. Anyway, I ordered more than I need of the brackets so please PM me if they are of interest (they are super-cheap!). Cheers, Guy Link to post Share on other sites More sharing options...
RBE Posted July 17, 2015 Author Share Posted July 17, 2015 Your solution looks neat too Guy. The issue I had was I wanted to build one that utilised a complete 180° throw of the servo and still only provide the tiny amount of throw at the point hence mounting them the way I have rather than as you did. By using a full 180° throw I have made it easier for anyone not wanting to control the servo via a special pulse driver and can just rip out the gubbins and use a switch. Secondly the servo has to travel farther which means it can go slower for a full switch of the point without trying to get a the servo to moves really realy slowly as the angular velocity on mine can be much higher than your for any given throw speed of the point. I dont need to worry about the end stop limits on mine either as the servo always uses full throw. Link to post Share on other sites More sharing options...
lyneux Posted July 17, 2015 Share Posted July 17, 2015 Hi Cav, can just rip out the gubbins and use a switch I'm really not sure why you'd want to go to the effort of doing this, only to make the servo less controllable! The whole point (no pun intended) of using servos for turnout control is that you can set them to travel to pre-defined positions. It's much harder to control them if you have to think about stopping them in the right place. If you intend to let them run to the full travel distance and then stall, this will damage the motor in the long run. Secondly the servo has to travel farther which means it can go slower for a full switch of the point Why? You can set nice slow speed with a controller (e.g. Switch Pilot Servo). Seriously, £5/6 per point (Switch Pilot Servo) is peanuts for full control (and there are even cheaper solutions from MERG if you don't need DCC). Do yourself a favour and get a driver board. If you're paying £4 just for the mounting bracket you shouldn't really balk at this cost. For the added cost of the 3D printed brackets you'd already be over halfway to covering the cost of a driver board. Guy Link to post Share on other sites More sharing options...
RBE Posted July 17, 2015 Author Share Posted July 17, 2015 Point 1 - The whole point for me of using servos is not to make them more controllable its to make slow action motors cheaper. Servos are a very cheap way to do so. At low voltage they can move very slowly as a motor and gearbox and can whithstand stalling. When used in aircraft (I do this as a hobby also - RC Helis) they are constantly being in effect stalled by the force of the air trying to move the servo whilst the current passing through the servo motor fights to stop it moving. The forces involved there way more than holding a point blade in place. Having said that when I used them previously in this manner I only fed power to them whilst the point moved and then turned them off. I dont intend to run them like that on Burton though. I plan on using an Arduino to provide route setting and signal control. Point 2 - Its a matter of gearing. If you want to move something a given distance on one side of a fulcrum by moving something on the other then the further away the control side is from the pivot point the further the control side has to move. Therefore for any given angle on the turnout side the servo has to travel further with my setup. If it travels further it must have to travel fast to achieve the same speed of turnout blade travel. What you say is correct about programming it to move slowly, you can. However to move slow it needs to increment itself in much tinyer steps if near to the fulcrum than if further away and hence provides a much lower positional resolution. This is common knowledge with helicopter control where some pilots sometimes set their control rods further out on the servo arms to give the helicoter a finer resolution of blade angle. Also servos are designed for fast reaction times to control aircraft and dont particluarly like to move slow, letting them move a bit faster lets them move a bit better but thats by the by its Point 3 - I dont need to faff in the programming setting movement angles to finetune my servos to acurrately move the blades just the right distance I can just set it to full movement and job done. This also takes care of any servo jitter because it is holding a full sweep and hence the arm is well past the point at which the blades are over and it at a point on the servo arms circular motion where it is 90° from the tiebars movement ao any jitter will have zero chance of opening up the blades to let a train derail should it be passing over at the moment. Link to post Share on other sites More sharing options...
Crisis Rail Posted July 18, 2015 Share Posted July 18, 2015 Whoooosh......... Can anyone explain what is a point motor? #handofgod Ian 1 Link to post Share on other sites More sharing options...
RBE Posted July 18, 2015 Author Share Posted July 18, 2015 Its the opposite of a reliant robin which is a pointless motor! Anyway I managed to catch and hour tonight to get some rail down. I'm really starting to feel this now. I also had a little go with some etched rail joiners. These are crazy small! I just wanted to maintain electrical continuity at that particular rail joint so soldered it on. I do like them even though they are hard to see with the naked eye. I may add some cosmetically once the tracks complete and wired! 5 Link to post Share on other sites More sharing options...
georgeT Posted July 19, 2015 Share Posted July 19, 2015 Looking good Cav, rather you than me, l struggled with SF-OO making the points for BS, it would do my head in trying N gauge, watching with interest... Link to post Share on other sites More sharing options...
Andrew P Posted July 19, 2015 Share Posted July 19, 2015 Hi Cav, just to re iterate what George has said above, OO is bad enough but N is one step to far, certainly for me with my 100W Solder Gun. Link to post Share on other sites More sharing options...
Marcus 37 Posted July 19, 2015 Share Posted July 19, 2015 Looking superb Cav. You really must have a severe amount of patience to pull that off in N. The comment "really starting to feel this now" is it feeling the strain or feeling as in getting a feel for it? If its the former don't go blowing your self out. Its all to easy to lose your mojo sometimes if you try doing too much. Luckily I've had a good attack of it over the last week so managed to get plenty done on PDW. Marcus Link to post Share on other sites More sharing options...
RBE Posted July 19, 2015 Author Share Posted July 19, 2015 Cheers Marcus. No no feel it as in liking it. The layout being a stopgap I was concerned I might not get enthusiastic about it but I'm really starting to like the way its going now. I've been watching your progress on PDW, its looking really good the rock faces are great. 1 Link to post Share on other sites More sharing options...
RMweb Gold Alister_G Posted July 19, 2015 RMweb Gold Share Posted July 19, 2015 Some lovely sweeping pointwork there Cav, and as the Dreadful Duo have said, rather you than me in "N" Those rail joiners are so small, I couldn't even see them until I enlarged the photo to full size. Blimey! Great work mate. Al. 1 Link to post Share on other sites More sharing options...
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