Switcher102 Posted June 7, 2016 Share Posted June 7, 2016 Wow Giles, I've just noticed that you are at it again with another exciting project. I look forward to its progress and I am sure the result will be a triumph of realistic operation.Funnily enough I am about to start working on motorizing a road vehicle myself but for some strange reason which I cannot account for I have decided that my first road vehicle will be one of the smallest …. a Fiat 126 (1:43 scale). Why on earth have I decided that I am not quite sure myself? The main reason perhaps is that it was my first car, but it also looks like not such a difficult job when you realize what small motors there are out there. Do you know about the tiny motors that make mobiile phones vibrate? This company makes them and other such exciting small stuff which I have already ordered and am finding really usefull for a rerailing jack I am making:-https://www.precisionmicrodrives.com/I wanted a really slow movement and they make a motor / gearbox combination at 700:1 at would you believe 6mm dia by 16mm length! How the heck they get such an enormous ratio in such a small size is beyond my imagination, and the gearbox itself is half that length.There's also these motor / gearbox combinations that you might find usefull:-http://www.clag.org.uk/axle-hung.htmlI am particularly interested in the Hybrid Belt plus Bill Bedford Gearbox Drives way down the page because it looks like there's room for a flywheel. Great believer in flywheels me, and the bigger the better Rich Link to post Share on other sites More sharing options...
Giles Posted June 7, 2016 Author Share Posted June 7, 2016 (edited) Yes, I've had a play with some of the small motors and (very nice) motor/gearboxes out there. The thing to watch is whether they will start at a slow speed, or whether they suddenly start at 15mph! It's for this reason that wherever I can, I stick with the Polulo/solarbotics style unit, which has very good low speed characteristics. Obviously for a car, one is struggling, though (I do have a half converted Ford Pop with a small unit, which is just about OK, but still a but sharp off the mark for my liking...) If you can conquer the slow speed controllability end, and keep the small size, then you've won! Meanwhilst, the motor gearboxes I bought for this arrived - a 14RPM one (6v) for the slew, and a pair of 6v 30 RPM ones for the winches. This lot only just fits. The slew motor is fitted (there is very little choice of location due to its requirement for full-height, and its position around the slew ring) and works nicely. I made up some profiles to mount the winch motors (which only JUST) fit, but I have yet to make some drums and fit them. Herewith the most rubbish video imaginable. It was only afterwards I discovered a cat hair right across the phone's lens.... Edited June 7, 2016 by Giles 5 Link to post Share on other sites More sharing options...
Switcher102 Posted June 8, 2016 Share Posted June 8, 2016 Looking good so far Giles. I hope your scaled operator didn't get dizzy during that test Oh yes, starts are most important, also the stops (that's why my insistence on flywheels). Thanks for the info on the motors you use. They look interesing, quite small (not small enough for my Fiat though), they even produce a dual shaft version to accommodate my flywheel fetish. I haven't tested my micro motors with a potentiometer yet to see how well they start.Anyway, as you wereRich Link to post Share on other sites More sharing options...
Giles Posted June 8, 2016 Author Share Posted June 8, 2016 (edited) This is the slew motor in position And the winch assembly (Derrick on the bottom, and hoist above) Edited June 8, 2016 by Giles 7 Link to post Share on other sites More sharing options...
Giles Posted June 8, 2016 Author Share Posted June 8, 2016 (edited) Winches fitted, now with drums (10mm X 10mm - turned from brass stock). They butt right up to the cab side in order to get the drums central enough - but it's ok. It's also an extremely tight squeeze in the other dimensions. I could have cut away the internal pillars, but actually they're in the ideal place, underneath the pulley shaft - so I really wanted to make the positioning work - and it does! Edited June 8, 2016 by Giles 2 Link to post Share on other sites More sharing options...
Giles Posted June 8, 2016 Author Share Posted June 8, 2016 In the photo above, you can also see the slip ring bringing the 6 wires up through the slew ring. All wired up, and reeved up. Cab on. When you apply a battery to the wires underneath, the Derrick raises and lowers, the hook hoists up and down, and the whole lot slews round and round...... 8 Link to post Share on other sites More sharing options...
Simond Posted June 8, 2016 Share Posted June 8, 2016 Excellent! I see the laser got used too, for the motor mountings About a hundred million years ago, I started to scratchbuilding a Stothert & Pitt 12 ton dockside crane. It all got put away when we emigrated, and it's still in its box, even though we've been back 6 and a half years. One of these days... Meanwhile, not getting (more) distracted would be a good thing. The next thing to do is a baseboard for the loco shed. Stick to the plan, Simon! (Where did the slip ring assy come from?) Best Simon Link to post Share on other sites More sharing options...
alastairq Posted June 9, 2016 Share Posted June 9, 2016 Hello Giles.....is the crane one of these? http://www.ebay.co.uk/itm/272203938454?_trksid=p2060353.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT Link to post Share on other sites More sharing options...
Giles Posted June 9, 2016 Author Share Posted June 9, 2016 Hello Giles.....is the crane one of these? http://www.ebay.co.uk/itm/272203938454?_trksid=p2060353.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT It is - yes! It's reasonably non-descipt (ish...!) when you take the Russian writing off, and it's of such useful proportions..... Link to post Share on other sites More sharing options...
Giles Posted June 9, 2016 Author Share Posted June 9, 2016 Simon, the slip rings came from a company called 'Digital Means Ltd' Link to post Share on other sites More sharing options...
Simond Posted June 9, 2016 Share Posted June 9, 2016 Thanks Giles. Presuming you're going to motorise the chassis too, have you a cunning plan to make the jacks operate? Will it need them in order to lift something? I guess not having suspension like the real thing will reduce the issue, but then I suppose you will equalise the front axle, so the issue doesn't entirely go away? I'm guessing that you'll have to build a box of some description to contain the batteries & r/c? Behind the cab? Much impressed, looking forward to watching your progress Best Simon Link to post Share on other sites More sharing options...
Giles Posted June 9, 2016 Author Share Posted June 9, 2016 Simon - I've already sneakily adapted the rear axle, and shoved a motor on - so that end's done, but I've got to do the front axle, which is time- consuming and always less straightforward. I'm putting a larger (650mAh) battery into this, due to having more work to do, and this may go between the chassis rails - but we'll see when it arrives. The jacks are much more of a problem, and may be a bridge too far. There is absolutely no way I can get even the smallest servos operating close to each pair of jacks, as there is simply not enough room. The only possible chance I have (and it's a very slim one) is to have a pair pulled down by Bowden cable with a spring return. I don't think I can afford the power to use memory wire, or anything like that..... Link to post Share on other sites More sharing options...
Switcher102 Posted June 9, 2016 Share Posted June 9, 2016 Giles - thinking of the jacks I think you deal with the people who supply these, you've mentioned Microns:-http://www.micronradiocontrol.co.uk/servo.html#hxt500I've got one of the Replacement Servos thinking of using it to work the steering on my Fiat but the trouble is making them move slowly enough, especially for a jack. Could they not be made to move slower with a low enough voltage? I've tried 1.5V and it still moves too fast for a jack. I did try resistors but that didn't work either unless I wasn't doing it right. Rich Link to post Share on other sites More sharing options...
Switcher102 Posted June 9, 2016 Share Posted June 9, 2016 (edited) Another point on motors. Have you thought about using T gauge motors for any of your projects? I will be using T gauge within O gauge to represent 5 inch gauge. I looked at T gauge at Warley last year and asked to see how well they start and stop and was amazed. Here's an example:- Doesn't show a start unfortunately but it shows a stop. I reckon I might even be able to convert them to radio control because being as they will be representing 5 inch gauge the 1:43 scale driver will be sitting on a carriage behind the locomotive and that carriage I think will be big enough to house one of Deltang's tiny receivers and a very tiny Japanese battery or button battery. Gosh, the possibilities of modern micro technology. Edited June 9, 2016 by Switcher102 1 Link to post Share on other sites More sharing options...
otherplanet Posted June 9, 2016 Share Posted June 9, 2016 Hi Giles. its looking great. if you do want to brave the jacks, here are a couple of options that I have found on my travels that might help. Although you may well have seen one or both of them previously. first a 4mm dia planetery gear motor, with 125:1 ratio. you could use this to drive a m1 or 14BA thread to actuate 2 or more jacks http://www.mikromodellbau.de/Shop/artikeldetails.php?aid=899 I have bought one of these it is quite smooth but the connection is small with a plastic output shaft. so low torque and you need to provide radial bearings. A kit to convert a 6mm gearmotor into a servo (well the mechanics of a servo, you still need the electronics), but it should be possible to canibalise a small cheap servo. http://www.mzr-online.com/Getriebemotor.htm not tried this but plan to in the future. But I have to say, I think you will knock the socks off any viewers at an exhibition. Anyone who complains about non working Jacks will probably still complain about something else, like the fact that the driver doesnt climb out of the cab. Link to post Share on other sites More sharing options...
Giles Posted June 10, 2016 Author Share Posted June 10, 2016 I'd thought about driving a screw - but I'd need a miniscule left-hand thread to do the job properly! However, I think I may have solved it - for the rear jacks, which will do...... I did a test piece this afternoon which basically worked (almost to my surprise!) but I could see that it would need reworking to allow for servo travel. I've cut the new bits, but not assembled them, and I can't test a powered version until I get my transmitter and receiver (servo testers don’t seem to give you full travel....) You'll see shortly - but I love our laser cutter!!! 2 Link to post Share on other sites More sharing options...
Giles Posted June 11, 2016 Author Share Posted June 11, 2016 The eureka moment was when I realised that I could (and should) be radical, and cut off the entire rear out-rigger assembly and start again, with the freedom to vary it a little if I needed to. This meant that I could just shove a servo in if I move the whole assembly rearwards 3mm (and why not?). What does this drive.... I looked at using cranks set at 180 degrees, but the only trouble with this is they lose efficiency the further round the circle they go. Also, although I was happy using them in tension, I was a little reluctant to use them in compression. The end fittings were going to become a major problem given how little space I was going to have...... Therefore this...... Laser cut gear (three laminations) mounted on the 1.7gm servo. 2 Link to post Share on other sites More sharing options...
Giles Posted June 11, 2016 Author Share Posted June 11, 2016 This is the innards - the slightly larger gear in the centre cluster is a temporary one to be substituted by the servo. The whole lot is laser cut, with 1.5mm silver steel stub axles 3 Link to post Share on other sites More sharing options...
Giles Posted June 11, 2016 Author Share Posted June 11, 2016 (edited) Rear view assembled. Front view raised And down It needs cleaning up and detailing. But it works, and works under power (servo tester) Edited June 11, 2016 by Giles 5 Link to post Share on other sites More sharing options...
Simond Posted June 11, 2016 Share Posted June 11, 2016 I'm ever so glad I asked... 3 Link to post Share on other sites More sharing options...
Switcher102 Posted June 12, 2016 Share Posted June 12, 2016 You work is beautifull Giles. I am very admirous of it and hope to emulate it myself but I have a lot to learn yet. Rich 1 Link to post Share on other sites More sharing options...
otherplanet Posted June 12, 2016 Share Posted June 12, 2016 I am going to have to get authorisation to buy one of those laser cutters! Beautiful piece of work Giles. I am going to have to get authorisation to buy one of those laser cutters! Beautiful piece of work Giles. 1 Link to post Share on other sites More sharing options...
Sun VI Posted June 13, 2016 Share Posted June 13, 2016 (edited) I found this thread and have been reading it, on and off, over the last three days. Absolutely amazing, both for your work Giles and John in Holland, fantastic work. May I ask, are you a trained engineer or are the skills something that you've developed as a hobby? Which ever route you've followed, the results are stunning. PS I saw 'End of the line' at the Uckfield show several years ago (19th October 2013) and was entranced by it, but did not appreciate the full effort and ingenuity that had gone in to its production. Edited June 13, 2016 by Sun VI 1 Link to post Share on other sites More sharing options...
Giles Posted June 14, 2016 Author Share Posted June 14, 2016 Bless you! John's workmanship is absolutely superb, and I had the pleasure of meeting him at Warley - and he's a delightful chap as well...... No, I'm not in anyway trained - but have evolved into a bit of a design engineer in my profession (by default, as things needed doing and problems needed sorting). I do find that skills in my hobby do feed into my profession, and visa versa, which is very satisfying. The daily use of AutoCad for work is a great help with this sort of thing, however, and had made the use of the laser cutter very much easier. 1 Link to post Share on other sites More sharing options...
Giles Posted June 14, 2016 Author Share Posted June 14, 2016 (edited) Apart from adding the screw jacks to the out-riggers, this end of the vehicle is now complete and functioning. The back axle is driven, the rear outriggers are operational (or they will be when hooked up to a receiver!) and the crane is fully operational. So it's just the front steering axle, servo and radio gear to go, followed by weathering - however I'm sure all of that will have its joys ready and waiting! I shouldn't think we'll get round to running actual trains on Denton Brook....... Edited June 14, 2016 by Giles 13 Link to post Share on other sites More sharing options...
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