RMweb Gold Stubby47 Posted December 11, 2009 RMweb Gold Share Posted December 11, 2009 Hi all, I've decided I'd like one of the Airfix cranes on Polbraze, and it would be really good if it could be made to work. I appreciate that for each movement I'd need a separate motor / control, but I wondered if anyone had actually done anything like this before. I'd be happy just to get the crane to slew and raise/lower the hook, but to get the crane to travel as well would be the ultimate result. Can anyone help, please ? Stu Link to post Share on other sites More sharing options...
shortliner Posted December 11, 2009 Share Posted December 11, 2009 Stu, the travelling might be possible by using something like the method used to move the old tuning dial fitted to radios where the marker moved along - or even better, something like the system for a pantograph arm on a draughting board keeping it parallel. Wheels on inset rails with a slot in the bottom with a rod through the slot fixed to the cord on both sides perhaps 1 Link to post Share on other sites More sharing options...
Bruciethefish Posted December 12, 2009 Share Posted December 12, 2009 I'm sure it can be done, but will take a lot of dedication, & possibly bad language! I'd suggest raiding the innards of an old mechanical clock as a possible starting point...... Good luck! 1 Link to post Share on other sites More sharing options...
bertiedog Posted December 12, 2009 Share Posted December 12, 2009 I did one of these many years ago, in the 1970's for a display at the London MRC Easter Exhibition. The drive for the whole thing moving involved using a straight quayside track, with one side of the track, (they were double rail like a tram track), having a hidden piano wire laying in the track groove, with the wire end bent up to engage the whole crane. The wire was led along the track groove to one end and was connected via cord to a pulley, (several turns to get grip), and a hanging weight, with the pulley controlled by a slow motion DC gear-head motor. The other end was taken to another pulley at the other end, with a weight to tension the return motion. (The weights were 1 lb bag of sand!). It moved very slowly, at about a foot a minute at minimum. The rotation was done by another gear-head motor, and a further one added for the jib. the control was by 2 rail pick-up from the track, with a RC tone decoder, so the best modern equivalent would be DCC , with two decoders, and a DC drive to the main movement (or another DCC decoder). The track can be basically two rail, you will need metal wheels etc and pickups. The whole crane will need a lot of ballast weight, and a bit of strengthening all round. The weight return system was chosen to eliminate needing tension springs, which a continuous loop of cord drive would need. I found the cord slipped to much with spring and induced drag, which the weights eliminated. Supplier of the motors, (with the highest ratios gearboxes) try: Precision drives , no connection except customer. Gears can be scrap, or inexpensive plastic gears for modellers, several sources. Stephen. 1 1 Link to post Share on other sites More sharing options...
bertiedog Posted December 12, 2009 Share Posted December 12, 2009 Shows layout for main drive, wire in the track groove, with cord to pulleys, one powered by geared motor, scale and size arrangement to suit your layout. With the gearhead motors the drive for rotation is very straightforward, simply replace the main bearing with the motor, and the jib drive is as simple as a pulley drum on the motor shaft in the cabin, mounted again direct on the geared motor shaft, nothing complex at all. Pick motor gearboxes with at least 200:1 or more, even over 1000:1 if available. Some surplus DC motors may be found at shows with these gearboxes fitted. Any DCC decoder could handle the control, or use mechanical switching. Stephen. 1 Link to post Share on other sites More sharing options...
Kenton Posted December 13, 2009 Share Posted December 13, 2009 I am pretty certain there is a layout around the circuit that has one operating on a dock side. I have been trying to remember its name but as yet cannot. It was IIRC an EM layout and it was either at Railex or Abingdon 2 or 3 years ago. The crane lift and rotation worked and magnets were used to attach items to the hook. It was fairly effectively used to raise bundles of wood from a hold of a freighter in dock and on to a flat wagon. I asked the operator for details and again I think he described it as servos. It was quite shaky and the planks wouldn't always line up. I don't recall it moving along the track. I think one of the biggest problems - Bertidog eluded to it - is going to be keeping it balanced. It is a pretty unstable kit (top heavy) on rather flimsy legs so adding anything to the cab is going to make it worse and it will need strengthening. adding more weight at the bottom would help but there is nowhere to hide it. Hence the idea of something attached and underboard make perfect sense. 1 Link to post Share on other sites More sharing options...
Kenton Posted December 13, 2009 Share Posted December 13, 2009 Of course there is always this HO kit http://www.greatlakesmodeling.com/headlines/hdln_Bearco_11_07_05.htm 1 Link to post Share on other sites More sharing options...
RMweb Gold Ramblin Rich Posted December 13, 2009 RMweb Gold Share Posted December 13, 2009 Of course there is always this HO kit http://www.greatlake...co_11_07_05.htm Looks impressive Kenton - but I think it might be a bit big.... This puppy is 2 feet tall and weighs around 25 pounds. :icon_wow: Link to post Share on other sites More sharing options...
RMweb Gold Stubby47 Posted December 18, 2009 Author RMweb Gold Share Posted December 18, 2009 As always, thanks for your replies. Kenton - I think, as Rich points out, that crane is probably a bit big for what I need, but it's very impressive. Jack - thanks for the idea, it seems quite similar to how Stephen describes his version. Stephen, Wow. Thank you indeed for the chapter & verse on how you actually did this. I have considered using DCC, but as I've not ventured that far with loco control yet, it seems a tad excesive just for a crane, although obviously I'd go the whole hog with the layout as well. DC control does, of course, bring it's own power supply problems for the cable winding and body rotation motors, but I'm sure I can fiddle something. RC as used in micro cars might be an idea. To keep in the design of the layout (being in a box I can just pickup and move) the weighted cord would probably not work, but by replacing the cord with a screw thread I can still use the slot in the baseboard method. So again, thanks to all for your input, it's proved it's a very feasible idea. Stu Link to post Share on other sites More sharing options...
Dawnflyer Posted January 2, 2022 Share Posted January 2, 2022 Hi, on doing a search for Dockside Cranes I came across your thread regarding motorising the Aitfix/Dapol kit. Did you go ahead with any of the suggestions as I’m tempted to have a go as I have something worked out in my head. Regards Barry Link to post Share on other sites More sharing options...
33C Posted January 2, 2022 Share Posted January 2, 2022 Tiny motors and gears/worms from old telephoto cameras would be a boon for this kind of project..... Link to post Share on other sites More sharing options...
Dawnflyer Posted January 2, 2022 Share Posted January 2, 2022 I have found ‘Micro geared motors’ on EBay with various voltages and rpm which I am considering using. Not started properly yet but a few musts are:- Be simple, be made from readily available parts and able to be made without any machining other than hand drill. No electronics ie. not use DCC for motor selection. Must have control of travel, swivel, jib and crane hook raise and lower. Link to post Share on other sites More sharing options...
RMweb Premium Nile Posted January 2, 2022 RMweb Premium Share Posted January 2, 2022 The July '21 issue of Railway Modeller has an article about doing this, using N20 motors with gearboxes. Link to post Share on other sites More sharing options...
RMweb Gold Stubby47 Posted January 3, 2022 Author RMweb Gold Share Posted January 3, 2022 23 hours ago, Dawnflyer said: Hi, on doing a search for Dockside Cranes I came across your thread regarding motorising the Aitfix/Dapol kit. Did you go ahead with any of the suggestions as I’m tempted to have a go as I have something worked out in my head. Regards Barry Hi Barry, No, like many of my ideas, this fell by the wayside. But 12 years on and technology has much improved, if doing this now I might consider using servos for the crane. Stu Link to post Share on other sites More sharing options...
Dawnflyer Posted January 3, 2022 Share Posted January 3, 2022 Hi Stu, I think I will give it a go and if it all works out I will post my findings. I have just read the article in July 21 Railway Modeller that NILE referred me to, most useful information. I intend to make the crane travel along the rails as well. Barry 1 Link to post Share on other sites More sharing options...
Dawnflyer Posted January 3, 2022 Share Posted January 3, 2022 19 hours ago, Nile said: The July '21 issue of Railway Modeller has an article about doing this, using N20 motors with gearboxes. Thanks for that NILE, luckily I have that issue which I have just read, very informative and it’s got me thinking. Barry 1 Link to post Share on other sites More sharing options...
Giles Posted January 3, 2022 Share Posted January 3, 2022 I did a small narrow gauge crane here Link to post Share on other sites More sharing options...
Dawnflyer Posted January 9, 2022 Share Posted January 9, 2022 Hi again, My crane kit arrived a couple of days ago and I have made a start on the mods. I have read somewhere that a modeller thinned down the corrugated roof to improve the looks and also the widow glazing bars but can’t find it again, can anyone point it our to me please? Link to post Share on other sites More sharing options...
33C Posted January 9, 2022 Share Posted January 9, 2022 Take a baked bean tin and cut the corrugated part of the side out. Leave a good margin and trim down. And it's pre-curved! Good, sharp scissors are fine to do the deed! 2 2 Link to post Share on other sites More sharing options...
Dawnflyer Posted January 10, 2022 Share Posted January 10, 2022 Thanks for that 33C I will leave the roof for now until I have installed all the motors etc and eaten some beans. 1 1 Link to post Share on other sites More sharing options...
firefly9 Posted August 28, 2022 Share Posted August 28, 2022 Any follow up to this? Link to post Share on other sites More sharing options...
Dawnflyer Posted October 12, 2022 Share Posted October 12, 2022 On 28/08/2022 at 13:55, firefly9 said: Any follow up to this? Hi Firefly9, only just revisited this topic so sorry for late reply. I have done some basic mods and drive build which show the ideas but have got sidetracked so not continued for the time being. I can forward photos if you want. regards Barry Link to post Share on other sites More sharing options...
firefly9 Posted October 13, 2022 Share Posted October 13, 2022 Hi Barry. That would be great. Thanks Richard Link to post Share on other sites More sharing options...
Dawnflyer Posted October 14, 2022 Share Posted October 14, 2022 Hi Richard, A brief explanation of main features. The rails were to be made of plastic angle and set on the edge of two pieces of wood the correct distance apart with the centre portion supported at the ends beyond the required crane travel. In other words there would be two slots say 1,5mm next to the rails in line with the flanges of the crane wheels. This would allow two thin say 1,0mm pieces of plastic rigidly fixed to the crane wheel assemblies to pass through and connect to the drive for the crane travel? Will knock up a sketch to explain this better, in the meantime here is the intended drive which I made comprising motor/gearbox, threaded rod, conti block housing nut and drawer slide. Link to post Share on other sites More sharing options...
Dawnflyer Posted October 14, 2022 Share Posted October 14, 2022 Sketch of proposed deck and rail construction Link to post Share on other sites More sharing options...
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