PenrithBeacon Posted January 23, 2015 Share Posted January 23, 2015 :whistle:Is it possible for a 4mm model to run with the cranks set at 120 deg? Just asking ... :whistle: Link to post Share on other sites More sharing options...
Dave Holt Posted January 23, 2015 Share Posted January 23, 2015 :whistle:Is it possible for a 4mm model to run with the cranks set at 120 deg? Just asking ... :whistle: Yes. I've got two examples (one with a centre crank and valve gear, the other without) and both run well. Dave. Link to post Share on other sites More sharing options...
58herbie Posted October 1, 2016 Share Posted October 1, 2016 Pacer. If you are still after a quartering jig I.have a hamblings jig that is left hand lead and will fit triang Dublo wheels Cheers Jon Thanks for the replies. Does anyone know of any other company still making the jigs for Tri-ang and Hornby Dublo? Link to post Share on other sites More sharing options...
RMweb Gold markjj Posted October 1, 2016 RMweb Gold Share Posted October 1, 2016 I'm glad you don't need them for 0-gauge lol..? Link to post Share on other sites More sharing options...
Ruston Posted January 10, 2018 Share Posted January 10, 2018 Thank you guys for your comments and suggestions. I have now done what I should have done in the first place and ordered a new one from George Watts. He could barely remember making a left hand lead jig and reckoned it must have been one of his first. If anyone is interested in buying one, the current price is £24.50 + £1.50 postage Can someone please tell me if these things are still in production and if they are, the current price and some contact details for George Watts. Thanks Link to post Share on other sites More sharing options...
RMweb Gold Bucoops Posted January 10, 2018 RMweb Gold Share Posted January 10, 2018 Can someone please tell me if these things are still in production and if they are, the current price and some contact details for George Watts. Thanks I was sent this about 5 months ago - so the 2014 prices amazingly appear to be still current. Link to post Share on other sites More sharing options...
Ruston Posted January 10, 2018 Share Posted January 10, 2018 Thanks for that. I have just telephoned and the price is still current. Link to post Share on other sites More sharing options...
decauville1126 Posted January 10, 2018 Share Posted January 10, 2018 Can someone please tell me if these things are still in production and if they are, the current price and some contact details for George Watts. Thanks George usually has an ad in Model Railway Journal and also does the 'quality' shows, such as Scaleforum and ExpoEM. He doesn't have an online presence or do card or other online payments - it's cash at shows or cheque by mail. Link to post Share on other sites More sharing options...
Jol Wilkinson Posted January 11, 2018 Share Posted January 11, 2018 Dave Holt is right. There is no reason why cranks set at 120 deg wouldn't work if correctly set, the same as LH or RH 90 deg. But ngtrains has it spot on. It's all down to personal preference. I don't care if mine are left or right leading or bit in the middle because I haven't got detachable eyeballs! As long they are accurately set! I know of many loco builders who set the cranks at 90deg when they should be at 120 but they don't lose any sleep over it! As far as I am concerned it really wouldn't bother me one way or the other providing they all match! Regards. Serron. The further away from 90 degrees you get, the less effective and even the transfer of effort through the coupling rods becomes. Try 180 degrees to see what I mean. 120 degrees was used for three cylinder locos, presumably to maintain dynamic balance and even out the six pressure strokes from the cylinders. Even if I were to build a model of a three cylinder loco (the LNWR didn't have any with coupled driving wheels, but that's another story) I would use 90 degree quartering. Link to post Share on other sites More sharing options...
David Bigcheeseplant Posted August 4, 2018 Share Posted August 4, 2018 Picked up a GW wheel press today at train collectors fair in Aylesbury, sitting in a box with make me an offer, so got it for £5! a two types of GW wheel and gear pullers and a set of Gibson crankpins for a £1 each! happy bunny David Link to post Share on other sites More sharing options...
PenrithBeacon Posted August 4, 2018 Share Posted August 4, 2018 The further away from 90 degrees you get, the less effective and even the transfer of effort through the coupling rods becomes. Try 180 degrees to see what I mean. 120 degrees was used for three cylinder locos, presumably to maintain dynamic balance and even out the six pressure strokes from the cylinders. Even if I were to build a model of a three cylinder loco (the LNWR didn't have any with coupled driving wheels, but that's another story) I would use 90 degree quartering.True enough for the prototype but it isn't true for a model powered by an electrical motor! Link to post Share on other sites More sharing options...
Jol Wilkinson Posted August 4, 2018 Share Posted August 4, 2018 True enough for the prototype but it isn't true for a model powered by an electrical motor! Why not? Link to post Share on other sites More sharing options...
PenrithBeacon Posted August 5, 2018 Share Posted August 5, 2018 Why not?Because the torque from an electric motor is more even, particularly a five pole motor and one equipped with a flywheel. Link to post Share on other sites More sharing options...
Guest Posted August 5, 2018 Share Posted August 5, 2018 I so wish GW Models were easier to order from as I would like a set of their rolling bars.. They tend to just attend Southern Exhibitions and use Royal Mail, Im in the North and my "wonderful" modern bank account does not provide a cheque book. So hard pressed to pay them. Even just a direct transfer into their bank account would be a help. Link to post Share on other sites More sharing options...
micklner Posted August 5, 2018 Share Posted August 5, 2018 Postal Order ?? , phone him he is very helpful, I am sure he had this problem before. Link to post Share on other sites More sharing options...
Jol Wilkinson Posted August 5, 2018 Share Posted August 5, 2018 Because the torque from an electric motor is more even, particularly a five pole motor and one equipped with a flywheel. David, The torque from the motor is smooth but quartering is needed to transmit that power evenly to the other axles. Try building a loco with 180 deg. crankpin alignment between axles. Power transmission will be good at 6 and 12 o'clock but at 3 and 9 o'clock things will go awry. There will be no vertical component to the effort through the rods. The horizontal component will not transmit any effort. 90 deg. gives the best compromise and the further you deviate from that the more uneven things get. The real thing used 120 deg. to even out the six power strokes from three cylinders. Jol Link to post Share on other sites More sharing options...
pete55 Posted August 5, 2018 Share Posted August 5, 2018 ….. and my "wonderful" modern bank account does not provide a cheque book. Think I'd change my bank.....cheques are still remarkably useful, despite what some would have you believe. Link to post Share on other sites More sharing options...
PenrithBeacon Posted August 5, 2018 Share Posted August 5, 2018 David, The torque from the motor is smooth but quartering is needed to transmit that power evenly to the other axles. Try building a loco with 180 deg. crankpin alignment between axles. Power transmission will be good at 6 and 12 o'clock but at 3 and 9 o'clock things will go awry. There will be no vertical component to the effort through the rods. The horizontal component will not transmit any effort. 90 deg. gives the best compromise and the further you deviate from that the more uneven things get. The real thing used 120 deg. to even out the six power strokes from three cylinders. Jol The cranks on the prototype are there to convert the reciprocating motion of the cylinders into rotary motion for the wheels. As an electric motor can only rotate it is not necessary to have the cranks set exactly at 90deg in an electrically driven model, indeed some RTR models drive entirely through gears with the coupling rods being cosmetic. I did once observe an 08 shunter at Willesden Junction with the cranks all to cock, but as the engine is driven by two electric motors with the coupling rods simply transmitting the torque (an exact analogue of the electrically driven model) it didn't matter in the slightest Link to post Share on other sites More sharing options...
Horsetan Posted August 6, 2018 Share Posted August 6, 2018 .....As an electric motor can only rotate it is not necessary to have the cranks set exactly at 90deg in an electrically driven model, indeed some RTR models drive entirely through gears with the coupling rods being cosmetic. OT, diesel bogies being the classic example where no quartering at all is necessary, but Continental HO has used gear trains between axles for donkeys' years - I think Maerklin still use this method in their 3-rail chassis. Also 2FS locos seem to use the geared axles method quite frequently. Link to post Share on other sites More sharing options...
davknigh Posted August 6, 2018 Share Posted August 6, 2018 OT, diesel bogies being the classic example where no quartering at all is necessary, but Continental HO has used gear trains between axles for donkeys' years - I think Maerklin still use this method in their 3-rail chassis. Also 2FS locos seem to use the geared axles method quite frequently. It appears that Rapido will be using the gear train method on their upcoming Royal Hudson. Cheers, David Link to post Share on other sites More sharing options...
RMweb Premium Izzy Posted August 6, 2018 RMweb Premium Share Posted August 6, 2018 I am not sure whether the info here :- modelengineeringwebsite.com/Wheel_quartering.html will aid discussion, or just raise more questions........ Izzy Link to post Share on other sites More sharing options...
Arun Sharma Posted August 6, 2018 Share Posted August 6, 2018 The further away from 90 degrees you get, the less effective and even the transfer of effort through the coupling rods becomes. Try 180 degrees to see what I mean. 120 degrees was used for three cylinder locos, presumably to maintain dynamic balance and even out the six pressure strokes from the cylinders. Even if I were to build a model of a three cylinder loco (the LNWR didn't have any with coupled driving wheels, but that's another story) I would use 90 degree quartering. As Iain Rice writes [regarding LHS/RHS lead], "If you can see both sides of an engine at the same time, you have bigger worries than what angle the cranks might be at" Link to post Share on other sites More sharing options...
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