Black5 Posted December 9, 2018 Share Posted December 9, 2018 Afternoon all, I`ve recently rebuilt a Jamieson Streamlined Coronation kit that I`d stripped for re-painting a long time ago. The motor is a Romford Bulldog so you can see how old things are!. After giving it a run on DC I decided to have a go at fitting a decoder which I have managed to do using an MX600 decoder and the loco runs albeit a bit growly. My question is, given that the loco and tender are pretty hefty, weight wise, the loco is becoming quite warm after a while, although it`s only an end to end layout. As the decoder is rated at 0.8A could someone suggest a more suitable decoder that might suit better? I realise the present decoder will get warm with use. but this seemed a bit excessive to me. The MX600 is protected with a clear case that is virtually moulded to it`s shape and I wondered if that may be partly why it`s getting so warm. Or, maybe it`s all how it should be. Many thanks, Jim. Link to post Share on other sites More sharing options...
JST Posted December 9, 2018 Share Posted December 9, 2018 For my older locos I have used Digitrax DN136D decoders. They handle 1.5 amps max and are relatively small. If you motor is old I would have the magnet re-magnetised. If it has lost power the motor will pull too many amps for the decoder. Link to post Share on other sites More sharing options...
Black5 Posted December 9, 2018 Author Share Posted December 9, 2018 For my older locos I have used Digitrax DN136D decoders. They handle 1.5 amps max and are relatively small. If you motor is old I would have the magnet re-magnetised. If it has lost power the motor will pull too many amps for the decoder. Thanks for that. The motor seems ok at the moment so i`ll look for the larger decoder and try it. Where would you go to get a magnet re-maganatised, having never been down that route before.? Many thanks. Link to post Share on other sites More sharing options...
NIK Posted December 9, 2018 Share Posted December 9, 2018 Afternoon all, I`ve recently rebuilt a Jamieson Streamlined Coronation kit that I`d stripped for re-painting a long time ago. The motor is a Romford Bulldog so you can see how old things are!. After giving it a run on DC I decided to have a go at fitting a decoder which I have managed to do using an MX600 decoder and the loco runs albeit a bit growly. My question is, given that the loco and tender are pretty hefty, weight wise, the loco is becoming quite warm after a while, although it`s only an end to end layout. As the decoder is rated at 0.8A could someone suggest a more suitable decoder that might suit better? I realise the present decoder will get warm with use. but this seemed a bit excessive to me. The MX600 is protected with a clear case that is virtually moulded to it`s shape and I wondered if that may be partly why it`s getting so warm. Or, maybe it`s all how it should be. Many thanks, Jim. Hi, If you have the money and the time you could buy a DC 3 Amp Analogue meter (mechanical type) such as CPC sell https://cpc.farnell.com/multicomp/sd-38-0-3a/meter-moving-coil-3a/dp/PM11428?mckv=I0JyMwHw_dc|pcrid|75179126737857|kword||match||plid||slid||pid|PM11428|&CMP=KNC-MUK-CPC-SHOPPING-M-440-Shopping-Electrical+and+Lighting-Industrial+Automation+%26+Control+Gear&msclkid=3b20a8086f1a12478d64f405253fe0f6&utm_source=bing&utm_medium=cpc&utm_campaign=M-440-Shopping-Electrical%20and%20Lighting&utm_term=4578778739727432&utm_content=Industrial%20Automation%20%26%20Control%20Gear Mount in a box (could be a used takeaway box or a blank electrical pattress box if the meter will fit) with a terminal block on the outside to wire in series with one output wire from your DC controller. Make sure the DC controller is switched to the appropriate direction before turning up the knob or the meter may hit the reverse stop. If your DC controller can put out more than 3 amps then you would have to buy a higher current meter. I use a current meter to measure each of my locos RTR or kit built before looking to see what DCC decoders might be suitable. A suitable DCC decoder check list might be: 1) will it fit?. 2) has it got enough current for the motor and lights etc?. 3) has it got the features I want (motor control, consisting,lighting effects, smoke generator control etc.)? 4) has it got good documentation? 5) has it got a good reputation for reliability? 6) can I afford it?. 7) does it have features I might use in the future (Railcom for example)?. Regards Nick Link to post Share on other sites More sharing options...
Suzie Posted December 9, 2018 Share Posted December 9, 2018 If the magnet in the motor has lost magnetism you are more likely to burn out the motor than the decoder. Get the magnet restored, or replace it with a new rare earth magnet to get previously unthoughtof performance from the old motor. Link to post Share on other sites More sharing options...
RMweb Premium Ray H Posted December 9, 2018 RMweb Premium Share Posted December 9, 2018 There's a Zimo MX635 decoder that handles 1.8 amp and 2.5 amp peak which might suit you. Link to post Share on other sites More sharing options...
Suzie Posted December 9, 2018 Share Posted December 9, 2018 If you put 2.5A through that old motor with a poor magnet it will burn out. Link to post Share on other sites More sharing options...
JST Posted December 9, 2018 Share Posted December 9, 2018 (edited) Thanks for that. The motor seems ok at the moment so i`ll look for the larger decoder and try it. Where would you go to get a magnet re-maganatised, having never been down that route before.? Many thanks. I had mine done by Scalespeed. http://www.scalespeed.co.uk I don't know if they do your type of motor though. If you go down the neo magnet route as Suzie suggested, these people may be able to help. https://www.first4magnets.com/rectangular-c35/Hornby-train-12-7-x-9-3-x-13-2mm-n42-neodymium-magnets-w-2-5mm-hole-p8065#ps_1-8254 Edited December 9, 2018 by JST Link to post Share on other sites More sharing options...
Black5 Posted December 9, 2018 Author Share Posted December 9, 2018 Many thanks for all the replies. certainly much to ponder on. Jim. Link to post Share on other sites More sharing options...
Black5 Posted December 10, 2018 Author Share Posted December 10, 2018 Good morning, Further to everyone`s helpful advice yesterday, I`ve ordered some Neodymium magnets from First4Magnets so that`s my starting point followed by a new decoder and I`ll see what happens. I can reduce the weight by making a new loco and tender chassis but I want to see what happens with these improvements first. Many thanks once again, Jim. Link to post Share on other sites More sharing options...
NIK Posted December 10, 2018 Share Posted December 10, 2018 Good morning, Further to everyone`s helpful advice yesterday, I`ve ordered some Neodymium magnets from First4Magnets so that`s my starting point followed by a new decoder and I`ll see what happens. I can reduce the weight by making a new loco and tender chassis but I want to see what happens with these improvements first. Many thanks once again, Jim. Hi, Loco current consumption is not necessarily related to loco weight. OO diesel and electric RTR loco weights have been going up in recent designs but the current consumption to weight ratio seems to be coming down (I haven't measured the weight and current consumption of every RTR diesel and electric). Regards Nick Link to post Share on other sites More sharing options...
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