Black5 Posted November 16, 2016 Share Posted November 16, 2016 Evening all, I have two Jameson loco kits that were stripped down for modification and a repaint some years ago ( one a Black 5 and the other a streamlined Coronation?) They both ran well on a dc system, driving wheels being insulated Romfords with pickups on the back of the wheels, both locos. The chassis on both locos is made from square section brass bar and was machined to accept the motors, My question is, Is it possible to dcc a motor like the romford, given that it`s surrounded by a lot of metal--- which would mean totally isolating it from the chassis or is it not worth the try? It seemed like an interesting project and would give me two more locos for the layout. I just wondered if anyone else had tried anything similar. Cheers just now, Jim. Link to post Share on other sites More sharing options...
RMweb Premium Izzy Posted November 17, 2016 RMweb Premium Share Posted November 17, 2016 Hi Jim, You say there are insulated Romfords on both sides with pick-ups. Do both wire individually to the brushes on the motors, or is one side then fed throught the metal chassis? If the chassis is electrically isolated from both pickups then of course it's quite easy, but perhaps a little work is needed if the chassis is 'live' to one side i.e. there would be the need to ensure both brush sides were isolated for the decoder motor feeds. No particular need to isolate the whole motor. Easy to tell by way of the individual brush connections. Izzy Link to post Share on other sites More sharing options...
hayfield Posted November 17, 2016 Share Posted November 17, 2016 As Izzy has said if both sides are insulated and wires going to the brushes its and easy fit, If one of the brushes takes the power from the motor frame touching the loco frame, then just insulate the brush (by copying how the other one is insulated) then run a wire from the chassis to the brush The DCC chip can then be wired by fitting between the pickups and wires Link to post Share on other sites More sharing options...
34theletterbetweenB&D Posted November 17, 2016 Share Posted November 17, 2016 ...I have two Jameson loco kits ...They both ran well on a dc system, driving wheels being insulated Romfords with pickups on the back of the wheels, both locos. The chassis on both locos is made from square section brass bar and was machined to accept the motors, My question is, Is it possible to dcc a motor like the romford, given that it`s surrounded by a lot of metal--- which would mean totally isolating it from the chassis or is it not worth the try?... Supplementary to the good advice above. Ensure that the chassis block - and thus body - is fully isolated from the rails. This is pretty much an essential for any all metal construction model, to avoid the potential for a short when buffering up two locos of 'one side live to rail' construction which happen to have their live sides on different rails. This was always best practise for a DC model, and optimistically that the extra money was spent by the constructor on fitting insulated wheels both sides and then arranging wiper pick up, that may well already have been done. If not modify the pick up arrangements to fully isolate the chassis from the track. One of the joys of the Triang XO motors, and the various others of the same generic design such as the Bulldog and MW005, is that the addition of a piece of insulating sleeve on the bare brush spring (motor as supplied) where it bears on the brush very simply does the job of making the motor DCC ready. Any of these motors in good condition perform well with a decent decoder, the five pole types better than the three pole, I have a Bulldog and 40:1 Romford gears with a Lenz standard on it, and the running is a good match for a medium sized Mashima although drawing about twice the current; 250mA rather than 100-150mA of the can motor. Link to post Share on other sites More sharing options...
Black5 Posted November 17, 2016 Author Share Posted November 17, 2016 To Izzy, Hayfield and 34theletterbetween B&D. Many thanks for your answers. I can confirm that the pickups on the driving wheels are soldered to a piece of copperclad paxolin gapped down the middle, this being screwed to the underside of the chassis and a wire taken from each side directly to the corresponding brush. I`ll change the wire colours to match dcc colouring. The wire brush spring that passes underneath the screwhead on top of the motor has no insulation nor does the screw that holds the motor to the chassis. Although using insulated drivers would it be ott to insulate both these points? The chassis and motor will need a good clean and a run in DC before a decoder goes in but it`s not quite as daunting a job as i first thought. Cheers just now Jim. Link to post Share on other sites More sharing options...
RMweb Premium Izzy Posted November 17, 2016 RMweb Premium Share Posted November 17, 2016 No need Jim. With both sides of the pickups being wired to the brushes the chassis is electrically dead (always assuming insulating sleeves are fitted to both sides of the spring - if not then an easy fix), which is always the best option for avoiding shorts, and as has already been mentioned when a metal body is involved. Perhaps a double check with a multi-meter to ensure this is the case might be a good idea before fitting a decoder. And of course making sure it's fully insulated from the metal body when you do. Izzy Link to post Share on other sites More sharing options...
Black5 Posted November 17, 2016 Author Share Posted November 17, 2016 Thanks Izzy, on closer inspection under a good light i could see one side of the brush spring wasn`t insulated so when i clean everything up i`ll put some sort of sleeving over both sides. I have a multimeter, though not an expert at using it, i usually set it it using the buzzer for anything like that. Thanks once again for your help, Cheers just now, Jim. Link to post Share on other sites More sharing options...
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