Crazy project needs advice

[CB47]

I recently aquired an older style class 47 which has a nice heavy metal chassis and an older style ringfield motor (the type with the brass frontplate. (I believe it is what was known as a silverseal motor (not sure about that one). Now the thing is that in a box of odd and ends, that I had bought some time ago, I had another of these ringfield motors of the same type and in working order. The idea occurred to me to try fitting this motor in place of the pickup unit in the non powered end and convert the loco into a twin motor powered unit. Pulling power!! It turned out to be a very easy task to convert the non powered end.

 

What I like about these older motor units is that they drive all six wheels instead of just four on the newer units. The only problem with them is that one of the brushes is not isolated from the chassis and therefore one side of the wheels. I overcame this problem by fitting a full set of insulated wheels to each axle (no traction tyres, that should please the purists among you). This now meant that both motor brushes are effectively isolated from the track, but at the same time meant that I had no electrical pickup from the track. This I solved by fitting the pickups from a class 9F 5 pole tender drive loco to each end of each bogie. I now have four two rail pickups to supply the power.

 

I am also fitting lights to each end. White LEDs to light the headcodes and 2mm red leds for the tail lights. These will be switchable via functions as either lights off completely, headcode lights only, or headcode and tail lights on. I am also fitting cab lights in both cabs (leds again) also switchable via functions.

 

Now we come to my question:

Can anyone suggest the best decoder for powering two ringfield motors and at the same time giving me at least four function outputs. I estimate that the combined stall current of the two motors is going to be in the region of 2 to 2.5 amps and the function load with all leds on will be in the region of 60ma.

Alternatively, does anyone know of any reason why I could not fit two decoders and program them to the same loco number. I thought this might be the better option as it would allow me to adjust the CVs independently to balance the performance of the two motors.

 

All suggestions (except dump the nutty idea) gratefully received.

[Oldddudders]

I have no experience with this sort of motor, but am confident that your idea of peak load is certainly not an overrestimate. Not cheap, but I suggest a large-scale Digitrax DG583S might do the trick - if you can fit it in. Try the usual DCC suppliers' websites for more details of its size, it seems to have a lot of function outputs, and can sink a lot of heat on them, too.

 

I don't think two decoders on one loco is ever the best solution, can lead to programming glitches, and if one end is hung-up for some reason, you could quickly fry a more ordinary decoder. The DG583S can handle up to 10 amps!

[Allegheny1600]

Hi Chris,

Ian's suggestion above is way better than what i had thought of but a couple of notes for you anyway.

From your description of the motors, i would say that these are the Ringfield motors made for Hornby by Fleischmann - and they're rather good!!

Before you fit any decoder whatsoever, PLEASE check that the motor brushes are fully insulated from track current - i have a friend who has converted several Fleischmann ringfields to DCC and he "thought everything checked out okay" only to find there was some residual leakage between track and brush. Result: one fried decoder!

May i also recommend that you give each motor a full MOT, clean the brushes, commutator, lubricate bearings, check windings etc etc before completing the digital installation (if not already done!).

Good luck with the project,

John E.

[CB47]

Thanks for the quick replies gentlemen, I will check out the Digitrax decoder as I have a Digitrax dealer not far from where I work. The loco has quite a bit of space available in the centre of it where you would normally put extra weight. However, with two motors and the metal chassis I don't think extra weight will be needed. I will strip and clean both motors as suggested, even though they both run well it can't hurt to give them a service. Thanks for the info about the manufacturer, you learn something new every day! I am sure that I have no circuit between the track and either motor now as I have tested both bogies on a high ohms range on my meter. It is a shame that the manufacturers of the motors didn't just isolate both brush holders and fit wire links still the insulated wheels seem to do the trick. Once again, thanks for the advice.

[Allegheny1600]

You're welcome, Chris!

Cheers,

John E.

[Suzie]

CB47

 

I would think about using a pair of good quality decoders because you are likely to be able to make good use of the BEMF in controlling what are likely to not be the smoothest of mechanisms given their age. If using a single decoder you will not be able to use BEMF and if one mechanism sticks there will be nothing to give it a kick.

 

Others may disagree but I suspect that a couple of Zimo MX64 or similar will give good results out of the box but you may need to adjust the BEMF.

 

 

 

 

 

[CB47]

Thanks Suzie, I did look at the Digitrax decoder that was suggested but on measuring the amount of space inside the loco I found that there was insufficient room for it. I also looked at a Lenz Gold Maxi. This would just about fit in the space available and would give 3amps continuous and 5 amps peak and is overload protected, but like you say using one decoder for two motors might give the BEMF a problem. I will look into the decoders you suggested. I am not in any hurry to complete the project so I have plenty of time to work out all the wrinkles. I know it is possible to control two decoders at the same time because that is what happens in double heading or banking, but I am not sure if you can control two decoders at the same time if they have the same address number. I will have to experiment with two small locos that have cheap decoders in them and see if it causes any conflicts. The advantage of having two decoders would be that the CVs could be tuned individually for each motor to balance their performance. The disadvantage would be, as previously pointed out, that if one motor failed the other would take all the stress and possibly knock out the decoder. I think experimentation may be the order of the day!

Thanks again for the advice, which is gratefully received.

[k9-70]

Thanks Suzie, I did look at the Digitrax decoder that was suggested but on measuring the amount of space inside the loco I found that there was insufficient room for it. I also looked at a Lenz Gold Maxi. This would just about fit in the space available and would give 3amps continuous and 5 amps peak and is overload protected, but like you say using one decoder for two motors might give the BEMF a problem. I will look into the decoders you suggested. I am not in any hurry to complete the project so I have plenty of time to work out all the wrinkles. I know it is possible to control two decoders at the same time because that is what happens in double heading or banking, but I am not sure if you can control two decoders at the same time if they have the same address number. I will have to experiment with two small locos that have cheap decoders in them and see if it causes any conflicts. The advantage of having two decoders would be that the CVs could be tuned individually for each motor to balance their performance. The disadvantage would be, as previously pointed out, that if one motor failed the other would take all the stress and possibly knock out the decoder. I think e4xperimentation may be the order of the day!

Thanks again for the advice, which is gratefully received.

 

Not a crazy idea at all.

 

If fitting two decoders and giving them the same address, then both decoders will operate as a one decoder.

 

I have a Mainline Class 45 fitted with two Mainline motors and working off a single Lenz Silver Plus decoder without any problems encountered.

 

K9-70

[CB47]

Not a crazy idea at all.

 

If fitting two decoders and giving them the same address, then both decoders will operate as a one decoder.

 

I have a Mainline Class 45 fitted with two Mainline motors and working off a single Lenz Silver Plus decoder without any problems encountered.

 

K9-70

[/quote)

 

 

Thanks for this info K9 70. I think you may have decided me on the way to go. Digitrax must have heard my prayers because they have just brought out a decoder that looks like it will fit the available space and gives 4 amps continuous output with 6 amps peak, which should be more than enough to run both motors and allow for stall current. So I will probably aquire one of those as you haven't had problems running two motors off one decoder. The info about two decoders able to run as one is also invaluable as it tells me that either option is viable. I have just finished installing headcode and tail lights into the bodyshell so my next move is to strip the motors and give them a service, as per previous advice, and then refit them and start wiring a decoder in. I will let you folks know how I get on as and when I have any news.

[RedgateModels]

I realise you are quite a way down the line with this one, but Here is a link to the old forum where I sucessfully DCC fitted a MkII ringfield (the MkI is the one with the all traction tyres). This motor is still happily pushing my Standard Eight around with a Lenz Gold in it ('cos it was spare, I'd normally use a Lenz Standard)

 

These are great motors, far better than the plastic rubbish that the accountants designed to replace it. All my Hornby tender drive locos on Summat Colliery use them, set the b2b correct at 14.4mm and they will handle Peco code 75 turnouts unlike their wobbly centre wheeled successors

[CB47]

Thanks Redgate,

 

Very interesting forum and detailed descriptions from you. I am about to strip down the first one of the motors to service it and I think I may well land up doing the last mod that you wrote about with the 5.5 mm hole and the epoxy as it would make absolutely sure I have no circuit from anything to the brushes. I have still not settled on a decoder or decoders, I will get both motors overhauled and modded first before I make a decision. Your mention of the normal motor current was most helpful, because I now realise that my motors both appear to be drawing slightly more than they should be (235ma and 250ma) which, as I had no in depth knowledge of these particular motors, I took to be around their normal working current. Obviously I have to work on them!

Chris B.

[RedgateModels]

check the tightness of mesh of the brass gear and the first nylon gear (the one with the circlip), if it's tight bend the pillar that the circlip fits to slightly to relieve the pressure. Most of these drives seem to have the first drive gear at a slight angle to the brass armature spindle gear .....

 

Current I quoted was no-load too, with wheels off the rails/rollers etc.

[Adrian Wintle]

If you choose to use two decoders, you probably shouldn't enable the BEMF as it could cause some 'fighting' between the two motor bogies. This can be an issue with consisting, and is the reason that Digitrax decoders default to no BEMF when in consist.

 

An advantage to two decoders is that you could adjust the speed curves to even out any differences in the motor performance. Treat each motor bogie as a separate loco and speed match them, then give them both the same address and install them in the chassis.

 

Adrian

[Suzie]

If you choose to use two decoders, you probably shouldn't enable the BEMF as it could cause some 'fighting' between the two motor bogies. This can be an issue with consisting, and is the reason that Digitrax decoders default to no BEMF when in consist.

 

An advantage to two decoders is that you could adjust the speed curves to even out any differences in the motor performance. Treat each motor bogie as a separate loco and speed match them, then give them both the same address and install them in the chassis.

 

Adrian

 

I have not seen a problem with enabling BEMF with two Zimo decoders in a loco, and if set up correctly it should work very well. I suspect that the way Digitrax decoders disable the BEMF says more about Digitrax decoders than anything else.

 

 

 

If your decoders support BEMF, set it up and try it. If it does not work then think about disabling it, but don't give up without trying - the benefit is worth having, especially with elderly mechanisms.

[Oldddudders]

I thought the ideal set-up with BEMF decoders was for one to have it set, and the other not. With both deploying BEMF there is scope for them to continuously try to compensate for each other. Hence my remark earlier in the thread re programming problems with 2 decoders. With 2 decoders on the same address, how do you turn off only one?

[CB47]

Thanks guys for all the info, especially the tip about the mesh of the gears causing higher strain on the motors. I had a busy weekend as it was our village fair on Sunday, so I haven't had time to do anything more since Thursday evening. I enquired about one of the 4 amp decoders that I mentioned, and was told that they were such a new product that my local store had not got any in stock yet. So if I decided to go with one of those I may have to wait some time or put in a special order if I do want to use one. Having read the write up about isolating the motor brushes from the metal frame I now realise that I could maybe use a couple of smaller decoders than I had first thought, which could work out a lot more economic than one big decoder and also, as you guys have said allow me to set up the motor speed curves to match each other. I am now thinking about the possibility of building a couple of small switches in to the underside of the chassis to switch off one or the other decoder for programming purposes and then switch both on together for running. All more to play with!

[Adrian Wintle]

I am now thinking about the possibility of building a couple of small switches in to the underside of the chassis to switch off one or the other decoder for programming purposes and then switch both on together for running. All more to play with!

 

If you use decoders that support advanced consisting (CV19) then you don't have to go to that trouble. Each decoder will have its own address for programming, but they will respond to the common address set in CV19 for motor control.

 

Adrian

[CB47]

Thanks for that Adrian. That would save me some wiring.