[Robert Stokes]

I have recently decided to go DCC and so have bought a Bachmann EZ quite cheaply. At some stage in the future I might go for something more advanced and more expensive but this will do for now, especially as I only have seven engines on my layout and don't anticipate getting any more. (How many times have you heard that?)
I have started by fitting decoders into two locos, both bought recently. These are a Hornby 8F and a Bachmann Jubilee which work all right. It suddenly occured to me that not all types of motor would be happy with DCC. I am thinking particularly of a Jinty that I have fitted with a portescap motor. (It's a beautiful slow runner; it really crawls!)
I put 'portescap' into the search facility on this forum and came up with a few threads but, although none seemed to have a definitive answer. two did imply that such motors might not take to DCC very well.
So can anyone advise me on what to do? Would it be best to sell the Jinty and get a replacement one with an ordinary motor just in case?

 

[Richard Johnson]

Hi

You asked: I have started by fitting decoders into two locos, both bought recently. These are a Hornby 8F and a Bachmann Jubilee which work all right. It suddenly occured to me that not all types of motor would be happy with DCC. I am thinking particularly of a Jinty that I have fitted with a portescap motor. (It's a beautiful slow runner; it really crawls!)All you need do is use a decoder with a high frequency silent drive.

Response:
I have many Coreless motors running on DCC and they are quite happy that way. The decoders I use with portescap are ESU LokPilot and the new Back EMF enabled TCS T-1 and MC-2, however both lenz gold and Zimo also work fine with coreless.

for ease of install and sheer performance I have found the TCS back EMF decoders truly superb - very reasonable cost, seeming to need no adjustment to run exceptionally well and at least as good "crawl speed wise" as the more expensive brands.

MC-2 will fit your jinty easily.

Be sure to specify it must have back EMF though - not all UK dealer stock will have it, as its a relatively new addition from TCS to the MC-2 and they wil lsell out the old model first.

Richard
DCcconcepts

 

[mikeg]

I used a TCS T1 with a portescap motor and it destroyed the chip by overloading it as the coreless motor has very little BEMF and the chip just tried to put the full 3.5amps through the motor which did not take it and the chip fried!

The supplier told me to switch the BEMF off it using the T1 or switch to Lenz gold as these have autodetect and therefore are safe with coreless motors. I have changed the motor to a mashima which although not as good works better with my DCC system.

Have not yet tried any cheap chips from bachmann or hornby as the general comments suggest they are unlikely to work well with the prodigy that I use, bought as I like the shunting mode and it feels right in the hand when using.

regards

mikeg

 

[Richard Johnson]

QUOTE (mikeg @ 28 Aug 2007, 00:17) <{POST_SNAPBACK}>I used a TCS T1 with a portescap motor and it destroyed the chip by overloading it as the coreless motor has very little BEMF and the chip just tried to put the full 3.5amps through the motor which did not take it and the chip fried!

The supplier told me to switch the BEMF off it using the T1 or switch to Lenz gold as these have autodetect and therefore are safe with coreless motors. I have changed the motor to a mashima which although not as good works better with my DCC system.

Have not yet tried any cheap chips from bachmann or hornby as the general comments suggest they are unlikely to work well with the prodigy that I use, bought as I like the shunting mode and it feels right in the hand when using.

regards

mikeg

 

[Richard Johnson]

Hello Mike

You said: I used a TCS T1 with a portescap motor and it destroyed the chip by overloading it as the coreless motor has very little BEMF and the chip just tried to put the full 3.5amps through the motor which did not take it and the chip fried!

Response: I do the installs as part of my business, and install many chips into locos with coreless motors. Whilst I have no doubt you fried the chip I really do not think it has anything to do with the combination of T-1 and Coreless motor - for three reasons

(1) If a coreless motor was exposed to 3.5 amps it would be destroyed. A coreless motor draws less than 100Ma at most, never at a high enough level to damage a decoder. I think perhaps your supplier mis-advised you

(2) I have several working very well in my own loco stud with exactly that combination, and they run smooth as silk with exceptionally good slow running and very low current draw...

(3) Adding or taking away the BEMF will affect motor control, but not influence motor current draw.

Kind regards

Richard

 

[mikeg]

QUOTE (Richard Johnson @ 27 Aug 2007, 17:29) <{POST_SNAPBACK}>Hello Mike

You said: I used a TCS T1 with a portescap motor and it destroyed the chip by overloading it as the coreless motor has very little BEMF and the chip just tried to put the full 3.5amps through the motor which did not take it and the chip fried!

Response: I do the installs as part of my business, and install many chips into locos with coreless motors. Whilst I have no doubt you fried the chip I really do not think it has anything to do with the combination of T-1 and Coreless motor - for three reasons

(1) If a coreless motor was exposed to 3.5 amps it would be destroyed. A coreless motor draws less than 100Ma at most, never at a high enough level to damage a decoder. I think perhaps your supplier mis-advised you

(2) I have several working very well in my own loco stud with exactly that combination, and they run smooth as silk with exceptionally good slow running and very low current draw...

(3) Adding or taking away the BEMF will affect motor control, but not influence motor current draw.

Kind regards

Richard
Richard, it did indeed destroy the motor, it was one of slaters with a gearbox attached and I have been able to take the gearbox off and put it on a 1833 which runs well on DCC. I know that coreless motors will run OK with DCC but can only state what happened to me.

regards

mike g

 

[Richard Johnson]

Hi Mike.

You Said: Richard, it did indeed destroy the motor, it was one of slaters with a gearbox attached and I have been able to take the gearbox off and put it on a 1833 which runs well on DCC. I know that coreless motors will run OK with DCC but can only state what happened to me.

** I have absolutely no doubt that it was a real occurrence - I'm just not convinced the reason you were given for it is right.

What I have sometimes seen is a motor (both coreless and not) with hidden problems which failed soon after the conversion which is just coincidence, or a motor that was actually only just OK at DC voltages but failed when a DCC system with too high a track voltage was used etc... Coreless motors actually have low tolerance for excess voltage, and will quickly get quite hot if run at above Mfr spec. This will soon cook the motor and the cooked motor will then fry the decoder.

As I said, I often combine back EMF decoders with coreless motors of several brands with truly excellent results.. as do several of the best UK custom loco builders.

Bear in mind that a decoder cannot output more power than the motor demands, and a motors heat tolerance is far higher than any decoder component, so a faulty motor or a motor with one lead shorted directly to track power can destroy a decoder, but a decoder itself really cannot destroy a motor.

Kindest regards

Richard