StayAlive for G-scale DC? (or Improvements to Bachmann Thomas and friends?)

AusrailQLD

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Ok, this is probably a dumb question, but does something like this exist for G-scale?

I'm currently in debate on whether to convert my Bachmann Thomas engines to basic DCC. (As much as I would love sound DCC, such correct sounds available is non-existent)
or see if there is another solution to their power pickup troubles, besides battery conversion.

The main trouble I'm having is that they are currently stall on a diamond crossover at slower speeds.

Been reading this topic in other places, but it's mostly for HO and smaller.
And most places say it can't be done due to the small size.
 

PhilP

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Power buffers are available for g scale loco's..

There is a TTTE decoder available, with Thomas sounds, but other than that, it is crippled. - Cut-down features.

Perceived wisdom, is to turn analogue support off, if you have a power-buffer fitted.

You would need a way of disabling / managing the power-buffer, for when you wanted to make any programming changes.

PhilP
 

dunnyrail

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Yes Massoth do stay alive buffers which are effectively a way of converting a chip to the equivalent of a 00 stay alive decoder that you speak of. On the set that I had from Massoth a switch was inserted in the buffer circuit to enable switching out of the buffer for programming. Not sure how disabling the buffer works in smaller stay alive decoders.
 

Diesel2000

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If you are concerned with not finding the right sound decoder then just put a driving DCC decoder in like a Massoth M or L with the power buffers. In analog with the Massoth decoders the buffers allow the decoder to simulate slow braking so the loco doesnt come to a dead stop when you drop under a certain amount of voltage to keep the motor moving. This might solve your issue going over a crossover.
 

Greg Elmassian

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Stalling and not restarting is a characteristic of the OEM'd Soundtraxx decoder from Bachmann. It is crap.

The next time it stalls, turn the speed down to zero, and then raise it again, normally it will start running.

This is under DCC. I am extremely disappointed in how this works. In my experience, every time Soundtraxx OEM's a decoder, they put some crippling feature into it. For example the first ones fitted to the Bachmann Shay would not tolerate NMRA G scale voltages.

I'm not sure a keepalive will solve this entirely. On another decoder, yes. You just get bigger/higher voltage supercaps. There is a whole discussion on how to hook them up, especially if you want to use service mode (the programming track).


Greg
 

Dan

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Bachmann does sell the 'Thomas' sound DCC decoder. It does contain several of the other Thomas line engine sounds selectable by a CV change. This decoder does have front and rear light connections and a contact for external volume control.
 

AusrailQLD

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Bachmann does sell the 'Thomas' sound DCC decoder. It does contain several of the other Thomas line engine sounds selectable by a CV change. This decoder does have front and rear light connections and a contact for external volume control.
From what I read, it's not very good. :-(

Hence why I thought their might be a more reasonable solution to my problem.
Basically is there any sort of cheap circuit that will help the loco keep going for a few seconds over dirty/deadspot trackwork?
(and bi-directional if possible.)
 

Greg Elmassian

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Yes, you can try, but there no connector on the board for a keepalive, and you probably need to add a resistor and diode to the supercaps.

Then you need to locate a place on the board past the full wave bridge.

So, you need to know a bit of circuit design, basic PCB debugging.

I plan to do this eventually to this crappy decoder, but I will probably sell the decoder and get a better one, since the only custom sound for my Emily is the whistle... can find that anywhere.

Greg
 

AusrailQLD

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Yes, you can try, but there no connector on the board for a keepalive, and you probably need to add a resistor and diode to the supercaps.

Then you need to locate a place on the board past the full wave bridge.

So, you need to know a bit of circuit design, basic PCB debugging.

I plan to do this eventually to this crappy decoder, but I will probably sell the decoder and get a better one, since the only custom sound for my Emily is the whistle... can find that anywhere.

Greg
The DCC's Emily whistle isn't even her current one either. :-\
 

PhilP

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Emily and her whistle, are a figment of someone's imagination, so you can have any whistle you like..

As the TTTE series decoder is carp, why not fit a different brand?
One that either already has caps. Or designed to have them fitted?

PhilP
 

dunnyrail

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From what I read, it's not very good. :-(

Hence why I thought their might be a more reasonable solution to my problem.
Basically is there any sort of cheap circuit that will help the loco keep going for a few seconds over dirty/deadspot trackwork?
(and bi-directional if possible.)
Hm not that cheep but options for battery control are available and for sound the My Loco Sound (MLS) card and battery control will give you all you want. The MLS also has a Thomas whistle.
 

jimmielx

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I’ve got a totally different suggestion. Assuming that you run Thomas with Annie and Clarabel, you could add pickups to the coaches wheels. I’ve done this, although I do also have DCC with stay alive, but maximising track pickups is a good thing. For pickups of A&C I have simply shorted the wheel on one side of each set to the axel and then made connections inside to the bearings which are also metal. In the pictures you’ll see resistors, ignore these as they are to allow current detection to work. You then need an electrical connection between coaches and locomotive . 515CD9EF-4CD1-4A8A-A819-C7AE4080BC38.jpeg . AD9520EF-A022-4100-9A19-0F645FE3F418.jpeg
Annie and Clarabel and the troublesome trucks allow this simple method of adding pickups, but the tankers wagons and guards van have plastic bearings so another solution would be needed for those. Obviously this only give you one additional contact per side per coach, and it’s not a particularly good contact at that. But it’s enough to significantly improve the overall connectivity to the track.
Another idea would be to try to add the skates to Thomas - all the LGB stuff has skates as does Piko and USA trains and I find their connectivity much better. Here’s one fitted to my Accucraft Baguley. image.jpg
The holder is just made of plasticard which has held up for about 8 years - I’m about to replace the holders with some 3D printed ones I’ve had made. Something similar would be very achievable on the Thomas range.
Maybe there’s a useful idea in here somewhere. Basically if you’re getting occasional track connectivity issues, try increasing the number of contacts to the rail.
 
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AusrailQLD

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Will defiantly consider the skates.
I'd just need to make at least 6 pairs as I have Thomas, Percy, James, Toby, Emily, and currently trying to order Devious Diesel.
 

Zerogee

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I’ve got a totally different suggestion. Assuming that you run Thomas with Annie and Clarabel, you could add pickups to the coaches wheels. I’ve done this, although I do also have DCC with stay alive, but maximising track pickups is a good thing. For pickups of A&C I have simply shorted the wheel on one side of each set to the axel and then made connections inside to the bearings which are also metal. In the pictures you’ll see resistors, ignore these as they are to allow current detection to work. You then need an electrical connection between coaches and locomotive ..
Annie and Clarabel and the troublesome trucks allow this simple method of adding pickups, but the tankers wagons and guards van have plastic bearings so another solution would be needed for those. Obviously this only give you one additional contact per side per coach, and it’s not a particularly good contact at that. But it’s enough to significantly improve the overall connectivity to the track.
.......
Wouldn't it be even more effective (and probably simpler, though admittedly more expensive) to just equip one or more of the coaches with one or two LGB ballbearing wheelsets or equivalents, the ones with the built-in power pickup connections, and then feeding the power from these back to the loco?

Not having any personal experience of TTTE stock I don't know if there are any technical reasons why this would not work.... is there a significant size difference between TTTE and LGB standard wheels, for example?

Jon.
 

jimmielx

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Jon, I think that would work well. And make for a very reliable solution. My ‘GWR Castle’ scratchbuild uses a Thomas mechanism with a pair of LGB ball bearing wheel sets with pickups on the tender. It is very reliable indeed. Just depends if you are happy to have a piece of stock ‘permanently’ with the loco.
 

Zerogee

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Jon, I think that would work well. And make for a very reliable solution. My ‘GWR Castle’ scratchbuild uses a Thomas mechanism with a pair of LGB ball bearing wheel sets with pickups on the tender. It is very reliable indeed. Just depends if you are happy to have a piece of stock ‘permanently’ with the loco.

Yes, my own personal preference is not to have to have "permanent" train configurations if possible - but I suppose if you're mainly running "prototypical" (!) TTTE stock then you could always fit either Annie or Clarabel AND one of the trucks with pickups and flying leads with plugs, then you'd have the choice of running Thomas in passenger or goods mode...?

Jon.
 

Fred2179G

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there a significant size difference between TTTE and LGB standard wheels,
I think the TTTE wheels are significantly larger than the regular wheels. Huge in fact! Even the freights have larger-than-usual wheels.
 

Fred2179G

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Here's an off-the-wall thought. If you had a battery of say 8V in the loco, and a DPDT sprung relay that is normally one-way when power is applied, to allow the power to get to the motor, but if power fails (e.g. bad connection on a frog,) then the relay flips and sends the battery power to the motor for that brief moment when track power is not available.

Clearly the battery voltage wouldn't match the speed, but it might keep the motor spinning long enough to get past the problem.
I imagine a 'power buffer' discussed above is similar for requires DCC and stuff.
 

jimmielx

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Following up on this I’ve just fitted new skate holders to a loco shown here.
Thread '3D Printed Pickup Skate Holders'
3D Printed Pickup Skate Holders

However, thinking about the Bachmann Sodor engines, there is a lot of side to side movement in the axels, so I’m not sure that the skates would be a good solution for those unless the side to side movement is was removed - the skate would be in danger of slipping off the rail or shorting on a turnout.

Another thought on the loco is have you added extra weight. Both of mine have had significant extra weight added, which obviously helps stop wheels spin, but should also aid pickups a bit. The weight should be added such that the centre of gravity of the loco is at the midway point between the driving wheels.

Final thought on the loco is to make sure that the axel contact strips and axels inside the block are clean.

If you do go DCC specifically to help with stalling due to pickup, then I’d go with a decoder that allows fitting of a big offboard stay-alive cap, or super-cap. The integrated stay alives I have on some ESU decoders do seem to have very limited effect.