Bachmann/Mainline Jubilee - Split Chassis DCC

[ianLMS]

Good afternoon folks,

I have just successfully converted my old Bachmann (Mainline) Split-Chassis Jubilee from Analogue to DCC. It was a challenge but through lots of research, especially RMWeb, I managed it. I used a Gaugemaster DCC26 compact 4 function, 8 pin decoder, cut off the pin PCB and then located it in the tender. Wires were hard-wired to the motor and chassis.

 

After dismantling everything, I removed the bushes, isolating the motor and soldered two wires, one to each tag on the motor. For the chassis connection, I used two self-tapping countersunk screws into the top of the chassis block (one on each side) to solder the other two wires and that's it. Re-assembling the chassis was the most challenging bit. Making sure the gap was insulated, but the two halves closed up enough so the body fitted over no problem and making sure the white nylon spacers where in the correct position where the hardest part of the whole job. A bit of heat-shrink to isolate the wires from each other, and black tape to hold it in place as the wires carried over the motor and down behind the firebox and I was then able to re-assemble everything.

 

 

In the end I mounted the decoder in the tender - looked like I would need to remove a lot of metal from the chassis to accommodate the decoder, so the tender was the easiest option. I filed some of the lower body section away under the cab so the wires fed through without fouling the wheels and routed the wires underneath the cab, and into a hole I drilled on the front of the tender. The wires then passed under the front wheel axle and into a hole in the floor, up into the tender space. I used a piece of heat-shrink to hold the wires together between the loco and tender and hide there bright colours. A test run ensured all worked well, but you need to leave enough slack in the wires or the tender wont bend round tight bends.

 

Next up - 2 x Mainline Jubilees, Hornby 3F Jinty, Airfix 4F, Bachmann Royal Scot, Hornby Fowler 2-6-4T.

 

Any tips greatly appreciated!! Especially on the Airfix 4F.

 

Thanks

Ian

[Pete the Elaner]

That's a useful description. How does it run once converted?

 

It sounds like you initially intended to mount the decoder in the loco.

Now that you know it needs to go in the tender, would you recommend mini or standard size decoders for future locos?

[ianLMS]

Hi Pete. It seems to run just fine. Not had chance to adjust the CV's yet but slow running was fine. Not too noisy either. The was no room at all for a de oder in the loco without removing chunks of metal from the chassis. I will stick to tbe DCC 26 Decoders for now. They seem to work fine with my layout and z21 control system.

[34theletterbetweenB&D]

You can fit a decoder up front on a Mainline Jubilee mech. if the one I have done (many years ago) was typical. This had a void up front to take a smoke unit (the older Bach USA split chassis steam products quite often had these fitted) and combined with the way power is routed to the pod motor made conversion a snap compared to having to split the chassis halves on the Bachmann design. Soldered the decoder red and black to a small piece of PCB, with nickel silver wire springs on each PCB track. By sitting the decoder and board in the void (modified the void by opening the front end) and then 'springing' the two wire contacts from the decoder mount onto the chassis sides inside the void, track power was routed to the decoder red and black terminals. Orange and grey went to the motor brush terminals which are fully exposed: these were easily isolated from track supply by just cutting through the screwed on 'prongs' which contact the brush terminal mounts on the motor casing.

 

Do you suspect that this is all just too easy? Well, what came next was that mechanism disintegrated after relatively little running on DCC. The driving wheels shifted on the axles big time while it was running fast, and it had really bent rods, a broken gear, and was binned. Unfortunately the driven wheelsets are on round stubs into the insulators. The audibly 'choppy' drive from the small ZTC decoder supplied for the job was my guess at the cause of failure, the vibration in the drive line enough to cause the wheels to shift in the insulators. (It had given the owner long service on a DC resistance controller layout, and I recall it had cost under a tenner new, so he felt it had yielded full value.)

 

The Bach Royal Scot motor in their split chassis mechanism will run really well on a Lenz Standard, completely silent, and running refinement limited only by the mechanical condition of the mechanism. I have worn out any number of Bach split chassis (once through the plating on the tyres, they are all done) and never once had a motor fail.

[peterfgf]

I posted some info in these posts about fitting decoders to Mainline Patriots:

 

#2614709 and #2613377

 

Peterfgf

[ianLMS]

You can fit a decoder up front on a Mainline Jubilee mech. if the one I have done (many years ago) was typical. This had a void up front to take a smoke unit (the older Bach USA split chassis steam products quite often had these fitted) and combined with the way power is routed to the pod motor made conversion a snap compared to having to split the chassis halves on the Bachmann design. Soldered the decoder red and black to a small piece of PCB, with nickel silver wire springs on each PCB track. By sitting the decoder and board in the void (modified the void by opening the front end) and then 'springing' the two wire contacts from the decoder mount onto the chassis sides inside the void, track power was routed to the decoder red and black terminals. Orange and grey went to the motor brush terminals which are fully exposed: these were easily isolated from track supply by just cutting through the screwed on 'prongs' which contact the brush terminal mounts on the motor casing.

 

Do you suspect that this is all just too easy? Well, what came next was that mechanism disintegrated after relatively little running on DCC. The driving wheels shifted on the axles big time while it was running fast, and it had really bent rods, a broken gear, and was binned. Unfortunately the driven wheelsets are on round stubs into the insulators. The audibly 'choppy' drive from the small ZTC decoder supplied for the job was my guess at the cause of failure, the vibration in the drive line enough to cause the wheels to shift in the insulators. (It had given the owner long service on a DC resistance controller layout, and I recall it had cost under a tenner new, so he felt it had yielded full value.)

 

The Bach Royal Scot motor in their split chassis mechanism will run really well on a Lenz Standard, completely silent, and running refinement limited only by the mechanical condition of the mechanism. I have worn out any number of Bach split chassis (once through the plating on the tyres, they are all done) and never once had a motor fail.

 

 

I posted some info in these posts about fitting decoders to Mainline Patriots:

 

#2614709 and #2613377

 

Peterfgf

Thank you both - I will take a look at my Mainline Jubilee's to see if there is a void up the front. I am sure when I checked the Bachmann one, there was zero space. No room along the side of the chassis either, as the wires were enough to stop the body from fitting. I am quite happy with the decoder fitting in the tender, but ideally I would like it to go in the loco, just without having to hack chunks out of the chassis or the body.

 

Thanks

Ian

[DCB]

The wheels fall off partly because the axles don't make good contact with the chassis and start arcing which warms the wheels and loosens them on the axles.  The wrong oil or grease accelerates this, it needs conductive oil. A partial cure is to fit wiper contacts to the chassis to bear on the wheel backs, one per side is often enough as the rods conduct current from wheel to wheel. 

[John40131]

On 17/07/2017 at 15:55, ianLMS said:

Good afternoon folks,

I have just successfully converted my old Bachmann (Mainline) Split-Chassis Jubilee from Analogue to DCC. It was a challenge but through lots of research, especially RMWeb, I managed it. I used a Gaugemaster DCC26 compact 4 function, 8 pin decoder, cut off the pin PCB and then located it in the tender. Wires were hard-wired to the motor and chassis.

 

After dismantling everything, I removed the bushes, isolating the motor and soldered two wires, one to each tag on the motor. For the chassis connection, I used two self-tapping countersunk screws into the top of the chassis block (one on each side) to solder the other two wires and that's it. Re-assembling the chassis was the most challenging bit. Making sure the gap was insulated, but the two halves closed up enough so the body fitted over no problem and making sure the white nylon spacers where in the correct position where the hardest part of the whole job. A bit of heat-shrink to isolate the wires from each other, and black tape to hold it in place as the wires carried over the motor and down behind the firebox and I was then able to re-assemble everything.

 

 

In the end I mounted the decoder in the tender - looked like I would need to remove a lot of metal from the chassis to accommodate the decoder, so the tender was the easiest option. I filed some of the lower body section away under the cab so the wires fed through without fouling the wheels and routed the wires underneath the cab, and into a hole I drilled on the front of the tender. The wires then passed under the front wheel axle and into a hole in the floor, up into the tender space. I used a piece of heat-shrink to hold the wires together between the loco and tender and hide there bright colours. A test run ensured all worked well, but you need to leave enough slack in the wires or the tender wont bend round tight bends.

 

Next up - 2 x Mainline Jubilees, Hornby 3F Jinty, Airfix 4F, Bachmann Royal Scot, Hornby Fowler 2-6-4T.

 

Any tips greatly appreciated!! Especially on the Airfix 4F.

 

Thanks

Ian

Hi Ian,

Ive just asked the same question on MERG and Dean Park Station and got this link, as I just got a Mainline Jubliee "Leander" with the small ringfield motor off ebay and was wondering about converting to DCC  ... and looks like you already done ... would be grateful if you took any pictures of the mods ...

 

Regards John

[ianLMS]

Hi John. Will see what i can do later ref the pics. If you can, it would be best to remove a chunk off the front of the chassis block for the decoder, however, i didn't have the right tools to do that so in the end fed the wires back to the tender and fitted the chip in there. I now prefer to use Zimo decoders where possible. A bit larger but seem to work better in my kit builds. 

Edited June 3, 2021 by ianLMS

[ianLMS]

Not sure if this will help, but here are a couple of photos of the Bachmann split chassis Jubilee i converted. 

 

I highly recommend the Peco booklet covering the fitting of DCC decoders. It really shows and explains what you need to do in order to isolate the motor from the chassis. I dont have it to hand but they are cheap to buy

 

https://www.ebay.co.uk/itm/20-Peco-Shows-You-How-DCC-Decoder-Installation-NO-20-/261546912508?_trksid=p2349624.m46890.l49286

 

Edited June 3, 2021 by ianLMS