tender drive scotsman

[GeoffBristol]

I am confused as to the drawbar couplings on a Flying scotsman tender drive ?

I am about to check it out as a new 'find' - but is something missing here ?

I see 'c' clip around pin to motor ok.

But I have another wire from the other front wheels to the lug on the top of the bar ? How can this connect to the tender electrically.

The tender has a plate under the bar thats continuous to the non tyred tender wheels ? but what should join them ?

[Topcat2018]

This is a Chinese made loco and should have two finger contacts on top of the drawbar, that make contact with the plate on the tender, but these are very flimsy and frequently get broken. See my recent post on "Missing or broken drawbar contacts on Chinese-made tender-drive locos".

You may be able to find a replacement drawbar, but these can cost over £10. An alternative is to rewire the loco to be the same as a British-made one, which uses only the bottom contacts. Cut the wire that goes to the bottom contact and insulate it. Cut the top wire from the solder tag and solder it to the bottom contacts.

I wouldn't try de-soldering the wires as you will probably melt the plastic part of the drawbar. I know from experience.

[ColinB]

You can resolder the wires you just need a reasonable temperature controlled soldering iron. I have done many. As I said on another thread I generally remove them as they are so problematic and easily broken, and replace them with the later 4 wire solution. Last time I looked these were not available new.

[96RAF]

The tender post should be metal to act as the other pole. If you look at the topside of the tender you would see two wires on a loco drive engine, but here I guess the tender motor is picking up from one set of tender wheels through the live chassis and the other pickup is from the opposite rail of the loco.

This is the normal springy finger loco drive drawbar as rigged for a DCC socket.

[Topcat2018]

@Geoffrey

I should have mentioned that rewiring the drawbar as I suggested only works if your system is analogue.

In the British tender-drive locos the bottom drawbar contacts are connected to the left-hand rail via the wheels of the loco and the right-hand wheels of the tender are connected to the right hand rail. In the Chinese-made locos the right-hand loco wheels are connected to the bottom drawbar contacts and the left hand wheels to the top contact. But the tender still has the right-hand wheels connected to the right hand rail so you don't need the connection from the right hand loco wheels to the bottom drawbar contacts. If you swap the wire connected to the left hand loco wheels from the broken or missing top drawbar contacts to the bottom the loco still works.

[ColinB]

The easier solution is to replace it with a two pin plug and socket solution, much more reliable. I did this with my earlier Margate based models when I added all wheel pickups.

[GeoffBristol]

Good to know something is missing !

Its on dc and it is wired exactly like that drawing - less dcc block. - and the fact the motor is in the tender ! All the wiring is that way.

Rignht pos rail engine to upper plate. This in the tender is wired to the non tyred wheels - right side.

Left neg rail to clips and main pin - then to tender tyred wheels - left side.

The issue with it was a dead link berween pin and brush inside tender ! Thats fixed now.

The tender has pickups on both sides - blades to chassis on tyred side - and blades to pos brush on non tyred wheels. So it will run badly as tender alone ( it was stopping on curves)

So the main fault is fixed.

I just now need an easy reliable way to feed pos side loco to plate ?

Maybe make a new brass blade to mount on top of drawbar with a new wire pre-attached back to loco. No soldering on drawbar needed ?

That is no problem for me to get over - thanks for the dawing.

I want to use the good 'three wheels' either side feeds - pos and neg - plus back up of tender both sides. It runs now as a split feed - neg loco/pos tender - but I do not want that.

I have rewired the tender - had to solder the inner pin wire pickup as it was a bad crimp - which was thicky without melting the tender frame. The main enigine wheels and blades look good - and all show continuity to drawbar.

Thanks

Geoff