Pirctures of Torque straps

[garethashenden]

With a CSB chassis the motor and gearbox must be able to move up and down, but they shouldn't rock forwards and backwards. A torque strap of some form is needed to hold these in place. I'd appreciate pictures of how this is actually done. I've seen a diagram, but I think actual pictures would be better.

Thanks!

[David B]

I have held mine with a pad of foam on top. This allows the up and down movement and minimises any rotational. In the picture below of my rail motor chassis, the brass rectangle is for mounting via a screw in the top. On a loco, I have stuck the pad of foam to the the boiler.

When I ran the chassis of the loco without the body, I tied it down with a bit of thread.

IMG_0018crw.jpg

[Will L]

A couple of Photos attached. A torsion reaction link doesn't only prevent the motor from revolving round the axle. On any chassis with suspension on the driven axle, a torsion reaction link must also prevent the torsion reaction from effecting the action of the suspension. To do that, it must act at right angles to the direction the axle is fee to move in. On a loco chassis that means it must act horizontally, as the axle moves vertically. With any other arrangement there is a danger that the torsion reaction will cause the axle to rise or fall under power. It is true that with a nice free running chassis pulling a small load you are unlikely to observe the effects due to a misapplied torsion reaction link. On a loco with a less than perfectly free chassis and/or a significant load on the draw bar, the drive axle may well be observed to hop once each revolution.

The picture below, out of a C12 seen often in these pages, is a classic application using an up-stand soldered to the chassis. It is not central on the chassis and I've often wondered if that might have any undesirable effects. The loco runs smoothly in all circumstances.

CSB C12 pickup detail.jpg

This one is of a J65 and the link is fitted centrally. Getting the up-stand in to what is a small prototype with full cab detail posed problems, so this one had to go in under the cab floor, but that seems to work well. The pickups have been sorted out since the photo.

buck into 2.jpg

[garethashenden]

Thanks guys. I see now where I was going wrong.