Turnout Operation (TOUs etc.)

[Bob Ellis]

I'm not sure I quite understand your question, Bob, or why you asked it. I'm envisaging you have two 0.7mm wires, each secured to the tiebar, and descending through an unknown length into tubes. It's not clear what the tubes are attached to, nor how that below-baseboard attachment is linked to or mounted on the Tortoise.

I didn't include any pictures because there is already a picture of the P4 Track Company's adaptor plates for Tortoise motors earlier in this thread (see Merlin46's posting on 8 August 2008). I should have pointed this out since people can hardly be expected to remember a posting nine months ago. Sorry! By the way, why is there no emoticon for 'embarrassed'?

The adaptor plates are made from some type of plastic and the bottom of the brass tube is secured in holes in the bar that is moved from side to side in a channel in the adaptor plate just below the baseboard by the operating rod of the Tortoise motor. I think the diagrams and photos in Merlin46's posting should make it clear. The two 0.7mm wires are soldered to the 'ears' of the tie-bar and descend, as you surmised, Russ, into the tubes. My question is how much side-play there ought to be between the wires and the tube and how critical the amount of side-play might be.

[Bob Ellis]

Of course, a diagram and/or picture in the July Scalefour news to supplement the track articles might be good ...
EditorJohn

No promises, but IF it works and IF I have time, I shall try to write something. However, 1 June is rather a tight deadline bearing in mind that I shall be out of circulation until 10 May and the next week will be taken up with preparing for and taking part in ExpoEM. I shan't even be able to install the point motors and associated gubbins until after 18 May!

So much to do and so little time.

By the way, I have now found the 'embarrassed' emoticon. I should have looked harder.

[Tim V]

Yes Bob, saw you were going to be there demoing, I'll try and drop by to say hello.

[Bob Ellis]

Yes Bob, saw you were going to be there demoing, I'll try and drop by to say hello.

I'll look forward to seeing you there, Tim.

[Russ Elliott]

Ok, Bob, I'm with you now. I'm not acquainted with the Tortoise adaptor actuator thingie, and do not know whether it has predrilled holes in it for tubes. But you'll need to pitch the tubes to be the same as that in the Maso tiebar. I would say use a thin-walled tube to be an easy sliding fit on the 0.7mm wire - ideally, you want the 0.7mm wire to retain its verticality - too much slop between wire and tube would invite the wire to take up a skewed position, thereby weakening the soldered joint between wire and tiebar, so maybe it might be an idea to have the tubes long enough to ensure that verticality. The Tortoise spring will keep the actuator pressed over sufficiently, and no further give is required in the 0.7mm to keep blades pressured against their stock rails in plain turnouts. Where you would need significantly more give in the 0.7mm wire is in a double-slip tiebar, which is attempting to keep two switchblades simultaneously pressured to their respective rails. In this double slip case, the distance of tube protrusion above the actuator might need to be at a minimum. A lot will depend on your baseboard + trackbed thickness.

tortoise-tube.png

[Bob Ellis]

Thanks, Russ. That's really helpful. I had suspected as much, but it is good to have my assumptions confirmed by someone more experienced than me. It reduces the risk of having to dismantle it and start again. I am going away for a few days, but I shall get on with it when I return and report back on progress.

[grovenor-2685]

Following some discussion on the MERG forum on various mounting methods for Servos as applied to RTR pointwork I have been inwardly digesting the ideas along with various trial installations of my own. As a result I have developed this solution suitable for hand made finescale points and making use of the Exactoscale Tortoise adapters. The version shown is mounted above the board and the Servo mounted with a larger than necessary footprint for demo purposes. The same components can be fitted under the board using the Exactoscale instructions and with the servo fitted more compactly to the adapter plate. The complete system needs a relay for crossing polarity switching and a servo driver board but still comes out significantly cheaper than using the tortoise.
I'll do a photo of the production rather than demo version asap.


Regards
Keith

[IBlenkinsopp]

Hi Guys,

can anyone direct me to an article on torsion bar operation for turnouts.

Thanks

Ian Bl.

[Tim V]

June '77 Model Railways.