A discrete but practicable 7mm tiebar

[Hayfield1]

I must have pinched this idea from someone else, but I need a tiebar for my COT track test plank and I found these items lurking in a draw. A bit of head scratching and I came up with this idea to experiment with. For a layout I would take a bit longer with the design, but its a good start to test out a few ideas



I started off with a brass bar 1 x 1,75mm and a 0.7 x 2.5mm double sided copperclad strip



I cut 2 pads 7mm long and soldered the bar with 221 degree solder



A second pad was also soldered with 221 solder with the outer edges 38mm apart



The Tiebars were soldered to the top pads with normal solder and the tiebar extended by 15mm past the outer stock rail. The tiebar could be cut flush with the outer rail and stiff wire soldered to the bottom of it to join an angle crank or activator



I filed the copperclad pads angled into the tiebar to disguise them more.

They might not be as prototypical as some want, but so much better than copperclad strip

The photos are larger than life and in the flesh do look much better

 

[Pencarrow]

The only downside of a solid joint to a bar is that it doesn't allow for any rotation. Yes the rotation is only small, but if the blades are moved a lot the soldered joint will fail. Might be ok on a lightly used home layout but using the same approach we had numerous joint failures and blades coming adrift.

These failures ceased when we amended the approach to have pins dropping down from the underside of the blades engaging with holes in an under board stretcher.

 

[John_B]

0.7 x 2.5mm copperclad strip

Presumably double sided, so soldering it to the bar was both possible, and doesn't cause a short.

 

[Hayfield1]

The only downside of a solid joint to a bar is that it doesn't allow for any rotation. Yes the rotation is only small, but if the blades are moved a lot the soldered joint will fail. Might be ok on a lightly used home layout but using the same approach we had numerous joint failures and blades coming adrift.

These failures ceased when we amended the approach to have pins dropping down from the underside of the blades engaging with holes in an under board stretcher.

Chris

Thanks for the suggestion, this is an area of concern and by using a 2.5mm pad and tinning the actual joint hopefully I have minimized the potential issue

John

 

[Hayfield1]

Presumably double sided, so soldering it to the bar was both possible, and doesn't cause a short.

Yes, otherwise one side will not accept solder

 

[Bigjohn]

Picking up a point by Pencarrow, above, the P 4 system of twin droppers and use of a plastic bar sliding in SWISH curtain rail track requiring no tie bar at all (dummy if you wished) was one of the mast underrated advances in pointwork control

 

[Hayfield1]

Thank you very much for the reminder about turnout operating units, but I am not at that stage yet

In 4mm scale I have both the original Studiolith (curtain rail type) under baseboard units and the excellent Exactoscale turnout operating units.

But this is for 7mm scale and neither of these methods provide a tiebar which is my first aim, I understand there are at least a couple of versions around, one is impossible to fold up and I don't think the other is available

What I require is a simple to build, yet sturdy unit for a test/demonstration track, I understand I run the risk of a solder joint failing, but its an improvement to a copperclad tiebar

Your ideas have given me and others some thoughts on improving the operational side. Thanks again

John

 

[Bigjohn]

My adaption to 7mm scale worked well on my layout…….omega loops 6 BA bolts as adjusters to GPO type micro switches extended from Perspex sq rod……….

 

[PaulRhB]

Would it be possible to shorten the tiebar and put in an insulating cut then use brass pins soldered to the rails to provide pivots.

https://flic.kr/p/2qMZW1W

 

[Hayfield1]

Would it be possible to shorten the tiebar and put in an insulating cut then use brass pins soldered to the rails to provide pivots.

https://flic.kr/p/2qMZW1W

Paul

Thanks for the visuals, But I am trying to capture the look (visual appearance) of a tiebar, I have not yet got to the actual operating linkage to what ever means which will be used to change the direction and polarity

I don't want to hide the tiebar, but superbly have it on show. Replace Tiebar for stretcher bar

 

[Pencarrow]

I've ended up with a mixture of cosmetic and working solutions. Working: the blades are driven under-board by tortoise point motors (droppers from the underside of the blade into a sliding bar). Cosmetic: castings on the side of the blades with some thin plasticard in between representing the tiebar.

 

[Jordan]

They might not be as prototypical as some want, but so much better than copperclad strip

They do look good.
A few years ago when I built my track, here at the Back of the Class I cut the pcb strip very thin for the tie bar, rather than use a full-sleeper-width piece. Despite the rigid soldered joints, the switch rails have not come away from the tie-bar, albeit this is a 'lightly used' home layout.
Photo here of the skeleton switch. The other ties (sleepers!!) were coffee stirrer strips cut to size, spiked with Peco N scale track pins....

 

[Softvark]

I use a very similar method to Hayfield but instead of using copper clad as the tiebar I use 0.5mm phophor bronze wire. This crucially gives the flexibility to avoid straining the solder connection to the copper clad under the rails. It is quite strong enough to move the switch blades and I've even used it for double slips where it's moving 4 switches at once.

Credit to Jim Snowdon for this method which he described in the Gauge O Guild Gazette Feb 2015.

Julian