An earlier poster mentioned remote control suppliers. The best wire-in-tube is to be found in shops which sell remote controlled model aircraft. It's all white plastic, a tube within a tube. The inner tube has a hole just the right size for a Gem omega wire with superglue. Run it on top of the baseboard in slots cut in the cork underlay. Omega wire at each end, one sticking up through the hole in the tiebar, the other fixed to a Gem lever frame. Cheap and utterly reliable.
But then it won't work correctly even if it was fixed all the way along, as the inner wire is able to move other than in a single axis. IOW there will be lost motion in the inner wire within the outer tube IYSWIM?
I use the old style Hornby points with the slidebar at the side which lets me run two wires to the point (also over the baseboard). Result: I can pull both ways to get a positive click.
Must give priority to overseas orders then.. or was just a one off. Took 6 weeks from placing order to receiving the goods, and they are based in the next county !!
I contacted RM as there is no other contact details in Model oils adverts other than their address. I was told that they had received around half a dozen calls that week requesting the same, and would give them a call on our behalf. A week later the goods turned up. This was my one and only time I used them, so I can not confirm otherwise if this was a one off occurance.
On what url John? I tried via the link I have on the Scalefour site and also via Google, they both went to a page of links run by a domain parking service with no sign of the modeloils page that used to be there. The rating on here seems to imply its hard to find as well!
I've just received the January "Model Rail", and for the first time ever, Modeloils are advertising therein. Not small individual ads spread out through the pages, but 8 panels together in a half-page ad. There is no mention of "Slippery Sid", or of any website.
Are they still advertising in the Modeller, or have they shifted their advertising as a result of the complaint(s) referred to above and in other messages in this thread?
No it does not, otherwise the wire would not bend, please find a clue! If you were correct there wouldn't be any need for a constant tube, just guild blocks akin to the stools that are used on full sized point rodding.
The inner wire is free to flex, if it's not being guided by the outer tube that is exactly what will happen, that is how you get lost motion.
The wire has innate stiffness. Consider a tube fixed into a quarter circle. When under compression the wire will follow the outer radius, and under tension the inner radius, a tiny difference. Now release the tube except at its ends. Under compression the wire adopts the same position, but under tension it will try to adopt a straight line position with the tube becoming concertinaed. If the wire is a close fit, the tube will prevent the wire from taking the shortest route, assuming the tube cannot be compressed as you stipulated. Wire-in-tube tends to be used in exactly this sort of situation.
There is a fine divide between what you call wire and rod. Most of the true wire in tube methods use sprung steel wire, that has some stiffness, but is still has enough flex in it that it can support itself over too longer distance.
Previously someone mentioned the bolen cables used in model aircraft. Well being a keen RC helicopter flyer, these cables still flex and are often replaced with the classic balsa or spruce strip push rods (in planes) or more frequently, carbon rod push rods to take out any flexing experienced when using a tube within a tube method to control a flying surface. This is most noticeable with the tail rotor pitch control on a helicopter, where you need a positive control with no "slop" in it at all.
getting back on topic, using the thin PTFE tube and 22swg wire that is commercially supplied, you will need to fix the outer tube to the baseboard at very regular spaces, unless the distance is short and in a straight line from the point to the control.Introducing any arc to the path and you simply can not get away with securing just the ends of the outer tube when using this system IMO.
If the wire has no stiffness pushing one end would not result in movement at the other. Full size rodding has so much stiffness it doesn't need continuous support. Coincidentaly I dismantled a baseboard recently which I built many years ago with wire in tube control, and made just your error at that time. I ended up lying on my back gluing the tube to the underside of the board. Simple enough to try for yourself. If you're short of tube I'll send you a bit I salvaged.
I ought to look at the adverts more carefully. Modeloils has another advert, this time for "Slippery Sid", on page 129. Still no mention of any website, however.
I was thinking more about the January issue (but I suppose that's not out yet), i.e. has Modeloils switched their advertising from the Modeller to Model Rail?
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