spikey Posted October 22, 2016 Share Posted October 22, 2016 Wire-in-tube is something I haven't done before, and right now I'm trying to work out how to do the tube runs to the two most distant points on the layout I'm building. It occurs to me that it would be handy if I can use hot-melt glue to fix the tubing to the baseboard where required, so before I go and buy a gun (which I can then use for other jobs) - can anybody tell me for sure whether that works OK with PTFE tubing? Link to post Share on other sites More sharing options...
hayfield Posted October 22, 2016 Share Posted October 22, 2016 Should do if not things like cable clips are useful, or a couple of pins either side of the tube. Link to post Share on other sites More sharing options...
Il Grifone Posted October 22, 2016 Share Posted October 22, 2016 It won't stick to the tubing, but should hold it in position firmly enough so that it won't shift about. A hot melt glue gun is a useful tool to have in any case. Link to post Share on other sites More sharing options...
spikey Posted October 22, 2016 Author Share Posted October 22, 2016 Cheers chaps. I can locate the end few inches of each of these runs firmly enough as it is, but hot-melt glue will make the in-between bits a lot easier. Just out of interest, is there any sort of generally accepted maximum length of run for wire-in-PTFE working Peco 00 points? Link to post Share on other sites More sharing options...
Il Grifone Posted October 22, 2016 Share Posted October 22, 2016 I don't know if there is a maximum, but it would depend on the radius of curvature of the tubing and the 'slop' between wire and tube. The straighter the better. Link to post Share on other sites More sharing options...
Chubber Posted October 22, 2016 Share Posted October 22, 2016 Hi Spikey, Don't know the answer to the length question, but can confirm that HMG will hold PTFE tube in place if you simply press a little strip of thin card over the tube at the gluey spot. Beware! It sure stings if you let your fingers touch the glue..... Doug Link to post Share on other sites More sharing options...
BG John Posted October 22, 2016 Share Posted October 22, 2016 I imagine it won't stick to PTFE, but this is what I've done with the Modratec tube supplied by DCC Supplies. I cut channels in the cork underlay to guide the tube, then added blobs of hot glue. This stuff is pretty stiff plastic coated metal tube, which is why using the channel in the cork helped, so I imagine it would help with the more flexible PTFE too. Incidentally, I've seen a few comments here and on another forum about wire in tube recently, and no one has mentioned that you can get copper tube quite cheaply on eBay, that is very close to the tube that used to be supplied with the Mercontrol system, before it changed to PTFE. Link to post Share on other sites More sharing options...
raymw Posted October 22, 2016 Share Posted October 22, 2016 I think the modratec tube is merely the stretchy curtain wire, obtainable from various diy/pound shops/wherever. You can get various gauge wires, in stainless/copper coated steel or brass, from a welding supplier (in 500gram reels, , or larger diameter filler rods in metre lengths, or maybe a welder will give you a few yards), and also the Teflon liner for mig handsets will reduce the friction of steel wire in a steel tube... Link to post Share on other sites More sharing options...
BG John Posted October 22, 2016 Share Posted October 22, 2016 I think the modratec tube is merely the stretchy curtain wire, obtainable from various diy/pound shops/wherever. You can get various gauge wires, in stainless/copper coated steel or brass, from a welding supplier (in 500gram reels, , or larger diameter filler rods in metre lengths, or maybe a welder will give you a few yards), and also the Teflon liner for mig handsets will reduce the friction of steel wire in a steel tube... I won't be using it again. I'm just using up what I bought when I failed to find any copper tube, and didn't fancy using PTFE. I found the copper tube easily available on eBay within a day or two of the Modratec arriving! Link to post Share on other sites More sharing options...
Mike Storey Posted October 22, 2016 Share Posted October 22, 2016 Length will depend on whether or not you remove the centre-over spring on Peco points. Take it out, you reduce resistance, but your operation needs to be much more precise, probably requiring an omega loop. Leave them in, then you can slop about all over the place, but you will need extra force to get the point over at all. It all depends on whether you want realistic slow movement or you are not that bothered. The difference is not that great. I used the GEM system many years ago, at a maximum length of around three feet from the lever frame, removed the springs, and probably spent more time getting that right than anything else. Was it worth it? Nobody who viewed the layout noticed...... Link to post Share on other sites More sharing options...
spikey Posted October 23, 2016 Author Share Posted October 23, 2016 Thank you gentlemen, Looks like my longest run's going to work out at 3ft, but I can make that one near-as-dammit straight. However, I've realised now that the two pairs of points on the passing loop are going to need bell cranks, so I think before I go any further with this I'll do another calculation on exactly how much W-I-T will save me over point motors ... Link to post Share on other sites More sharing options...
burgundy Posted October 23, 2016 Share Posted October 23, 2016 Spikey There have been a number of previous threads on wire in tube operation, which may be helpful - possibly this one. I used the method for Vintners' Yard on which the runs of tube to the turnouts include 90 degree corners (suitably curved). There is also a crossover which is operated by a single switch, where the angle crank to "reverse the thrust" is built in to the switch panel - but beware of the opportunity to create a short circuit! It took me ages to track down. Best wishes Eric Link to post Share on other sites More sharing options...
DCB Posted October 23, 2016 Share Posted October 23, 2016 Has anyone tried Mig welding wire in car brake pipe for point operation. Link to post Share on other sites More sharing options...
spikey Posted October 23, 2016 Author Share Posted October 23, 2016 Thanks for that, Eric. Very interesting ... Link to post Share on other sites More sharing options...
bertiedog Posted October 23, 2016 Share Posted October 23, 2016 I did some experiments for the L&B layout with wire in tube, including mig wire in PTFE and copper, and net curtain rail tube, The length limits are about the same as Mercontrol, but it depends purely on whether the run is straight or curved. With straight you can get over 12 feet, and I do mean straight, turns being done by the T or L cranks that Mercontrol make. The same applies to copper and PTFE or net tube. It drops dramatically as curves are added, about 4 foot max, even with PTFE and a smaller wire than the Mig type( .8mm). The original intention of the designers, who were Essar I believe, later Hamblings and GEM, was to use the L Cranks, (and T cranks), on flat surfaces, and use the through the board crank to change surfaces. They did not intend any form of curve except very large radius indeed. However you can improve on the distance and get curves very easily indeed, and that is to reverse the whole idea, and use a cable in the tube, under tension, not pulling and pushing. The cable is multi strand stainless steel, .5mm diameter, and I am using PTFE tube, but any other works. It is sold on Ebay in 10metre rolls, as is the PTFE The far end of the cable is terminated on a small coil spring, not the point, and a wire is attached to the point to operate it. As the tension alters the point operates, very simple. The strength of the coil spring is not critical, about the size of a pen spring or a bit bigger. You can also use a leaf spring, or a wire spring, and all can be totally hidden, because the cable can go past the point and the spring hidden on the surface or below. Only the cable goes near the point, to have the operating wire soldered to it. The increase in range is up to the length of the cable, which comes in 10 metre lengths, there is no limit ! The stainless cable is available on Ebay, as is the PTFE or copper etc. At the lever end the cable is fitted to the lever arm with a small sleeve of brass tube, or by a wire wrap. To set up simply pull the cable till the pint rips, and solder on the connection to the arm, as the arm moves the cable slackens and the spring pulls the point over. If the spring is too weak it will not work, too powerful and it strains a bit as it moves, but will not damage a peco point, as all the forces are on the cable not the point tie bar. A leaf spring made from nickel sheet or phosphor bronze will also work, and is more adjustable, but the spring is soldered to the cable and set at right angles. The drawing shows the variant for the L&B, but could be arranged in dozens of different ways, with springs or leaf springs, over or under the board etc. But the basic point is the limit on the distance virtually disappears., and it will go around radiuses of about a foot with PTFE. Stephen Link to post Share on other sites More sharing options...
bertiedog Posted October 23, 2016 Share Posted October 23, 2016 The L&B design is for use with Peco sprung points, other types may need an omega loop to force the cable to move more than required so as to leave pressure to hold the blades. Peco work very well with this system. A really heavy solid bladed point would work, but it would need experiment to get the spring pull right to balance the force needed to move it. These stiffer points may be better on the rod method, with it's length limits. The sprung cable works very well with signals. Stephen Link to post Share on other sites More sharing options...
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