hayfield Posted May 30, 2014 Share Posted May 30, 2014 I have bought today what I believe are a set (have 2 sets) of switch blade clearance gauges and would like some assistance with their use please. I think that these are either from Studiolith or K&L part ref GL 53 I also have, back to back (GL 459), check rail (GL460) and a couple of Combined track and crossing gauges (GL 458) ref numbers in brackets There are 3 gauges made from hair grips, 2 are double clips the third is just one The left one is 2 grips stuck together with some brass strip added at the tip the width of the central part is 0.84 mm. The central one is just a clip and both tips are 0.65 mm The right one is 2 grips stuck together with some brass strip added at the tip the width of the central part is 1.7 mm thick at the tip I assume that the outside two are used to set the distance between the stock rail and switch rail and the plain one is used to hold the other switch rail to the stock rail. Would the thinner one be used at the tip and the other at the end of the plaining point. Help would be very welcome, thanks in advance Link to post Share on other sites More sharing options...
hayfield Posted May 30, 2014 Author Share Posted May 30, 2014 Here is a photo of the gauges mentioned above Back to back gauge (GL 459) Check rail gauge(GL460) A couple of Combined track and crossing gauges (GL 458) I guess the washers are for gauge widening? Link to post Share on other sites More sharing options...
RMweb Gold martin_wynne Posted May 30, 2014 RMweb Gold Share Posted May 30, 2014 Hi John, When one switch blade is closed against the stock rail, the other one should be open by 1.4mm at the tip for correct scale*. Maybe 1.5mm in P4. In 00 and EM the usual dimension is 1.7mm -- set using the thickness of a 20p coin. So it's a bit difficult to know how these clips are intended to be used. Normally when fixing a switch blade you should have it clipped against the stock rail. *4.1/4" regards, Martin. Link to post Share on other sites More sharing options...
hayfield Posted May 30, 2014 Author Share Posted May 30, 2014 Martin Thanks. I have seen early articles where these hair clips have been used in ply and rivet construction. As the other gauges are for P4 its a fair bet these are early P4 gauges.This is a pure guess but I guess its safe to think that the single one is used to hold one switch rail flush against the stock rail, and it seems the 1.7 mm one is there abouts for a P4 gap between the stock and switch rail. The other one has had the ends of 1 clip cut off in both sets on purpose, also not clear in the photo the thicker one in each set has the outside of one clip stained green Just found this from the Scalefour society Switch Blade Gauges The only non-standard Gauge set is the Switch Blade Gauge which is used to assist the modeller in setting the correct gaps in a pair of switches when attaching the Turnout Operating Unit. The set consists of three clips (Fig. 8), one simply to hold a switch blade against its stock rail, while the other two are used to hold the remaining switch blade at the correct heel gap and toe gap. The use of these Gauges is described in Instruction Leaflet 4.1.7. Here is a link to a couple of photos Switch Blade Gauges http://www.norgrove.me.uk/history_files/mrc13/fig-7.jpg http://www.norgrove.me.uk/history_files/mrc13/fig-6.jpg The only non-standard Gauge set is the Switch Blade Gauge which is used to assist the modeller in setting the correct gaps in a pair of switches when attaching the Turnout Operating Unit. The set consists of three clips (Fig. 8), one simply to hold a switch blade against its stock rail, while the other two are used to hold the remaining switch blade at the correct heel gap and toe gap. The use of these Gauges is described in Instruction Leaflet 4.1.7. Something gone wrong with the copy and paste to show smilies !! Link to post Share on other sites More sharing options...
Grovenor Posted May 30, 2014 Share Posted May 30, 2014 For the track gauges see http://www.scalefour.org/history/p4gauges.html for the switch blade gauges see http://www.scalefour.org/history/p4tracklaying.html Regards Keith Link to post Share on other sites More sharing options...
hayfield Posted May 31, 2014 Author Share Posted May 31, 2014 Keith Thank you very much and to show the link to compare with my gauges. I did try to find the page with 4.1.7 without any luck Clip one switchblade to the stock rail using the Silver clip from the gauge set and solder the wire to the switch blade using solder paint or solder cream. Now, with the Silver clip, clamp the second switch blade to the other stock rail at (A) and insert the Blue gauge in position ( B ) so that the gap between the stock rail and the heel of the switch blade is correctly set by the centre prong of the gauge, leaving the outer prongs to hold switch blade and stock rail securely. Place the Green gauge in position ( C ) in the same manner at the toe of the switch blade so that only the tip of the blade is held in the gauge. Solder the second wire to the second switch blade, rotating the wire in the tube as necessary to give a close fit. Clip A is the single clip being used to hold one blade to the stock rail as thought Clip B (mine is not blue) which is the smaller one I guess looks to be at the end of the plaining 0.84 mm gap Clip C which is green and leaves a gap of 1.7 mm is clamped to the stock rail and the very tip of the switch blade. This looks to give a larger gap at the tip of the switch blades than to where the plaining ends 4 sleepers later, which seems to be born out by the photo Coming back to Martin stating a 20p piece is the correct size, just measured it and it comes in at 1.75 mm thick. Now if we used P4's principals in EM it would be about 1.70/75 mm narrowing to 1.25 ish or is it just a straight 1.7 mm in both places ? Again thank you both for the info Link to post Share on other sites More sharing options...
RMweb Gold martin_wynne Posted May 31, 2014 RMweb Gold Share Posted May 31, 2014 Coming back to Martin stating a 20p piece is the correct size, just measured it and it comes in at 1.75 mm thick. Now if we used P4's principals in EM it would be about 1.70/75 mm narrowing to 1.25 ish or is it just a straight 1.7 mm in both places ? Hi John, The prototype narrows to a minimum of 2" which scales to 0.67mm. That's the minimum for P4. In 00 and EM it should narrow to a minimum of 1.0mm to match the flangeway gap. Use your crossing flangeway gauge shim to check it. Martin. Link to post Share on other sites More sharing options...
hayfield Posted May 31, 2014 Author Share Posted May 31, 2014 Martin Thanks, I was just doing a pro rata increment. Good news is that if I run out of twenty piece pieces I can use the C gauge for EM at the tip Its strange when following the SMP copperclad instructions 40 odd years ago nothing like this was ever mentioned, simularly no A<B or C crossings, sets or blunt crossing noses. I still have the Aluminium flat bar track gauge that came with the kits, and yes they are 16,5 mm wide and 1.22 mm thick. Not bad for pre digital days. Also track building seems to fall into two groups, those who like to be dead on and those who accept slight inaccuracies so it works better. One friend in EM likes a slightly wider gap of 2mm at the point blades and a slight rebate in the stock rail, this I think allows more RTR wheels to be used with increased back to backs. Others to prefer rebates in the stock rails in 00 gauge again I think to accommodate less than perfect wheel sets. Link to post Share on other sites More sharing options...
roythebus Posted June 2, 2014 Share Posted June 2, 2014 As a bit of an aside, ISTR Keith and myself laying what was probably the first P4 test track on the MRC's test track in the late 1960's. It's still in service today. It was laid using copper-clad sleepers and Jones Bros TT flat-bottom rail; Keith worked out that by fitting a check rail all round, this would give an additional 00 gauge circuit as well! Link to post Share on other sites More sharing options...
hayfield Posted June 2, 2014 Author Share Posted June 2, 2014 Clever, but the gap must have been a bit wide, unless it was EM rather than 00 18.83 v 16.5 = 2.33 mm 18.83 v 18.2 = 0.63 mm (about right) Link to post Share on other sites More sharing options...
Grovenor Posted June 2, 2014 Share Posted June 2, 2014 The test track set up is for dual gauge rather than a check rail as such, the gap just has to be at least a check rail gap, as suggested it is somewhat wider so does not function as a check rail. The test track includes EM as well but on a different track from the P4, and one of the tracks has 9mm gauge as well, I don't remember now whether 12mm is also included but anyone going to Keen House can have a look. Keith Link to post Share on other sites More sharing options...
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