Liddy Posted November 6, 2011 Share Posted November 6, 2011 Hi, Worried Here, I'm learning to build a P4 point, I have an already built point that I got 2nd hand and I've got the Scalefour gauges. I'm worried that when I set back-to-backs on wheels sets then try them on the point they appear 'sloppy', yet the S4 track gauges are tight! I have gone-back-to-basics and set the b2b on 4 x wheelsets (make unknown, steel rims on plastic split-spoke centres, backs of plastic centres not flush with backs of wheel rims) setting the b2b with an S4 L-shaped 17.7mm gauge and checking against an Intercity Models brass gauge. The b2b gauges concur, so I think my b2b's are correct. The S4 roller gauge won't roll, the track gauge (TG) is tight and the 3-point gauge is tight, yet the wheel-flange/track have 'sideplay' when rolled through the trackwork. I'm not happy with the looseness of some of the rivets in the ply sleepers, but that isn't my concern right now. I'm worried that the roller gauge is tight and the wheels appear loose! I have the parts to build a new point on copperclad sleepers, but I need to know first if I am doing something wrong. Any help greatly appreciated. P.S. I have 2nd hand Ratio plastic sleepers labelled EM 18.83, again the wheelsets roll through just fine, but the Roller gauge, TG and 3-point gauge are tight! Link to post Share on other sites More sharing options...
Guest oldlugger Posted November 6, 2011 Share Posted November 6, 2011 Hello Liddy, I would trust the Scalefour gauges more than the back to back measurements of the wheel sets. It sounds as though the rail on the rivets is moving inwards and tightening on gauge. Personally I would opt for a slightly looser fit with the track gauge - just a tad - so that the S4 gauge will fit smoothly between the rails but still snugly. Ply and rivet track can come loose over time and cause gauge tightening. Curves are especially prone to gauge tightening and is something to watch out for on turnouts and plain track. I would alter your back to backs accordingly; move the wheels outwards slightly. By the way, are you sure the wheels are P4 and not EM? I'm curious as to why the Ratio sleepers are called EM, but with the P4 18.83mm gauge marked on them? Odd... Cheers Simon Link to post Share on other sites More sharing options...
Liddy Posted November 6, 2011 Author Share Posted November 6, 2011 Hi Simon, Thanks for your advice, I'm most concerned because so far I've been working off the straight stock rail to ensure an accurate datum and haven't got to the diverging rails yet. I'm sure the wheels are P4 as they have very fine treads. Also, as a way of checking the Ratio sleeper base I will get an EM roller gauge on the plain track. Thanks again Liddy Link to post Share on other sites More sharing options...
Guest oldlugger Posted November 6, 2011 Share Posted November 6, 2011 Hello again Liddy, Perhaps you could post a photo of one of the wheels (face on) to show the depth of the flange? EM wheels are also pretty fine - tread and flange - and I believe there are two wheel standards in this gauge. Someone else with more knowledge of EM than me will provide more info I'm sure. It is possible to use EM wheels on P4 track with an adjustment of the back to backs. It looks as though you might have a mixture of P4 and EM here... Cheers Simon Link to post Share on other sites More sharing options...
brossard Posted November 6, 2011 Share Posted November 6, 2011 EM gauge wheels from Exactoscale have fine threads as well. B2B for P4 is nominally 17.7mm +/- 0.03mm. I suggest you use a digital or dial caliper to measure what you have. Physically measure your B2B gauges and your track gauges (should be 18.8mm +/- 0.03mm at worst). Measure the track gauge on your point as well. For the diverging road depending on the point angle you should probably use your 3 point gauge (the right way round) to give a (very) slight gauge widening. Rice says that, according to S4 Digest, Running Clearance should be between 0.3 - 0.5mm. Flangeways in EM are 1mm and in P4 (IIRC) 0.7mm. Your wheels and point geometry at the crossing will need to be cock on for success. I have two books that are well thumbed: 1) Trax2 Track Construction by Jeff Geary and John Shaw. This comes with a track design software. 2) An Approach to Buiulding Finescale Track by Iain Rice If I were you, I'd start by building the point in copperclad to get the feel of it all before going on to more complex methods. John Link to post Share on other sites More sharing options...
Grovenor Posted November 6, 2011 Share Posted November 6, 2011 There should always be some clearance between the wheels and the rail, check your wheelsets through the crossing, they should run smoothly through and the check tails should stop the flanges from hitting the crossing nose, if that is OK then you have nothing to worry about with the points. The Ratio track is another matter, you will find it is tight to gauge even on the straight and will cause derailments. I tried to use mine up in straight sidings but it caused problems even there, it all ended up in the bin. For plain track bases use C&L if you want thin sleepers to match ply and rivet points or Exactoscale if you want the thick sleepers. Some track building info here http://www.norgrove.me.uk/points.html and here http://www.norgrove.me.uk/shed-relay.html Keith Link to post Share on other sites More sharing options...
brossard Posted November 7, 2011 Share Posted November 7, 2011 Not sure what S4 Society offers in the way of tools but EMGS has some very good ones that are not gauge specific. These are: 1) Vee construction jig. Provison for 1 in 5, 6, 7 and 8. There's another for 1 in 9, 10, 11, and 12. 2) Switchblade planing jig 3) Common crossing assembly jig They're not cheap but IMO well worth having. I have made points without these but the tools make the work quicker and more repeatable. John Link to post Share on other sites More sharing options...
hayfield Posted November 7, 2011 Share Posted November 7, 2011 I have just checked my P4 wagon on a piece of plain track and a copperclad turnout, and there is a small amount of side play.I only have an old Studiolith back to back (will get a new one when I place an orede with C&L) so cannot guatentee the wheels are spot on. The wagon rolls smothly through the turnout though. EM wheels will run (badly) on P4 plain track, but there is a lot of side play. Stops at the V Link to post Share on other sites More sharing options...
RMweb Premium kevinlms Posted November 7, 2011 RMweb Premium Share Posted November 7, 2011 The Ratio track is another matter, you will find it is tight to gauge even on the straight and will cause derailments. I tried to use mine up in straight sidings but it caused problems even there, it all ended up in the bin. Keith There IS another use for the 18.83 track. Give it to an EM modeller, where the undergauge comes in handy when using it for EM curved track. When I used it on a former EM layout, it come down to about 18.4mm from memory - so perfect gauge widening. I purchased the 18.83 in error. Kevin Martin Link to post Share on other sites More sharing options...
craigwelsh Posted November 7, 2011 Share Posted November 7, 2011 Set your b2b to 17.75mm would be my suggestion anyway as per the new Exactoscale b2b gauge, the older L gauges are generally 17.67mm. B2b can go up tot he S4 exact standard of 17.87mm and go through P4 fine. Have you got digital calipers to check the gauges are nominally correct? If the roller gauge is the same large turned one in a box I have i'd certainly use that as your guide to what is appropriate. It should just be able to run through your trackwork. Link to post Share on other sites More sharing options...
Liddy Posted November 7, 2011 Author Share Posted November 7, 2011 Hello All, Thank you for your sharing your experience, such wisdom is very precious when I'm sitting here confused and considering if I've messed-up somewhere. I've included a couple of photos to illustrate my plight Firstly my wheel options; unknown make of wheels, Keen Maygib 18.83 and Wizard EM (used to try on the plain track) This photo shows the L-Shaped gauge, nominally 17.7mm, mine measures 17.72mm so within tolerances, my criticism is that when 'miking-it-up' I discovered slight ridges on the ends of the arms, I can only guess where the cutting tool didn't run-off the end of the work, this means that wheel sets have to be dropped into the corner, not slid along an arm. I haven't photographed the cylindrical brass b2b gauge, yet measuring it showed it to be 17.91mm ..... not accurate enough for it's intended purpose! I think my next move has to be to solder-up some plain track with the Scalefour gauges and check that for smooth running using wheelsets gauged from the L-shaped b2b and if that feels right then at least I have matching standards. Then build a copperclad point from scratch using known gauges and wheelsets. Wish me luck Liddy Link to post Share on other sites More sharing options...
Guest jim s-w Posted November 7, 2011 Share Posted November 7, 2011 There should be some movement. (remember on real track the flanges dont touch the rail as the coning keeps the wheel centered. You can tel when a flange touches the rail as it will squeal You can check the back to back with a point. if one wheel is hard up against the rail then the back of the other one will be hard up against the opposite check rail HTH Jim Link to post Share on other sites More sharing options...
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