craigwelsh Posted January 8, 2011 Share Posted January 8, 2011 I'm a total novice in loco building too and I've been attempting to build a chassis for a RTR engine for some time. I'm about to start on my third attempt! I have to say that much of the stuff that's been written here is no help at all. Is there a blog to which the tyro can attend? Regards Write your own blog with pictures of where you've gone wrong and you'll get more useful corrective suggestions. Link to post Share on other sites More sharing options...
RMweb Premium polybear Posted January 8, 2011 RMweb Premium Share Posted January 8, 2011 It's very simple, John. The bogie's not sprung with the rest of the chassis; it's still basically a simple swinging arm/pivot to the body, with a light spring to hold it down. However, the clever bit is that one axle runs conventionally in plain holes, but the other moves up & down in slots, pivoting on a vertical plate in the centre. Have a go - you'll not regret it Cheers Mark Sounds a bit like a method known as "compensation" to me; apparently someone called a Mr. Sharman wrote a book about it. I read somewhere that it's a waste of time and doesn't work.... Brian Link to post Share on other sites More sharing options...
Metropolitan Posted January 9, 2011 Share Posted January 9, 2011 Sounds a bit like a method known as "compensation" to me; apparently someone called a Mr. Sharman wrote a book about it. I read somewhere that it's a waste of time and doesn't work.... Brian At a guess I would imagine that Mike Sharman's compensation system was really invented to try and reduce the number of derailments for those modelling in P4. Unfortunately, from what I have actually witnessed in real life, in that endeavor it utterly fails!! The use of EM wheels might be a better bet?? Link to post Share on other sites More sharing options...
MarkC Posted January 9, 2011 Share Posted January 9, 2011 Well, I can only speak as I find, and I'm certainly no 'expert'. However, the piece of kit in question is very simple, and <touches head in absence of convenient piece of wood > has produced the best-running chassis I've ever built, which speaks volumes to me Link to post Share on other sites More sharing options...
PenrithBeacon Posted January 9, 2011 Share Posted January 9, 2011 Write your own blog with pictures of where you've gone wrong and you'll get more useful corrective suggestions. Thank you for the advice, I might just do that. Basically I'm a returnee to modelling which I gave up when the children were very small because I didn't have the time. Now they've left, I'm retired and divorced, so have the time. I also have an engineering apprenticeship from 50 years or so ago but it's difficult to remember the techniques I learned during that time as I was one of the fortunates who was able to move from a craft apprenticeship to a technician apprenticeship and so spent my working life specifying, designing and testing rather than making. There are also the disadvantages to my condition. My eyesight isn't what it was (depth of field closeup is a particular problem) and my fingers, always short and stubby are now pretty inflexible at the joints and insentitive at the tips. Small components are difficult to see and pickup and fix in place and this has been a major factor in the failures so far. The basic idea is P4. It was before I gave up and it is now. I can understand the attractions of the simplicity of OO and EM, but the improvements in appearance, running and reliability that P4 has always offered clinch it for me. The problem of course is that P4 adds a layer of complexity which the tyro finds difficult, particularly when I'm trying to remember long gone techniques and have the physical disadvantages of rising 67. I've tried following Ian Rice's book but although it offers some good advice it also has a number of weaknesses. I'll order another chassis kit tomorrow and see ... Regards Link to post Share on other sites More sharing options...
RMweb Gold Barry Ten Posted January 9, 2011 RMweb Gold Share Posted January 9, 2011 A few minor observations: I've only built five loco chassis to date, but in all instances getting the basic chassis assembled true, and with coupling rods on, proved fairly painless. I never had to open out the rod holes more than a smidge to get a smooth rolling chassis. If the kit manufacturer has done their work properly, there should be no need - the axle centres should be in accurate alignment with the coupling rod holes. After my first kitbuild (a DJH C2X) I bought a couple of Comet alignment jigs, which I've used subsequently. They're not a cure for all ills, nor do they remove the need for care in assembly, but they are a help. I'm sure that the various chassis assembly tools that have come on the market in recent years are even more useful. The problems I have encountered have been much more to do with pickups, gear meshing and connecting rods/slide bars than the basic chassis assembly. I have cured the first by using Tony Wright's advice on pickups - read his book, or watch the Right Track DVDs. Gear meshing has been a non-issue ever since I standardised on DJH gearboxes and motors, already assembled. As for connecting rods, slide bars, valve gear etc - I guess the only advice is that practise makes things easier, and that having one engine built and running gives you confidence when you hit snags in the next. By far the trickiest thing, I have found, is diagnosing a running fault when you don't have years of experience to draw on. If an engine doesn't run completely smoothly, is it the pickups? Is it stiffness in the slide bars? Is it a transient short caused by a wheel touching a brake block? I have been caught out by all these things - indeed, with my first loco, I dismantled the whole thing back to the bare chassis and started mucking about with reamers and broaches, before taking the loco along to one of the Missenden Abbey weekends. Tony Wright took a good look at it and reassured me that the chassis itself was fine - the fault had to be in the pickups or the motor/gearbox. Tony put his own pickups on it, and that made a difference, but it was only when I swapped out the gearbox that the loco ran as well as I wanted it to. I guess the moral here is to have confidence in your own work; don't assume the worst if something doesn't run well - the cure may be relatively simple. I later worked out that I'd knackered the motor bearing in the original Mashima when cutting off the motor spindle with a slitting disk. All my locos are built rigid, but then I operate on 00 track - I'm open minded to the benefits of springing or compensation in the finer gauges! I've used Carrs solder paste on my recent builds (indeed, in all my soldering) with no difficulties. Most of my chassis sit under proprietary bodies, but those that are white metal were built with a combination of superglue and araldite. I hope to graduate to all-soldered construction eventually, but I need more practise with low-melt assembly. I use a very basic toolkit - some cheap reamers, an Antex 25w soldering iron, a few files and broaches. Nothing that can't be put on the coffee table when there's a good film on. I have no illusions that I am more of a bodger than an engineer, but I have got my locos to run so there is hope for anyone B) Link to post Share on other sites More sharing options...
bertiedog Posted January 9, 2011 Share Posted January 9, 2011 Only a passing observation, a lot of modellers notice that really smooth gliding silent locos are often diesel outline, steamers tend to have more problems, and trying to squeeze the last drop of smoothness out of a steam chassis can seem impossible, and indeed.... it is.... for a little considered reason........ The whole rotary action of a model steam chassis is out of balance, the quartering results in the weight of the rods, and pistons, alternating a thrust, and you can't remove it or balance it easily on a model.. It affects O scale, and bigger, more than OO, the rods are heavier etc., but the result in OO is there, a slight audible "Waa-Waa" noise from the gears as the pressure on them from the weight of the rods vary on each rotation. The higher the quality of the gears the more noticeable, all other things being equal. In practice on a real model the effect is masked by drag, friction, oil grease and wear and tear, but when Portescap motors, P4 and precision assembly are combined, the effect can surface and be noticed, and the modellers looks to other solutions, without realising the high standard has brought the issue to the surface. Diesel and Electric model trains do not do this, and appear a lot quieter and smoother, as long as the gears and wheels are true etc. Stephen. Link to post Share on other sites More sharing options...
Portchullin Tatty Posted January 9, 2011 Share Posted January 9, 2011 Penrith Beacon There is some very good advice on the Scalefour Society's forum: Parts one and two of a beginner's loco-building project run by the West of Scotland Area Group; it may seem long but there is a fair amount of chat within it. There is advice within this for the absolute beginner to the pro and it is very practical. Also, you will be able to skip big parts of it because it relates to a scratch building project and if you use one of the High-Level, Comet or Bill Bedford chassis as suggested, a lot of this is done for you. Beginner's loco building part 1 and Beginner's loco building part 2 The other link worthy of looking at is again a step by step project, this of one of Bill Bedford's chassis for a J72. J72 loco chassis link Captain Albino I am sure you are quite frustrated as to the manner in which this topic unfolded but there is some very good advice in these threads; nearly all of it is relevent to both rigid chassis and compensated/sprung chassis. Whilst I think perhaps your initially desired loco is not the place to start (do try one of the sources of quality chassis noted above); starting is the way to go! Do just check the various relationships between wheelbase, coupling rods and axle throw as you go, they must be consistant for a good chassis. Link to post Share on other sites More sharing options...
Kenton Posted January 9, 2011 Share Posted January 9, 2011 If the kit manufacturer has done their work properly, there should be no need - the axle centres should be in accurate alignment with the coupling rod holes. Oh how very true that statement is - the problem though is sadly too many do not. This is not be deliberate design, it is usually that the kits are old and the etch masters hand drawn with inevitable imperfections. There is absolutely no excuse for modern CAD masters and modern etching processes to produce poorly aligned parts or the infamous oversize holes of yore. Link to post Share on other sites More sharing options...
PenrithBeacon Posted January 9, 2011 Share Posted January 9, 2011 Penrith Beacon There is some very good advice on the Scalefour Society's forum: Parts one and two of a beginner's loco-building project run by the West of Scotland Area Group; it may seem long but there is a fair amount of chat within it. There is advice within this for the absolute beginner to the pro and it is very practical. Also, you will be able to skip big parts of it because it relates to a scratch building project and if you use one of the High-Level, Comet or Bill Bedford chassis as suggested, a lot of this is done for you. Beginner's loco building part 1 and Beginner's loco building part 2 The other link worthy of looking at is again a step by step project, this of one of Bill Bedford's chassis for a J72. J72 loco chassis link Thanks for the advice I have bookmarked the URLs Regards Link to post Share on other sites More sharing options...
craigwelsh Posted January 13, 2011 Share Posted January 13, 2011 Thank you for the advice, I might just do that. I'll order another chassis kit tomorrow and see ... Regards I'd really recommend getting some photos of how far you got up here somewhere in a thread of its own. Saves you potentially doing the same thing again on a new chassis and someone may have a method of salvaging the old one depending on what it was and what you did. I agree that the S4um threads given should help but its always possible you have something specific to deal with in your kit. Link to post Share on other sites More sharing options...
Metropolitan Posted January 14, 2011 Share Posted January 14, 2011 Only a passing observation, a lot of modellers notice that really smooth gliding silent locos are often diesel outline, steamers tend to have more problems, and trying to squeeze the last drop of smoothness out of a steam chassis can seem impossible, and indeed.... it is.... for a little considered reason........ The whole rotary action of a model steam chassis is out of balance, the quartering results in the weight of the rods, and pistons, alternating a thrust, and you can't remove it or balance it easily on a model.. It affects O scale, and bigger, more than OO, the rods are heavier etc., but the result in OO is there, a slight audible "Waa-Waa" noise from the gears as the pressure on them from the weight of the rods vary on each rotation. The higher the quality of the gears the more noticeable, all other things being equal. In practice on a real model the effect is masked by drag, friction, oil grease and wear and tear, but when Portescap motors, P4 and precision assembly are combined, the effect can surface and be noticed, and the modellers looks to other solutions, without realising the high standard has brought the issue to the surface. Diesel and Electric model trains do not do this, and appear a lot quieter and smoother, as long as the gears and wheels are true etc. Stephen. Hi Stephen I was interested to read your informative post. However, your explanation does nothing to support the generally argued virtue of compensation; namely, that it improves running quality?? In fact it suggests that other factors are more important than complicating matters with wobbly beams and sticky hornblocks and that rigidity and simplicity is most likely to produce a smooth running model? Modesty prevents my using my recently built V2 as an example so I will stick to my Hornby Black 5: It creeps. It is smooth. It is silent. There is no sign of out of balance forces acting on it. It's haulage power is very good. It never falters due to bad electrical conductivity. In fact it is difficult to know how it's performance as a model could be bettered? It is un-compensated and un-sprung. If you, like me, accept that it's performance is exemplary we can only conclude that compensation is more likely than not to have an adverse effect? Link to post Share on other sites More sharing options...
Kempenfelt Posted January 14, 2011 Share Posted January 14, 2011 Sticky hornblocks are no fault of compensation! This is purely down to the care put into the model by it's builder! If you can't manage to get a hornblock to slide properly without sticking then yes plump for a rigid chassis, until you have sought advice and corrected your problems. Sticky hornblocks in my experience are usually down to excess solder or not getting the horn blocks and guides square and true in the chassis. Yes a badly compensated will worse when compared to a rigid chassis, same with anything that is made badly! Get it right however and watching a successfully compensated chassis is leagues above a rigid alternative! A rigid chassis should perform pefectly on a pefectly flat bit of track, its downfall is when it meets a not so perfect piece of track! At this point a rigid chassis will lurch far more than a compensated one! The argument of why didn't you get your track right in the first place does not wash! All thing's move over time! With the above praise mentioned above in favour of compensation, this is not the ultimate in chassis construction. CSB is the bee's knee's and produces the smoothest ride for any model loco i've seen. I have similary treated my Bachmann Mk1 coaches and there is no way i'd revert back to a rigid chassis having been in awe at the results. If you want to compare exemplary performance then watch one of Chris Pendelenton's pacific's or Deltic going the clappers, anybody who considers this a step backwards from a rigid chassis is beyond me! Regards Paul Link to post Share on other sites More sharing options...
Horsetan Posted January 14, 2011 Share Posted January 14, 2011 .....I will stick to my Hornby Black 5: It creeps. It is smooth. It is silent. There is no sign of out of balance forces acting on it. It's haulage power is very good. It never falters due to bad electrical conductivity. In fact it is difficult to know how it's performance as a model could be bettered? .... ...and it wasn't built in a record-breaking hurry by you? Link to post Share on other sites More sharing options...
Kempenfelt Posted January 14, 2011 Share Posted January 14, 2011 Sorry chaps and possible chapesses, i've well and truely taking the bait here! All the OP needed to know in this thread is that there are currently 3 common methods of chassis building! Rigid Compensated Sprung (CSB) (Prehaps a combination of methods too if you're being finickity!) I feel the merit's of rigid Vs compensated/sprung should be taken elsewhere, prehaps it's own thread? (although I believe we've been there before!) At least people who want to learn how to start loco building then don't get pulled into a non-essential debate that has polluted this thread and instead have a choice to read about it! Regards Paul Link to post Share on other sites More sharing options...
Neill Posted January 14, 2011 Share Posted January 14, 2011 There's one class of locomotive that I've always wanted to add to my collection, and thats a GWR 72xx. However, after always entering Bachmann and Hornby wishlists back as far as I can remember, its never been put into production. I guess I'm in the minority here. However kits are available, with a very nice looking one being made by PDK models. There is just one thing that puts me off going down that route.... soldering brass! My soldering skills are good enough for electrical work, but will that suffice for putting a set of frames together? Also seeing a brass etch fills me with dread! So really my question is, how easy is it to deal with making brass frames, is a 72xx too big for a beginner, and should I make something smaller first such as wagon kits or a starter loco kit? As a newbie to this site, I'm going to take this thread back to the original question. I'm not knocking any of the chassis advice at all though, it's very good indeed. My first etched loco was the Mitchell 517 tank in 7mm. Before that I'd built a couple of Connoisseur Models wagons to hone up soldering skills (I'd never soldered anything at all before, electrical or otherwise) etc. An 0-4-2T seemed like enough of a chassis to start with and the kit went together a treat. Soldering up frames is not really that difficult providing you are meticulous about squaring things up, and make sure that the centres for the connecting rods are exactly the same as the axles. Cleanliness is next to godliness where solder is concerned and don't be afraid to use lots of flux, I've given up with Carrs and now use a water based flux from Building O Gauge online, it's far less corrosive and works equally as well. A 72XX is a lot of loco though, I'd suggest building a wagon or two so you don't need to worry about soldering when you go for the loco itself. If you decide you want to build more one of the chassis jigs you can buy is worthwhile, but they are pricey. They do the job though. My next loco will be sprung and use Hobby Holidays hornblocks and bearings - I'd personally not have the confidence to do that without a jig. Link to post Share on other sites More sharing options...
bertiedog Posted January 14, 2011 Share Posted January 14, 2011 You can't alter the basic science, a 4 wheel unsprung loco stands on three wheels*.....unless the track is perfect...and the wheels perfectly identical, but a sprung loco sits on four wheels all in contact with the rail, whatever the state of the track., or even with slightly miss-matched wheels due to wear etc. (* it might only be by a micron, but it is still out of contact) The same applies however many wheelsets there are, in the sprung version all are in contact, and with careful design all apply the same pressure on the rail with compensation. It is not complex to fit, some designers have made it so, and the Sharman type methods when badly applied is over complex in appearance and a bit messy. If a chassis has bearings, they can be sprung, pure and simple. RTR is a bit of a different case, loose tolerances, slightly flexible plastic chassis, U shaped slot bearings, all allow wheels to shift about to remain in contact. Some designers try to mix "real" hornblocks with complex compensation additions, nice on a scale loco chassis, but over complex in a kit.. Gordon Varney in the States solved the problem in the 1940's, he designed a simple wire spring on each side of the chassis that bore on sleeve bearing's, an engineers solution that works. Not exact scale, the bearings are from one side to the other as a sleeve, but it gave a fully floating suspension, all wheels in contact, all picking up power,, with a floating gearbox and motor. But it added cost, and British kit designs were simplified purely to save cost, springing was rare, and not allowed for at all with solid cast or brass chassis. Tri-ang lead the RTR world with simple design, but got away with it as they were actually accurate builders, and the flanges overcame deficiencies in tolerances, aided by magnets used to pull the wheels on to the track. Hornby got away with no springing due to the tyre shape and heavy weight, plus decent engineering aided by 3 rail pickup.. But springing always was and always is desirable, the real thing depends on it, the best models depend on it, and Fine scale EM, P4 and HO Proto depend on using suspension, in the same way as a loco does in real life. On whether your own model works well or not is pure speculation here, from your description fine, but years in the trade and building models means I take the position as a devil's advocate, I take the model as I see it, and can only compare to standards that I know. Many times I have been shown " perfect" mechanisms, but frankly I have not had the heart to say how bad they are in some aspects. This does not mean I am commenting on Metropolitan's, just saying from long experience I know how a good loco should run, and it always involves springing the chassis. A danger of relying on weight as a solution, forcing the chassis tolerances to adopt the track profile, is that such weight may ruin the gears, some of which are plastic in modern designs and not able to stand the strain, especially in multi stage gearboxes. Most gears are also very slim, the face dimension is low, and wear from loading is a worry. Years ago Romford gears were the standard, they were brass, sometimes very wobbly etc, but when true ran quite well, but if say a fully weighted Duchess was driven by a Romford set it could wear out in a few months of use. Varney's old 1940's loco's were heavy, solid brass and lead, but used gears with 1/4inch faces, much larger and could stand the wear and tear. Portescap went the opposite way, a delicate gearbox, but precise, and they assumed modest loading on the gears, with brass sheet locos, or hand made scale locos, hardly likely to be put to the grind like RTR Varney, Hornby etc. They also assumed the chassis would be sprung, as it is a unit gearbox. Springing is not complex, it is dead easy, most more complex designs can be simplified, they can have single wire instead of multiple springs etc and still work, providing the pulling power and electrical advantages. After all this, compensation is not so needed, springing results in it automatically on models, but Mike Sharman and others, have advocated it , some people even without full suspension, confusing the issue a bit. Adding a "system" design to an existing chassis does make it complex, but the latest decent designs in chassis have evolved to have less complex installations. Finney designs in particular are not too complex, just to the same level as the rest of the kit. I would always advocate ball raced, sprung, mechanisms with sealed gearboxes, quieter, electrically sound, and able to pull because all the wheels are on the track! Even on a fairly strict scale model races can be added to hornblocks, and individual springs dropped in favour of single wire or CSB methods. The point of this is getting a balance between ease of construction for a newcomer to loco construction, not to put them off, but guide them to the best results. Link to post Share on other sites More sharing options...
Kenton Posted January 14, 2011 Share Posted January 14, 2011 Sticky hornblocks are no fault of compensation! This is purely down to the care put into the model by it's builder! If you can't manage to get a hornblock to slide properly without sticking then yes plump for a rigid chassis, until you have sought advice and corrected your problems. A rigid chassis should perform perfectly on a perfectly flat bit of track, its downfall is when it meets a not so perfect piece of track! So why is it apparently permissible to have badly laid track whereas sufficient skill must be acquired for a sprung/compensated chassis. Perhaps we should get the track right first? The point of this is getting a balance between ease of construction for a newcomer to loco construction, not to put them off, but guide them to the best results. Absolutely and the simplest way to start is rigid chassis and NOT 2-8-2 - you could always add springing later when you believe it to be absolutely needed or a worthwhile exercise. Link to post Share on other sites More sharing options...
Kempenfelt Posted January 14, 2011 Share Posted January 14, 2011 Apologies Kenton, I didn't make my point clear. I am not suggesting that it is permissible to have badly laid track. What I am saying is that despite best efforts and getting the track right to begin with, track faults and iregularities can develope over time. Therefore the argument of getting the track right in the first place, doesn't mean it will stay that way. Bertiedog Thankyou for possibly the clearest, most valuable and informative posting with regards to compensation/springing on this thread to date! Very interesting reading with information that is new to me, hopefully a good place for anyone interested in compensation/springing to start! Best Wishes Paul Link to post Share on other sites More sharing options...
Metropolitan Posted January 14, 2011 Share Posted January 14, 2011 . RTR is a bit of a different case, loose tolerances, slightly flexible plastic chassis, U shaped slot bearings, all allow wheels to shift about to remain in contact. Exactly. Simple and effective. And why should a kit loco be any different?? There is absolutely no reason that I can imagine why, when building a kit loco, that we should not follow RTR proven practice. I dont see why RTR is a different case? if it works it ain't broke!! Am I missing something here? Once again I ask, how can the performance of my Hornby Black 5 be improved by compensating it? Link to post Share on other sites More sharing options...
bertiedog Posted January 14, 2011 Share Posted January 14, 2011 Right, lets be more blunt ......the Hornby 5 is made by Hornby a respected TOY maker, the fact by chance that Chinese factory workers have made a plastic moulding that takes mazak plated wheels accurately enough for your purposes is not the pinnacle of comparing a Guy Williams model or a Fiiney kit or any model engineering project with such toy based products. Four wheels on a Mini does not a Rolls Royce make.........Hornby are OK for what they are,RTR Model Trains, they work fine, but are not comparable with hand made models either from kits or scratchbuilt. Everything in the design is suborned to production of a low cost, easy to sell item, in relative terms on cost, I know they are expensive!! Top model, lathe turned cast iron wheels or accurate plastic with steel rims.......Hornby unturned die cast nickel chrome mazak, same as shirt button...... Top model, ball raced motor, 7 pole steel and bronze gears(1940 Varney spec)...Hornby 3 or 5 pole Chinese can motor, based on Johnson designs., with Nylon gears with stub plastic bearings in some cases. Top model... metal all sprung chassis,...,Hornby mouded die cast or plastic, little use of brass bearings, bearings cast in place. Body on top model , brass or steel,........ Hornby plastic, albeit now very good, but lacking weight. Top Model, relies on own traction weight,.......... Hornby rely on rubber tyres in some cases. Despite all the minus points Hornby are good producers, for the market they are intended for, which is not the same market as the original poster was aiming for, which was a custom built 7200 to the finest standards the kit can deliver, my point all along is this is not as difficult as some posters say, it is just that it needs attention to detail, looking at other examples, and building up a satisfying model. Modern kits can be confusing, the designers ideas on suspension can overtake common sense engineering, but they are offering a high quality product, would that similar quality motors were offered, even Matsumi are a bit poor with no ballraces etc.and gearboxes are still badly designed for ease of assembly.. It has to be remembered that many designs are modellers designers, not from engineering experts, I always defer to proper experts in gears like Muffets etc who know the in's and out's. In the past I nearly gave up model railways due to the old gear makers, who could not machine an accurate gear to save their life. With the 7200, get the kit, carefully assemble the chassis , add wheels, Gibson or Ultrascale, matsumi motor and gearbox, get it all running , and then do the body... this is then way ahead of any RTR makers offerings and always will be. Link to post Share on other sites More sharing options...
bertiedog Posted January 14, 2011 Share Posted January 14, 2011 Exactly. Simple and effective. And why should a kit loco be any different?? There is absolutely no reason that I can imagine why, when building a kit loco, that we should not follow RTR proven practice. I dont see why RTR is a different case? if it works it ain't broke!! Am I missing something here? Once again I ask, how can the performance of my Hornby Black 5 be improved by compensating it? After the complex reply...simple junk the Hornby chassis and fit another with decent wheels and springing, it will run better ..I assure you it will..! Link to post Share on other sites More sharing options...
Kenton Posted January 14, 2011 Share Posted January 14, 2011 After the complex reply...simple junk the Hornby chassis and fit another with decent wheels and springing, it will run better ..I assure you it will..! I'm still with Met on this one. It is not that I disagree that a really well built compensated/sprung chassis will run better than one that isn't. It is just that I don't see the point of going to all the fuss and bother if you don't need to. if a rigid chassis runs perfectly well then there is little point in improving on it. It is a bit like saying that something is 99.9% perfect and if you spend several more hours perfecting it then it will be 99.99% perfect. Just because you can doesn't mean that everyone has to. I can also see that in P4 the difference might be exaggerated, but the same argument if it runs well enough why bother? Link to post Share on other sites More sharing options...
bertiedog Posted January 14, 2011 Share Posted January 14, 2011 I should have added that a rigid chassis must also by definition have trouble over a transition over a hump or the transition from the flat to an incline.This does not cause any derailment risk, but means only the centre wheel touch on a hump and outer on the start of an incline momentarily reducing traction, and may cause a slight stall.over a hump. Why does this not show much?, it is the play in axle holes and slots on RTR, which cover it up. ......but traction will be reduced with a heavy train. If the traction tyre is on an outer axle it may even come away from the track, and you will have a dramatic lurch. under load. A sprung chassis has none of these issues at all, and saying P4 requires it is a tail over from early statements about P4, whose proponents were biased towards P4 in a rather excessive way on suspension.as a cure all. Humps and transitions do not turn up on P4 scale track to any degree that will affect the loco. Repeating that suspension is complex and also unneeded, only puts people off seeking higher standards, and the improvement difference is bigger than a few decimal points. Link to post Share on other sites More sharing options...
Kempenfelt Posted January 14, 2011 Share Posted January 14, 2011 Personally my reason for ditching the Hornby Black 5 chassis is because the whole thing is a compromise and clunky when travelling over board joints. I am looking at this from a P4 point of view and like you say it exagerates everything and isn't everyones cup of tea I know! I actually have a Hornby Black 5 and purposely bought it without the chassis. The reason being that a good friend has done a conversion and it runs ok but rocks and bounces across any sort of joint. It also doesn't have the level of detail I require. As a result I am going to do a completely new chassis, fully sprung, with ultrascale wheels and with the ability the dismantle it into key components for maintenance. To me, this becomes a far superior model, it is closer to scale, has finer detail, runs far better and not only will I be happier with it but I will have enjoyed getting there! The reason for the Hornby body then? Because the lining is better than I can produce myself! But this is my personal preference, everyone else is entitled to their own! Best wishes Paul Link to post Share on other sites More sharing options...
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