garethashenden Posted February 9, 2015 Share Posted February 9, 2015 I'm currently working on three tiny wagons in EM and I'm wondering if fitting sprung suspension would help them stay on the track. They have a 6'6" wheelbase and will probably be pretty light. I think they'll need all the help they can get staying on the track but I'm not sure that this is the way to go. Thoughts and experience would be appreciated. Link to post Share on other sites More sharing options...
mikeandnel Posted February 9, 2015 Share Posted February 9, 2015 Hello Gareth What about the use of lead shot under a false bottom? Michael dJS Link to post Share on other sites More sharing options...
garethashenden Posted February 9, 2015 Author Share Posted February 9, 2015 Michael, I'm planning on adding lead sheet/shot under the floor around the w-irons. The sides are only 2'6" high so a false floor would be too obvious. Even with the weight I'm worried about their stability. For those curious these are ex Cornish Mineral Railways iron bodied wagons. Link to post Share on other sites More sharing options...
mike morley Posted February 9, 2015 Share Posted February 9, 2015 My trackbuilding skills are pretty poor so all my rolling stock has to have some sort of suspension if it is not to take to the ballast on a regular basis. Most of it is compensated, some of it is sprung. Compensation suits some prototypes and/or models best while springing suits others. However, what is very noticeable is while the smoothest runners are always those that are sprung, any Limping Lulu's are also invariably sprung wagons with stuck sliders. In other words, springing may be superior but compensation is far more forgiving. Link to post Share on other sites More sharing options...
Jeff Smith Posted February 9, 2015 Share Posted February 9, 2015 Gareth...if EM then presumably OO wheels (RP25-110) so fairly generous flanges (versus P4). Do the wagons have to be empty? Perhaps a 'heavy' load? Link to post Share on other sites More sharing options...
Spitfire2865 Posted February 9, 2015 Share Posted February 9, 2015 Sprung w irons arent my favourite thing in the world. In my experience, just a simple rocking axle would suit most wagons fine. Ive built 3 wagons with (I believe) Bedford sprung w irons, (2 whitemetal and one wood scratchbuild) and getting all 4 irons sprung evenly is difficult at best. I seem to always get one which sticks. Link to post Share on other sites More sharing options...
RMweb Premium ullypug Posted February 10, 2015 RMweb Premium Share Posted February 10, 2015 Gareth. I tend not to spring EM wagons these days. Flanges are deeper and with such a short wheelbase, as long as there's a little bit of slop (file off the pin point slightly is enough), you shouldn't have a problem. It's almost a coach bogie. Getting sine weight under the wagons would help though. I do spring all my P4 stuff as standard, but in my experience you need weight to make them work effectively too. Link to post Share on other sites More sharing options...
Adam Posted February 10, 2015 Share Posted February 10, 2015 It wouldn't have occurred to me that making the additional complication of springing for a wagon of such a tiny wheelbase worth the effort, certainly not in EM and probably not in P4: plenty of people seem to have coaches on bogies of longer wheelbase than this working perfectly happily with only drop in wheelsets in the latter standard. That said, I'm the kind of philistine that solders sprung chassis kits solid... Adam Link to post Share on other sites More sharing options...
34theletterbetweenB&D Posted February 10, 2015 Share Posted February 10, 2015 My long ago scratchbuilt 7'6" wb NER three bolster wagon set ran uncompensated in EM perfectly successfully. The surviving vehicle that I have (the other two have emnigrated) still runs as a match wagon with a Bobol D in the middle of a sixty wagon goods in OO. These wagons were built from a sheet of code 7 lead as their main structural element, with the brass frames, white metal W irons and vestigial sides soldered on. Nice and heavy, in original form didn't need the bolsters to be made in metal, they were Balsa. Link to post Share on other sites More sharing options...
iak Posted February 10, 2015 Share Posted February 10, 2015 With that wheelbase, one can probably not bother. Built properly with sensible weighting, you should be fine. Mind, I do not spring anything up to a wheelbase of 10ft in P4... The thought police will be after me now - ha ha ha! Link to post Share on other sites More sharing options...
garethashenden Posted February 10, 2015 Author Share Posted February 10, 2015 I've decided to be scientific about this. I'll build two wagons at the same time, one sprung one ridged. I'll weight them equally and see if one stays on the track better than the other. I tend to have trouble with rocking underframes, they never actually want to rock... Link to post Share on other sites More sharing options...
nberrington Posted February 10, 2015 Share Posted February 10, 2015 The problem is there are a few variables that will determine track holding. Couplings, buffers, back-to-back, the mass of the adjacent vehicles, etc. In my experience, unless you are a very good kit builder, (an things are super square), wagons do better either compensated or sprung. One can get away with rigid RTR with a wheel swap because thins are pretty square with no torsion. I say let them rock! Bill Bedford w-irons (from Eilleens Emporium these days) are easy to,use and you can use thinner gauge guitar string if the wagon is light. Link to post Share on other sites More sharing options...
Hawk Posted February 10, 2015 Share Posted February 10, 2015 I say let them rock! Bill Bedford w-irons (from Eilleens Emporium these days) are easy to,use and you can use thinner gauge guitar string if the wagon is light. Agreed. The Bill Bedford type of W-irons are easy to install and adjust, and are are almost invisible even on open-frame wagons. The do not only help to keep the wagons on track, the wagons rolls very smoothly with no rocking. I have "pirated" the design for a home-cooked etched kit, and I am very happy with the design. Link to post Share on other sites More sharing options...
Kenton Posted February 10, 2015 Share Posted February 10, 2015 The problem is not so much that compensation is better than springing as that in the vast majority of cases it is easier to do and do well. Springing invariably adds more complication and more room for error as well as the tolerances being much finer and introducing more issues of imbalance. If done really REALLY REALLY well then springing should be better. But in the majority of cases it isn't. The whole problem comes down to mass. Models (even more so in the smaller scales) simply do not have the mass appropriate to the vehicle. Adding weight is a solution we use to counteract this but it is not the same. In EM I would stick to compensation. Link to post Share on other sites More sharing options...
Jeff Smith Posted February 10, 2015 Share Posted February 10, 2015 A while ago I built several Radley Models white metal Underground cars in P4. These use short wheelbase rigid bogies and re-wheeled Tenshodo power units. They run through my P4 points well but I'm sure the weight really helps..... Link to post Share on other sites More sharing options...
Jeff Smith Posted February 10, 2015 Share Posted February 10, 2015 In EM I would stick to compensation. I am not totally familiar with EM but thought that basically it is wider OO, ie. RP25-110. So theoretically if compensation is not required for OO why should it be for EM? As per my post above, the wagon should be heavy enough to prevent any wheel flanges lifting onto the top of the rail - unless of course you have really bad track...... Link to post Share on other sites More sharing options...
Kenton Posted February 10, 2015 Share Posted February 10, 2015 I am not totally familiar with EM but thought that basically it is wider OO, ie. RP25-110. So theoretically if compensation is not required for OO why should it be for EM? As per my post above, the wagon should be heavy enough to prevent any wheel flanges lifting onto the top of the rail - unless of course you have really bad track......But there lies the rub. My comment was more about the problems with building (especially related to the addition of springing) but also applies to the general issues of building perfect geometry track. Although the wheel dimensions are the same as OO the track dimensions certainly are not. Until there is such a think as RTP EM or even P4 track - we are very much reliant on track building skills as much as the ability to spring any vehicle competently. 3-point compensation is not foolproof and itself can fail abysmally with lazy positioning of weight. In such cases even the addition of weight will never solve the issue. An unbalanced wagon with compensation is no better at holding the rails than a Reliant Robim Link to post Share on other sites More sharing options...
Jeff Smith Posted February 10, 2015 Share Posted February 10, 2015 Kenton - yes, believe it or not I used to own one of those - an even earlier model than that actually.... I agree that compensation by rocking axle is the way to go rather than springing if you are unsure of your track laying/building skills Link to post Share on other sites More sharing options...
Andy Reichert Posted February 11, 2015 Share Posted February 11, 2015 But there lies the rub. My comment was more about the problems with building (especially related to the addition of springing) but also applies to the general issues of building perfect geometry track. Although the wheel dimensions are the same as OO the track dimensions certainly are not. Until there is such a think as RTP EM or even P4 track - we are very much reliant on track building skills as much as the ability to spring any vehicle competently. 3-point compensation is not foolproof and itself can fail abysmally with lazy positioning of weight. In such cases even the addition of weight will never solve the issue. An unbalanced wagon with compensation is no better at holding the rails than a Reliant Robim A rocking W iron wagon has two just as wide wheels at it's leading end and movement stops that only allow a small amount of body tilt before it becomes effectively rigid (and a tad twisted). So the Reliant is nowhere near a valid comparison. As an ex - souped-up-Frisky driver, I was smart enough to insist that my two wheeled axle was almost always at the front. Link to post Share on other sites More sharing options...
PatB Posted February 11, 2015 Share Posted February 11, 2015 I don't consider myself qualified to comment on specific cases as my model building and running experience is far less than most others here, but as an engineer, I agree with the general case of Kenton's point at post #14 and as touched upon by others. That is, that a theoretically inferior but easy to build system which actually works beats a theoretically superior but complex or temperamental system which doesn't. So a squarely built rigid chassis should outperform a compensated one with sticky rockers. A halfway decent compensated one should beat a sprung example with one axlebox glued into place. From my own, limited, experience, I'd say that a working rocking axle compensation system is probably easier to achieve than either a square rigid arrangement or good springing. It is for me anyway, sloppy builder that I am . Link to post Share on other sites More sharing options...
Hawk Posted February 11, 2015 Share Posted February 11, 2015 The problem is not so much that compensation is better than springing as that in the vast majority of cases it is easier to do and do well. Do you file the Bill Bedford type of W-irons under compensation or springing? Link to post Share on other sites More sharing options...
Kenton Posted February 11, 2015 Share Posted February 11, 2015 Do you file the Bill Bedford type of W-irons under compensation or springing?compensation: one rocking axle to give 3 point/wheel on track - the rocking needs only to be about 1-2mm (or the track should be fixed first!)springing: where 2 or more wheels are independently sprung - eg with torsion wires or by hornblock style spring units. IIRC (and it has been a while since I used the BB units) they fit in the springing category. As indicated I think that they are an over complicated solution to the problem requiring much diligence on behalf of the builder and not needed for OO or EM (questionable even for P4) Just like springing/compensation in locos I think far too much effort is applied to solving what wouldn't be a problem if the track was laid correctly in the first place. So I think skills and time would be better spent on fixing the problem (poor track) than wasting it on making the stock cope with the poor track. I'm not trashing these units or those who go to the additional effort to add springing - just that I consider this to be wasted effort and fraught with problems. Link to post Share on other sites More sharing options...
mike morley Posted February 11, 2015 Share Posted February 11, 2015 I'll risk going off at a bit of a tangent here and apologise in advance to anyone who objects, but has anyone tried the MRD torsion bar set-up (not-quite mentioned by Kenton above) and, if so, how did they get on? When I first saw it I thought it offered a good compromise between the simplicity of compensation and the sophistication of springing, but I've had two attempts so far and neither has been a success. Link to post Share on other sites More sharing options...
Spitfire2865 Posted February 11, 2015 Share Posted February 11, 2015 Which units are you referring to? Never heard of MRD. Link to post Share on other sites More sharing options...
Andy Reichert Posted February 11, 2015 Share Posted February 11, 2015 compensation: one rocking axle to give 3 point/wheel on track - the rocking needs only to be about 1-2mm (or the track should be fixed first!) springing: where 2 or more wheels are independently sprung - eg with torsion wires or by hornblock style spring units. IIRC (and it has been a while since I used the BB units) they fit in the springing category. As indicated I think that they are an over complicated solution to the problem requiring much diligence on behalf of the builder and not needed for OO or EM (questionable even for P4) Just like springing/compensation in locos I think far too much effort is applied to solving what wouldn't be a problem if the track was laid correctly in the first place. So I think skills and time would be better spent on fixing the problem (poor track) than wasting it on making the stock cope with the poor track. I'm not trashing these units or those who go to the additional effort to add springing - just that I consider this to be wasted effort and fraught with problems. You don't need equalization just for bad track. Any vertical transition or curve on a grade at model railway radii really requires it for proper adhesion and track holding. Link to post Share on other sites More sharing options...
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