Flexi Chassis an Appreciation

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Russ Elliott
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Re: Flexi Chassis an Appreciation

Postby Russ Elliott » Tue Apr 11, 2017 2:50 pm

proto87stores wrote:Image

Here's how we can do a 6 wheel chassis. 6 wheel full equalization, then four point springing of each fulcrum to the frame. Four point sprung mounting over equalization gives 100% of the possible benefits of both equalization and springing.

Yes, good for 6-wheel trucks where the frame length is too short for a CSB, Andy. UK commercial implementations of drive bogies of such length, like Penbits, tend to be based on beam springs using the principle of the Digest's fig 51.

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Re: Flexi Chassis an Appreciation

Postby jon price » Tue Apr 11, 2017 3:17 pm

Horsetan wrote: It's not so much the arguing, more the sneering.


I agree wholeheartedly. I'm following this thread because I'm interested in how flexi-chassis works. I have almost finished a CSB loco, and it is proving significantly more complex than I thought it would be. I also have kits by Mike Edge and by Chris Gibbons. They are designed with beam suspension, by competent designers, and can be guaranteed to run properly if the instructions are followed. They therefore make P4 accessible, not of course to the unwashed masses but to those willing to take up the basic tools. I do not aspire to be a 33rd degree Inspector General of the art. I havn't got the space, time, or money to equip myself with the necessary machine tools. I am happy for those who can, and fascinated by those immaculate kits with working inside motion. But there has to be room for us lower orders as well, and if we are not supported by the trade, and that trade is not supported by the society, then P4 is doomed to get smaller and smaller until it disappears.
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proto87stores

Re: Flexi Chassis an Appreciation

Postby proto87stores » Tue Apr 11, 2017 4:17 pm

Crepello wrote:
proto87 wrote:The 4 point body mounting would then instead be on the fulcrum centres of the additional upper side beams and the fulcrum centres of the two transverse beams. In that way the chassis also handles moderate twist, but still fully equalizes.


To be as analytically thorough as you wish the springing converts were, you need to quantify "moderate" please. Now that you have successfully reduced a six-wheel truck to four suspension points, how do you guarantee these four suspension points remain co-planar? If they don't, then loading is surely going to vary between any 3 of 4 rather than equalise?


Thank you for posting those questions. You are absolutely correct that what I'm suggesting without springs should have firm, true, coplanar support. In the case of the 12T mineral wagon, that can the underside of the flat floor. For a kit built brass locomotive, there have to be four suitably located coplanar points on the underside of the (presumably) rigid body. However adding body springing at those points can accommodate a reasonable amount of coplanar error, while at the same time give an improved cosmetic ride. Regardless, any springing should be made to a value that will avoid any observable running wobbles. But that is the same precautionary (and more complicated) situation for just about any form of springing.

I also agree with your concern about the extent of the "moderate twist". The idea of the final (top level) beam having considerable length does affect the extent of the track twist, as it can only really practically turn with its ends within the limits of the set max bump height stops. (say =/- 0.5 mm). The longer the fixed wheel base of the vehicle, the less the angular track twist can be accommodated by that. But the twist height limit is constant.

Andy

proto87stores

Re: Flexi Chassis an Appreciation

Postby proto87stores » Tue Apr 11, 2017 4:42 pm

billbedford wrote:
proto87stores wrote:It''s not economic or as convenient to make long, strong, custom length, equalizing beams and their fulcrums for full size vehicles when springing wheels can be done much less expensively, and by using higher volume, lower weight, standard components. If you are considering human vehicles that also have "ground level entry" and/or "steering", then it becomes even more troublesome.


How is this different from a model? It seems to me that there is a good economic and convenience case to be made for using two fine steel CSB wires instead of filling the space between the frames with levers, that all have to be made to tolerance, and will take up the space that is better used for motor, gearbox, ashpan, motion plate, slide bars and possibly inside motion


I've never suggested you need to place any beams between the frames. Nor suggested crafting any high tolerance components. Quite the opposite when you consider I'm trying to avoid the need for any hornblocks and the inconvenience of soldering and skilled parts placement and adjustments.

And if you don't know the weight of the vehicle, how can you possibly supply the right wire in the kits?

Andy

proto87stores

Re: Compensation and Articulated Beams

Postby proto87stores » Tue Apr 11, 2017 4:57 pm

Lindsay G wrote:I find myself agreeing again with Bill (we were also in accord recently in disposing of miniscule amounts of flux). Here’s an item that I put together last night but didn’t get round to submitting :

I really must bar myself from reading endless threads, or articles, on articulated beams or attempts to improve upon rather out-dated compensated arrangements - such time-consuming distractions with lots of theory and counter theory but little substance. I can’t help but draw an analogy with an elderly die-hard trying to improve upon the gas mantle decades after the light bulb is invented.

No-one is ever going to conclusively win the debate on whether compensation or springing provides the better running and road holding– not within the printed word at least so I’ll leave that to one side. How about pondering the other major differences between a compensated system and a sprung one – flexibility, bulk, and visual impact. Within compensation you have a gearing arrangement on a fixed axle and elsewhere a rather large beam (or beams) arrangement, both just a tad unprototypical and nasty looking beneath the modelled boiler - what’s more, taking up valuable space better occupied by larger motors, pick-ups, lead, decoders, capacitors, cosmetic (or working) motion, etc., etc.. Have a look at those 3 Caley engines produced by Steve Duckworth in Snooze 201 (or engines by Steve and others throughout the Great 3F build off thread) and consider what the underside of the boilers would have looked like with a compensated arrangement in place. (Oh dear, lots of consideration might now be given to making compensated arrangements look better......please, no!).

Wouldn’t it be better to look forwards rather than backwards and get into debates on better understanding and appreciation of, or improving upon, sprung (or other yet to be devised) arrangements aiming for both superior running and appearance?

Helmet on, ducking for cover,

Lindsay


I think the Catholic Church felt the same about Copernicus. But then Galileo invented a telescope and noticed some dots regularly transiting across the face of Jupiter. . . .

On final point. I'm not talking about or proposing anything to do with "compensation". I'm focused on "equalization" as improving chassis construction and performance. . . and sharing a means of going forward as you suggest. I'm no longer a member of the S4 Society, so the sharing part really only benefits you, rather than me.

Andy

proto87stores

Re: Flexi Chassis an Appreciation

Postby proto87stores » Tue Apr 11, 2017 5:11 pm

Russ Elliott wrote:
proto87stores wrote:Image

Here's how we can do a 6 wheel chassis. 6 wheel full equalization, then four point springing of each fulcrum to the frame. Four point sprung mounting over equalization gives 100% of the possible benefits of both equalization and springing.

Yes, good for 6-wheel trucks where the frame length is too short for a CSB, Andy. UK commercial implementations of drive bogies of such length, like Penbits, tend to be based on beam springs using the principle of the Digest's fig 51.


Which presumably complicates CSB systems even more if you want the axle boxes to move up and down correctly with the suspension and as simply as they do in this beam based example?

Andy

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Will L
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Re: Flexi Chassis an Appreciation

Postby Will L » Tue Apr 11, 2017 5:52 pm

jon price wrote:... I have almost finished a CSB loco, and it is proving significantly more complex than I thought it would be...


In the spirit of processes improvmnet, I would be interested in what it was you found more complex than expected?

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Re: Flexi Chassis an Appreciation

Postby jon price » Tue Apr 11, 2017 8:40 pm

Will L wrote:In the spirit of processes improvmnet, I would be interested in what it was you found more complex than expected?


the mechanics has so far been easy. High Level hornblocks and CSB jig, but the number of variables is high (point location, weight of loco, weight distribution). Establishng the weight requires a full build of the body and in many cases it is recommended that the chassis comes first. Then each point location is variable (so four for an 0-6-0 or five for an 0-8-0). without knowing the importance or significance of the relative positions in relation to the axles it is in effect a combination lock with four or five single or double digit tumblers. In the end I called for help on here and other people (yourself included I think) offered solutions, but I still don't know how to guage the likely best solutions for a given wheelbase, which means either a call for help for each loco or a long period of guessing numbers and trying them in the spread sheet..
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Russ Elliott
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Re: Flexi Chassis an Appreciation

Postby Russ Elliott » Tue Apr 11, 2017 9:47 pm

proto87stores wrote:Which presumably complicates CSB systems even more if you want the axle boxes to move up and down correctly with the suspension and as simply as they do in this beam based example?

Yes of course, and particularly for that example (which is why I commended it), but, in the general case, and especially for commercial applications, where utilization of common components becomes a significant factor, I would separate consideration of the suspension system involved and the desire/demand to get outside axleboxes moving. It's a cultural thing as much as anything. In the UK, both for drive and non-drive bogies, there seems to be an acceptance of putting the suspension inside the cosmetic sideframe (or inside the wheels) and not wishing to do anything too drastic to the sideframe itself. (And many drive bogies do not have sideframes these days, let alone equalising beams.)

Personally, if a set of instructions started with "First, make 4 identical coil springs of your desired springrate...", my reaction would be 'err, gulp!'

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Re: Compensation and Articulated Beams

Postby Julian Roberts » Wed Apr 12, 2017 5:50 am

Lindsay G wrote:I really must bar myself from reading endless threads, or articles, on articulated beams or attempts to improve upon rather out-dated compensated arrangements - such time-consuming distractions with lots of theory and counter theory but little substance. I can’t help but draw an analogy with an elderly die-hard trying to improve upon the gas mantle decades after the light bulb is invented.

No-one is ever going to conclusively win the debate on whether compensation or springing provides the better running and road holding– not within the printed word at least so I’ll leave that to
one side. How about pondering the other major differences between a compensated system and a sprung one – flexibility, bulk, and visual impact. Within compensation you have a gearing arrangement on a fixed axle and elsewhere a rather large beam (or beams) arrangement, both just a tad unprototypical and nasty looking
beneath the modelled boiler - what’s more, taking up valuable space better occupied by larger motors, pick-ups, lead, decoders, capacitors, cosmetic (or working) motion, etc., etc.. Have a look at those 3 Caley engines produced by Steve Duckworth in Snooze 201 (or engines by Steve
and others throughout the Great 3F build off thread) and consider what the underside of the boilers would have looked like with a compensated arrangement in place. (Oh dear, lots of consideration might now be given to making compensated arrangements look better......please, no!).

Wouldn’t it be better to look forwards rather than backwards and get into debates on better
understanding and appreciation of, or improving upon, sprung (or other yet to be devised) arrangements aiming for both superior running and appearance?


I have to say I think that both systems, and perhaps even within hornblock springs, have
their place. This thread seems as good a place as any to discuss the relative merits, though I do very much agree with Horsetan that it's the sniping that is what we don't need. As far as I am concerned
what matters more than cosmetic perfection below the boiler is simplicity of construction and reliability of running. Andy seems focused on bringing both without losing the cosmetic verity.

Jon's experience with CSBs as a first timer are interesting to me, one who has yet (if ever) to venture down that route, and I await responses to
his perception of the difficulties.

Looking at my first use on the HiLevel Barclay Tank of the 0-6-0 compensation model where there is no fixed axle but a beam linking the two rear wheels on each side, and a single beam midway over the front axle, the whole arrangement is hardly visible. And it is not necessarily particularly difficult to make beams cosmetically appear like something else, as I have done on my LMS Compound where the inside con rod is approximated by the beam between bogie and front driving wheel.

But my feeling is that much as I admire perfect modelmaking, what can't be seen from normal distances or perspectives is far less important than reliable running, where the least informed
observer can see a train off the line, an all too frequent sight.

A fascinating discussion has been had on a concurrent thread regarding my Snooze articles (199, 200, 201) on modifying the compensation fulcrum points to improve track holding, that I referred to briefly much earlier in this thread.

I will put the link here next.

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Re: Flexi Chassis an Appreciation

Postby Julian Roberts » Wed Apr 12, 2017 5:54 am

viewtopic.php?f=19&t=5293

starting with Andrew Jukes' post on 3rd April

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Re: Flexi Chassis an Appreciation

Postby zebedeesknees » Wed Apr 12, 2017 6:05 pm

A few points come to my mind here.

Modellers are generally conservative, and the thought of going away from at least one fixed axle, and the ease of driving same, replaced with the complication of a floating motor or gearbox and the need for torque reaction control in a fully sprung system is clearly going to be resisted without a demonstrable reward.

I for one have a couple of reasons for preferring CSBs, firstly because I want to 'do it right' by driving the axle that was driven on the real loco, and compensation systems usually preclude that option. CSBs with one wire per side and no adjustment necessary seem to be preferable to adjusting individual springs over each driving wheel.

Secondly, staying on the track is not as important to me as haulage, or drawbar pull. It has been shown that for a given weight a sprung loco pulls up to twice that of a flexi-suspended loco, but more, sprung stock has a lower rolling resistance, so longer trains up steeper gradients become possible.

I'll keep doing it my way...

proto87stores

Re: Flexi Chassis an Appreciation

Postby proto87stores » Wed Apr 12, 2017 8:51 pm

zebedeesknees wrote:A few points come to my mind here.

Modellers are generally conservative, and the thought of going away from at least one fixed axle, and the ease of driving same, replaced with the complication of a floating motor or gearbox and the need for torque reaction control in a fully sprung system is clearly going to be resisted without a demonstrable reward.

I for one have a couple of reasons for preferring CSBs, firstly because I want to 'do it right' by driving the axle that was driven on the real loco, and compensation systems usually preclude that option. CSBs with one wire per side and no adjustment necessary seem to be preferable to adjusting individual springs over each driving wheel.

Secondly, staying on the track is not as important to me as haulage, or drawbar pull. It has been shown that for a given weight a sprung loco pulls up to twice that of a flexi-suspended loco, but more, sprung stock has a lower rolling resistance, so longer trains up steeper gradients become possible.

I'll keep doing it my way...


Although I admit, the definition of "compensation" is in the eye of the beholder, I still find both springing benefit claims (greater pull, lower resistance) very difficult to accept in terms of Physics. I'm not sure any cyclists would agree with you.

Andy

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Re: Flexi Chassis an Appreciation

Postby Will L » Wed Apr 12, 2017 11:36 pm

jon price wrote:
Will L wrote:In the spirit of processes improvmnet, I would be interested in what it was you found more complex than expected?


the mechanics has so far been easy. High Level hornblocks and CSB jig, ...

That is what I would have hoped for. Given you can produce a compensated chassis, and that would bother some, a CSB chassis shouldn't be a problem.
...but the number of variables is high (point location, weight of loco, weight distribution).

May I suggest that this is more lack of familiarity than any thing else. Once you become familiar with the process it seems to drop into place and makes you wonder why people seem to find it complicated. I'm fairly sure Flexi Chassis produces similar concerns in people who have only ever built rigid chassis.

Establishng the weight requires a full build of the body and in many cases it is recommended that the chassis comes first.

That's because from the chassis design point of view, the important thing about loco weight is not how much of it there is, but how that weight is balanced . I.e. where is the loco's Center of Gravity, so you make an assumption as to where the CofG will be, and ballast the built model to suit. Adjusting for the true weight of the model (so the buffer height is right) is the one thing we can do on the completed CSB fitted model. Traditionally we have always advised putting the CofG where it ensures an equal distribution of weight on the driving wheels, because that gives the best haulage performance and why would you want to design a chassis with compromised performance?

Then each point location is variable (so four for an 0-6-0 or five for an 0-8-0). without knowing the importance or significance of the relative positions in relation to the axles it is in effect a combination lock with four or five single or double digit tumblers. In the end I called for help on here and other people (yourself included I think) offered solutions, but I still don't know how to guage the likely best solutions for a given wheelbase, which means either a call for help for each loco or a long period of guessing numbers and trying them in the spread sheet..

It is certainly true that just guessing results and trying them isn't a productive way of designing a CSB chassis. The existence of spreadsheets that can do the sums for you ought to be a significant aid, but being mathematical models they do tend to give worryingly precise answers. I would like to reassure you that much of this precision is illusory as CSB would be useless if you could not build them successfully within the normal modelling tolerances ( typically to the nearest half a milimeter).

You are also right that to calculate the fulcrum points successfully you do need to have some understanding of the game you are trying to play, however a little knowledge/experience should make it rather less daunting. I think this post from my back catalogue gives a fair understanding of what you are trying to achieve. For the totally spreedsheet phobic there is a paper and pencil method of deriving an answer (reproduced below), but ultimately the spreedsheets do a better job. Of the three available from the CALG website, the original Rodger Wyatt version requires that you have a good understanding of what will work and what you are trying to achieve, and for this reason I would recommend new users should avoid that one. The other two provide a lot more help. Of these Alan's has by far the simplest interface so is probably the best for the inexperienced user, while mine certainly looks more complicated but it does come with quite extensive instructions on how to use it (look under the Notes tab). It also implements a version of the paper an pencil method given below to give you a working solution which you can then adjust to suit your loco. Once you get your eye in both Mine and Alan's versions will allow you vary the location of the CofG.

One further point I wanted to include above, but it overcomplicated what I was trying to say.

In designing a CSB chassis we are making you aware that the weight distribution is an issue which you need to take into account. Similar considerations also affect compensated chassis as do stability issues which are unknown on a CSB chassis, but these often go unconsidered, so that avoiding a compensated chassis that disappoints is to some degree a question of luck.

The Paper and Pencil method

This is illustrated by this diagram
Image
Simply put, this deals in what for the lack of a better name I will call a standard fulcrum distance (SFD). This is what you get if you divide the total wheel base by twice the number of fulcrums that will occur within it. I.e 2 for 4 axles, 4 for 3 axles, 6 for 4 and 8 for 5. The fulcrums within the wheel base are then set symmetrically at 1, 3, 5 etc SFD. The outer two fulcrums are set at 0.57*SFD which will make the centre wheel suspension softer than the outer two. Actual fulcrum points can be rounded to the nearest 0.5mm unless you feel confident that you have the where-with-all to mark them up more accurately than that!

This compromise method and the 0.57 constant I have derived from long hours of thumbing in different configurations and seeing what happens. For best results the constant needs to be varied from between 0.6 and 0.55 depending on the exact dimensions of the chassis. My revised spread sheet contains an implementation of this method, that calculates the fulcrum points for you, allows you to vary the constant to see what gives the best results, and gives guidance as to what the best result might look like. But 0.57 will produce a workable result. I find it ironic that, after all I’ve said, here I am playing with a figure accurate to two decimal places!

I’m sure it is possible to argue that as a method, it is unlikely to produce the optimum configuration for a given chassis, particularly if it isn’t symmetrical. I may be moving away from the P4 "get it all right" way here, but my position is that it gets close enough to produce a satisfying result.

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Re: Flexi Chassis an Appreciation

Postby Will L » Wed Apr 12, 2017 11:45 pm

proto87stores wrote:... still find both springing benefit claims (greater pull, lower resistance) very difficult to accept in terms of Physics. I'm not sure any cyclists would agree with you.


Greater than what Andy. There is no question that equal distribution of weight will improve haulage power. We can argue the toss over whether our CSBs or your fully equalised chassis are best at this, but compared with many compensated or rigid chassis, they win hand down.

Lower resistance? that's a new one one me.

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Re: Flexi Chassis an Appreciation

Postby andrew jukes » Thu Apr 13, 2017 12:25 am

Will L wrote
There is no question that equal distribution of weight will improve haulage power. We can argue the toss over whether our CSBs or your fully equalised chassis are best at this, but compared with many compensated or rigid chassis, they win hand down.

I bought into most of this but have had great difficulty demonstrating it in comparative testing. Taking achieved coefficient of friction as a measure of haulage power, my best performers were not the all-sprung designs nor those with equal axle loads. The locos tested admittedly did not include a CSB-fitted loco but the results were such that it is hard to believe CSBs would add enough magic to win hands down.

My feeling is that there is nothing like enough comparative testing and that we end up taking firm positions without the necessary real data. Perhaps my fault to some degree as, when Deputy Chairman, I did nothing to encourage continued Deputy Chairman's Cup testing.

Regards Andrew

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Re: Flexi Chassis an Appreciation

Postby proto87stores » Thu Apr 13, 2017 12:29 am

Will L wrote:
proto87stores wrote:... still find both springing benefit claims (greater pull, lower resistance) very difficult to accept in terms of Physics. I'm not sure any cyclists would agree with you.


Greater than what Andy. There is no question that equal distribution of weight will improve haulage power. We can argue the toss over whether our CSBs or your fully equalised chassis are best at this, but compared with many compensated or rigid chassis, they win hand down.

Lower resistance? that's a new one one me.


Equal distribution of weight on the drivers maximizes non-slip hauling power. Or at least they all slip at once.The c of g position of course may make exact equality not possible.

I have one question that is CSB related. Since the wire can slide, it presumably is possible to press down hard at one end of a loco and have the wire slide to make the loop at that end taller, without changing the other loops much. Ditto for pressing down at the other end. Does that not imply that there are two equilibrium positions, slight tilt forward and slight tilt back. Or maybe a whole somewhat stable range between the two positions. If there aren't, then what is the restoring force? Since there is some friction at the wire supports, the wire freely sliding all the way back is unlikely.

Andy

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Re: Flexi Chassis an Appreciation

Postby Julian Roberts » Thu Apr 13, 2017 4:19 am

Zebedeesknees I was not trying to persuade anyone to any particular method.

Rather, I think Lindsay's gas light analogy is not wholly apposite, and that a closer analogy might be that while gas central heating might suit most houses best, electric oil and even solid fuels still can be equally appropriate and it all depends on the circumstances. And gas light can still be the most useful when camping!

Just because the latest method might generally be thought to be the best doesn't mean it's the only game left in town.

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Re: Flexi Chassis an Appreciation

Postby billbedford » Thu Apr 13, 2017 9:07 am

Julian Roberts wrote:Just because the latest method might generally be thought to be the best doesn't mean it's the only game left in town.


Its the finescale time-warp inaction again. Its over 15 years since I design my first frames kit with CSBs. I'm amazed that people are still find CSBs at all novel or controversial.
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Re: Flexi Chassis an Appreciation

Postby billbedford » Thu Apr 13, 2017 9:13 am

proto87stores wrote:Which presumably complicates CSB systems even more if you want the axle boxes to move up and down correctly with the suspension and as simply as they do in this beam based example?


There is a good reason for wanting sliding axleboxes. Because the wheels are, and should be, fixed to the axles, it is the most practical and economic way of getting wheelset in and out of the frames.

It works for the likes of Bachmann and Hornby, and well as all builders of full-sized railway equipment.
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Re: Flexi Chassis an Appreciation

Postby billbedford » Thu Apr 13, 2017 9:31 am

proto87stores wrote:I've never suggested you need to place any beams between the frames. Nor suggested crafting any high tolerance components. Quite the opposite when you consider I'm trying to avoid the need for any hornblocks and the inconvenience of soldering and skilled parts placement and adjustments.


Then I assume you haven't yet considered non-bogies vehicles with more than two or three axles. Even in Sharman original books, while the six-couples designs were relatively easy to follow, the ten coupled ones we're a dog breakfast.

And if you don't know the weight of the vehicle, how can you possibly supply the right wire in the kits?


You can't, just as you can't tell what gauge the kit is going to be built for, so you don't put wheels in the kit.
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Re: Flexi Chassis an Appreciation

Postby jon price » Thu Apr 13, 2017 9:45 am

Thanks for this detailed explanation Will. I will attempt to read and inwardly digest at my leisure
Connah's Quay Workshop threads: viewforum.php?f=125

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Re: Flexi Chassis an Appreciation

Postby zebedeesknees » Thu Apr 13, 2017 4:18 pm

Julian Roberts wrote:Zebedeesknees I was not trying to persuade anyone to any particular method.

Rather, I think Lindsay's gas light analogy is not wholly apposite, and that a closer analogy might be that while gas central heating might suit most houses best, electric oil and even solid fuels still can be equally appropriate and it all depends on the circumstances. And gas light can still be the most useful when camping!

Just because the latest method might generally be thought to be the best doesn't mean it's the only game left in town.


Julian, since you have chosen to address me personally...

Your name and theories have been all over the model railway media that I enjoy, lately.

Since we are playing with analogies, this one works for me.. We're back in the 1920s, and there is a salesman who is telling me that he is very happy with his horse and cart, because it can travel over the tracks on his farm without falling over. It may not be as comfortable a ride on these new-fangled metalled roads, nor pull as much as these 'motor cars' with their difficult-to-maintain rubber tyres, but four wobbly legs and a rigid axle work well enough for him, so we should all be told about it.

That many of us have been there, done that, and worked out why we won't do it again, doesn't mean we shouldn't be reminded.. often.

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Re: Flexi Chassis an Appreciation

Postby jon price » Thu Apr 13, 2017 4:34 pm

zebedeesknees wrote:
Since we are playing with analogies, this one works for me.. We're back in the 1920s, and there is a salesman who is telling me that he is very happy with his horse and cart, because it can travel over the tracks on his farm without falling over. It may not be as comfortable a ride on these new-fangled metalled roads, nor pull as much as these 'motor cars' with their difficult-to-maintain rubber tyres, but four wobbly legs and a rigid axle work well enough for him, so we should all be told about it.

That many of us have been there, done that, and worked out why we won't do it again, doesn't mean we shouldn't be reminded.. often.


Not wishing to intervene in a domestic, but analogies are tricky beasts. The logging industry is mostly still wedded to massive motorised machines, but it turns out that if you want to cause less damage to the hydrology, and your ecosystem in general, rather than get the biggest fastest financial hit at the expense of your neighbours downstream and the wildlife, horse drawn logging is best. ;)
Connah's Quay Workshop threads: viewforum.php?f=125

proto87stores

Re: Flexi Chassis an Appreciation

Postby proto87stores » Thu Apr 13, 2017 4:43 pm

billbedford wrote:
proto87stores wrote:Which presumably complicates CSB systems even more if you want the axle boxes to move up and down correctly with the suspension and as simply as they do in this beam based example?


There is a good reason for wanting sliding axleboxes. Because the wheels are, and should be, fixed to the axles, it is the most practical and economic way of getting wheelset in and out of the frames.

It works for the likes of Bachmann and Hornby, and well as all builders of full-sized railway equipment.


Sorry, I really don't understand this post. Are there any wheelsets in Model Railway vehicles that don't have the wheels fixed to their axles?

Andy


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