Flexi Chassis an Appreciation

This section allows guests to comment or ask questions. Posts from guests require explicit approval (which generally takes a day or so), before they appear, so that we can prevent unwanted spam.
User avatar
Will L
Posts: 1542
Joined: Sun Jul 20, 2008 3:54 pm

Flexi Chassis an Appreciation

Postby Will L » Fri Feb 03, 2017 11:44 am

In a thread not very far away but on a different topic, an interesting conversation about Fexi chassis and it originator Mike Sharman started here. It was way off topic where it was and as I would like to honour something Bill Bedford said answer with a fulsome response, I would like to recap.

billbedford wrote:[...I would suggest that trying to get ...flexichas to work well has put more people off finescale than just about anything else.


I replied
Producing a reliable running chassis by what ever method you use has always been a bit of a challenge, but trying to suggest that Mike Shaman flexi chassis is notably more off putting than any other method is distinctly questionable. For me flexi chassi was the first method which enabled a kitchen table modellers to produce a chassis that would work reliably. In those days, producing a good rigid chassis needs tools and techniques which I didn't, (still don't) have. Remember at the time the accurately etched fold up chassis which can be assembled rigid was in the future.

It is true that compensated chassis as a breed do have problems and disadvantages, but given the pick up issues to which rigid chassis are given, they still represented the best way forward until really workable sprung chassis stated to appear, and these built on the techniques developed to implement flexi chassis.

No one single person is ever solely responsible for the pushing our methods forward, but I can't help feeling that Mike Sharman gave as big a push to the wheel as anybody.


billbedford wrote:
Will L wrote:Producing a reliable running chassis by what ever method you use has always been a bit of a challenge, but trying to suggest that Mike Shaman flexi chassis is notably more off putting than any other method is distinctly questionable. For me flexi chassi was the first method which enabled a kitchen table modellers to produce a chassis that would work reliably. In those days, producing a good rigid chassis needs tools and techniques which I didn't, (still don't) have.


The original Flexichas idea had square bearing blocks with a turned groove in them running in slots (hand) cut into thin frames. So not only had you to cut square and parallel slots in the frames, you had to assemble the frames square and then find a way of stopping the bearings turning with the axles. Then once the loco was built and running it was realised that the horn guide bearing surfaces were totally inadequate and the loco stopped running due the general sloppiness around the bearing. Of course various manufacturers made improvements to the system such as separate hornguides with proper bearing surfaces etc, but it wasn't until recently with the advent of commercial assembly jigs that building Flexichas frames became a simple operation for the majority of modellers.

While there are many here who would contend that Flexichas is well within the capacity of most modellers I would suggest the it's complexity and fragility compared with the simple mechanical, if not aesthetic, robustness of 1/32" plate frames drilled for axles and frame spaces lost the finescale end of the hobby many potential adherents.
Remember at the time the accurately etched fold up chassis which can be assembled rigid was in the future.


It has always surprised me that fold-up frames came so late and have been taken up by so few designers.


This deserved a full answer but it was definitely off topic where it was, we shall continue here.

But before I got round to this and as it is relavent and it deserves not to get lost
dal-t wrote:
billbedford wrote:

It has always surprised me that fold-up frames came so late and have been taken up by so few designers.


...but I've always assumed that was because it's commercially crippling - don't fold-up frames have to be Gauge-specific, so if you go for any one of the 4mm Gauges you're foregoing sales to people working in either of the other two?


edited for spelling
Last edited by Will L on Mon Mar 27, 2017 1:50 pm, edited 2 times in total.

User avatar
Will L
Posts: 1542
Joined: Sun Jul 20, 2008 3:54 pm

Re: Flexi Chassis an Appreciation

Postby Will L » Fri Feb 03, 2017 12:35 pm

billbedford wrote:The original Flexichas idea had square bearing blocks with a turned groove in them running in slots (hand) cut into thin frames. So not only had you to cut square and parallel slots in the frames, you had to assemble the frames square and then find a way of stopping the bearings turning with the axles.


The whole point about flexi chassis is that that description is not true. I don't doubt some people may have done it like that, but either because they were too cheep skate to buy the book (I got out my copy of the book and checked my facts before I wrote this) or because they thought they knew better and had missed the point. The separate horn guides were always part of the design as it was this feature that made flexichasis a practical kitchen table technique. They mean that a perfectly flat and square chassis became nice to have rather than an absolute nececity, and that the axles spacing could be made to suit the rods.

Then once the loco was built and running it was realised that the horn guide bearing surfaces were totally inadequate and the loco stopped running due the general sloppiness around the bearing.


Actually the bearing block were round at the very beginning and you were supposed to file flats on them so they ran in the slot in the frame proper and couldn't turn, although some did miss that point too and had bearings that turned is the slots rather than axle that turned in the bearing. Then they could have suffered as you suggest. But only because they had done it wrong and you can't blame Mike or his method for that. Mike started producing square Bearing Blocks quite early in the process

Of course various manufacturers made improvements to the system such as separate hornguides with proper bearing surfaces etc, but it wasn't until recently with the advent of commercial assembly jigs that building Flexichas frames became a simple operation for the majority of modellers.


I've already pointed out that separate hornguides were always part of the method. The original flexichass book showed exactly the jig axle (overlong axle with turned down ends) many of us still use today. Not having a lathe I couldn't make my own but I was able to buy some in the early 80's. It is probably true that some of the current crop of chassis assembly jigs do make the job easier, but that brings us on to your next point

While there are many here who would contend that Flexichas is well within the capacity of most modellers I would suggest the it's complexity and fragility compared with the simple mechanical, if not aesthetic, robustness of 1/32" plate frames drilled for axles and frame spaces lost the finescale end of the hobby many potential adherents.


Show me a man who believes what you just said and I will show you a man with a lathe and a plller drill and the knowledge of how best to use them. It was exactly the difficulty in drilling axle holes acculturate and squarely though two layers of 1/16 brass plus two layers of NS coupling road blank that was so totally inaccessible to me on my kitchen table. Not to mention having the assemble the dam thing totality and exactly square. I still have the piece of plate glass, foot long bits of 1/8 silver steel rod and the scars to prove it. Any chassis assembly has always required a modicum of skill and making them run after that requires a bit more, and it is true that either the skill or the patience to develop it isn't given to everybody. None the less my experience is that Fexi chassis significantly extends the group of modellers able to produce a satisfactory working chassis.

edited for spelling
Last edited by Will L on Fri Feb 03, 2017 5:27 pm, edited 1 time in total.

essdee
Posts: 338
Joined: Sat Nov 29, 2008 4:47 pm

Re: Flexi Chassis an Appreciation

Postby essdee » Fri Feb 03, 2017 12:44 pm

Good idea Will, pleased to see this thread - I felt much the same as you.

From my earliest P4 attempts in 1982, using the Maygib nylon (!!) hornguides and sprung brass bearings, I well remember my struggles to get anything running reliably - and was very relieved to find that Flexi-chas, with Perseverance components, suited me much better. Without this, I would very probably have become 'one of the fallen', at a relatively early stage.

Bill's comments about having to stop rotating bearings are quite correct of course, and in an odd way I think the various wheezes I adopted to achieve this, helped to develop my own 'engineering' skills for the future. Like Bill, I did also have a worry about the longevity of the thin bearing surfaces involved, but this seemed a relatively minor worry in those early days.

My suspicion of 'very small springs' remained, while I completed a number of Flexi-chas locos, until I heard about the CSB suspension method, which I now adopt as first choice. I built my first two wire-locos using my own variant of this, which did not have a 'beam' element, merely a continuous spring wire. This was far more laborious, and less sophisticated, than classical CSB suspension, hence my happy adoption of the latter.

However, I firmly believe that I would not have persisted with P4 modelling if Mike Sharman's Flexi-chas system had not been there as a proven system; and I look forward again to seeing Barry Luck's wonderful locos built on this system, on Plumpton Green at Scalefour North in April.

Re the comment about Brassmasters fold-up frames being gauge specific; surely they are made to suit either EM or P4 models, depending on which way you fit the bearings, and how you add washers? I have built three LNER Pacific chassis so far, and I am sure they are thus 'convertible'. I am not sure how many '00' modellers would require something to provide them with a sprung chassis of that degree of sophistication, anyway?

I am very interested to hear what other folk's experiences of early springing vs Flexi-chass were, certainly.

Kind regards,

Steve

essdee
Posts: 338
Joined: Sat Nov 29, 2008 4:47 pm

Re: Flexi Chassis an Appreciation

Postby essdee » Fri Feb 03, 2017 12:50 pm

"Show me a man who believes what you just said and I will show you a man with a lathe and a plller drill and the knowledge of how best to use them. It was exactly the difficulty in drilling axle holes acculturate and squarely though two layers of 1/16 brass plus two layers of NS coupling road blank that was so totally inaccessible to me on my kitchen table. Not to mention having the assemble the dam thing totality and exactly square. I still have the piece of plate glass, foot long bits of 1/8 silver steel rod and the scars to prove it. Any chassis assembly has always required a modicum of skill and making them run after that requires a bit more, and it is true that either the skill or the patience to develop it isn't given to everybody. None the less my experience is that Fexi chassis significantly extends the group of modellers able to produce a satisfactory working chassis."

Just read this update after posting my own response, Will.

Absolutely! Hammer head bang on the nail there, my experience exactly.......

Kind regards,

Steve

User avatar
Le Corbusier
Posts: 1066
Joined: Wed Feb 11, 2015 3:39 pm

Re: Flexi Chassis an Appreciation

Postby Le Corbusier » Fri Feb 03, 2017 1:01 pm

Please excuse my lack of historical knowledge ... being pretty new to both kit building and P4.

Is the flexi chassis system that used in the Perseverance chassis kits currently sold by Chris Parrish and stamped with the name of Rod Neep? It certainly seems to fit Will's description. If so, this has been my first foray into chassis building along with Iain Rice's Chassis building book (which refers directly to the Perseverance range). I also got from Chris the extended pointed axels for setting the blocks to the coupling rod spacing at the same time.

As a complete novice I have found the system pretty accessible and the end result appears to run smoothly .... I think.

Tim
Tim Lee

User avatar
Will L
Posts: 1542
Joined: Sun Jul 20, 2008 3:54 pm

Re: Flexi Chassis an Appreciation

Postby Will L » Fri Feb 03, 2017 1:55 pm

Le Corbusier wrote:Please excuse my lack of historical knowledge ... being pretty new to both kit building and P4.

Is the flexi chassis system that used in the Perseverance chassis kits currently sold by Chris Parrish and stamped with the name of Rod Neep?


Yes Rod Neep was an early adopter and did much to popularise the form, though if I remember correctly he did perpetrate a version with revolving bushes at one point. Our Mr Rice had connection with Rod at various points which is why I think the Chassis book comes over as it does.

User avatar
Tim V
Posts: 2114
Joined: Tue Jul 29, 2008 4:40 pm

Re: Flexi Chassis an Appreciation

Postby Tim V » Fri Feb 03, 2017 2:40 pm

My first forays into P4 were in 1976. The Flexichas as extolled by Mike Sharman was a bit later. Who remembers his roller coaster test track?

I think he produced bearings only. Perseverance took the idea on commercially, with the round bearings, my 1984 Perseverance catalogue shows the original etchings. Later an "improved"design came out the etch had little lugs that engaged with a wire you soldered to the bearing to stop it rotating.

Was Flexichas a "Good Thing"? Bill seems to think not.

I disagree. I was able to build successful locos using the Perseverance components. My skills at the time were rudimentary.

Limitations at that time were the lack of wheels. Studiolith were unobtainable. Sharman sold at exhibitions (I think) and weren't the "correct" profile, though later he produced improved wheels.

Here we are some 30 odd years later. I would say it is as easy/difficult as always to get things right. The crucial matching wheelbase to coupling rod centres in my opinion has still not been mastered effectively. We have good gearboxes these days (notwithstanding the original thread this spawned from), but wheels are a curate's egg.
Tim V

User avatar
Jol Wilkinson
Posts: 702
Joined: Mon Jul 21, 2008 7:39 pm

Re: Flexi Chassis an Appreciation

Postby Jol Wilkinson » Fri Feb 03, 2017 4:43 pm

As Tim says, wheels are something of a Curate's Egg.

In response to Bill B's comment regarding his (dormant) range of wheels in that other topic, where he asked what I would want, I regret to tell him that I would require only a total of 34 wheels (17 axles) for eight loco kits at present, with four different tyre sizes, and six different centre options (spoke numbers, type and crankpin location).

I have already gathered enough old technology products to provide what I need but would be willing to buy a new product, especially for the large (7' 0" prototype) wheels if it provided accurate appearance and performance plus ease of accurate fitting. Of course, it would also have to be at a "reasonable" price, by which I mean probably not more than 35% of the kit cost for the driving wheels ( or in the case of a single driver LNWR Bloomer, even less).

Is that doable for a "small" range of wheels, especially if parts have to be outsourced? While wheel centres can possibly be produced by 3D printing techniques, tyres, crankpins and axles would still probably require traditional materials and production processes.

Ultrascale are about £24.50 per axle and that is a well established business, which does much of it's own manufacturing and that for produces for OO, EM and P4 modellers. Exactoscale have very similar pricing (plus fitting tool at £40:00) but I expect that they buy in the majority of their finished products. However, Exactoscale haven't developed their P4 only wheel range beyond that created several years ago by (as I understand it) Len Newman with Andrew Juke's backing. Does that indicate that their is insufficient sales turnover/profit to fund new products in a specialist wheel range?

Apologies if this seems to be wandering from the thread's title, but if we are to recognise the value of what Mike Sharman, Iain Rice and other's did in the early days of P4 loco development, we need also to understand where it is now leading us, and what new developments are/are not viable.

Jol

Philip Hall
Posts: 1114
Joined: Mon Aug 10, 2009 7:49 pm

Re: Flexi Chassis an Appreciation

Postby Philip Hall » Fri Feb 03, 2017 4:59 pm

Will,

Good of you to set the record straight here. I first came across Flexichas when Mike was a tutor at one of Iain Rice's courses in Chagford. It seemed a sensible path to take then and so too today.

Originally, you had to cut your own hornguides (I still have the beginnings of a chassis for a Beattie Well Tank with home made hornguides; it never got finished when my interests changed). The original bearings also did not have a parallel groove in them, it was tapered outwards which alllowed an axle to tilt from side to side which helped with curves. A sliver of brass up against one side of the bearing stopped them revolving.

My first Perseverance chassis had slots cut upwards in the chassis for the bearings as etched rods, drawn on the same centre line as the hornguide slots, were accurate enough. That chassis did indeed have circular bearings, and as I knew no better, I allowed them to revolve with the results Bill described, save for the fact that the engine always ran impeccably despite an enormous amount of slop as it got older!

Tim is quite correct, wheels were only obtainable at selected shows direct from Mike over the counter of the famous 'hot dog' stand. Very much later on he ventured into mail order but with a very specific order form so there could be no mistakes. I seem to remember you didn't ask for a wheel with so many spokes and diameter etc., you asked for a wheel for a LSWR M7 or whatever and Mike would supply the correct wheel. As time went on there were a huge number of variations even of one diameter. Mike's profile always seemed OK to me and worked well. Where he differed from the One True Path, I think, was in tyre width. EM was 90 thou, P4 was 80 thou and Mike used 85thou for both, which meant the EM wheel was a bit narrow and the P4 wheel a bit wide, which caused some grief with awkward outside cylinder engines but was generally OK.

I still have some of his milled brass gearboxes which were beautiful pieces of work. I have engines they will go in to one day.
And to get back on topic, the rollercoaster test track was quite an assault course! Climbing a matchstick over the rail head was a doddle by comparison. It was an 'over the top' (sorry!) demonstration of what a Flexichas-ed engine could do though.

Philp

Albert Hall
Posts: 182
Joined: Mon Nov 23, 2009 9:22 pm

Re: Flexi Chassis an Appreciation

Postby Albert Hall » Fri Feb 03, 2017 5:02 pm

Jol Wilkinson wrote:Exactoscale have very similar pricing (plus fitting tool at £40:00) but I expect that they buy in the majority of their finished products. However, Exactoscale haven't developed their P4 only wheel range beyond that created several years ago by (as I understand it) Len Newman with Andrew Juke's backing. Does that indicate that their is insufficient sales turnover/profit to fund new products in a specialist wheel range?


Correct on all counts and with the ongoing ownership of C+L subject to a degree of uncertainty that situation is unlikely to change any time soon.

Roy

User avatar
Noel
Posts: 858
Joined: Wed Jun 23, 2010 1:04 pm

Re: Flexi Chassis an Appreciation

Postby Noel » Fri Feb 03, 2017 5:06 pm

Will L wrote:I've already pointed out that separate honeyguides were always part of the method.


I think you may need to adjust your text predictor, Will! ;)
Noel

User avatar
Tim V
Posts: 2114
Joined: Tue Jul 29, 2008 4:40 pm

Re: Flexi Chassis an Appreciation

Postby Tim V » Fri Feb 03, 2017 5:16 pm

The Perseverance etches from 1984:
Perseverance Catalogue Page 24.jpg

how about those prices!
Tim V

User avatar
Will L
Posts: 1542
Joined: Sun Jul 20, 2008 3:54 pm

Re: Flexi Chassis an Appreciation

Postby Will L » Fri Feb 03, 2017 5:17 pm

Noel wrote:
Will L wrote:I've already pointed out that separate honeyguides were always part of the method.


I think you may need to adjust your text predictor, Will! ;)


You'll be giving me the bird next!

User avatar
Will L
Posts: 1542
Joined: Sun Jul 20, 2008 3:54 pm

Re: Flexi Chassis an Appreciation

Postby Will L » Fri Feb 03, 2017 5:21 pm

Jol Wilkinson wrote:...Apologies if this seems to be wandering from the thread's title, but if we are to recognise the value of what Mike Sharman, Iain Rice and other's did in the early days of P4 loco development, we need also to understand where it is now leading us, and what new developments are/are not viable.


I was torn at to how much to carry across Jol, and in the end went for the minimum I could get away with, but I'm quite happy to continue on the broader front if that is what makes sense.

Philip Hall
Posts: 1114
Joined: Mon Aug 10, 2009 7:49 pm

Re: Flexi Chassis an Appreciation

Postby Philip Hall » Sat Feb 04, 2017 3:18 am

Looking at Tim's scan of the Perseverance components, it shows quite clearly the tapered groove in the bearings which was a part of Mike's original design. Some of the later ones of various manufactures didn't seem to continue this feature. A great boon of these etched hornguides was that you didn't have to cut your own!

Philip

User avatar
Allan Goodwillie
Posts: 684
Joined: Sun Jul 20, 2008 7:00 pm

Re: Flexi Chassis an Appreciation

Postby Allan Goodwillie » Sat Feb 04, 2017 10:18 pm

Happy to go with jol and Will,

It was a good idea to move this discussion on to a different thread Will, being particularly ancient myself I started by using Romfords turned down on a school lathe which I had access to and EM axles spaced out using washers - sounds crude, but it was possible to get it working OK. I used plain brass bushes which travelled in slots cut in the brass frames and filed to have a thin outer edge.

Getting thin brass was difficult and I personally had no access to the material - I do know one or two friends who at the time used tinplate sheet. Our local model shop sold 1/16th Brass strip and when I could not get that I used brass curtain rail with the webbing cut down and filed. The bushes however were sprung by soldering spring wire (sold as handrail wire) on to the bearing tops and the other end to the chassis spacers. Interestingly there is an example of that in Ahern's book (Pub 1947) which I have mentioned before, but which I did not know about at the time.
:D
When I joined the West Scotland Group I discovered that Mike Gilgannon had produced locomotives the same way and was surprised to find that Chris Pendlenton, who was also a member of our group had built unsprung and uncompensated locomotives and had managed to get them to work on very well laid track. He was kind enough to lend me a D49 for the stand at Scalefourum, which he had built in 00 originally and converted to P4. It has been interesting following Chris's ideas on rubber and wire springing over the years.

By the time I had discovered the West Scotland group most of us were buying Studiolith components for sprung chassis. Eventually it was my friend Jim Pugh who came across Mikes system of compensation first and built an engine using it. Being a curious person myself, I thought I would try it out and found that it was probably quicker and what's more worked just as well as the springing units I was using.

By the time Melrose Museum came around in the mid eighties my collection of engines was about half and half and frankly, watching engines running on the big layout you could not tell the difference in the running or the haulage power. Another friend and member of the West Group at the time was Steve Duckworth who was kind enough to build a chassis for one of my new engines which was a hybrid of both systems - Steve using it as a test bed for some ideas he had at the time. It worked pretty well, but I do not think he took the idea any further. I enjoyed reading Steve's account of building the three Caley locos in the snooze recently and had the pleasure of watching them take a turn around on Dubbieside last year at Glasgow as a very pleased owner looked on beside me. They ran beautifully and were a real credit to Steve's locomotive building ability.

Of interest might be the first meeting the Livingston Starters group had. We gathered around our dining table and with a section of track down the middle ran a range of locomotives up and down, each one slowly and then fast. (Could have done with a bit more space for the A4 to get up to speed!) Everyone was asked to write down just what system they thought was being used - compensation, sprung or springy beam. The results were interesting as no-one could tell any difference.

All the lads have worked their way through the loco chassis building course and that has been interesting, as they have chosen to build something which they already have the components for. The ones who managed to get their chassis working first have used compensation and a couple of them now have two chassis working.

The standard sprung chassis modellers came next with the springy beams still not quite there yet, however I do not consider this as being a problem with springy beams, it is more likely that it just takes longer to build one of Chris Gibbon's chassis than it takes to build other chassis types. This is not a criticism of Chris's kits in any way and even before we started I did point out to the prospective builders that given the level of detail and sophistication in the chassis they would take longer to build.

The lads have had a high success rate with quite a few locomotives running really well and the one or two still to be completed will follow them as good runners which is what it is all about. A year from now when they have all built their track and managed to get it laid we will probably have another run by to see if there are any differences in the running of the locomotives and I bet everyone will probably have forgotten who did what and all the locomotives will still run well.

Moving to the West Group who also did my locomotive building course a few years ago now. I would like to mention Julian Roberts who has really enjoyed building engines and taking them beyond the perceived wisdom in certain areas including loading of the axles. (Again have a look at the snooze - we often have conversations on club nights as how to deal with specific things locomotive, and it is always a joy to see someone who is willing to go a bit further and not just take perceived wisdom. Julian's locos do run beautifully at slow speeds and haul well, but he like the rest of us is constantly looking for better which is an attitude I am sure we all share.

I, personally, use whatever is the easiest to use and do not religiously follow one system only - it all depends on the locomotive type. Mike's flexichas system did allow quite a number of modellers turn to P4/S4 at a time when the Society really was expanding and I have only praise for his friendly approach and willingness to provide wheels for prototypes beyond the main English railways and I know from personal experience up this end of the country the loss of his wheels has made finding something approximate more difficult. There is a lot of work in producing wheels, if you have ever had a go at doing it at home with basic equipment we should all be thankful for all those who are willing to take time from their own modelling to produce items we all may be able to use!

As to ways of moving forward, I think we have to be careful here. I was concerned when a few years ago it seemed that the only way forward in the hobby was to buy a chassis jig costing big money and with track go for really expensive kits, etc. I could not think of anything more off-putting for new members to our scale. Even basic things like using a Brooke Smith Punch and riveter are considered to be passe and are like hen's teeth at the moment. I do appreciate that Terry has to make these by hand and only a few get made every now and again, but for someone starting, it is still the best and easiest way to make track and get it working first time for a reasonable cost. Cosmetics can come later, but it does allow for quick assembly to get it running in a reasonable amount of time. Remember I am talking about starters in the gauge, different if you know that you will spend a lot of time building engines or if you have a big cheque book to move your layout on quickly.

It is also of some concern in that there are only a very few people producing key items for the gauge for it to continue to advance. Not everyone would be happy to go back to producing locomotives etc. in the way some of us did all these years ago, especially given the quality of ready to run these days. It is regrettable that Mikes range has dropped into the hands of someone who seems unwilling to produce even part of the range, without going into the whys and wherefores. Getting people started in the gauge will lead to more buying the items we ourselves need and will help to make the future brighter for all of us.

The starters group threads I have been writing are based on people actually starting out and doing things with minimal cost, minimal equipment and parts and yet getting good working results. Not all of what I am using as a course could be considered standard, but it is all based on a long number of years of experience. Nor is it prescriptive, as I know there are other ways of doing things that will work equally well and that will be for them to go off and explore as they gain confidence in what they are doing. I am also keen that they put their own experiences on the web as I know that you will all give good advice based on experience. :)

Ended up saying far to much as usual! Sorry.

Enigma
Posts: 174
Joined: Tue Aug 13, 2013 2:49 pm

Re: Flexi Chassis an Appreciation

Postby Enigma » Sun Feb 05, 2017 10:45 am

The only rigid chassis I ever built was a K's one in 00 for the 14XX tank, built on the dining table. No lathe or extensive tool selection then! It was one of the 'keyhole slot' versions with the plastic motor - and it didn't work. Thankfully, not long after this sad (and very frustrating) event, I was introduced to P4 by people who are still S4 Soc members (they were Protofour Soc members then) and, basically, I've never looked back. The Flexichas system came as a revelation. Accuracy and care was still needed but the builder didn't have to be paranoid about getting all wheels totally flat. I found it was a lot easier than a rigid chassis. The 14XX chassis was converted to compensation with some of Mike's wheels from the hot dog stand and an early D11 motor. A Hornby 57XX had a chassis built using Romford gears and another D11 and eventually several other GWR locos appeared - all simply built using the basic Flexichas principles. I still only use compensation. My locos don't necessarily 'glide' over pointwork, they tend to 'bump around' a bit - but so did the real thing at times! My experience I am sure can be echoed by many members of the S4 and EM societies and personally speaking, I can only thank Mike Sharman for his insight and ingenuity in proposing and developing the Flexichas idea.

I too have a large selection (ie - stock) of Perseverance etches for hornguides etc. Also MJT, Impetus, etc. ones along with bags of axleboxes both circular and square. Most of them I cannot remember where they came from but they should see me OK for the foreseeable future. Included in this motley collection is a small plastic bag with some nylon moulded 'axle boxes' containing an integral spherical brass bearing. Mike introduced these for a very short time. They are possibly one of the very few items of his that weren't very succesful.

But - I have been lured by the idea of CSB and have a couple of HL Pannier chassis to build. I'm sure that a compensated version would be a lot quicker and simpler - but I'll have a go.

What I do not have is an equally large stock of wheels. Thank goodness for Gibson ones which seem to cover my needs - but I wish Mike was still around with his stand!

User avatar
jon price
Posts: 432
Joined: Mon Jun 07, 2010 2:34 pm

Re: Flexi Chassis an Appreciation

Postby jon price » Sun Feb 05, 2017 10:53 am

My first P4 chassis (well second, but the first was araldited so doesn't count and has been dismantled) was/is a completely rigid 0-6-0 and runs perfectly. My second was/is a straightforward rewheel of a Bachman 0-8-0 chassis and that seems to work fine as well. I'm in the middle of makling a chassis with CSB and although I am getting there it is slow. Finding one axle was not in the right place and having to fill the cutout, recut the cutout and make new halfs for the jointed con rods hasn't helped there. I also have some chassis that are etched with rigid beams for compensation. What I don't know is how to attach the beams. I know where to attach them, and which way up they have to go, but can't be confident that I will attach them to the frames properly. So anyone like to offer some guidance?

FCA
Posts: 41
Joined: Wed Jul 23, 2008 2:49 pm

Re: Flexi Chassis an Appreciation

Postby FCA » Sun Feb 05, 2017 12:26 pm

For me there were two seminal developments in the 1970/80s which helped me actually to make models in P4 that worked. Mike Sharman's flexichas concept and components and etched gearboxes from the likes of Perseverance, Rod Neep and others whose names have, sadly, faded from my memory.

Our little corner of the hobby owes these pioneers a huge debt of gratitude in my opinion.

Richard

User avatar
Allan Goodwillie
Posts: 684
Joined: Sun Jul 20, 2008 7:00 pm

Re: Flexi Chassis an Appreciation

Postby Allan Goodwillie » Sun Feb 05, 2017 12:29 pm

Hi John, :D

Given the implications of what you are talking about could I recommend the following thread which starts with some simple jigs which can be made at home over a couple of evenings for very little cost , but which will sort out similar problems which you are talking about. They can be used for any system of compensation or springing as you will find as you scan through the content of the thread. It was written as a course which can be followed to get a chassis running first time whether kit or scratch built.

https://www.scalefour.org/forum/viewtopic.php?f=39&t=666

The first part of the thread gets a lot of use- over 40,000 hits so far, so far more than starters using it - there are another two parts. The flexichas part does show how to make and assemble just such a chassis and later more complex ones are also looked at. So plenty of help available there. Livingston Starters group have been following the same course with the lads building most of their locos using kits, so that is also worthwhile as it looks at motor/gearbox combinations etc. that are being used, in the form of a review.

User avatar
Flymo748
Posts: 2113
Joined: Sun Jul 20, 2008 6:00 pm

Re: Flexi Chassis an Appreciation

Postby Flymo748 » Sun Feb 05, 2017 12:42 pm

jon price wrote: I also have some chassis that are etched with rigid beams for compensation. What I don't know is how to attach the beams. I know where to attach them, and which way up they have to go, but can't be confident that I will attach them to the frames properly. So anyone like to offer some guidance?


Hi Jon,

I'm sure you'll have plenty of advice given here. Some of it may even be relevant and/or useful ;-)

Why not start a separate thread in this area, and post some details and maybe a picture or two of what you have? Then folk can better visualise what needs to be done.

Cheers
Flymo
Beware of Trains - occasional modelling in progress!
www.5522models.co.uk

billbedford
Posts: 611
Joined: Tue Oct 02, 2012 2:40 pm

Re: Flexi Chassis an Appreciation

Postby billbedford » Sun Feb 05, 2017 2:37 pm

It really doesn't matter how many people found the introduction of Flexichas an inspiration, the fact remains that the majority of people who build loco kits do not use the system. It is a commercial imperative any manufacturer of loco kits that they should be able to be built rigid using the traditional three rod method of squaring the frames, and all the evidence is that that is the method that the majority use.

While most people here would see this as as sadness, I believe that it really a failure to understand the difficulties that the majority of modellers have with systems based on Flexichas and similar systems. And it is that failure of understanding that underlies much of the animosity against finescale in general and P4 in particular. However understanding such failures should give an insight into how designs can be improved, at least in terms of easy of construction. In a recent post Tony Wright said something to the effect that he had put together a set of working pacific frames, from a kit, in an afternoon and doubted that he could have done the same if he was working in P4. And of course he is right. The way the kit market has developed has meant that newer kits have become more complicated and take longer to build, while there is still a healthy market for older kits which have the virtue of simplicity, if not accuracy.

The question is what is to be done. To my mind there is a need in the market for kits where the mechanics are very much simplified, not beginner's kits, but kits for people that would prefer to to spend more time on the aesthetics of the loco and less on just getting the bloody thing to work. Of course I have my own ideas about this, but I would be interested to know if others are thinking along the same lines.
Bill Bedford
Mousa Models
http://www.mousa.biz

User avatar
jon price
Posts: 432
Joined: Mon Jun 07, 2010 2:34 pm

Re: Flexi Chassis an Appreciation

Postby jon price » Sun Feb 05, 2017 3:46 pm

I agree with Bill. I model in P4 for the look, but obviously I want things to run properly. I'm not an expert at engineering, but I can just about make things in metal now. I also know that manufacturing these days can produce things to a high degree of accuracy. A problem raised is that the mass market (even for kits) is 00, a much smaller market for EM, and a tiny market for P4. So how about a system where a solid, accurately machined core, which perhaps can contain some form of springing or compensation, is mated to frame overlays which are thicker dependent on guage, and to matched con rods. I don't see a particular requirement for gearboxes to be any wider for P4 than for 00, but in P4 a larger motor can be mated to the box. This is not a million miles away from the Easichas conversion kits for RTR models, and these have springing in the overlay.

I don't know what amount of play there is in real steam locos, but our most sophisticated systems appear to allow .5mm either way. A travel of 1mm is 3" in full sized. Are main line steam locos built to cope with 3" jumps in track height? We put a lot of effort into suspension, but perhaps that effort would be more productive if it went into track that didn't have 1mm steps in it? No doubt I will find out when my track laying progresses, but my rigid frame 0-6-0 stayed firmly on the track as it pottered around someone elses layout, with gradients and fairly tight turnouts, which had clearly been laid well.

Proto87Stores

Re: Flexi Chassis an Appreciation

Postby Proto87Stores » Sun Feb 05, 2017 3:52 pm

My thanks to the Society and membership for making this topic open to non-members.

The US region of the hobby has very little history of individuals making model chassis with working suspension, nor of course much in the way of using scale wheel flanges in HO. So there is no "past range of methods" to either draw on, or be critical of. Almost all of the initial thinking of the very few of us interested in scale wheels, was adapting the experience and know-how thankfully gleaned from the Scalefour Society.

This means that almost everyone who wishes to pursue the Proto:87 standard in US modelling is effectively a complete beginner, unlikely to possess a mechanical engineering background and sufficient tools and skills set. Which implies that most really need the help of a cottage industry range of "make it easy" parts to overcome the starting hurdle of just keeping their first vehicles on the track.

So I'm also very much in support of the goal of Bill's last post above, and have been thinking and, unfortunately slowly and rather as a lone wolf, working to achieve those same results. But in my case, working from first principles of the requirements, rather than improving an existing body of work. The launching of new "bogie" range is intended to be just the first stage of a what I expect to be a system that solves the "100% working - zero derailments" suspension issues for every type of model vehicle that modellers need to build, but

And the same goals of course, low cost, low skill, and easy application/assembly by even novices without complex jigs and/or tools. So far the bogies fit all those criteria. But they lean very much toward an advanced version of "Flex-Chas" technology, than to other methods.

Andy

User avatar
grovenor-2685
Posts: 2974
Joined: Sun Jun 29, 2008 8:02 pm

Re: Flexi Chassis an Appreciation

Postby grovenor-2685 » Sun Feb 05, 2017 4:04 pm

The question is what is to be done. To my mind there is a need in the market for kits where the mechanics are very much simplified, not beginner's kits, but kits for people that would prefer to to spend more time on the aesthetics of the loco and less on just getting the bloody thing to work

Personally I'm not interested in rigid chassis, but I see the imperative for a manufacturer who want to tap the 00 market, to me your (Bill B) designs of CSB chassis are simple and straightforward, the problem area I see as often commented on by the 00 builders is the quartering of drivers and fitting them to axles such that they can be removed and refitted without deterioration. We need P4 versions of Markits wheels.
Another that would help a lot is particular a simple secure method of fitting return cranks for outside valve gear.
Those two items would make a huge difference to me.
Regards


Return to “Guest Book”

Who is online

Users browsing this forum: No registered users and 1 guest