Flexichas Or a Way to Build a Fully Compensated Chassis Pdf Free

FLEXICHAS OR A WAY TO BUILD A FULLY COMPENSATED CHASSIS PDF, EPUB, EBOOK

How it works Knowing that the centre of gravity of the complete loco lies between axles 1 and 2, axle 3 could in theory be dispensed with and the loco would balance on axles 1 and 2 alone, like an off-centre Got out the rivet punch once all sides were properly shaped. Spectacles on the windows were created from thin cuts of 6mm brass tube filed and sanded until smooth and thin. It is not possible to cover every possible variation of suspension arrangements for every possible wheel arrangement, but it is hoped that the following sections, which contain examples of both good and less good practice, will provide enough material on which sensible judgements can be made and sensible solutions achieved. Used, Mike french models Mike french models. Another convenient way of viewing how three-point suspension works is by inverting the stool, i. Very well done! The lower the centre of gravity of the loco, the less any transverse shift of the effective centre of gravity line will be. If all is running freely and the loco isn't suffering wheelspin, it shouldn't occur, but nude certain conditions e. Figure 6 illustrates this principle. Equations concerning such deflections are beyond the scope of this Digest sheet — see annex 9. Colin R Posted August 7. Best way to do projects, all together! I think I'm lost with it!! A springy equalising beam need not be subject to the limit of 'only three points' of rigid beam three-point suspension. Descriptions of constructional methods have been limited to those aspects necessary for the understanding of the principles involved. The principle of moments requires that the clockwise sum of the moments about the centre of gravity line must equal the anticlockwise moments about the same line. If this is not possible, the end of the beam can be arranged to have a swivelling forked yoke, the ends of which bear on the axleboxes on each side of the frame, as in the example of figure Boiler barrel was formed from some brass tube and an insert with captive bolt was created using threaded rod and a nut. A roof would be nice, so we still have more work to do. In figure 87 , the force F required to move an object over a surface is proportional to the coefficient of static friction applicable to the two materials involved. Etched chassis are included for both locomotive and tenders. Postscript I am satisfied that the logic of the method described is correct - not only as a consequence of the "tests" but also because a structural engineer should have a good grasp on such matters! Proportions are starting to look a little better - improved camera angle no doubt helping! Build progressing nicely. In such a chassis, it would be usual to drive the fixed axle, as this makes things easier from the point of view of mounting the gearbox and motor, but the drive could be on any of the axles. For the purposes of this section of the Digest, the following definitions apply. Figure 66 compares a variety of suspension systems using an example of a real loco with a prototypical centre of gravity. Here, there is an equally-spaced wheelbase and a projected centre of gravity at a distance d from the middle axle centreline. Note : The hornblock can be below the spring as shown or above the spring. Also, it's not in the Workbench section 'wags finger'. Essentially it puts all cases on even ground. Some wheels were installed to get some idea of how the rear compensating unit will operate. For a or , the loco centre of gravity should be placed to favour the fixed driven axle. Secondary suspension points do not need to be within the triangle formed by the primary suspension points, although the one nearest the fixed axle always will be see figure On the two new locos, I had very deliberately positioned the pinion which turns the drivegear directly above axle 1. In critical cases, e. The torque reaction control link must be rigid, but can be a relatively thin piece of wire. The drill is then directly below the centre of gravity. Figure 34 a shows how a cross member can be arranged with a central pivot point to both control height and allow pivoting, and figure 34 b shows a common equivalent solution using a simple rod. On a positive note regarding the sound, while it is a loud enclosure, I did not find the sound to be unpleasant. By accessing any content on this site or its related media channels, you agree never to hold us liable for damages, harm, loss, or misinformation. Once I'm happy with the compensation, the pins need to be cut back and soldered to fix them in position. For an or , a different consideration applies, as we are unlikely to want an equal weight distribution between axles; indeed, it is desirable that a majority of the weight should be on the coupled wheels, and moreover, as only four coupled wheels are involved, an equal weight distribution between the two coupled axles is also desirable. It's worth taking a ladder with you if you are going to dig yourself a deep hole! Seems like a nice enclosure for the money. I got the 0. Rigid chassis models with no suspension act as though they have a maximum of three wheels. Flexichas or a Way to Build a Fully Compensated Chassis Writer

Glover Posted October 3, The method above can be applied to any loco, regardless of the complexity of its wheel arrangement. The bogie rubbing bar incorporates a hole both sides of which are washers soldered to a spring wire passing through the hole. Secondary suspension points do not need to be contained within the triangle of the three primary suspension points — see figure 41 , for example. For a hornblock on a spring beam, figure 24 shows how handrail knobs can be used as the fulcrum points of the beam and as a means of holding the hornblock on the beam. Could have done with a bit more space for the A4 to get up to speed! In effect, it is simply a metallic rigid beam made thin enough in the vertical plane so that it becomes flexible. In all cases of sprung pony or radial trucks, the vertical force exerted on the track by the pony or radial truck will be the same as that applied upward to the loco chassis, i. Got some more work done this weekend. Even a cooling box is integrated under the passenger seat. DiveController Posted September 9, For steam non-tender locos, the fixed axle is usually placed at the rear firebox end of the loco, since the ashpan and firebox provide convenient hiding places for gears and motors respectively. Essentially it puts all cases on even ground. However, we are starting to get a smart looking locomotive even if I do say so myself! Remember me? In this arrangement the beams are on each side of the engine, and each axle is controlled in its movement at both ends. 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. Thanks for the comments guys - much appreciated. Where rigid beam suspension is employed, we therefore need to persuade our model vehicles to have only three suspension points, thereby keeping all their wheels on the track. Proportions are starting to look a little better - improved camera angle no doubt helping! Would you like to proceed to the App store to download the Waterstones App? Figure 27 shows examples of how a rigid equalising beam can be implemented, and figures 28 a and 28 b show how springy equalising beams can be implemented. Motor was wired up and put on the test track to see how it performs. Still need to do the bunker tanks, and put in some false tank ends inside the cab. Note : The hornblock can be below the spring as shown or above the spring. For very heavy pony and radial trucks, where a complete separation of vertical and side control forces is desirable, a rubbing plate arrangement is shown in figure The proportion of the weight W acting at the ends of the beam in figure 15 is in proportion to the distance from the end of the beam to the point of application of weight W. I think a lack of exposure is certainly evident. This arrangement has the same effect as a beam bearing on the middle of an axle, and therefore does not alter either the longitudinal or transverse weight distributions. A Bo bogie, since it will always be used in conjunction with another bogie in a complete chassis, could have its axles suspended by springy equalising beams of the kind shown in figure 12 d on both sides of the chassis. 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 a break from the build, I decided to start on another locomotive. It was written as a course which can be followed to get a chassis running first time whether kit or scratch built. Two beams are pivoted from frame 'A', both of which bear on the middle axle hornblock. Love the last image. A travel of 1mm is 3" in full sized. If the prototype axle weights are known, the centre of gravity of the loco can be calculated from the wheelbase dimensions using the principle of moments. Since the distribution of torque between the wheels is indeterminate, it follows that any of them could slip, and therefore maximum haulage is produced by a loco with an equal weight distribution. 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. I think he produced bearings only. Moreover, if the spring rating is not chosen to match the weight being supported, a loco fitted with spring-assisted hornblocks may show non-optimal haulage, depending on the state of the track. Cookies This site uses non-intrusive cookies to provide analytics to enable us to provide a better user experience for our visitors. 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 combination can under certain circumstances be applied to a group of axles; an example of this is the trailing bogie of an T, where a single suspension point may bear on the bogie frame, but the individual axles of that bogie could be sprung. Secondary suspension points do not need to be contained within the triangle of the three primary suspension points — see figure 41 , for example. Perseverance took the idea on commercially, with the round bearings, my Perseverance catalogue shows the original etchings. I seem to remember you didn't ask for a wheel with so many spokes and diameter etc. Coupling rods, if present, hold the wheelbase, and washers are fixed to the pivoting rod to restrict end play. Separate sprung hornblocks on both sides of a pony truck can be incorporated: the space typically available around pony trucks means that leaf springs will be required — see figure Head on, it looks a little better, but once the body is filling out the shape, it should look better. Flexichas or a Way to Build a Fully Compensated Chassis Reviews

The blood pH is normal, but it falls on the alkalotic side. Instead of describing the thought processes I went through to resolve this, I will now jump ahead directly to the solution and explain how it works. For s and s, the carrying wheels can have their bearings in the main chassis frame; a little sideplay either on the carrying wheels or the middle axle should be provided, since the total wheelbase is about the same as corresponding types. On frame 'B', two secondary beams are pivoted on a primary beam, the secondary beams again both bearing on the middle axle hornblock. Absolutely superb job, sir; hats off to you! Regards, Ken. You can post now and register later. Body was then dry fitted to the footplate for fit. The greater weight is put on the end of the beam nearer to the point of application of weight. Ride height can then be adjusted by tweaking the bar until the unit sits at the right height. Performance Testing Upon booting the system I was struck by how loud it was. 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. Although each of the individual errors may be small, together they can add up to a considerable amount. 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. For engines with carrying wheels at both ends, such as s, or 'balanced' types such as s, the balancing problem is not so acute, and these engines can, for practical purposes, be treated as s and s respectively, thus 'qualifying' for a fixed axle. I think. Brake time! If a wheel starts to slip on a loco with unequal weight distribution, the other wheels might be able to carry the additional load, but if it is a heavily loaded wheel that is slipping, this will not be the case, and the other axles will start to slip too. At this point I could already tell that trying to make the cable routing look tidy was going to be an adventure. The term 'better running' may be looked at from several viewpoints; of these, the most important is freedom from derailment, followed closely by controllability of locomotives and their performance in terms of balance, stability and haulage capacity. What's nice about this is it's in the location of the firebox so seves two functions. 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 site uses cookies to offer you a better experience. To prevent shorting in such cases, either:. We can see that this is a metabolic problem due to alkalosis. When traversing a curve whether superelevated or flat , a loco's centre of gravity takes on a horizontal component owing to the centripetal force. A variation of the use of springy equalising beams is shown in figure 51 , where four springy beams are used. If the spring is too strong, the weight of the loco will not cause it to operate properly over irregularities in the track, while if the spring is too weak the loco is likely to show dynamic instability. The exact positioning of beam pivot points will have an important effect on both stability and drawbar pull, as will the centre of gravity. In essence, the principle of moments states that, for any body at rest, the sum of the moments about any point is zero.

Flexichas or a Way to Build a Fully Compensated Chassis Read Online

The maximum frictional force from a tyre is proportional to the load carried by the wheel. Figure 70 shows examples of how centralising springs can be arranged within the bogie to grip either side of the bogie fixing. Although the type had been produced before that date this batch is the namesake for the Atlantic type. The loco would still operate, but wheels lifting off the rails are totally contrary to the concept of compensation! A simple wire clutch arrangement allows removal of the Fleischmann motor without upsetting the worm wheel mesh. The degree of roll can be minimised by strengthening some or all of the springs, and springy equalising beams display a greater roll stiffness compared to the use of individual coil or leaf springs. Everyday examples of this are tricycles and three-legged stools see figure 3. Simple "wiper" pickups were added by using copper clad and some phosphor bronze wire. Posted August 8, The weight is unsprung in this rigid truck, and does not detract from the adhesive weight on the driving wheels given by the weight of the loco body. Refine by region. Secondary suspension points do not need to be within the triangle formed by the primary suspension points, although the one nearest the fixed axle always will be see figure Our policy is fully explained here. The effect of the drawbar couple will be less pronounced the more axles there are, and will be less pronounced if the wheelbase is long. Wider spacing would need some marks on the material, as there is no indexing facility with this tool. I wonder what happened to this loco. Once I'm happy with the compensation, the pins need to be cut back and soldered to fix them in position. And behold a running chassis - Eh, No. A little more pressure and the whole thing came apart in less than two minutes. Rate this topic 1 2 3 4 5. The pony truck is of 'A' frame construction and is pivoted from a point as far back along the chassis as possible to give the best radius of arc, and the centralising action is again provided by a spring wire, one end of which is soldered to the chassis, the other end sliding in a bush on the pony truck frame see figure Prev 1 2 Next Page 1 of 2. Seriously impressive!!! Note : The example in the figure shows the axle spacings and centre of gravity of a prototype GWR T loco. All other wheels; no effect. In all cases of sprung pony or radial trucks, the vertical force exerted on the track by the pony or radial truck will be the same as that applied upward to the loco chassis, i. L2 drops into dip. Figure 63 shows the weight distribution for an example of an T with a fixed axle, compensated as per figure 61 , and where the pivoting point of the primary beam is halfway between the non-fixed coupled axle and the bogie centre. Otherwise I'm in for a thorough glass fiber pen scrubbing job! Under the weight of the loco, the spring compresses either fully to bind the coils together or until the hornblock is restrained from further upward movement by some limiter device fitted to the hornguide or the frames of the loco — see figure 8. In a loco with rigid beam suspension, the reaction force between the wheels and the railhead will also be that same proportion of the loco weight bearing onto the axle, regardless of the state of the track. For lightly-weighted pony trucks, figures 54 and 55 show single-spring arrangements. Remember me? See figure Two trunnions between the frames carry a longitudinal pivoting rod, to which is soldered a tube in which the axle is placed. So tank connectors and roof on, we get this. I would summarise the pros and cons as follows: Advantages The compensation of a chassis maintains superior electrical contact with the rails compared with a rigid chassis. Figure 34 a shows how a cross member can be arranged with a central pivot point to both control height and allow pivoting, and figure 34 b shows a common equivalent solution using a simple rod.

https://files8.webydo.com/9583203/UploadedFiles/2E936437-AB3E-0773-7446-C6C8C65489E7.pdf https://cdn.starwebserver.se/shops/oliwerhenrikssonny/files/dark-star-safari-overland-from-cairo-to-capetown-276.pdf https://files8.webydo.com/9584268/UploadedFiles/D159EB21-14F6-C5F0-D171-A3B7B0876561.pdf https://files8.webydo.com/9584226/UploadedFiles/74120176-5F51-E54E-2746-EE71D77C83CD.pdf