I AM PARTICIPATING IN A COMPETITION WHERE TRACK IS OF CROSS SECTION 0.5*0.5 INCH.
WHAT SHOULD BE THE FLANGE DEPTH OF THE WHEEL
Please turn your caps lock off. All caps is considered yelling.
ok
but atleast give the aswer
Look in the PM you sent me. I generally don’t pay much to prototype practice so it’s just a guess.
A modern wheel used on standard gauge track has a flange that is 1-inch deep and 1&5/32-inch wide, but wear on the tread may make it appear to be deeper and wear on the side may make it a bit narrower, but there are limits on how much wear is allowed before the wheel must be replaced.
What scale does your track represent? Take that scale and apply it to the prototype wheel. Then figure that the flange will be too small to work well at that scale, so it will probably need to be bigger if you plan on running a train at that scale.
LION has the wheel and track gauges around here somewhere. They were given to me by a retired accident investigator.
Engineers know the dimensions, workers have the gauges. PASS or FAIL
ROAR
As a method of determining the proper flange for your example, you might check on the National Model Railroad Association (NMRA) standards for the various scales. They are based on experience, and will include the amount of “oversize” necessary for proper operation at less than 12 inch to the foot scale.
I Also want to know that is there any criteria for setting flange depth
HARMAN,
Your question needs more explanation in order to answer it. The flange is made to a profile that includes several dimensions. The main ones are the height, thickness, and base fillet. Both sides of the flange are eased inward with large fillet radii, and the tip is radiused as well. Both sides of the flange are eased because they both encounter guidance elements.
There is a standard profile for standard gage North American equipment. I don’t know if that extends worldwide. There are other gages, and I suspect that their flange profile is different than U.S. standard gage. Transit systems might use a different flange profile. When I google it, there seems to be a lot of different standard profiles.
Generally, as rolling stock gets smaller, the flanges are made taller because the smaller equipment weighs less and therefore needs more assurance of maintaining wheel and flange contact with the rail. This principle extends right on down into operating model trains, including the range of live steam trains and park size trains.
Besides the lower weight, another factor that requires raising the flange with smaller equipment such as mining and industrial locomotives and cars is the probability of rougher track and the lack of suspension that would help the wheels stay in contact with the track.
This could also apply to models, depending on whether or not they are built to fine scale, have actual sprung suspension, etc. It would also depend on whether the models are intended to operate or just be static. A fine scale model that is just intended for display could have flange
sir the model is intended to operate on a track of gauge 6cm and the cross section of the guide rails is 0.50.5 inch (1.271.27 cm). on the following link you will find the image of the track
http://www.techfest.org/resources/ps/competitions/solar_express.pdf
And i want to know that whether a wheel with flange depth 1.5mm work on this track and prevent the train from derailing? the diameter of the wheel is 22cm(flange depth excluded) and the tread is 7mm.
Now I see what you are doing. I will look that over, but I have a few observations at this time. That particular application for a competition of a controlled experiment is highly specialized, and I can see the following examples of conditions that it might impose on the flange design.
Your suggestion of 1.5 mm flange height would probably be fine, but you could go higher. Going taller would depend on what conditions are encountered in the curves, and any tendency to climb. Technically, it is not the flange that guides the wheel, but rather, it is the fillet radius at the base of the flange. But in severe bouncing and possible wheel lift, the whole flange may come into play.
But for normal running, you don’t want the side of the flange scrubbing along the side of the rail head. If this were the case, and the wheel entered a curve, the flange on the outside of the curve would scrub hard against the side of the rail head, and it would translate into a wheel-lifting action that could derail the train. This is the effect of the so-called “sharp flange” which is a defective condition of wear.
I don’t immediately grasp whether you will build the track to the specifications indicated or if that track will be provided. If it is provided, the top edges of the rail head might be nearly sharp. If it is provided, it would be helpful to know how much radius, if any, will be on the flange side of the rail head. If you will build the track, I suggest a radius of about 1-2 mm. To pick a round number in inches, I would say use a 1/16th inch radius. If you are using bar stock or maybe a channel, some degree of stock radius will probably
The contest organizers are making this harder than it needs to be. They should use off-the-shelf rail and wheelsets, so that the focus of the team’s work could be on the solar power aspects of the train instead.
Taking the 60mm (2.36 in. or 2-3/8") dimension as being the track gauge (roughly inside to inside, not center to center), which is 1,435mm for US standard gauge (also used in India, I believe), that is a scale reduction of 1:23.91 - call it 1:24, which is 1/2" = 1 ft. As it happens, that’s one of the ‘live steam’ gauges, so some equipment is available. More useful may be the “G scale” or “Garden Scale” gauge of 45 mm, which is more common and has several manufacturers of electrically powered equipment. See generally: http://en.wikipedia.org/wiki/Rail_transport_modelling_scales and http://en.wikipedia.org/wiki/Garden_railway
The analysis above by Bucyrus seems well thought-out and comprehensive. The only comment I add or emphasize is that the critical point is the square edge of the inner corner of the rail shape - your equipment will be light enough and the distance traveled small enough that weight and wear are not factors. So I would use a wheelset from G scale that has a very rounded profile - especially in the fillet from the flange to the tread - to counteract that square corner.
Finally, note that the curve radius shown in figure 2 on page 4 of 7 is 75 cm (29.53" or 2.46 ft.) to the centerline. Applying the same 1:24 scale factor, that corresponds to a real-world radius of about 18m or 59 to 60 ft. Those are values for trolleys or trams, not railroads, so perhaps that should also guide your selection of wheel flan
In reading about the contest, I take it that the track will be provided for the contestants. Before building a train for it, I would make sure I knew what that gage is. Their information on the track could use come clarification. You would not want to show up with a train that does not fit.
The trains are expected to stop at the stations due to the interruption of the solar light source. What will cause the trains to stop on a dime just because the electric power is cut off? If the train coasts through the interruption of power, it will just keep going, and thus miss the stop.
This seems like it is going to be a very complex competition to judge.
thank you friends for your great help…really appreciated all your efforts …and yes you are right the track will be provided…and aas far the wheel lubricants are considered i would like to ask whether they will affect the track also because all the competitors have to perform on the same track and if it might cause a problem to them??..moreover we are bit limited on the mechanical resources as the main thing is SOLAR so i have decided to use the ready made F608ZZ BALL BEARING as the wheels i hope they will do??..any suggestions
http://www.bearings-china.com/Catalog/Flange-Metric-series.htm
The flange bearings would probably track just fine as wheels, but as I undestand it, you will need to get power to the wheels of the pulling unit. I don’t know what level of force the motor will develop as traction, so it might be possible to drive only one wheel. So perhaps you could bond a small timing belt pully to the back of one of the bearings (running as a wheel).
The other issue I see is the ability to abruptly stop when the power is cut at a station. A worm gear drive would do that, but that might not be the ideal drive overall. The choice of the motor and the design of the drive train seems like it will require some careful thought.
yeah i will try and do that only…motor will be connected to only one of the front wheel and rest of the bot will be pulled
Using square stock for rail will make tracking worse dure to lack of corner radius as others have previously described.
It looks like the designers intend to make the curve out of short straight pieces of bar stock rather than curved bar stock. That will cause a series of lurches as the lead axle hits the kink between tangent sections. That would be a terrible track design. If that is how they build the track, the winner will have lots of lateral motion on both the lead and trailing axle and much deeper, and much flatter than scale flanges. If you are only going to drive one axle, I would make it the middle of three and add load from the center to the ends to maximize adhesion on the driven axle.
Mac