dstarr wrote:Ruler and stop watch, works for me. I measured the length of the mainline with an ordinary steel tape measure (bends around curves). Convert from inches to miles by dividing by 12 to make it feet, and then dividing by 5280 to make it miles. Multiple by 87 to make it HO scale miles. Convert seconds to hours by dividing by 3600. For extra accuracy time a couple of loops around the main line. If you don't get the same (or nearly the same) time, you have a measurement problem.
Ruler and stop watch, works for me. I measured the length of the mainline with an ordinary steel tape measure (bends around curves). Convert from inches to miles by dividing by 12 to make it feet, and then dividing by 5280 to make it miles. Multiple by 87 to make it HO scale miles. Convert seconds to hours by dividing by 3600. For extra accuracy time a couple of loops around the main line. If you don't get the same (or nearly the same) time, you have a measurement problem.
wjstix wrote:You can do it by timing the train as it goes around the layout. My last layout's continous run loop turned out to be very close to one scale kilometer in length, so it was easy to work out speeds in KPH (If at train took 1 minute to go around the loop, it was going 60 KPH; two minutes = 30 KPH etc.) and then convert that to scale MPH's. BTW an easy way to measure your mainline is to make up a train of cars and juggle the cars of varying length around until you come up with a train that is say 3' long. Then you can push the 'train' around the layout one trainlength at a time until you've gone all the way around the layout. Then multiply the number of trainlengths by 3' or however long the train is. That way, you don't have to try to use pi to calculate the curved tracks. Once you know how long the mainline is, it's pretty easy to convert that to scale miles, and then to calculate how fast a train is going if it takes x amt of time to go around the layout once. Of course, you can just mark of a shorter distance on the layout and do it that way, but the longer the 'sample' is you take, the more accurate the result will be.
You can do it by timing the train as it goes around the layout. My last layout's continous run loop turned out to be very close to one scale kilometer in length, so it was easy to work out speeds in KPH (If at train took 1 minute to go around the loop, it was going 60 KPH; two minutes = 30 KPH etc.) and then convert that to scale MPH's.
BTW an easy way to measure your mainline is to make up a train of cars and juggle the cars of varying length around until you come up with a train that is say 3' long. Then you can push the 'train' around the layout one trainlength at a time until you've gone all the way around the layout. Then multiply the number of trainlengths by 3' or however long the train is. That way, you don't have to try to use pi to calculate the curved tracks. Once you know how long the mainline is, it's pretty easy to convert that to scale miles, and then to calculate how fast a train is going if it takes x amt of time to go around the layout once.
Of course, you can just mark of a shorter distance on the layout and do it that way, but the longer the 'sample' is you take, the more accurate the result will be.
David Starr www.newsnorthwoods.blogspot.com
One simple speedometer is to use a bicycle speedometer, I bought mine at Big W (like Walmart) It has a small LCD display with 2 buttons and a remote wired reed switch. You're supposed to put a magnet on the bike wheel and it counts the revolutions and using the wheel diameter or circumference calculates the speed. Just use the scale wheel diameter in the calculation the speedo askes for when you set it up. Use the magnet and reed switch supplied with the speedo or maybe a smaller magnet on the axle of an old freight car. the whole thing fits in a box car if you're modeling in HO and is sufficiently accurate for most things.
cheers
Alan Jones in Sunny Queensland (Oz)
ShadowNix,
I was wondering if you bought the speedometer car from CP4E and if you did what do you think?
Rod
Thanks... I found that out and have the 2006 Sept RMC being mailed to me.... I will document my progress if I have time!
Brian
I custom-built a wireless speedo not so much for tuning CVs, but to monitor consist speed in real time. The sensor used the optical interrupter wheel method with many evenly-spaced holes around the circumference. The wheel is limited in size by needing to clear turnouts or grade crossings but maximum holes were needed to get good resolution at slow speeds. The flatcar is powered by 3 AAA batteries and transmits the data over RF. The receiver displays scale MPH or can switch to an odometer for elapsed distance. An RS-232 output in the receiver sends info in real time to a PC such as for data logging or plotting speed vs. time.
My eventual goal, if I ever get to it, is to integrate this into a car located behind the tender with a strain gauge to measure ounces of drawbar pull. Combined with the speed data, I could watch scale Horsepower in real-time just like the prototype dynamometer car. I haven't worked on this for years now and see that superior wireless methods are now more readily available - custom-built stuff just takes too much effort. Bluetooth modules with their tiny antennas would fit completely in a car whilst I used the FM radio band which required longer antennas for good range. A few years ago it seems someone (Walthers?) introduced some kind of wireless measurement car and maybe there's something that could be used from there. IIRC a shoe company (Nike?) came out with a shoe sensor that transmitted running data to a watch for display. Combining the bicycle speedometer with something like that would be a neat DIY project.
Wow, mike...NICE!!! Again, do you remember what article/year? I will have to find that article! Man looks really nice. Is the meter on the L for the weight/drag?
Sorry if I was not clear in my last posts... I have DCC (NCE Powerhouse Pro)
IronGoat wrote: Flashwave... how do you convert the readout to scale mph when you use that "gun"??? IronGoat
Flashwave... how do you convert the readout to scale mph when you use that "gun"???
IronGoat
There's a switch reads "scale"
Also, I saw the Toys R Us in Ohio had booku of them for 7.76 Some Sound decoders will actually tell you the speed.
-Morgan
My thoughts:
One Speedometer is 'fixed', the other mobile. Matching engine drive's gearnig with DC is problematical as you can 'comparison select', but not 'change'.
DCC allows some modifications, but you haven't stated that you HAVE DCC, or which brand therof, therefor I am assuming you don't.
With DC, your best bet is to buy multiples of the same engine, from the same manufacture, and from the came production run. I have three Kato SD-45's, two from the same production run (which run together) and one a year older, which doesn't.
Manufacurers change motors, lighting circuits, etc. People buy DCC to give them increased control - or is it simpler wiring? Individual speed control is one of the benefits of DCC - I think.
My system:
"Looky there, Bubba--that loco's movin' on down the track FAST!"
or
"Let's see what Tim Taylor and some Binford Tools can do to speed up this one."
Yes - doing proper 28-step speed-matches allows complete universality of being able to operate any loco with any other.
It is interesting that, in this world-wide, but US-oriented site, there are but two of us (myself and Mike Ruby - see above) independently advocating on behalf of the 28-step speed curve - Mike lives about 4 miles from me, on the other side of Plymouth, in the UK, we both are members the local US Model Railroading club, and I know him well. As can be gleaned from his own answer, he knows how do lots of stuff I couldn't even begin to grasp, but even I can readily custom speed-curve my whole loco fleet using the towed speedo.
Brian M
Brian M wrote: Glad I could be of Help, Brian. It's worthwhile spending the time doing it.Brian M
Glad I could be of Help, Brian. It's worthwhile spending the time doing it.
I agree... I have some 3.3% grades that require double or triple heading for any real train length... I find consisting them at the base of the hill gives some interesting operations, but you have to have them well matched to get them to work! I have an FA-FB set that works well, (same motor, same decoder, so duh....pretty easy, even for me!). BUT, I just got a GP7 and H16-44, as well as a RSC-2 I would like to have the option of consisting on or two.... I think the time you pay to do it up front RIGHT will make it easier later...
Interesting thought. How much did the whole thing cost you? Any pic's of it to share so we could view/get an idea? And, do you remember which magazine/year? (I will search on this!)
Brian M wrote: With all due respect to jrbernier and wjstix, using only two CVs (plus momentum in 3 & 4) to adjust the mid and start speeds is very "rough and ready", and will not give you nearly as much running similarity as you would by inputting a whole 28-step custom speed-curve using CV29 Bit4-1 and then CVs 67 through to 94. This allows you to give each speed step a specific speed, so that each locomotive you own (irrespective of manufacturer) will run at an identical speed at each speed step. This is why a wagon towed behind the locomotive IS so useful - you decide upon a specific set of speed levels you require for all your locomotives, and then adjust each loco to match each selected speed at each point in the 28-step curve, using the read-out from the towed wagon to adjust things accordingly. It's best (obviously!) to do this on a loop where all the track is constantly visible, so that you can always see the read-out.As an example, using this method, all of my locomotives will run at a scale 8mph at speed step 5, 12smph at step 7 etc. That is something you cannot achieve simply by using one start point, one mid point and one max point, especially with the different running characteristics of different manufacturer's motors.So the statement "a speedometer would only help you match the top speed basically" is incorrect. You will still have to adjust momentum individually too, with this method, but that is not too much of a problem, and takes only a couple of minutes to match them up, using a "master" locomotive.This method obviously takes a wee bit longer than just using three CVs, but provides an almost perfect match. I reckon I can input a 28-step speed-curve into a locomotive in 20 minutes. My BLI and IM Cab-Forwards, Bachmann consolidations, Athearn Genesis and Proto F7s, Proto SD7s, SD9s, GP9s, FA/Bs, 2-8-8-2s and Trix mikados ALL run at identical speeds right through the 28 steps. Brian
With all due respect to jrbernier and wjstix, using only two CVs (plus momentum in 3 & 4) to adjust the mid and start speeds is very "rough and ready", and will not give you nearly as much running similarity as you would by inputting a whole 28-step custom speed-curve using CV29 Bit4-1 and then CVs 67 through to 94.
This allows you to give each speed step a specific speed, so that each locomotive you own (irrespective of manufacturer) will run at an identical speed at each speed step. This is why a wagon towed behind the locomotive IS so useful - you decide upon a specific set of speed levels you require for all your locomotives, and then adjust each loco to match each selected speed at each point in the 28-step curve, using the read-out from the towed wagon to adjust things accordingly. It's best (obviously!) to do this on a loop where all the track is constantly visible, so that you can always see the read-out.
As an example, using this method, all of my locomotives will run at a scale 8mph at speed step 5, 12smph at step 7 etc. That is something you cannot achieve simply by using one start point, one mid point and one max point, especially with the different running characteristics of different manufacturer's motors.
So the statement "a speedometer would only help you match the top speed basically" is incorrect. You will still have to adjust momentum individually too, with this method, but that is not too much of a problem, and takes only a couple of minutes to match them up, using a "master" locomotive.
This method obviously takes a wee bit longer than just using three CVs, but provides an almost perfect match. I reckon I can input a 28-step speed-curve into a locomotive in 20 minutes. My BLI and IM Cab-Forwards, Bachmann consolidations, Athearn Genesis and Proto F7s, Proto SD7s, SD9s, GP9s, FA/Bs, 2-8-8-2s and Trix mikados ALL run at identical speeds right through the 28 steps.
Exactly what I am trying to do!!! Thanks!
johncolley wrote:Why the need for "gadgets"? I'm lucky, I guess, because I use mostly all 40 footers and all I have to do is count seconds for 2 cars to go past a tree, signal, building, or any other object. Real 60 mph = 88 ft/sec. HO is 1/87 scale and 40 foot cars are about 6" over the couplers, eh? So 2 cars = 1 foot and 1 second = 60 mph approximately, which my late '40's/early '50's freights would never do. But the rest is very simple math....2 sec= 30mph, 3 sec=20, 4 sec=15, 5 sec=12, 6 sec=10, 8sec=7 1/2, 10 sec=6, 12 sec=5. Enjoy! jc5729 John Colley, Port Townsend, WA
Good idea, John.... I have all 40 footers also, so that'll work just fine!!!
Thanks, Bob ( IronGoat )
Isn't how each locomotive performs under load, and the size of that load, going to have a big impact?
I have been debating how I want to approach speed matching, and wondering how useful it would be outside of a MU of identical locmotives since once you put some cars behind the loco its speed is going vary from model to model, or so it would seem to me.
chris
I use
Or I would, If I could find mine again...
25 bucks at walmart/target/hobbytown USA
I used to inspect equipment for the club, for locomotives I made a 10 foot mark and timed it for slow, mid, and high speeds. Then the operator had an engine card and could estimate the running speed based on throttle position.
I tried to make a speedometer car but the project waffed, never finished it. I decided doing a speedometer isnt really the big deal that it needs to be or could be, its a nifty oh thats cool, but I don't thinkl for the model I will be trying to run at required "35mph" limits than to guessimate my speed. I think its an interesting idea if you have one to use to work the mind how fast your really going, but I will use my eye as my speed guess. I know when my train is slow, and fast...