Hand timing is plenty accurate - any user delay in clickign the button will be about the same every time and therefore a slight delay licking at the start will have the sme delay clickign past the stop point - negating any delay effect. Sure, you can buyor buold a speedometer accurate to 3 decimal places if you want, but there is no need for locos to be matched that accurately to run well. Another one of those thigns you CAN do with DCC, bu is completely unecessary and sometimes maes the DC die-hards laugh at us for all the effort we have to do to MU locos. That's just it - they don;t HAVE to be that accurately matched - same as back when there was no DCC and people still ran multiple powered locos together. It may be nice to knwo how fast you really are going, in which case a scale measured mile (the real guys mentally timed mileposts and other known lineside markers to help maintain legal speed) or, slightly more sophisticated, an app like Modelspeed is plenty good enough.
That said, I am making a speed trap speedometer with an Arduino, because it's cheap and fun. I'll run my locos through it, but if one trips the trap at 23 mph and another is 27 mph I'm not goiing to keep tweaking, that will be good enough. Exact speed response for all locos is not something I'm after. Limiting top speed to a prototypical one per loco type - that I will do, and similar types I will adjust for close response - for example, all my F7's wold have come on oen order, all with the same gearing and options, so they should all perform similarly. Lockstep, no, but I won't have them all run at a top speed of say 79mph and then have one with a mid speed of 30 and another with a mid speed of 50 - thay sort of thing I WILL adjust.
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
crusader27529 ModelSpeed is nothing more than a fancy phone based stopwatch with the ability to convert measurements to scale speeds. It's completely manual, and accuracy is dependent on the operator.
ModelSpeed is nothing more than a fancy phone based stopwatch with the ability to convert measurements to scale speeds.
It's completely manual, and accuracy is dependent on the operator.
I completely agree with that statement. But ModelSpeed works for me and cost almost nothing. I have been able to set the max speed of all my locos according to prototype and speed match all locos of the same type (switchers, road switchers or all those I wanted to mue together) easily. I just prefer to invest in car kits and locos than in a speedometer.
Guy
Modeling CNR in the 50's
Bayfield Transfer Railway As I said in the other speedometer thread, I've got the Bachrus test stand/speedometer combination, and I'm very happy with it.
As I said in the other speedometer thread, I've got the Bachrus test stand/speedometer combination, and I'm very happy with it.
I also use the bachrus speedometer. It allows me to put the locomotive on the roller stands and not have to run it back and forth thru the speedometer. I also have the accutrak one but never use it since u got the bachrus one.
Colorado Front Range Railroad: http://www.coloradofrontrangerr.com/
For those who have an iPhone, no need to buy a speedometer. There is a simple app named ModelSpeed that do the job very easily. I set the maximum speed of all my locos with it and also do speed matching quite easily.
Disclaimer: This post may contain humor, sarcasm, and/or flatulence.
Michael Mornard
Bringing the North Woods to South Dakota!
I'm currently in the final design phase of a speedometer/odometer CAR for speed matching. It's Arduino based, and displays MPH and KPH plus shows average MPG and total miles since being reset.
It's based on using a 36" scale sized wheel, so the electronics module will work with no changes on any scale as long as the truck/wheel used is 36" scale sized. So, one set of electronics would work in multiple scales.
I have the same one as Ed. Very accurate...
Jim
Modeling BNSF and Milwaukee Road in SW Wisconsin
gdelmoro Amazon 12v power supply
Amazon 12v power supply
This is the one I use and I like it very much.
It does not require an Amazon power supply it runs on AAA batteries.
I may have bought it here but don't exactly remember:
http://store.sbs4dcc.com/ModelRailroadTechnologiesAccutrackIITrainSpeedometer.aspx
Good Luck, Ed
Gary
How about $25 .... http://arduinotronics.blogspot.com/2016/11/arduino-model-railroad-scale.html
Steve Spence
KK4HFJ (Ham Radio)
http://arduinotronics.blogspot.com
hi all, there are several HO Digiotal speedometers on the market From $50 -$80 Any advice as to which is best to use for speed matching locomotives?