JJ73 Posted June 25 Author Share Posted June 25 Thank you RB51 @ Going Spare :- Even thou I haven't used my Scalextric in many years - I do believe that the Scalextric Cars do use a different Motor than the Motors in the Locos I think, so it is differcult to say really!!! 🤔🚂 Link to comment Share on other sites More sharing options...
What About The Bee Posted June 25 Share Posted June 25 (edited) Going Spare There are entirely too many variables to determine why the voltage on one is higher that the others. Friction and Stiction in motor/mechanism Cogging of motor Cleanliness of track / wheels / commutator / brushes As JJ points out, different motor = different characteristics, like nominal resistance What JJ's questioner wanted was the base voltage of the controller, with a locomotive on track, slow speed. That fellow is looking for the best controller to get slow speed and thinks this is the way to find it. Bee Edited June 25 by What About The Bee Two, to, too Link to comment Share on other sites More sharing options...
atom3624 Posted June 25 Share Posted June 25 (edited) Hi JJ, both Scalextric / slot cars and model railways require reliable motors, but there's a fundamental difference. Slot cars require more revs and generally rely on motor reliability at a reasonable to higher revving rotational speed - standard are I think 18k (rpm) maximum, but can nearly double that (I've had a few 25k motors which were quite fun!!) Model railways do require a designed in calculated speed, but this won't be huge. The important thing for railways is torque - turning force - and from low voltage / low revs, to permit nice, realistic-looking departures from stations. Obviously gearing can help here - it's been said Britannia, Castle, King locomotives might be a little too high-geared, compromising their low speed performance. A little creativity I find on the throttle overcomes this generally, leaving you with an impressive express passenger locomotive! Al. Edited June 25 by atom3624 Link to comment Share on other sites More sharing options...
JJ73 Posted June 26 Author Share Posted June 26 Opps - I forgot to say - I did make a video of this in the end & here is the link of it :- 1 Link to comment Share on other sites More sharing options...
What About The Bee Posted June 27 Share Posted June 27 In your video, you said that you were not sure what the numbers VDC meant. I made this diagram up to help you to see the meaning. Study it and see if it helps Bee 1 Link to comment Share on other sites More sharing options...
JJ73 Posted June 27 Author Share Posted June 27 Ok Thanks Bee - In either direct ( minus - or plus +) Higher VDC - faster the Loco goes - well that doesn't seem to difficult to understand... SIMPLES!!! 😉🚂 1 Link to comment Share on other sites More sharing options...
What About The Bee Posted June 27 Share Posted June 27 You got it JJ! Link to comment Share on other sites More sharing options...
What About The Bee Posted June 27 Share Posted June 27 Hi JJ, This is the next step. Here is what Alex was asking. He wanted to know what your controller does in the little blue circle, when the VDC is small. Your testing shows when motion starts. Notice your numbers are all above 1.5 VDC? The locomotive starts moving when the VDC is high enough. But the video also shows the lowest VDC your controller can make. It is around 0.3 VDC. The reading does not go 0.0, 0.1, 0.2, 0.3, 0.4, 0.5 on the meter. It goes 0.0, 0.3, without showing 0.1 or 0.2. This is the dead zone. You should do the test again. Set your vertical slide bar to 5 instead of 20. This means no more than 5 VDC. NEVER GO ABOVE 5 VDC. Slowly, really slowly turn up the controller. What is the smallest VDC you can get? Stop before you reach 5 VDC or you can ruin your meter!! Bee Link to comment Share on other sites More sharing options...
JJ73 Posted June 27 Author Share Posted June 27 There is a next step??? 🤔🚂 I thought that I'd finished it!!! Link to comment Share on other sites More sharing options...
What About The Bee Posted June 27 Share Posted June 27 Hi JJ You can get better results You can also learn more about your meter Only do it if you want to Bee Link to comment Share on other sites More sharing options...
JJ73 Posted July 16 Author Share Posted July 16 Hiya - I know it's been a few weeks since we have done this...but I'm going to have another go at this...Bee said to "Set your vertical slide bar to 5 instead of 20." but there is no "5" (if you look on the above photos) so I'm going to set it to "2" instead!!! 😉🚂 Link to comment Share on other sites More sharing options...
JJ73 Posted July 16 Author Share Posted July 16 If I remember how to do this that is!!!... 😐🚂 Link to comment Share on other sites More sharing options...
LTSR_NSE Posted July 16 Share Posted July 16 (edited) @JJ73 - if you set the meter to 2, be extremely careful to only turn the controller up to 2 volts & no further else you will blow the meter! Edited July 16 by LTSR_NSE 1 Link to comment Share on other sites More sharing options...
JJ73 Posted July 16 Author Share Posted July 16 Thank you LTSR - It's a bit difficult to know what is 2 Volts is on my H&M Duette - cos it doesn't really say!!! Link to comment Share on other sites More sharing options...
Rog RJ Posted July 16 Share Posted July 16 The basic rule of using a meter is to start with it on the highest range if you don't know what voltage or current (Amps) is present. You then reduce the meter settings step by step until you get a sensible reading on the meter. As you are dealing with model railway controller voltages, the 20volt setting is a reasonable scale to start with. 1 Link to comment Share on other sites More sharing options...
JJ73 Posted July 16 Author Share Posted July 16 Link to comment Share on other sites More sharing options...
LTSR_NSE Posted July 16 Share Posted July 16 17 minutes ago, JJ73 said: Thank you LTSR - It's a bit difficult to know what is 2 Volts is on my H&M Duette - cos it doesn't really say!!! You already used the 20v meter setting to find the loco start voltages. So use the 20v setting to find where to turn controller dial to get meter to read 2v & then never turn controller dial further than that if you set meter to 2v. Link to comment Share on other sites More sharing options...
ntpntpntp Posted July 16 Share Posted July 16 (edited) 52 minutes ago, JJ73 said: I'm going to set it to "2" instead!!! NO!!!! I wouldn't!! As the others have said, you always start with the highest range setting on the multimeter not the lowest! We know our model railway systems are nominally 12V but could read higher, so a 2V range setting would just risk blowing the meter! You need the 20V setting to get a reasonable reading across the range of the controller knob. I really don't see what trying to use the 2V range would give you? The 20V range is good enough to observe the starting voltage, the meter probably has enough precision to give you readings down to 0.1V and I expect down to 0.01V. Trying to be really accurate isn't worth it, each example of the Duette will be slightly different due to manufacturing tolerances and age of components anyway. Edited July 16 by ntpntpntp Link to comment Share on other sites More sharing options...
JJ73 Posted July 16 Author Share Posted July 16 Oh ok - may be I'll try the 200 on my Meter then??? 🤔🚂 Link to comment Share on other sites More sharing options...
ntpntpntp Posted July 16 Share Posted July 16 What are you trying to read - the lowest voltage the Duette can output? We know it's likely to be less than 1V so the 200V range won't have the precision, but 20V will be good enough and should be safe in case you accidentally turn up too high 🙂 Common sense 🙂 Link to comment Share on other sites More sharing options...
JJ73 Posted July 16 Author Share Posted July 16 T. b. h. - I'm not sure what I am doing here, just getting a random amount of numbers!!! I'd thought I'd try & finish this off by what Bee had said!!! Link to comment Share on other sites More sharing options...
ntpntpntp Posted July 16 Share Posted July 16 (edited) OK, Bee assumed you'd have a 5V range setting on your meter. Mine's got specific 2V, 20V, 200V settings but I leave it on Auto-Range. Yes a 5V or 2V range setting would give an even more accurate reading (maybe down to 0.001V) but frankly it's more precision than necessary for the original question and given the tolerances as I mentioned before. As an exercise in using your meter then fair enough but be very very careful not to turn the knob up too high. Connect the meter with the controller definitely in the off position and remember that under no load (no loco connected to the output) the voltage probably will be higher 🙂 Edited July 16 by ntpntpntp 1 Link to comment Share on other sites More sharing options...
JJ73 Posted July 16 Author Share Posted July 16 Oh ok - well I don't have / got a '5 range' nor do I have a 'Auto-Range' on mine!!! 🚂 Link to comment Share on other sites More sharing options...
Brew Man Posted July 16 Share Posted July 16 @JJ73 Stick to the 20V range. Link to comment Share on other sites More sharing options...
JJ73 Posted July 16 Author Share Posted July 16 Oh ok Brew Man - looks like I'm going to end up with the same reading as b4 then!!! 😀😉🚂 Link to comment Share on other sites More sharing options...
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