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AndyID

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AndyID last won the day on July 15 2020

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    Pacific Northwet

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  1. Hi Tony, Greetings from the Pacific Northwet (although it is actually snowing!) I thought you might find this interesting or at least slightly entertaining. What's going on here is that there is an "electronic flywheel" (consisting of four small capacitors - those blue things in the video) attached across the motor. In the first video they are disconnected then they are connected in the second video. Everything else is exactly the same. This is DC of course and the capacitors act as a short term battery that maintains a supply to the moto
  2. For three reasons. To measure low resistances properly the meter's probes need to make very low resistance contact otherwise the results will be inconsistent. The second reason is that most inexpensive meters do not measure low resistances very well. 0.1 ohms is typical for a decent DVM but inexpensive analog meters might only measure tens of ohms. The third reason is that most people easily understand a voltage drop whereas a resistance is often more obscure. For instance a 2 volt loss between the controller and the loco will strike most people as being a
  3. Good to hear although I was sort of hoping you'd discovered a hitherto unknown physical phenomenon You can actually use a voltmeter to debug problems like this and it's actually better than an ohmeter. You just need a 27 ohm power resistor attached to crock clips by flying leads to represent the motor load. You clip the resistor across the rails and measure the voltage drops around the complete circuit with the controller turned on. You can quickly find a bad connection. For example, half a volt across a fishplate is a problem. You also might be surprised at just how much voltage
  4. Another video. This time with the caps on the loco disconnected. The meter is showing the DC track voltage. Same thing except the caps on the loco are now connected. Nothing up my sleeves, 'onest guv. The 3F chassis collects current on all wheels. The wheels and track are not impeccable, probably pretty typical. No pulse power, no nuthin. Just smooth DC from a LM217 regulator.
  5. Looks like the upper part of the front molding has been removed. I have one of those but I have not run it in ages. I think they run OK but I just dug mine out and I see I made a new extended bearing at the shaft end. IIRC it didn't take long for the original bearing to wear out. You might do better if you can replace it with a Sagami 10 x 15 if you can find one on Ebay. Unfortunately I believe Sagami is no longer in business. They made very good motors, particularly the round can ones.
  6. The circuit is here. It's not very complicated https://www.rmweb.co.uk/community/index.php?/topic/159701-keep-alive-for-dc/&do=findComment&comment=4253910
  7. I was heading in the RC direction. Primarily for controlling shunting locomotives while the rest of the layout does its own thing on automated DC. (At least that is the general idea ) But then I wondered if I could get control that was almost as good as RC by simply adding an electronic flywheel to my locomotives. I've been doing a fair bit of experimentation on that and it actually seems to work. One of the big advantages of this method is it's dirt cheap! (Possibly that is a slight exaggeration, but it really is not expensive.) Anyway, there might be a "hybrid" solut
  8. That's a nice demonstration of how a "helix" doesn't have to be circular. If you have the room you can ease the gradient by splitting the helix in two and add straight inclines. Another way to ease the gradient might be to make the the helix more like an old type woodscrew where the radius continuously changes. That means that you don't have to achieve the unit vertical clearance in a single turn, but might take a lot of space too EDIT: I think I know now why the woodscrew helix idea is baloney but I'll leave it up there for entertainment.
  9. But is it sealed for particles as small as 0.0002 inches? I suppose you could do a "reverse witch" test. If it floats it's sealed. If it sinks, problem solved.
  10. Yes, life is full of risks but usually there is a reward for taking a risk. In this case I don't see any reward which is why I won't take the risk and I don't encourage anyone else to either.
  11. Has anyone ever tried an automated switchback as an alternative?
  12. The fibers would not escape if the unit was hermetically sealed but it isn't and the small gaps in the casing are far greater than the size of dangerous asbestos particles. To make matters worse the controller actually "breathes" as it heats up and cools down and every time the control knob is rotated it disturbs the surface of the asbestos former. Is it a huge risk? Probably not but I would not let my grandchildren use one. There are far better controllers available anyway so why take any risk?
  13. Good point about only using lubricants that are compatible with plastic. Many are not. The commonly used ones in the US that are compatible are sold by Labelle. I bought my A4 (Golden Fleece) used and I thought I would replace the tender drive with a loco drive. But after lubing the main bearings, tweaking the pickups and replacing the traction tires with RTV I'm not sure I will bother. (I suspect the coiled spring for the rear axle suspension was dislocated too but I can't be sure.) When I attached the electronic flywheel it performed beautifully. Not sure about the top speed but
  14. They were very nice in their time but as they are getting on for 50 years old (or more) there are quite a few reasons to scrap them. I don't have any but if I did I'd probably re-use the case, the control knob and the transformer and replace everything else with some better electronics. Come to think of it that might be a business opportunity for some enterprising person
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