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Old 30-12-2010, 03:41 PM   #1
alfaz-di-pi
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Default Hornby R751

Hello everyone, this is my first post, and needless to say I need a bit of help.
I have 2 of the R 751 diesels, but one does not run in the right direction. In other words one of them will go forward as all my other engines, if I put the odd one on it goes backward.
I have tried changing wires over but that does not seem to help it is still going backward. Any suggestions please. At the moment I am running on DC but hope to change to DCC when I have sorted the layout.
I am sure that when I do change I will have all sorts of trouble, mainly with my poins, which carry the power through with the little wires underneath, and I have not put in any isolating fishplates. On Dc they work fine.
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Old 31-12-2010, 10:48 AM   #2
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Hi
The cause is the motors magnet has been fitted the wrong way around at some stage.
Carefully strip down the motor and turn the magnet through 180- degrees. SRestore all parts and wiring and it will then run the correct way as all others.

BTW the standard for dc running is..... Positive supply to right-hand rail with loco on track and looking from the cab towards its chimney, this will give forward movement. (Steam outline loco)
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Old 31-12-2010, 07:39 PM   #3
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Thanks Flashbang I will try that tomorrow and see if that is the cause. I will admit that I did strip down the motor to clean and service it, so I could quite well be the culprit. I will keep you posted. I never even thought of a reversed magnet, have i changed the field then.
There are three Magnets, one ontop of each axle and one around the motor, which one do I turn around.
Thanks again.
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Old 31-12-2010, 09:13 PM   #4
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Hi
Yes you have accidently reversed the motors polarity by fitting the motors coil magent around the wrong way.
The motor magnet is the one on the motor.
I suspect the other magnets are for use with steel rail Tri-ang/Hornby called it Magnheasion.
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Old 03-01-2011, 02:49 PM   #5
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Default R751

Hi Flashbang, I eventually managed to get the loco running correctly, it did take three goes though. However it only took 5 minutes on the last attempt as I got used to doing it.
I should have asked you wether I was doing a vertical 160 degree turn or a horizontal 180 degree turn, it ended up being the horzontal that did the trick. Unfortunately on my first attempt, I moved the peices each side of the magnet, thinking they were the magnet, and the magnet was only a spacer.
However it is working the same as all the rest of my Loco's which was what I needed.
Thanks for the tip.
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