drgj Posted July 9, 2013 Share Posted July 9, 2013 I have done this to my Dublo 8f and it is ok. I stripped the motor and got all the crud out. I put it back together but now it won't run. I put everything back as it was (I hope). I didn't touch the adjustable top bearing. There is end play on the armature it seems to turn ok. I didn't touch the wheels or gear on the axle. Sometimes it will turn a bit but mostly it just trips the cutout in the controller. I checked for shorts with a meter. It was running ok before but the whole thing was full of fluff and dirt mixed with oil. Any ideas? Dave Link to post Share on other sites More sharing options...
Gordon A Posted July 9, 2013 Share Posted July 9, 2013 Have you checked for a circuit from one brush, throgh the commutator to the other brush, and is there power on either side? The only other thing I can think of is the magnet the right way up and round? Gordon A Bristol Link to post Share on other sites More sharing options...
Il Grifone Posted July 9, 2013 Share Posted July 9, 2013 I hope I'm wrong, but it sounds like an open circuit armature winding - My Dublo Co-Bo* suffers from the same thing - there's a wire detached from the commutator, which needs to be resoldered, if my eyesight is up to it. * Similar ringfield motor, but applies to any motor. The magnet orientation won't affect operation beyond running in the wrong direction, but it will have lost magnetisation if the motor has been dismantled, unless it's a neodymium type. This usually results in slow/gutless running and overheating. Link to post Share on other sites More sharing options...
drgj Posted July 9, 2013 Author Share Posted July 9, 2013 I didn't realise that the ringfield magnet would lose magnetism if I removed it! Can anyone remagnetise it? When I did the 8f I think the magnet stayed in the chassis. Does just removing the brush housing spoil the magnet? Luckily it still runs ok. I checked the armature and it seems ok visually. I have a multimeter so could check continuity. Dave Link to post Share on other sites More sharing options...
drgj Posted July 10, 2013 Author Share Posted July 10, 2013 I am kicking myself for dismantling the motor. Oh well! Does anyone remagnetise these locos? What shoud a good Dublo 2 rail 8f with ringfield motor be capable of pulling? Dave Link to post Share on other sites More sharing options...
RMweb Premium Trainshed Terry Posted July 10, 2013 RMweb Premium Share Posted July 10, 2013 I would buy new magnets for the said model, but I for the life of my brain can remember who sells them. Terry Link to post Share on other sites More sharing options...
stewartingram Posted July 10, 2013 Share Posted July 10, 2013 No need to buy a new magnet! PM me and I'll remag it for you at cost of postage. Stewart Link to post Share on other sites More sharing options...
sagaguy Posted July 10, 2013 Share Posted July 10, 2013 I didn't realise that the ringfield magnet would lose magnetism if I removed it! Can anyone remagnetise it? When I did the 8f I think the magnet stayed in the chassis. Does just removing the brush housing spoil the magnet? Luckily it still runs ok. I checked the armature and it seems ok visually. I have a multimeter so could check continuity. Dave I don`t think Ringfield magnets suffered from losing their magnetism so much as the old vertical motors.I converted a few 2 rail locos to 3 rail & got them to run in the right direction by rotating the ringfield magnet through 180 degrees.I don`t really think that remags are worth it these days.Ebay is the place for the new magnets,just search for Hornby Dublo spares. Ray. Link to post Share on other sites More sharing options...
34theletterbetweenB&D Posted July 10, 2013 Share Posted July 10, 2013 ...What should a good Dublo 2 rail 8f with ringfield motor be capable of pulling?... On level track it will drag along twenty to thirty H-D 'no roll' wagons, or as many free-running pinpoint bearing wagons as the average layout has space for... Link to post Share on other sites More sharing options...
Il Grifone Posted July 10, 2013 Share Posted July 10, 2013 A Dublo wagon should start to roll down a 1 in 30 and a pinpoint one down a 1 in 100. It follows that pin point bearings allow something like 3 times the length of train. My 8F manages about 17 or 18 Dublo wagons, but is a 1/2" motor 3 rail version. She has been converted to 2 rail (and back) with nickel-plated wheels on one side (genuine Dublo). I find the nickel wheels more prone to slip than the plain mazak though. The heavy die-cast tender doesn't help! The armatures should read around twelve ohms between adjacent commutator segments (they are 'star' wound). EDIT From the horse's mouth, 4 (presumably Dublo SD) coaches up a 1 in 25 gradient and 28 seconds for 5 laps of the standard oval (about 10 feet round), again with 4 Dublo coaches. I find that roughly one coach equals 3 wagons load wise. (From the date of the former test I assume a ringfield model and the latter is the standard test specification for a new ringfield 8F Locomotive. Repaired locos were allowed an extra second and 1/2" motors an extra five. Link to post Share on other sites More sharing options...
drgj Posted July 11, 2013 Author Share Posted July 11, 2013 I haven't done any haulage tests but I have checked the power consumption of my other Dublo locos. I ran them light engine and the 8f used about .5 amp, while the 2-6-4 used .5 amps but .6 in the other direction for some reason. As I have never messed with the 2-6-4 I am satisfied that the 8f's similar consumption means it is ok. For comparison I tried one of the latest Hornby LMS class 5s and this used about .25 amps . However the latest Hornby 08 and the Bachmann Jinty used only .06 amps- a lot less than even the Class 5. Dave Link to post Share on other sites More sharing options...
stewartingram Posted July 11, 2013 Share Posted July 11, 2013 In my experience anything over about 350mA is excessive for HD. Usually a sign of the magnet starting to weaken. HD locos last for ever. The 08 is a particularly good chassis, heavy and well geared for shunting, the Lima is exactly opposite on both counts. Remags are no problem with the correct tool! Stewart Link to post Share on other sites More sharing options...
drgj Posted July 13, 2013 Author Share Posted July 13, 2013 I tested the resistance of the armature windings as suggested by ll Grifone and there was almost a short between two of the commutator segments. As the windings looked ok I cleaned the commutator gaps, put it all back together and it ran like before! I had just decided to have one more go after I read somewhere else that you can in fact remove Ringfield magnets without spoiling them. Thanks to all for suggestions and offers of help. Thanks very much to Stewart for the remag offer and once have done a few haulage tests I will get back to him if they are not up to scratch. Dave Link to post Share on other sites More sharing options...
stewartingram Posted July 13, 2013 Share Posted July 13, 2013 Trust me, DO NOT remove the magnet without a keeper - it WILL need a remag. How many times do I need to repeat this - I was taught this at school in physics, all magnets NNED a keeper plate to maintain the magnetic path. Stewart Link to post Share on other sites More sharing options...
drgj Posted July 14, 2013 Author Share Posted July 14, 2013 I know, stewart, but I had already taken it out and it was too late. It was just that this other article stopped me giving up! It certainly runs the same as it did before, luckily. How do they get the magnets in without spoiling them when the models were first made? Did they fit them and then magnetise them in situ? Dave Link to post Share on other sites More sharing options...
sagaguy Posted July 15, 2013 Share Posted July 15, 2013 Meccano Ltd used a magnetiser to magnetise the whole motor after it was assembled.Your best bet is to Google HD ringfield magnets,these are the new type which don`t need magnetising,Iv`e fitted these magnets on some vertical motors & they don`t half go!!!!. Ray. Link to post Share on other sites More sharing options...
RMweb Gold Colin_McLeod Posted July 15, 2013 RMweb Gold Share Posted July 15, 2013 I would buy new magnets for the said model, but I for the life of my brain can remember who sells them. Terry There is a selection on E Bay: http://www.ebay.co.uk/sch/i.html?_odkw=ringfield+magnet&_osacat=0&_from=R40&_trksid=p2045573.m570.l1313.TR0.TRC0.Xdublo+ringfield+magnet.TRS0&_nkw=dublo+ringfield+magnet&_sacat=0 Link to post Share on other sites More sharing options...
Il Grifone Posted July 16, 2013 Share Posted July 16, 2013 Trust me, DO NOT remove the magnet without a keeper - it WILL need a remag. How many times do I need to repeat this - I was taught this at school in physics, all magnets NNED a keeper plate to maintain the magnetic path. Stewart This is true for all magnets, except neodymium types. Both Hornby Dublo and Tri-ang were emphatic in their instructions to not dismantle the motors. In their 'The First Ten years' book tri-ang quoted a loss of at least 10% IIRC*. According to them there was "Plenty left." Dublo mechanisms were definitely assembled first and then magnetised. * My copy got thrown out many years ago! Link to post Share on other sites More sharing options...
Ian Kirk Posted July 16, 2013 Share Posted July 16, 2013 Hi, Preventing the loss of magnetism if you want to dismantle the motor is relatively simple. Back in the mists of time when modellers had to make things for themselves we used to shorten triang motors (to leave the cab for cab detail) and simply kept a bent strip of steel to slide the magnet into as a keeper. Hornby dublo vertical mechs needed to be re-magnetised from time to time anyway but the late Sid McCracken who had a local model shop had a special electromagnet and re magnetised these for a few shillings. These new " super " magnets are great but I don't know how they work (not losing magnetism I mean). best wishes, Ian Link to post Share on other sites More sharing options...
stewartingram Posted July 16, 2013 Share Posted July 16, 2013 I suspect they may be stronger, losing a bit if they are removed basicically is not noticed? My simple theory anyway! TBH I'm not sure about putting a stronger magnet in anyway, I'll stick to remagnetising mine as and when I need to. If it ain't broke, don't fix it.... Stewart Link to post Share on other sites More sharing options...
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