Il Grifone Posted September 14, 2015 Share Posted September 14, 2015 I thing 'grinding' (screeching is nearer sometimes) is actually the gears binding (Dublo armature/pole piece spacing is quite wide and they are unlikely to touch). This is due to wear all round - axles, coupling rods, bearings and the gears themselves. I have bushed axles in the past which has improved things. Acquiring new parts is the problem as those available are ex-equipment and probably already worn. Graphite grease on the gears might help. Link to post Share on other sites More sharing options...
Andy Reichert Posted September 14, 2015 Share Posted September 14, 2015 Golly. I just noticed the 4-5 year gap in this topic! RM Webs server hard drives are hanging in there pretty well. My "screeching" problem was a late 50's schoolboy story. Many years later, with far more knowledge and disposable income, it was instantly fixed merely by swapping out the motor. The plain bearing at the commutator end was completely shot. Andy Link to post Share on other sites More sharing options...
sagaguy Posted September 14, 2015 Share Posted September 14, 2015 Somewhere in my collection,i have an early ringfield motor 8f 2-8-0 with a plain oillite bearing at the commutator end which screeches after running a short while Although i tried soaking it in warm oil but never cured the noise.I know you can get replacement bearings but wondered if the later adjustable bearing type took a different armature. Ray. Link to post Share on other sites More sharing options...
Il Grifone Posted September 14, 2015 Share Posted September 14, 2015 I don't think so. I've only seen one type of Castle/8F armature offered for sale. The service sheets are no help as they only give the complete motor assembly. Link to post Share on other sites More sharing options...
Andy Reichert Posted September 14, 2015 Share Posted September 14, 2015 Somewhere in my collection,i have an early ringfield motor 8f 2-8-0 with a plain oillite bearing at the commutator end which screeches after running a short while Although i tried soaking it in warm oil but never cured the noise.I know you can get replacement bearings but wondered if the later adjustable bearing type took a different armature. Ray. That was my symptom exactly. Andy Link to post Share on other sites More sharing options...
mikesndbs Posted October 4, 2015 Share Posted October 4, 2015 Well I took the plunge and things are already running much better! Link to post Share on other sites More sharing options...
mikesndbs Posted October 17, 2015 Share Posted October 17, 2015 Anyone got a supply for those little ball bearings that go each end of Wrenn 8F and West Country motor armatures? I need four. Link to post Share on other sites More sharing options...
sagaguy Posted October 17, 2015 Share Posted October 17, 2015 You can buy them on ebay very cheaply, http://www.ebay.co.uk/itm/BEARING-OPTIONS-BALL-BEARINGS-316-STAINLESS-STEEL-FREE-UK-NEXT-DAY-DELIVERY-/200896321455?var=500145081965&hash=item2ec65a97af:m:mBOq-7v-XltCkUO6welURdg £2.99 for 10. Ray. Link to post Share on other sites More sharing options...
mikesndbs Posted October 17, 2015 Share Posted October 17, 2015 You can buy them on ebay very cheaply, http://www.ebay.co.uk/itm/BEARING-OPTIONS-BALL-BEARINGS-316-STAINLESS-STEEL-FREE-UK-NEXT-DAY-DELIVERY-/200896321455?var=500145081965&hash=item2ec65a97af:m:mBOq-7v-XltCkUO6welURdg £2.99 for 10. Ray. Great, what size do I need please? Link to post Share on other sites More sharing options...
sagaguy Posted October 17, 2015 Share Posted October 17, 2015 Great, what size do I need please? 1/16" of an inch,Meccano always used imperial sizes. Ray. Link to post Share on other sites More sharing options...
mikesndbs Posted October 17, 2015 Share Posted October 17, 2015 Top man, thanks Ray Link to post Share on other sites More sharing options...
mikesndbs Posted October 18, 2015 Share Posted October 18, 2015 Hi guys, wonder if you can help me with this one. Wrenn 4MT 2-6-4 T lovely loco. Ever since I had it, it grinds away and does not sound nice and smooth at all. I have done a full strip down and once the brushes are out I can turn the armature by turning the wheels so I know its all free running. I adjust the top bearing to just allow a fraction of up down movement. Put her all back together and still she grinds back in 2004 I fitted a neo magnet, took that out having recharged the original, no great difference in noise but she it gutless and can be stalled with a big train. Put the neo back and solved that (150mA) but this grinding gets to me. Any ideas as to what I can do please? Would you like to see and hear a video of her? Link to post Share on other sites More sharing options...
mikesndbs Posted October 18, 2015 Share Posted October 18, 2015 Here is the video https://www.youtube.com/watch?v=BmWkCBeMJ1s Many thanks Link to post Share on other sites More sharing options...
stewartingram Posted October 18, 2015 Share Posted October 18, 2015 Hi guys, wonder if you can help me with this one. Wrenn 4MT 2-6-4 T lovely loco. Ever since I had it, it grinds away and does not sound nice and smooth at all. I have done a full strip down and once the brushes are out I can turn the armature by turning the wheels so I know its all free running. I adjust the top bearing to just allow a fraction of up down movement. Put her all back together and still she grinds back in 2004 I fitted a neo magnet, took that out having recharged the original, no great difference in noise but she it gutless and can be stalled with a big train. Put the neo back and solved that (150mA) but this grinding gets to me. Any ideas as to what I can do please? Would you like to see and hear a video of her? Any magnet should be remagnetised IN SITU, not away from the chassis then refitted. Make sure that is done to start off with. The gear wheel on the axle has 2 grub screws, loosen them to test the armature under pwer. Any free float on the top bearing should be minimal, just enough to feel vertical movement and no more. Adjust the srew in the centre of the top bearing - don't forget to loosen the large nut 1st (and retighten afterwards!). When that seems ok, tighten the axle gear grubscrews. Early versions of the 2-6-4T had a magnetic shunt adjusted by a screw at the rear of the loco, through the bunker. In my experience, best to remove this totally. Any problems get back to me. Stewart (former service engineer and still have the remag tool) Link to post Share on other sites More sharing options...
mikesndbs Posted October 18, 2015 Share Posted October 18, 2015 Hi Stewart Thanks for that. I've not tried slackening off the gear wheel and will get on to that in a bit. Think I have the bearing adjusted just as you say so that's good Not sure about the magnetic shunt, so I am guessing mine does not have this, can you see from the video if it does? I did remagnetize in situ and it was a lot more powerful after but she was still very weak and would stall as per my post. I'll report back soon. Just as an aside, I have the Wrenn class 20, which used to run like silk, still does but every so often loses pickup at random places on the track, have cleaned and checked everything. Last thought I had was some kind of carbon build up on the axles for chassis return, any experiance of this and if so am I able to remove the wheels to get access to the axle and bearing? Many thanks Link to post Share on other sites More sharing options...
mikesndbs Posted October 18, 2015 Share Posted October 18, 2015 Update, Hi Stewart. OK I undid the grub screws and ran the motor, it was still spinning the pinion on the axle but of course the wheel stayed still I then slowly screwed down the top bearing until most of the rattle stopped, at this point the armature also slowed a little. I then jiggered about so that tightening the lock nut just increased bearing bite to a point where I only lost a tiny bit of armature speed. I then recentered the drive pinion with the worm, before it was able to go to one side of it, I still have full side to side play on the rear wheels. The result has been a 40% reduction in the noise you can hear so that is very good. The trade off is a little lost speed, but that is not issue at all to me. I have kept with the neo magnet as despite taking your advice, the motor was still very poor. Now she is running freely at 120mA. What do you think? Link to post Share on other sites More sharing options...
sagaguy Posted October 18, 2015 Share Posted October 18, 2015 The magnetic shunt was fitted on early 2--6-4s to compensate for the slow running on the controllers at the time,i think it was to move the magnet backwards between the pole pieces, ican`t remember the science now..As controllers got more sophisticated,the magnetic shunt was dropped.The Wrenn & HD class 20 was one of the few failures of Meccano 2 rail locomotives,it suffered from the same symptons that you describe.It seemed to be caused by inadequate pickups & the traction tyre didn`t help,i don`t know if they cured it,i did speak to a Wrenn representative at a model engineer show in the early 70`s about this but he was very non commital.All HD magnets should be remagged with the armature in circuit,the instructions with the loco always gave dire warnings about taking the motor apart. Ray. Link to post Share on other sites More sharing options...
Il Grifone Posted October 18, 2015 Share Posted October 18, 2015 Hello Mike, Wrenn 4MTs (at least the later ones) did not have the magnetic shunt. It puts a iron bar across the the magnet to reduce the flux through the motor, so that the locomotive runs more slowly. The position and hence the effect of the shunt is adjustable by a screw. Mine lost hers not long after I received her for Xmas 1954! It was rather pointless as the loco ran well enough without it and they had reduced the gear ratio anyway. (The reason why spares are specified as fine or coarse gears.) A serious downside is a large hole in the centre of the rear of the bunker. Yours has the later Wrenn armature with the small commutator. The long brushes are intended for these. I fail to see any reason for the reduction in diameter (apart from saving copper). I would have thought it more prone to wear and arcing. The brush tension is quite critical, especially it the magnet is below par. In my youth, I spent quite a lot of time tuning my locomotives.... Some do suffer from noisy gears (production tolerances?) while others are smooth as silk. You could try running it in with toothpaste*. I have seen car valve grinding paste recommended, but it seems a bit OTT to me (it's not intended for brass and not so easy to find these days anyway - vehicle engines no longer need decoking, reboring etc. at frequent intervals as they used to). At worst spare gears and armatures are available on eBay. I wouldn't tighten the bearings to reduce noise it will only increase wear * The cheap and nasty stuff is quite OK. It's abrasive effects are what is wanted here. Wash off afterwards and relubricate. I think the problem with the 2 rail Bo-Bo was due to poor pickup (from the trailing bogie I believe (I'm not sure as my two are both 3 rail, even if they are D8000 and D8017*). Most manufacturers put the traction tyres on one side of the power bogie and pick up from the other side, returning the current through the trailing bogie. * One has the magnet reversed for prototypical nose to nose double heading. (Not necessary for 2 rail of course.) Link to post Share on other sites More sharing options...
sagaguy Posted October 18, 2015 Share Posted October 18, 2015 The 3 rail version ran perfectly,from what i remember about the 2 rail version was that one of the reasons for poor running was that the arcing between the wheel & the rail caused a build up of crud on the wheel which had to be cleaned of frequently,whether Wrenn changed the composition of the metal,i don`t know. Ray. Link to post Share on other sites More sharing options...
Il Grifone Posted October 19, 2015 Share Posted October 19, 2015 The bogie suspension isn't very clever* and allows the bogies to rock excessively. In the 3 rail version, with six wheels making contact (plus the flanges of the tyred wheels, though this is rather tenuous) pickup is not a problem, but when reduced to two on one bogie problems arise. * The pivot is high up in the loco body rather than low down, where it belongs (I think Wrenn modified this?) and the bogie is quite light in weight.. Tri-ang power bogies suffer from the same thing, but the pickups are on the power bogie and benefit from the weight of the bogie (in some cases aided by 'Magnadesion'). Some later models benefit from the addition of pickups on the trailing bogie (one per axle). Link to post Share on other sites More sharing options...
sagaguy Posted October 19, 2015 Share Posted October 19, 2015 The bogie suspension isn't very clever* and allows the bogies to rock excessively. In the 3 rail version, with six wheels making contact (plus the flanges of the tyred wheels, though this is rather tenuous) pickup is not a problem, but when reduced to two on one bogie problems arise. * The pivot is high up in the loco body rather than low down, where it belongs (I think Wrenn modified this?) and the bogie is quite light in weight.. Tri-ang power bogies suffer from the same thing, but the pickups are on the power bogie and benefit from the weight of the bogie (in some cases aided by 'Magnadesion'). Some later models benefit from the addition of pickups on the trailing bogie (one per axle). Your post jogged the memory,i recall that when starting,the bogie tipped up under load causing two of the wheels to lose contact with the rails.Without digging everything out from a large chest,i think the Deltics had a shoulder screw located in a radial slot in the chassis thus preventing the tipping.I can`t remember if the Bo Bo had this arrangement. Ray. Link to post Share on other sites More sharing options...
mikesndbs Posted October 20, 2015 Share Posted October 20, 2015 Hi all Well over the last several days I have been working on, puzzling over and very nearly giving up on my class 20 and 4MT. However today I have it all sorted The 4MT unfolded much as seen above. Remag in situ worked! Tightening down the bearing on the armature has greatly reduced the noise. Centreing the pinion on the worm also helped. She now runs smoothly and controllably. Just waiting for the brushes to bed in. The class 20s body has been on and off more times than I can count. Just as I think I fix a issue, she still runs badly. However the fix was as follows, in fact multiple issues. 1) motor brushes had become somehow corroded and dark such that the spring and insulated plate were not making reliable contact. The fix was to polish up with fine wet & dry. 2) Trailing bogie was making erratic contact. Tried adding weight, while this helped it did not solve. The fix was to remove the wheels and axles from the bogie. The axles had built up a carbon film (maybe old oils from years back) as had the bearings. Again, fine wet and dry had this sorted. 3) The wire that runs from the brush to the trailing bogie had a bad connection. The fix was to replace it. 4) the plate/round connector at the brush end of the same wire was not making contact with the brush arm: fix for now is direct attachment to the brush keeping the insulating sleeve in place of course. 5) Motor bogie pickups were very erratic. The fix was a bath for the whole bogie in IPA cleaner in my ultrasonic bath, I suspect the same carbon build up but did not fancy dismantling due to the gears etc. After the bath and a good air clean I removed any deposits I could find and re lubricated with Hob-e-Lube ultralight oil. Has this fixed it? yes it has Never give up lol p.s ordered my ball bearings as per sagaguy's tip above £2.99 for 10 when someone wanted to charge me £1 each plus p7p lol Link to post Share on other sites More sharing options...
sagaguy Posted October 20, 2015 Share Posted October 20, 2015 Excellent,glad to be of help. Ray. Link to post Share on other sites More sharing options...
Il Grifone Posted October 21, 2015 Share Posted October 21, 2015 p.s ordered my ball bearings as per sagaguy's tip above £2.99 for 10 when someone wanted to charge me £1 each plus p7p lol Been there! They were for Tri-ang Motor bogies though. (The problem is that I can't remember where I stored the surplus spares!....) Link to post Share on other sites More sharing options...
mikesndbs Posted October 24, 2015 Share Posted October 24, 2015 Morning all, in between visits to A&E I managed to get this video sorted out. Shows all four motor types I have being serviced and discusses what I needed to do, at the end there is a running session so you can see how they are now. Big thanks again for all the advice, that i hope I have managed to pass on to help others. Link to post Share on other sites More sharing options...
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