peter220950 Posted November 12, 2014 Share Posted November 12, 2014 When I were a lad the spivs used to put a handful of sawdust into noisy car gearboxes, it mixed with the oil and produced a thick mousse that killed the noise. 7mm sawdust anyone? Link to post Share on other sites More sharing options...
JeffP Posted November 12, 2014 Share Posted November 12, 2014 I wouldn't bother too much about removing grease from bearings. Spray grease sold for chain saw lubrication will soon put it back. Link to post Share on other sites More sharing options...
Guest Isambarduk Posted November 13, 2014 Share Posted November 13, 2014 "Could the GB03 with glass reinforced sides have been dropped due to noise issues?"Now that is quite possible. Although roller bearings offer lower friction, they are not generally as quiet as plain bearings.David Link to post Share on other sites More sharing options...
Simond Posted November 13, 2014 Share Posted November 13, 2014 Ozzy I think it's fine to clean the grease out of the bearings - indeed I'd suggest that you really want to! Those spray cans of switch cleaner will extract a mountain of cr@p, or you could use your ultrasonic bath with a suitable solvent - though I'd take the motor off first. As long as you re-lubricate, should be no problem S Link to post Share on other sites More sharing options...
Horsetan Posted November 13, 2014 Share Posted November 13, 2014 When I were a lad the spivs used to put a handful of sawdust into noisy car gearboxes, it mixed with the oil and produced a thick mousse that killed the noise..... ...and probably killed the gearbox not long after. Link to post Share on other sites More sharing options...
Killybegs Posted November 13, 2014 Share Posted November 13, 2014 In those days, as long as it got off the forecourt they weren't worried! Link to post Share on other sites More sharing options...
ozzyo Posted November 13, 2014 Author Share Posted November 13, 2014 Hello all, I did think about the sawdust idea, but I think that this gearbox maybe for a better type of car. Ho Ho. After a bit of a clean this is what the inside of the gearbox looked like, The helical drive gear (nylon) was a bit of a surprise as it's only a push fit on the "axle". Also it looks like some of the bearings are open. More news to follow. This should have been a very good gearbox. But it looks like it was let down by the plastic (glass reinforced sides) to it. If it had brass M/ced sides it could have been a very good gearbox, and it could have still used the roller bearings. OzzyO. Link to post Share on other sites More sharing options...
JeffP Posted November 14, 2014 Share Posted November 14, 2014 Do you know anyone any good with a milling machine? I thought you had one? Or make the sides from fairly thick brass, fabricate some spacers, and fill in with thinner brass/nickel silver sheet? Link to post Share on other sites More sharing options...
Guest Isambarduk Posted November 14, 2014 Share Posted November 14, 2014 Sorry, I lost the plot here somewhere! Why do we think that replacement brass cheeks would be better/quieter than the existing glass-reinforced plastic ones? (Or is this so that the ball bearings may be omitted?) David Link to post Share on other sites More sharing options...
david.hill64 Posted November 14, 2014 Share Posted November 14, 2014 I wondered if the noise was because the gearbox sides were no longer supporting the axial thrust sufficiently, allowing the teeth to chatter. If it is this, then stiffening the sides will help. Link to post Share on other sites More sharing options...
Simond Posted November 14, 2014 Share Posted November 14, 2014 Ozzy Now that you have it clean, and the motor off, if you reassemble the sides, does the spur gearing turn sweetly & quietly when driven by hand from the axle? You might want a drop of light oil around the bearings to check this. If so, you can concentrate on the helical gear mesh. If not, you can look at the alignment & centres of the spur gears. If the spurs, start by checking each shaft and its bearings in turn - might be challenging with a closed gearbox - but the bearings should be totally smooth. Then pairs of gears, then three together, etc. Bit like coupling rods! Trial, error and elimination should enable you track down the demon that's hiding in there somewhere! Fundamentally, there's a reason, and once you find it, you'll know. Generally, I don't see why a composite gearbox (ie plastic & glass fibre) should be a problem - it is a common engineering material, and lots and lots of mechanical things are made from these materials, from camera bodies, vacuum cleaners, food mixers, to large chunks of your car, possibly even Ixion locos. Have a look at recycling marks - you'll find things like <PP GF30> or similar moulded into the underside of things - the GF is, you've guessed it, glass fibre. Best (and good luck) Simon Link to post Share on other sites More sharing options...
Pete Harvey Posted November 15, 2014 Share Posted November 15, 2014 Having "heard" the gearbox which sounds like a Class 66 starting up on a very cold frosty morning, I would say the two sets if not all of the bearings have had it, mainly from excessive side thrusting one way to salvage it would be to remove the bearings and turn some brass bearings for the shafts to turn in, mounted on new side frames, the side float could be controlled this way and should run smoothly and quietly, the down side of doing this would take time to build and may not work out as cost effective as buying an existing gearbox. Defiantly a better could and should be found as the existing one is terrible. Pete Link to post Share on other sites More sharing options...
Jon Fitness Posted November 15, 2014 Share Posted November 15, 2014 Having "heard" the gearbox which sounds like a Class 66 Ooooh scrap it now! .... Link to post Share on other sites More sharing options...
Guest Isambarduk Posted November 15, 2014 Share Posted November 15, 2014 "I would say the two sets if not all of the bearings have had it"That's the downside of ball-bearings: compared with plain bearings, they are a bit noisier to start with but they are much nosier later; they do not run in they just wear out, as you may have heard if you have an old computer with a well worked cooling fan.David Link to post Share on other sites More sharing options...
RMweb Gold farren Posted November 15, 2014 RMweb Gold Share Posted November 15, 2014 Don't SMB bearings have some replacements which could be used. Link to post Share on other sites More sharing options...
ozzyo Posted November 15, 2014 Author Share Posted November 15, 2014 Hello all, thanks for the suggestions about the gearbox. The more I think about it, I think that the bearings are out of alignment from one side of the box to the other and this is causing the bearings to run on the sides of the groove (top R/H side, bottom L/H side, say). Pete has come up with a good idea of replacing one side with plain brass bearings, turning the bearings up should not be a problem, the main problem that I can see would be removing the roller bearings without damaging the shaft ends. I don't think that the gearbox has had enough running to have worn out the bearings. After talking to the owner last night, he has decided to change the motor and gearbox for an MSC models one from the MT helical range, using one of the 3 stage ones with a 40;1 gear ratio. I have used a number of these boxes with very good results. So I'm now waiting for the postman to work his magic. OzzyO. Link to post Share on other sites More sharing options...
Simond Posted November 15, 2014 Share Posted November 15, 2014 Seems like a sensible solution to replace it, so that the loco can work, but as an exercise, I'm interested in what has gone wrong with the box. If the moulds were made correctly, then the alignment should not be an issue, assuming it was assembled correctly the first time. I think we can assume that if one gearbox worked (ever) then the design, and mould tools were ok, (must have been at least "good enough to sell", but then again, Too Many Spams' Pannier...) so my guess is it's down to poor assembly, or damage. Both should be evident. Assuming you can get the bearings out of both sides, it should be possible to see whether there is damage, or a foreign body in the bearing pockets, if so, it may have damaged that bearing, and a replacement is indicated. Getting the bearing off the shaft.... Creaking the outer race should not be too difficult. Then I think I'd have a go with a Dremel and grinding disc. Hope to get the race thin enough to crack without scarring the shaft. Might take a while. HTH Simon Link to post Share on other sites More sharing options...
Grasshopper John Posted November 17, 2014 Share Posted November 17, 2014 I'm with you Simon, I would be curious as too whats causing the noise. I'm no engineer by a long stretch but if anyone can solve this dastardly mystery the Ozzyo is the man Grasshopper J. Link to post Share on other sites More sharing options...
ozzyo Posted December 19, 2014 Author Share Posted December 19, 2014 Hello all, I've had the motor and gearbox bench running to get some lub. around the bits and to see how it runs, nice and smooth and quite. A photo of the old and the new, The motor and gearbox fitted into the frames, This is when the big bloke came in and kicked me in the chuds with his size nines. It runs at about the speed that I would expect in reverse but at about half the speed in forward. I did think that my controller may have started to play up, so I turned the loco around and the same thing happened, so I don't think it's the controller at fault. As a start today I'm going to drop the rods off and see if that makes any difference to the speed. I have had a similar problem once before with a Cannon motor but that loco ran OK in both direction at about the same speed but it was as weak as a kitten. So it got a good looking at. The first thing that I spotted was a lot of end play on the motor shaft, as seen below, Then when I opened up the motor this is what I found, I don't really want to have to start opening the motor up as it's brand new, but if anyone can give me any pointers it would be appreciated. TFAH OzzyO. Link to post Share on other sites More sharing options...
Guest Isambarduk Posted December 19, 2014 Share Posted December 19, 2014 "Then when I opened up the motor this is what I found ..." Ah, that's not so good! "... if anyone can give me any pointers it would be appreciated." Well, when I was in this position once, I put shim washers between the worm and motor bearing on one end of the shaft, and between the flywheel and motor bearing at the other, to take up nearly all the end-float. Worked a treat :-) David Link to post Share on other sites More sharing options...
Jon Fitness Posted December 19, 2014 Share Posted December 19, 2014 We've had a few Canon motors go like that over the years when we had the garden railway. I've done the same with the shims and it tends to be little more than a temporary fix before the motor dies altogether. By the time they get that damage inside they're already on the way out... Not even sure why they do it as some of the Canon motored Ron Chaplin gearboxes have been fine over a similar mileage. JF Link to post Share on other sites More sharing options...
ozzyo Posted December 19, 2014 Author Share Posted December 19, 2014 "Then when I opened up the motor this is what I found ..." Ah, that's not so good! "... if anyone can give me any pointers it would be appreciated." Well, when I was in this position once, I put shim washers between the worm and motor bearing on one end of the shaft, and between the flywheel and motor bearing at the other, to take up nearly all the end-float. Worked a treat :-) David Hello David, that is a good solution to the problem, but all it does is mask a problem that should not be there in the first place. I could fit thrust washers to both ends of the motor shaft and still have the same problem that then adds cost with no results. This is what the inside of the old Cannon motor looks like from the side, this one has been replace with a new motor and runs well, If the reason that the motor runs in the way that I've described it can then be pointed out to MSC then they can start talking to Cannon about the problem and then maybe get the problem sorted out at that end. If it's too much end movement in the motor shaft the damage could have already have been done! OzzyO. PS. just spotted the post by Jon, the gearbox's have always been fine just the odd motor. Link to post Share on other sites More sharing options...
Sandy Harper Posted December 19, 2014 Share Posted December 19, 2014 Hello David, that is a good solution to the problem, but all it does is mask a problem that should not be there in the first place. I could fit thrust washers to both ends of the motor shaft and still have the same problem that then adds cost with no results. This is what the inside of the old Cannon motor looks like from the side, this one has been replace with a new motor and runs well, Copy of 3.JPG If the reason that the motor runs in the way that I've described it can then be pointed out to MSC then they can start talking to Cannon about the problem and then maybe get the problem sorted out at that end. If it's too much end movement in the motor shaft the damage could have already have been done! OzzyO. PS. just spotted the post by Jon, the gearbox's have always been fine just the odd motor. Has this got anything to do with the mounting screws being too close to the windings? ie too long? Sandy Link to post Share on other sites More sharing options...
ozzyo Posted December 19, 2014 Author Share Posted December 19, 2014 Has this got anything to do with the mounting screws being too close to the windings? ie too long? Sandy Not the last time mate. It was the armature running on the bearing. That said not enough shims on the motor shaft. OzzyO. Link to post Share on other sites More sharing options...
Guest Isambarduk Posted December 19, 2014 Share Posted December 19, 2014 Sandy makes a very good point about those pesky over-long screws - I have come across that as well."that is a good solution to the problem, but all it does is mask a problem that should not be there in the first place"I agree! I have put the thrust washers on the inside before now, which is where they should be; but if you don't wish to dismantle the motor, putting them on the outside will sort it. "If it's too much end movement in the motor shaft the damage could have already have been done!"As long as the windings have not been damaged with a break(s), I doubt that the motor would be any the worse once the shim washers are in place." I could fit thrust washers to both ends of the motor shaft and still have the same problem that then adds cost with no results."I don't quite follow but are you concerned about the cost of the washers? Why "no results"?" it can then be pointed out to MSC then they can start talking to Cannon about the problem and then maybe get the problem sorted out at that end."There's no doubt that this is by far the best approach ... me, I just go in my workshop and try to sort it! I much prefer this to trying to negotiate with people - I'll leave that to those with a more sociable outlook :-) David Link to post Share on other sites More sharing options...
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