N15class Posted January 25, 2015 Share Posted January 25, 2015 I am reading the HMRS livery register, it seems that most if not all O2's had a 9" longer Southern than normal. I know it does not effect you but sort of makes it harder for me. Link to post Share on other sites More sharing options...
RMweb Gold Donw Posted January 25, 2015 RMweb Gold Share Posted January 25, 2015 Chatting to Jim (Mr connoisseur) today and mentioned I had been following this thread he seemed pleased and interested. I would have bought a Macaw but the wallet was empty by then. Don 2 Link to post Share on other sites More sharing options...
RMweb Premium 2ManySpams Posted January 26, 2015 Author RMweb Premium Share Posted January 26, 2015 Infamy, infamy... Simon Dunkley has referenced this thread in his blog. http://ewjr.org/2015/01/26/the-joy-of-1366 Thanks Simon! Link to post Share on other sites More sharing options...
RMweb Premium 2ManySpams Posted January 31, 2015 Author RMweb Premium Share Posted January 31, 2015 Not much progress today as I've been doing DIY around the house. An annoying bathroom pull switch that repeatedly fails. Three in the house and this one is now on it's sixth replacement. Grrr. Also fixing a pink wheel barrow and the plumbing in a very muddy field. No, really. Link to post Share on other sites More sharing options...
RMweb Premium 2ManySpams Posted January 31, 2015 Author RMweb Premium Share Posted January 31, 2015 Anyway, bogie Slaters thankfully sent the right bearings to go with the smaller bogie wheel axles. To fit these Jim's kit bearings have to be opened out a smidge. Trial fitting the axle I noticed a snag. The distance across the bearings is larger than the distance between wheel backs. Jim's bearings stand proud of the frames. So they are being filed down flush. And shown here with the Slaters reducer bearing placed in. 8 Link to post Share on other sites More sharing options...
N15class Posted January 31, 2015 Share Posted January 31, 2015 This is coming together very well. At least you don't need dozens of washers to control the side play. It won't belong before you are throwing some paint at it. Link to post Share on other sites More sharing options...
RMweb Premium 2ManySpams Posted January 31, 2015 Author RMweb Premium Share Posted January 31, 2015 This is coming together very well. At least you don't need dozens of washers to control the side play. It won't belong before you are throwing some paint at it. Throwing paint, now that will be exciting. Link to post Share on other sites More sharing options...
chaz Posted January 31, 2015 Share Posted January 31, 2015 (edited) Moving on... Wheels. rps20150125_174205.jpg Wheels and body. rps20150125_174244.jpg Balanced nicely on the front wheels with only one weight added. With your compensation scheme you might need to put some weight on the bogie to get its wheels planted firmly on the rails. With no downwards force I would worry for the tracking, particularly in reverse. i suspect the CoG might be best placed somewhere between the driving wheel beam pivots and the bogie pivot. Best to sort that out by experiment? Chaz Edited January 31, 2015 by chaz 1 Link to post Share on other sites More sharing options...
RMweb Premium 2ManySpams Posted January 31, 2015 Author RMweb Premium Share Posted January 31, 2015 You're talking Jackson Pollocks, aren't you? I normally get accused of talking pollocks but, paint-wise, I had something slightly neater in mind! Link to post Share on other sites More sharing options...
RMweb Premium 2ManySpams Posted January 31, 2015 Author RMweb Premium Share Posted January 31, 2015 With your compensation scheme you might need to put some weight on the bogie to get its wheels planted firmly on the rails. With no downwards force I would worry for the tracking, particularly in reverse. i suspect the CoG might be best placed somewhere between the driving wheel beam pivots and the bogie pivot. Best to sort that out by experiment? Chaz Chaz, Jim has thought of that and included a spring to push the bogie down onto the rails. With all the weights fitted I've found that the CoG is between the two main drivers. Link to post Share on other sites More sharing options...
RMweb Premium 2ManySpams Posted January 31, 2015 Author RMweb Premium Share Posted January 31, 2015 Bits all placed together to see how it all looks. 8 Link to post Share on other sites More sharing options...
N15class Posted January 31, 2015 Share Posted January 31, 2015 What has Jim sorted for the side control on the bogie? Link to post Share on other sites More sharing options...
RMweb Premium 2ManySpams Posted January 31, 2015 Author RMweb Premium Share Posted January 31, 2015 What has Jim sorted for the side control on the bogie? I was going to ask the assorted throng about the sideplay on the rear bogie. At the moment there's a fixed bolt coming down from the chassis that goes into a hole in the top of the bogie. As such the bogie rotates but has no sideplay. I was toying with cutting a slot in the top of the bogie and putting in some wire springs to keep it centred. Any thoughts on this plan? Link to post Share on other sites More sharing options...
Simond Posted January 31, 2015 Share Posted January 31, 2015 (edited) Chaz, Jim has thought of that and included a spring to push the bogie down onto the rails. With all the weights fitted I've found that the CoG is between the two main drivers. Chris Are you sure? The CoG should definitely place some weight (say, one third) on the bogie, and the rest split between the drivers, which their compensation will take care of. So my guess is that the CoG should be somewhere about the rear edge of the rear drivers. If it is forward of this, I'd be concerned, as Chaz has mentioned, of poor tracking of the bogie. If it is lots forward of this, see if it will pull a wheelie in reverse! (Possibly whilst pulling a train) The spring won't push the bogie down more than the weight applied to it. HTH Simon Edited January 31, 2015 by Simond Link to post Share on other sites More sharing options...
Simond Posted January 31, 2015 Share Posted January 31, 2015 Re sideplay. My advice is do nothing. If you find that it won't go round small radius corners and you need it to, then your plan for slots & springs is the remedy, but I wouldn't start remedial action until you know you have a problem! Best Simon Link to post Share on other sites More sharing options...
RMweb Premium 2ManySpams Posted January 31, 2015 Author RMweb Premium Share Posted January 31, 2015 Chris Are you sure? The CoG should definitely place some weight (say, one third) on the bogie, and the rest split between the drivers, which their compensation will take care of. So my guess is that the CoG should be somewhere about the rear edge of the rear drivers. If it is forward of this, I'd be concerned, as Chaz has mentioned, of poor tracking of the bogie. If it is lots forward of this, see if it will pull a wheelie in reverse! (Possibly whilst pulling a train) The spring won't push the bogie down more than the weight applied to it. HTH Simon At the moment the front two axles are fixed as I've not fitted the compensation beams. Without the rear bogie in place the loco sits on the front two axles. My conclusion was that the CoG was between the two drivers otherwise the loco would have tipped back on its arse. It's not that far forward of the rear driver though. Link to post Share on other sites More sharing options...
N15class Posted January 31, 2015 Share Posted January 31, 2015 With a 0-4-4 you want the cog in front of the rear driver, there will be enough for the bogie pivot spring to push against. simplest way of side control would be two holes fore and aft in the bogie with guitar string either side of the bogie pin. Only fix them at one end, let the other end have some movement, might be a bit of trial and error to get the right wire. I would try something about 0.015" first. Link to post Share on other sites More sharing options...
N15class Posted January 31, 2015 Share Posted January 31, 2015 I see from the pictures which maybe I should of looked at more closely. That the bogie just rotates. It should all work well with out any sidewways movement, as the total wheel base short. 1 Link to post Share on other sites More sharing options...
RMweb Premium 2ManySpams Posted January 31, 2015 Author RMweb Premium Share Posted January 31, 2015 With a 0-4-4 you want the cog in front of the rear driver, there will be enough for the bogie pivot spring to push against. simplest way of side control would be two holes fore and aft in the bogie with guitar string either side of the bogie pin. Only fix them at one end, let the other end have some movement, might be a bit of trial and error to get the right wire. I would try something about 0.015" first. I suspect that's where the loco's CoG is. I'm expecting that when the compensation is added the loco will sit down at the rear and apply weight to the bogie. I did read that lengthy web article Mark posted a link to a few weeks back. I used it to calculate the pivot point for the compensation beams and that should in theory apply a 1/3 of the weight to the bogie. Link to post Share on other sites More sharing options...
mike47j Posted January 31, 2015 Share Posted January 31, 2015 I removed the spring on the bogie on mine. Not only does the spring push the bogie down, but also the body up, so you would have to put more weight on the bogie to stop the rear of the body bouncing. Surely it must be better without it ? Link to post Share on other sites More sharing options...
Simond Posted January 31, 2015 Share Posted January 31, 2015 At the moment the front two axles are fixed as I've not fitted the compensation beams. Without the rear bogie in place the loco sits on the front two axles. My conclusion was that the CoG was between the two drivers otherwise the loco would have tipped back on its arse. rps20150125_174244.jpg It's not that far forward of the rear driver though. Chris, The photo is pretty clear that the CoG is in front of the rear axle, or it would, indeed, sit back on its arse. The compensation beams will only divide the weight between the drivers, not apportion it between drivers and bogie, but as the beam pivot is ahead of the rear axle, I guess it will allow/cause the loco to tip back a bit. But I think it needs more weight aft - I think it probably should tip back if the bogie is removed, otherwise, there's no weight on the bogie (apart from its own weight, of course). The spring will only lift the back of the loco up - which you'd have to correct by adding weight at the back - so same outcome I think. HTH Simon Link to post Share on other sites More sharing options...
RMweb Premium 2ManySpams Posted January 31, 2015 Author RMweb Premium Share Posted January 31, 2015 I see from the pictures which maybe I should of looked at more closely. That the bogie just rotates. It should all work well with out any sidewways movement, as the total wheel base short. I think I'll take the wait and see route on the bogie. Link to post Share on other sites More sharing options...
RMweb Premium 2ManySpams Posted January 31, 2015 Author RMweb Premium Share Posted January 31, 2015 Chris, The photo is pretty clear that the CoG is in front of the rear axle, or it would, indeed, sit back on its arse. The compensation beams will only divide the weight between the drivers, not apportion it between drivers and bogie, but as the beam pivot is ahead of the rear axle, I guess it will allow/cause the loco to tip back a bit. But I think it needs more weight aft - I think it probably should tip back if the bogie is removed, otherwise, there's no weight on the bogie (apart from its own weight, of course). The spring will only lift the back of the loco up - which you'd have to correct by adding weight at the back - so same outcome I think. HTH Simon Not sure I agree with your reasoning Simon. If the CoG is exactly over the compensation beams pivot then in theory the bogie will carry no weight and the weight will be split equally between the drivers. If the CoG is forward of the compensation beam pivot point then the loco body will tip forward and in theory the bogie will be lifted of the track. If the CoG is behind the compensation beam pivot point then a proportion of the weight will be applied to the bogie. The further back the CoG, the more weight will be applied to the bogie. The remaining weight will be split equally between the compensated axles - as long as the pivot is central between the compensated axles. Link to post Share on other sites More sharing options...
RMweb Premium 2ManySpams Posted January 31, 2015 Author RMweb Premium Share Posted January 31, 2015 The following section of the Clag website is worth a read. http://www.clag.org.uk/41-0rev.html#figure64 Link to post Share on other sites More sharing options...
RMweb Gold Stubby47 Posted January 31, 2015 RMweb Gold Share Posted January 31, 2015 (edited) Don"t forget, if you add metal figures as crew they will add weight to the rear, as will real coal. I don't recommend adding real water in the tanks. Edited January 31, 2015 by Stubby47 2 Link to post Share on other sites More sharing options...
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