I bought some "Liquid Gravity" at the Wakefield show (other weights and model railway shows are available :) )
And then I went and bought a set of "pocket scales"
So.. I've weighed my loco fleet - well most of them. The lightest was 30 grams (!) and the next two were both 34gm.
I have embarked on a body-building programme for the lightweights. The idea is to get them all to be over 40gm at the very least. The lightest one now weighs in at 45gm.
Good idea, Hugh. You will find a heavy loco will run far better than a light one, apart from the hauling power. I think that is caused by an improved wheel/rail contact and more 'bulk' so it will bounce on the track far less. My locos are bigger than yours and I make them quite heavy, from 70g (for a pugbash) to about 200g for the Garratt. A big tank engine like 'Atlantic' or 'E.R.Calthrop' will weigh about 150g.
I have to watch against over-doing it - the requirement is that it will have to slip comfortably without straining the motor. Probably you won't run into that in a small loco.
The important point to bar in mind is that it is not just the weight alone that matters. All weight must be balanced around the driving wheels as equally as possible. But, yes, heavy locos (usually) run much better than lightweights.
Rod
Rod is correct balance on the driving wheels is vital.
I weight all my locos as much as possible. I use old stick on car wheel balance weights that I shape in a vice and cut to size as required. I make everything from tiny thin sheets and blocks to go in the smallest places to toolboxes, complete buffer beams and even boiler fittings. It all depends on the loco as to what is required.
But balancing the weight evenly on the driving wheels is the most important thing. I will always sacrifice overall weight to get the balance correct.
Brian Meldon
Quote from: rod335 on December 09, 2013, 06:40
The important point to bar in mind is that it is not just the weight alone that matters. All weight must be balanced around the driving wheels as equally as possible. But, yes, heavy locos (usually) run much better than lightweights.
Rod
Agreed absolutely Rod. Way back in about 1989 I built a crude balance for checking 4-coupled locos using air gun pellets to ascertain the amount of ballast I needed, and where. I constructed it when I was building 'Cackler'.
6-coupled locos were done in an even cruder way - a level piece of track and see how it overbalances with just the centre wheels and one axle on a length of track, turn round, do it again and compare. Crude but effective.
(Short pause to get some new glue...)
Right - lightest loco is now 41 gm. I don't think I can get it any heavier.
And yes, I am aware of balance. I have still to sort out my Cackler.... (ooh er missus)
Hugh
With Cackler, I'm sure you've done it already anyway but the first course of action, even though it reduces the weight in the short term, is to replace the cast cab roof with either plasticard or nickle silver/brass. This should get rid of the worst of the 'tail-heaviness' which I'm sure you will have at present. The thin edges will also look MUCH better.
Rod
Cast cab roofs, and even bunkers, on whitemetal kits are the usual source of balance trouble. Most 009 locos will be tail heavy if not adapted. You'd need to put at least a third of the weight on the front wheels, and preferably more if the kit body allows.
Quote from: rod335 on December 09, 2013, 17:02
Hugh
With Cackler, I'm sure you've done it already anyway but the first course of action, even though it reduces the weight in the short term, is to replace the cast cab roof with either plasticard or nickle silver/brass. This should get rid of the worst of the 'tail-heaviness' which I'm sure you will have at present. The thin edges will also look MUCH better.
Rod
Yes indeed Rod.
I use tin, rather than nickel silver, brass or plasticard. It can be cut with scissors, it easy to bend into shape, it can be soldered and is easy to get, often for free with biscuits or sweets in at Christmas!
Brian Meldon
While lead is okay for weighting locos depleted uranium is much better - apparently it's two-thirds heavier than lead - but it can be difficult to get hold of, I believe (unless you happen to be in Iraq where I think it can be found just lying around on the ground if you know where to look :o)
David.
And have your loco glow in the dark? ;D
Well... they won't glow in the dark, but being an alpha-emitter even though it's depleted, it still presents a hazard if swallowed or breathed in. Depleted doesn't mean it's any less nasty - just that it won't go bang when put together in large amounts...
As a 'more dense than lead' and 'less toxic than depleted uranium' (and probably the lead too) tungsten is pretty good, especially if you have a big pot of some of the metal in a granular form...
Quote from: JulienW on December 12, 2013, 15:16
As a 'more dense than lead' and 'less toxic than depleted uranium' (and probably the lead too) tungsten is pretty good, especially if you have a big pot of some of the metal in a granular form...
I think that is what 'Liquid Gravity' is made of.
That's very likely, given tungsten's high density and (as far as I know) low toxicity, and being fairly inert the tungsten shouldn't react with PVA in the same way as lead.
Mine was obtained when the lab I worked in closed down (and yes, I did ask if I could have it!), and to give people an idea my 5kg pot is about the same size as a 100g coffee jar.