Has anyone had any experience with the DCC Concepts Power Base for improving adhesion and pick up? They reckon that they have tested a 20cm rise over 50cm although I don't know what they ran.
I need to fit the incline and decline in about 180-200 cm so I'm thinking I ought to be able to try for 10cm rise? Does that sound feasible? Maybe 6-7cm would be more realistic though? I have a Bachmann Hunslet Penryn Quarry (6.7cm length) pulling 3 bug boxes. Part of the incline will be on a curve but not tight, around 50cm radius.
Thank you.
It is the old grade question again!!
In general a 1 in 30 grade is ok.
1 in 25 will be limiting on what you can run.
1 in 20 is too much and will be very restrictive on what you can run.
So to get 10cm in height you realy need 3m of track!
To get 7cm in height you need 2.1m of track.
To get 6cm in height you need 1.8m of track.
If you have 200cm of track you should be able to get 6.6cm of height with a 1 in 30 grade, so this should be ok.
However, I would recommend you test a 1 in 30 grade with the locos and vehicles youu want to use first.
50cm curves should be fine.
The controller you use will not make any difference, the weight on the loco driving wheels is what matters.
There are other factors that will affect what the locos can haul.
Using 'railzip' or graphite on the layout will make the locos slip a lot more on the grades so these needs to be avoided.
Cleaning the track with a fine track rubber can help a tiny amount, but using fluids to clean the track does not help at all.
One point. I think you will find it hard to fix the magnets under the loco because there is so little clearance and space.
Thank you, a helpful point.
I've used the HO/00 version of Powerbase successfully. It works but there are a couple of issues worth considering at the planning stage.
The distance between magnets and the steel plates under the track needs to be as small as possible. In his note above, Alec mentioned the magnets. They do need to be as low as possible, which I have found tricky in 00. As Alec points out, there is even less apace in 009.
Conversely, the plates under the track need to be as high as possible, so really, you have to lay the track directly on top of them. The plates each have a couple of holes in them, but not in very useful places, so you probably need to glue the track down. I found Woodland Scenics Foam Tack worked well for this as it remains flexible after it sets and copes quite well with the non absorbent surfaces. You do need to pre-bend flexible track carefully as you can't use pins to hold it to the right curve. I also used the same glue to hold the plates down to the polystyrene foam I had used to form the gradient.
Plates occasionally need to be trimmed (for turnouts in my case). The metal is soft enough to use tin snips but I found I had to flatten the plates afterwards by squeezing them in a vice.
I hope that's helpful.
Ian
I've not used Powerbase, but looking at the magnets they have for sale and photos of installation I suspect there are things that can be done to improve performance whilst reduce the size of the magnets under a loco.
Reducing the separation is key as Ian says, but shaping the magnetic field should have a significant effect too, maybe a doubling. A magnetic field tries to follow a path of least resistance (Reluctance) so trying to reproduce a horseshoe magnet and keeper plate (or loudspeaker magnet or magnetic door lock or bench magnetic clamp, or indeed an electric motor) type arrangement should help. It might be possible to do this with a pair of strong but very thin magnets separated from each other, one with N pointing down and one with S pointing down and their upper poles connected by an iron or steel shim.
Then the magnetic field lines instead of spilling out of one pole a magnet and finding its way back to the other pole of the same magnet will be channeled largely to the other magnet through the shim. Then the magnetic field at their other poles will look for the easiest path back towards each other which hopefully will be the Powerbase.
In that way it should be possible to have the Powerbase intercept more magnetic field lines and provide a stronger hold. (This approach is, or was at least, permitted as a defensive strategy in some classes or Robot Sumo and the Dohyo constructed of powder coated steel for the purpose. The robots could clamp limpet-like to the doyho, though there is an inactivity timeout and disqualification penalty. - I used to run a competition in another life!)
Coming back to the original post...
QuoteI need to fit the incline and decline in about 180-200 cm so I'm thinking I ought to be able to try for 10cm rise? Does that sound feasible? Maybe 6-7cm would be more realistic though?
Putting that into numbers that I can better understand...
Aiming for a rise of 10 cm would give us figures of 1 in 10 (100cm) or 1 in 9 (90 cm).
Aiming for a rise of 7 cm would give us figures of 1 in 14 (100cm) and 1 in 13 (90 cm).
Aiming for a rise of 6 cm would give us figures of 1 in 17 (100cm and 1 in 15 (90cm).
Looking at the real railways Glofa bank on the Welshpool is 1 in 29 (iirc)...
I doubt a full size Quarry Hunslet would be able to climb a 1 in 9 gradient on it's own, let alone with 3 FR bug boxes in tow.
A Bachmann quarry Hunslet might be able to manage this feat though. Set up a length of straight track propped on blocks at one end to test to loco out, maybe also incorporating a 50 cm (18") curve if you can. If it doesn't work out try lowering the gradient until it does, and once you a 'proven' gradient you can incorporate this into your layout plan.
But to be honest I'd try to avoid anything steeper than 1 in 25 or 1 in 30 it as it may be asking too much of the loco and may not look too realistic.
As to adding something to the loco to increase its adhesion I'd try to avoid that...
An experienced and well known modeller who swore that Roco 0-6-0 chassis were the best thing since sliced bread for his exhibition layout, until he fitted them to etched brass locos bodies he had stuffed so full of lead they were practically solid and were several times the mass of the original Roco plasic bodies. The chassis then wore out very rapidly and he then swore
at them, and at Roco for supplying a (supposedly) 'not of merchantable quality' product, until it was pointed out that his use was not what they had been designed for - particularly with the weight the chassis were being asked to carry!
I can see that adding magnets to the underside of the loco so that it is pulled down towards a steel strip is going to put mechanical strain on the chassis (mainly the bearings) that they have not been designed to take, leading to premature wear and failure - much in the same way as adding lead ballast.
Might I make an alternative suggestion, Elizabeth? Rather than trying to get the height clearance you need to go over one line might it be possible to gain some of that height differential by
lowering the track under the bridge? That would give you more length overall and should reduce the gradients to something more manageable?
Another thought would be to use a diamond crossing (you can get 60 and 90 degree crossings for 9 mm gauge from the US) and have the tracks crossing on the level thus getting rid of the gradients, but then you might have problems with short wheelbase 4 wheel locos and 'dead frogs' in the crossing.
I know that's probably not a definitive answer but I hope it helps...