Good day all,

I want a scale length, 8 coaches plus 2 power cars, FGW HST. I anticipated that this might be too long for the power car to push on return journeys, thus, clever dick that I am I bought 2 sets, using a power car at each end. Reversing the pickups to one car was a challenge to my arthritic old hands and failing eyesight, but I got away with it. Now to the problem. One power car, the modified one, runs faster than the unmodified one. This results in the train pulling apart when the faster car leads, or derailing in the centre when the faster car is at the rear.

I do not wish to go down the route of DCC; therefore, can anyone suggest how I can slow the faster car down? Resistor or something? Please bear in mind that my electronic knowledge is almost non existent.

As an aside, does anyone run a HST with 8 coaches and only one power car? Does it work in both directions; have I tried to be too clever?

Thanks,

John T

My  Dapol  works   with   5   coaches,  runs    beautifully in  both   directions

why did you have to reverse the pickups,  they both should be going the same direction straight out the box?

i've done a power car at both ends of mine (2nd generation poole chassis), all i achieved was more derailments on return curve to the fiddle yard.  Works much better with only one power car with 2+8 on my layout.  1st generation single motor boggie ones might struggle hence that why they had  2 of them in a set.

my 3rd generation bach/far ic exec set are infinately quieter in operation than the ic 125 orginals.

Apparently Graham Farish tried this when they first brought the HST out, with much the same results The coaches are just too light for this to work in our scale, hence why all HST sets since have been sold with only one motorised unit.

Truth is a single power car should easily be able to push/pull 8 coaches and a dummy PC - both my Farish (China) set and my Dapol one will achieve scale speeds of 110 with 8 coaches on - not quite 125 but it's hard to tell the difference 


Paul

I have a 2+8.

When it was the usual with one powered and one dummy it ran really well pushing or pulling, incuding 1:30 gradients. Only issue was flickering lights on the dummy.

In acquiring more coaches i ended up with two power cars. I now run it with two power cars and the lights don't flicker.

I did not reverse any pick ups as each end should run the same direction whichever way it is facing.

If i run the two separately, one is faster. But when i run them together i don't get any uncoupling or derailing in either direction.  So i am not sure of the cause of your problems, unless your curves are tight.

Hope this helps.
Mark.

I have a full Bachmann Farish FGW HST rake with interiors (and sound). One power car and it handles my grades ok. I need to redo the sound though and put something much louder in for the speaker set up so I can get a proper HST feel.

Alan

Thanks for your comments. Seems that I have complicated life. 

At least I can now build 2 trains, not my original intention as I only wanted to set one up so that my Grandchildren could see something which they associate as a 'train'. I am late steam early diesel BR WR. Pity that Dapol have not made any more FGW HST, need some more of Adam's graphics.

I reversed the contacts because the trains ran in different directions, perhaps they had been set up differently at the factory?

John T

I've run Farish single powercars with a full set before no problem. So sounds like using a sledgehammer to crack a nut. But will depend on how severe your gradients are and how tight any curves on them are.

You should not have needed to reverse the pickups on one unless someone has previously been at it and reassembled it wrong. And even if the pickups were the wrong way about you could just reverse the magnet to change the direct it runs.

They should run pretty similarly if they are identical, so if they don't one or both probably needs overhauled and checked.

I suspect once this is done you should have less problems, although I'd have tried one set first and seen if there was enough power to get over your trackwork before buying a second.

But then again if you find one's enough then you've got 2 HSTs.... 

Cheers,
Alan

as said you should be able to run one power car and 8coaches + a dummy with out any issues. unless you have steep grades i do not see the point in running two power cars.

Hi,I run two hst's sets,these being in 2+8 rakes.Both my hst's are Dapol blue/grey models and can handle these full length trains with ease.
I also have gradients on my layout and they handle these with equal ease whether they are pushing or pulling.
Unfortunately for me though,I have one rake with all Dapol mk3's and a farish TRFM and a farish mk3 with Electra graphics TGS vinyl overlays and an equally split Dapol/Farish rake of mk3's.The Dapol coaches are absolutely fine,but the farish ones are too light and need additional weight added due to their propensity to derail quite often.Although this situation will cease once Dapol release another batch of Inter City 125 mk3 TSO's and TFO's as well as the RFM and TGS's.

Pete

have you considered something along these lines, fitting a variable resitor to the live feed to the second cars motor you can then adjust it to match the speed quite easily ?

Not sure if this is the exact one you would need, but food for thought maybe

http://www.ebay.co.uk/itm/5-x-10K-Ohm-Thumb-Adjust-Variable-Resistor-Potentiometer-Preset-Trimmmer-Pot-/290664304286?pt=UK_BOI_Electrical_Components_Supplies_ET&hash=item43acf14e9e

When I first bought my Dapol HST I tested it with the rake I had for it (2+6 as no buffet/TGS) plus the 6 loco hauled Mk3 coaches I used to run as a shortened WCML rake, effectively running the HST as a 2+12. I found it ran more reliably when pushed than pulled, the saggy couplings on the coaches and resultant difference in heights meant the train uncoupled all over the place when pulled; when pushed on that layouts 1:60 gradients there was not a single problem. The only HST where two motorised power cars is needed is the old old Farish one with the single motor bogie!

To prevent uncoupling in use, you could try using more rigid couplers. The Dapol "dummy" knuckle couplers should work well for this as they are designed for fixed rakes where uncoupling in use is not required. They are less prone to uncoupling and work better for propelling too.

Quote from: Karhedron on September 21, 2012, 12:44:48 PM
The Dapol "dummy" knuckle couplers should work well for this as they are designed for fixed rakes where uncoupling in use is not required.

In theory, but in practice not with the HST as the coupler heights are all mismatched (in particular the power cars are different height to the coaches).

Regards,
Alan

Quote from: Karhedron on September 21, 2012, 12:44:48 PM
To prevent uncoupling in use, you could try using more rigid couplers. The Dapol "dummy" knuckle couplers should work well for this as they are designed for fixed rakes where uncoupling in use is not required. They are less prone to uncoupling and work better for propelling too.

They are far less rigid than you think, they allow a considerable degree of lateral pivoting about the knuckle-knuckle interface which actually reduces the effective operation of the close coupling mechanism. The Rapidos are far more suitable for coupling CCM equipped models as the square blocky shape of the couplers themselves prevent much pivoting between the couplers and force the CCM to do its job more effectively. The only way to improve on the CCM performance over the Rapidos is to use a rigid bar, any form of knuckle (Dapol/MT/Unimate etc) inherantly allows too much movement.

For info though, I did test running the 2+12 rake with knuckles and I experienced derailments when propelling due to corridors contacting on curves below 13" radius and when being pulled the uncoupling issue persisted due to the mismatched NEM pocket heights.