Hornby loco running problems.

On Sat, 01 Jan 2005 13:29:37 GMT, "Andy Howes" I happen to have a couple of old Relco units. Would fitting these to the

Never used Relco units. I understand they don't actually clean the track, but ionise the dirt instead.

Assuming a) the wheels/pickups and track are clean, and b) you are using electrofrogs; the problem is not power pickup as such.

Most likely IMO, the problem will be the incompatibility between wheel standards and turnout specs, and/or traction tires. Older Hornby locos have, um, weird wheels, which rarely work well on other mfr's turnouts. (Hornby's wheel standards are much better these days, so a newer Hornby loco will have no troubles on Peco track.) Eg, deep flanges may lift the wheel above the rail at the frog, thus interrupting contact.

Also, Hornby's traction tires are poorly fitted in my experience, not sitting flush with the tread as they should. This means that slight tipping of the loco lengthwise can occur, raising a pickup wheel off the track, which interferes with power pickup.

Other people with more experience with Hornby than I will no doubt have other useful suggestions.

It's unfortunately the case that old trains do not work as well as the more recent products. This problem exists everywhere, but nowhere more so than in England and Germany, where each mfr insisted in doing their thing with no thought of compatibility. As once-dominant firms such as Marklin and Hornby lose market share, they are revising their antipathy to compatible standards, which is a good thing for us.

HTH&GL

Andy Howes wrote:-

Setrack uses insulated frogs for its turnouts. Substituting Code 100 Streamline points with electrofrogs will cure that problem but create others (with DCC for instance).

That won't solve the dead frog problem.

(kim)

He says he is using Peco "set track" which is all insul frog.

Mark Thornton

I'm intrigued by this issue of electrofrogs being problematic with DCC. Over the last few weeks I have been building a small dockside type layout in OO, using peco code 100 trackwork with Electrofrog points.This is my first dabble with DCC, using the simple Bachmann starter set to get a feel for the basic system. Motive power is currently limited to the 2 locomotives supplied in the Bachmann set, ie, Thomas and Percy in different colours. I went for electrofrog points for all the usual and obvious reasons, though the chap who served me at the model shop was adamant that electrofrog points wouldn't work with DCC. The layout is now up and running (though plenty to do n the scenic front), but am I missing something with this electrofrog/DCC argument? No-one's actually explained to me the nature of the problem, and I've yet to encounter any issues for myself. Cheers, Bill.

Mark Thornton wrote: [...]

Ok, thanks, I'll try to remember.

As a fellow 'intriguee', the best explanation I have had is that DCC cuts out much quicker than our average analogue controllers. Any touching of wheel backs on the centered point blade with DCC will cause a short (dependant on wiring configuration) which instantly cuts all power to the track and stops operation. Analogue cut-outs allow somewhat longer periods of intermittent shorting.

Regards, Greg.P.

Phil: Picking up on Greg's explanation...(to expand on it a bit) With electrofrogs, as supplied by Peco, BOTH switch rails are connected to a/ the frog (the good bit) but also b/ to each other therefore (the bad bit). The RISK is that, PARTICULARLY WITH OLDER WHEELED STOCK ('coarser wheels', as found on Hornby until recently), the chances are that a (wide) loco wheel could touch the switch rail that is not in contact with the running rail, with its flange, whilst still in contact with its own running rail - hence a short circuit. Modern DCC controllers have a 'high' current capability of 3 to 5 Amps* without dropping voltage (ie they have a low source impedance) - and therefore they can supply about 50Watts into the short circuit. (They are designed to supply MULTIPLE locomotives) An OLD resistance style individual dc controller, or a sets controller, might provide only a maximum of 1 AMP or less before being limited by voltage drop or cutout. Of course there are examples of modern dc controller which can supply more than 1 amp - but the chances are that you are not crossing the pointwork at full speed, and therefore the full voltage (and max current) is not therefore possible.

Also more modern stock, is less likely to touch the switch rail. BUT more modern stock now has metal wheels, which were previously plastic....and this becomes more of a potential problem when they are interconnected as a means of lighting coaches etc. Southern Region also occasionally have problems with collector shoes bridging gaps - such is real life.

When Airfix's MTC came out, they advocated varnsishing the narrow insulation area of Peco insulfrog points. By comparison, Bachmann, Hornby and Fleischmann points have a larger insulated area than Peco insulfrogs (not sure about their set track types) so that shorting at the frog is not a problem with any type of wheel.

"Phil" wrote

I don't have plastic wheels on *any* of my stock and run it all on un-modified Peco Electrofrog points using DCC control. The crucial aspect is that the wheels confirm to something like NMRA standards and are set to the correct back-to-back measurement.

The only item of stock which causes (that should really be caused) problems is a recent Hornby class 110 dmu. Here it was difficult to set the b-t-b of the driven wheelsets wide enough because they can then lose contact with the driving gears.

John.

The main problem is that with DCC all tracks are live. So you could get a circumstance where the crossing or frog is fed with both polarities and a short would result. So the best advice is insulate the frog connections and feed from the toe of the points only.

Chris

I've had this problem too. A thin washer placed behind the non-geared wheel usually fixes it!

(ab)

Phil: My solution has been to replace them with Ultrascale wheelsets - so as to gain the improvement in back to back of modern wheelsets. (That now just leaves me with 2 schools and 2 M7s with old standard wheelsets, and 3 other old tender drive locos))

Actually Diamond crossings in Live frog (a more accurate term, and avoiding trade names which imply a particular manufacturer who DOESN't have a world monopoloy, as much as they would like it) must be the biggest pain - no point motor necessarilly associated with them directly to provide a ncessary external switching of the frog according to which route is being used.

Hence 'dead frog, non switching/isolating points' is the easier option for dcc (eg Fleischmann with the wire clips left in), or Fleischmann with the wire clips removed for dc (where the point is being used to route power INTO a siding or station platform - the 'power' being applied to the the 'route' between places, and being the equivalent of the 'token'/staff. Just choose a good design (eg also Roco) that minimises the dead frog area and meets your wheel standards.

This posibility has nothing to do with DCC, just basic 2-rail wiring logic. Exactly the same will happen with DC if you don't allow appropriate insulated joints. You need to draw a plan of the propossed layout, colour one rail red, the other black and frogs green. Ensure you put insulated joints wherever different colours meet and between frogs belonging to different points. Keith Make friends in the hobby. Visit Garratt photos for the big steam lovers.

How is that different from DC? It seems to me that DCC wiring is simpler than DC.

Guy

In most track formations there will be points 'associated' with the diamond, a double junction being the obvious example. Isolated diamonds are very rare in UK practice. It just requires an extra contact or two on the levers or point motors.

I do agree that dead frogs make life a lot easier if you can live with them. For those of us building our own track and expecting it to appear prototypical its not so easy. I have not been able to build dead frogs that meet the above criteria and can be crossed by short wheelbase steam engines. Its easier if Bo-Bo diesels are your smallest locos but you can still be caught out by consecutive frogs in complex formations such as scissors crossovers and double junctions. For example Keith

Keith

Make friends in the hobby. Visit Garratt photos for the big steam lovers.

"ab" wrote

Agreed but it also makes the thing run slightly lop-sided.

John.

But on DC operations sections tend to be isolated via switching and this situation is less likely to occur.

Chris

Think it through. You have to take the same precautions to avoid connections betwen the two rails, unless you want to get random shorts depending on which sections you happen to have turned on.

Why do you want to describe normal 2-rail wiring features as 'DCC problems'? It doesn't help anyones understanding. Keith

Make friends in the hobby. Visit Garratt photos for the big steam lovers.

The major changes involved are higher available current and instant cut-out with DCC as compared to analogue control.

Regards, Greg.P.