Crossing stutter

[Romeo]

Chris,

the crossing runs well when I run my tornado even at very low speed, unfortunately when I run my Panier tank again at low speed it stutters at the same point every time on one line only, if I swap to the other line it works fine, I have inspected the track in fine detail and all is well, any suggestions would be gratefully appreciated 

R

[Chrissaf]

Romeo, More likely an issue with the loco than the track. Check the 'back to back' wheel measurements. Look for good pickup wiper contact on the back of the wheels. If the Panier is an 0-6-0 then it could be susceptible to track not being perfectly flat, particularly at the joints with the adjacent track pieces i.e any ridges between connecting rails (a finger run along the tops of the rails is the best way to detect any irregularities). A pickup wheel lifting clear, if they have no vertical play in the axle. With power off, place the straight edge of a metal ruler along the tops of the rails, see if there are any high or low spots. Give the Panier wheels a really good clean.

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If the crossing is pinned down with track pins, then maybe easing them off a little might help. I had a couple of points where I was perhaps a bit over zealous nailing them down. Loosening off the pins solved one point that had a derailment issue with certain passenger coaches.

[Romeo]

Thanks Chris For the ideas will be on it later , fingers crossed

[2e0dtoeric]

Tornado has lots of wheel pick-ups, a Pannier (or any other tank engine) only has a couple. If one doesn't make good contact (or the wheel is dirty) and the other one is resting on a plastic frog, no power will get to the motor.

Some of the bigger loco's have pickups on the driving wheels AND the tender wheels.

[Romeo]

Gents,

All track joints are smooth and flat, track pins removed and levels check all fine there, done a volt check and no drop, all cleaned as well as the loco wheels, inspected the pick ups and they are fine as well. I can now run the loco at very low speed and get it to stop on the crossing, if I gently push it side ways it starts of, I suspect it is the wheel width as there seems play in the axel, I no there should be play but not sure how much. If I run the tornado as slow as possible, ie on step it has no issue, so I am wondering if there is any thing I can do with the pannier, it is a really smoth runner now it's run in apart from this lit.tle issue 

R. 

[Chrissaf]

Romeo, last outstanding thing to check, particularly as you said pushing the side of the loco got it going again, is to check the 'back to back' wheel measurements are 14.4 +/- 0.05mm. They might be too close together on an axle that has pickup wheels on them. Being a bit further apart would limit the sideways play. This is going the be difficuult to do with a ruler, ideally you need a gauge or a digital vernier. Examples of which are below:

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Gauge

Digital Vernier

[Romeo]

Hi Chriss

Vernier aquired, and as suspected the wheel sets are all different, rears are 14.2, Middle 14.3, fronts 14.1 so the need to be widened slightly to take out the slack, 

is there a specific way to do this or a tool required, I think a future plan is to check all running stock and adjust as required so a tool would be of good value. 

Cheers for now

R

[Chrissaf]

Romeo, The wheels will typically be tight friction fits on the axles. I think you will have to work out for yourself what is going the be the best way to ease the wheels apart on the axle. Be extra careful not to damage the pickups. You might be able to get a flat bladed screwdriver between the back of the wheel and the chassis and twist the screwdriver blade to apply gentle force. Ideally, the force is best applied at the hub of the wheel rather than its rim. Applying pressure at the rim is less effective and might even result with the wheel ending off true (i.e a resultant wobble). I would also suggest packing out the gap on the other wheel (the one not being adjusted) between the wheel and the chassis so that you have something for the wheel being adjusted to push against. 0.1 to 0.4mm is a very small adjustment needed. So take it easy and keep checking measurements as you go, as you may not even see any movement visibly with your eyes, but the Vernier will show it up.

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In an ideal world, I would go for the brass gauge and then push that in between the wheels. The adjustment forces will be more evenly spread across both wheels simultaneously, as with the gauge you are effectively pushing one wheel equally relative to the other.

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I would expect other's here may disagree with my suggestions, so if you feel that someone else's suggested method is better, then follow that instead.

[RB51]

As Chris has said it Romeo is exactly what I do. I use the Vernier to check and then the brass gauge to move the wheels apart. Gently Bentley is the key. R-

[2e0dtoeric]

It might be easier to GENTLY bend the spring wiper a little so it presses more firmly against the wheel back, rather than try to move a wheel 0.2 of a millimeter sideways!

The clue was - press the loco sideways, and it goes - suggesting the wiper is losing contact.

[Chrissaf]

Just to add, using the brass gauge as the adjustment leverage means that you don't over do it and then end up with the wheels going the other way and being too far apart.

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Before making any adjustment to the wheels. Try looking at the wipers and see if you can see them moving away from the wheels as you move them from side to side (based on 2e0 comment). It could be a wiper issue, or it could be that the slight narrowing between the wheels is just enough for the wheel rim taper on a particular pick up wheel to give a tiny air gap between the wheel rim and rail, loosing electrical continuity.

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I tried adjusting a wiper once with them still in situ and made a complete pigs ear of it. Ended up having to fit completely new wipers. This was on a 0-6-0 loco too.

[Romeo]

Gents

i had ordered a brass gauge so will wait for that to arrive,  it means all my stock will all be the same,  I have assess the contacts and even with the side to side movement they hold a good contact visually, I no that's visual to electrical is quite different, but trying to test the resistance between the contact and wheel would be at best a very rough measurement, 

Thanks for all the info and fingers I resolve the issue 

R

[96RAF]

I use those micro 'toilet brushes' used for flossing your teeth to clean grot out from between my wheel backs and pickup wipers. They can also be used to tease bent wipers back into shape, else it down to carefull use of long pointed tweezers.

[Romeo]

Hi Chris, yes me again, I have not posted for a while as I felt I was asking the daft questions, so have solider on, I thought I would let you no I still have the crossing issue, I bought a very nice ddc with sound Deisil shunter hour hornby one  , same wheel base as the pannier tank, give or take a bit, at very low speed which it runs so well and sounds great, when it is going across the crossing it stutters, with sound it makes it worse, what I noticed Is that as the front wheels cross the isulated joint the back set are in the plastic frog section, leaving only the middle wheels as pick ups, checked the internal wheel gap and no where near the correct distance, so I am now going to have to disassemble which I'm not to happy about and reset the wheels, any advice before I attempt the daunting practise 

• R

 

[walkingthedog]

If it's new return it.  

[Chrissaf]

Can't remember if it was in one of your threads or not, but somewhere I posted that my Hornby Shunter R2902XS had pickup issues. It was this particular shunter that made me develop the crossing frog mod in the first place. As you say stuttering at low speed, and cutting out if the 'sound' was on. It was out of warranty and I sent it away to Peter's Spares where new pickups and wheels were fitted. It's not perfect, but now runs 100% better than it did before.

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The pickup assembly is very delicate and difficult to remove, as are the wheels. The motor has to be removed to get the wheels out. I got as far as removing the body, then decided to put it back together and send it off once I realised what was involved in taking it apart.

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Just to be clear, I sent mine off because the pickups were damaged. My back to back wheel measurements were OK. If in your case it is just 'back to back' wheel adjustment you want to do, then I would try and do that with wheels in situ. Just be very careful to avoid touching the pickups.

[Fishmanoz]

Agree with WTD, return under warranty and let someone who knows what they are doing fix the back-to-back for you, then see if it has improved. 

[RDS]

... as I felt I was asking the daft questions ...

 

 

Please, don't ever think you are asking daft questions.  If you want to ask a question, feel free to do so.  

The forum is here to help us all.  There is no such thing as a daft question, if you don't know the answer.

[Romeo]

Gentlemen, as always thanks for the fast response, it is brand new, and considering the cost, I will take the route of taking it back to the retailer and seeing what the next option is, I have to go there as I need some supplies, so two birds and one stone springs to mind, I decided to check my other stock and there seems to be no consistent size, whT ever happen to quality checks during manufacture process, i will post  what resolution happens, in the mean time many thanks for your support. 

R

[Romeo]

Gents, I have been back to the shop and he reset the wheels to the required size, unfortunately there is no change, I have now replaced the four lengths of track, so all new solder joints, replaced the plastic  joints as well as new metal ones, I have ensured the rails are flush and there is no step from rail to rail, and it still stutters, when I run , it seems as if the loco is twisting when it runs through the plastic middle section of the crossing, I am tempted to buy another crossing thinking the one I have used is faulty. It's getting to the point where I'm thinking of also removing it completely and re routing some how so I don't need it, which would be a shame, when I say twisting I mean it's as if it's guiding the wheels a little to much if that makes sense, if I could video it and post I would 

R

[Romeo]

Gents, I had a conversation with a fellow modeller, and I related the issue i was having and he stopped mid sentence and told me he has had the same issue, with the plastic crossing and the wheel lenght off the shunted, he has told me I can fit a unit( capacitor style) that takes care of the issue, thought I would ask if anyone else has heard or even used one and where they are available from

R. 

[Chrissaf]

The product you are trying to describe is called a 'Stay Alive' also sometimes referred to as a 'Keep Alive'. The better quality ones are designed around the use of 'Super Capacitors'. The issue with Super Capacitors is that individually they have a voltage limitation typically around 5 volts max. This means that they have to be built as a series circuit to build up the voltage to 15 volts or more. These 'Stay Alives' are usually therefore best purchased as a ready made product.

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The other issue is how they are fitted. They have to go across the output of the bridge rectifier that supplies the DC voltage / current to the decoder chip on the decoder circuit board. Some DCC decoders are designed from the outset to be 'Stay/Keep Alive' compatible and will have specific connection points built in (TCS decoder products for example).

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Your shunter is a Hornby XS sound model, thus it will have a Loksound decoder in it. Almost certainly a version 3.5 decoder. Google "fitting stay alive to a Loksound 3.5" it can be done but needs skill and a delicate hand, bearing in mind that the decoder is worth about £80 to replace. To fit a 'Stay/Keep Alive' to a Loksound 3.5 decoder requires locating the bridge rectifier on the PCB, identifying the DC output of same and soldering wires from the capacitor onto it. You might also need to include an easy way of disconnecting the capacitor as it is rumoured that the presence of the capacitor may affect the ability to read and write to the decoder CVs.

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The primary issue is space. The Hornby XS shunter already has virtually all the space taken up inside with the motor, the Loksound decoder and the speaker. The 'Stay/Keep Alive' capacitors are fairly large. The Hornby XS shunter is very unlikely to have the space inside to accommodate one.

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I did research this topic to resolve stuttering with my own Hornby XS shunter model and came to the conclusion that it wasn't viable.

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There are companies offering to fit 'Stay/Keep Alives' for you on a commission basis. I would assume that they would only undertake such a commission on something that they think is actually doable. It would be worthwhile seeking their advice, specifying your particular model number.

[john_doman]

Gents, I have been back to the shop and he reset the wheels to the required size, unfortunately there is no change, I have now replaced the four lengths of track, so all new solder joints, replaced the plastic  joints as well as new metal ones, I have ensured the rails are flush and there is no step from rail to rail, and it still stutters, when I run , it seems as if the loco is twisting when it runs through the plastic middle section of the crossing, I am tempted to buy another crossing thinking the one I have used is faulty. It's getting to the point where I'm thinking of also removing it completely and re routing some how so I don't need it, which would be a shame, when I say twisting I mean it's as if it's guiding the wheels a little to much if that makes sense, if I could video it and post I would 

R

 

[Romeo]

Cheers for the heads up Chris, I need to make some dessions as to next steps but, if it's like this now on my first one then maybe a different approach is needed when buying stock, as always many thanks for a great explanation and your valuable help

R

[Chrissaf]

Romeo, have a look at the recent thread titled "0-4-0 Sentinel" in the General Section - start at page 2 of the thread, similar issue. One solution was to add a permanent wagon with extra pickups.

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When you remove the bottom cover of the Hornby XS shunter the existing pickup connection point is readily visible and gives a convenient easy position where additional pickup wires could be soldered to route back to an external wagon with supplementary pickups.

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Not ideal I know, but is doable and provides the reliability you are looking for. Shouldn't look too much out of place if the right style of wagon is chosen. Plenty of after market pickup kits are available to convert a wagon. The hardest thing would be finding a miniature two pin connector, but they are available. i.e to make wagon removable.

 

If you did decide to do this mod, then just be extra careful to keep the wagon pickups wired to the same side as the loco pickups. If they become reversed, then you create a 'short'. A 'keyed' miniature connector would alleviate that happening.