Trofimow

Before my time.

Obviously I missed out on some fun...

A featured gimmick perhaps....

3 minutes ago, cctransuk said:

 

Given the currents that are being talked about with DCC, I would have thought that a direct electrical connection between plunger and lead - ie. bypassing the spring - would be essential.

 

CJI.

That is standard practice in analogue applications such as brushes for automotive alternators or high power electric tools. The currents involved may be higher, but the principle is similar.

14 minutes ago, stevemmm said:

It is disturbing that DCC systems like NCE can produce 7.5 amps with 14 volts on the track at any time, even with intermediate circuit breakers or suppressors this can be reduced to 2.5amps, this is still enough to anneal tiny plunger springs in the event of a derailment or running into points set incorrectly. In my 10 years experience with DCC in a club with 300 members on a OO 14m x 7m layout with 300m of track specializing in prototypical operation and shunting, it seems most models can stand the punishment DCC gives except for the 15xx.

Which is similar to my experience, but gives pause for thought. My  points, of which there are lots, all use autofrogs, which need an instantaneous short to work. I wonder if running over a succession of these on a points ladder could have an effect on the springs. The pickups didn't last very long on my layout.

Respect to anybody who takes on the task of doing this mod to make the loco run properly.

It's a real shame that what is otherwise such an excellent model requires such input. One has to wonder why it was felt necessary to use a pick up design so far removed from proven practice, and how extensively it was tested to prove the reliability of the implementation.

Provided it was mounted above the lighting gallows and end plates, it would not be a problem to the Industrial branch operator, but it would be more to transport, set up and break down, and there's plenty of that already.

They are 3D printed and the material can be a bit brittle. Fine in normal use, but probably not best suited to repeated plugging and unplugging.

9 hours ago, Butler Henderson said:

Some dcc systems can put out higher than normal voltages. That  can be capped by using a different power supply or using a string of bi-directional diodes in one leg of the track connection so is it a case of handling upto x volts is okay but beyond that is where failures occur? Or  are the dcc systems in question capable of puttiung out a current beyond that the springs can cope with in the event of a momentailly short before the dcc system trips?

At the time I was having repeated failures of the pickups, my Lenz DCC system was only delivering 12.4V at the rail, and the layout instrumentation was not showing any greater than normal current draw, so I don't think DCC vs DC is an issue.

I've also had this happen. I use malware bytes and not McAfee. A scan came up clean.

19 minutes ago, cctransuk said:

 

I know that it shouldn't be necessary but - have you thought of sourcing some more effective springs?

 

CJI.

I concluded that the only way to make mine behave satisfactorily would be to retro fit wiper pickups. Something I was not prepared to faff about doing to an expensive new model, so it went back for a refund.

IMHO those plunger pickups as fitted will never be satisfactory. I just hope that Rapido will not use the design on any future models.

What a fascinating and informative thread - which goes a long way to explaining the performance issues I have been seeing with some locos and why my sole stay alive fitted loco behaves strangely. RM Web at its best.

I run Lenz with 10 amps available power, normal load is around 7.5 amps.

The system is fed from Lenz TR 150 transformers which provide 15 volts into the command station and booster.

I am seeing 13.8 volts out of the command station, even after maxing out the voltage adjustment CVs.

By the time it has gone through the PSX breakers and LDT occupancy detectors, there is only 12.4 volts at the rail.

The loco recoder will reduce the voltage available at the motor even further.

Measurement is done with a RRAmmeter, Alpha meter and my digital multimeter, which all agree.

Looks like I need to replace the Lenz transformers with something providing a minimum of 18 volts.

Must check what the spec is for the maximum input voltage to the command station and booster.

On 18/01/2024 at 15:24, Nick C said:

Made possible by enthusiasts yes, but still doing a normal job, running a scheduled PolRegio service. I think you're right about only having the one loco at the moment though, and they're also getting short of qualified crews.

I understand that The Wolsztyn depot have not applied to renew the PolRegio contract when the current period expires.

The PT47 is now below 1000 Kms left on the tyres and no new blanks are available.

I guess I may be a little unusual in that I have a large layout designed for intensive operation and I DO require my locos to work reliably for their keep . It does very quickly reveal any shortcomings.

Quite so. The pt47 is the only remaining loco in ticket, and only has around 1200 k remaining tyre wear and various other mechanical issues. There's a small shunting loco, but nothing else in the pipeline to take over the regular services as far as I am aware.

56 minutes ago, rapidoandy said:

We have no ‘standard’ pickup method (these things that modellers believe are often a fallacy) we look at things on a case by case method depending on a large number of factors.

 

Always  remember the golden rule of the internet - a far greater percentage of negativity will be posted rather than positivity. Whilst there will always be problems that we will help resolve - it’s not as dire as many people posting in threads will have you believe.
 

 

PM sent.

This was my only Rapido locomotive purchase.

As a matter of interest is the plunger pickup their standard system or is it unique to this model?

23 minutes ago, cctransuk said:

 

My experience of plunger pickups is that they jam - I won't touch them with the proverbial disinfected bargepole!

 

CJI.

Quite.

Do I vaguely remember 14xx models back in the 80's having similar troubles?

The 15xx saga finally staggers to a conclusion.

It came back this week from its second warranty trip to Rapido, having had some of its pickups replaced.

Eureka - all was good - for about 15 minutes, until the erratic running and stalling returned.

Inspection revealed that two of the pickup pins on one side had retracted with the sideplay as the loco rounded a curve and had remained retracted, leaving only one pickup working on that side of the loco.

That's three times this loco has been "rectified" under warranty, once by the retailer, and twice by Rapido, and it's no better.

Enough is enough, it's on its way back to the retailer for a refund.

They have been excellent about it and very understanding considering it's not their fault.

Kudos to Rails of Sheffield.

10 hours ago, Kaput said:

 

Don't suppose you have any pictures?

Since you ask...

I'm afraid I didn't take a "before" picture.

Here's an "after" pic - the left hand bogie had the problem, but now all wheels of both bogies are properly on the surface, and the loco actually runs as it should.

The shim is an offcut of DCC Concepts Powerbase plate glued to the underside of the chassis below the side bearer.

Yes, it's crude, it's addressing the symptom rather than the cause,  but it's simple and it works.

I bought two of these, both very nice models.

The first one runs perfectly out of the box, smooth, quiet and powerful.

The second one, oh dear - it just won't stay on the track.

Standing the model on a mirror reveals the warping problem mentioned by  others. One bogie has the innermost and centre  wheel on one side clear of  the surface.

It's not much of a gap, but enough to cause trouble.

I dismantled the model  to investigate, and I'm not convinced that the fault actually lies with the bogie. Removed from the loco it seems OK.

Something is clearly out of true and I suspect that the error is with the chassis casting, either a  minute distortion lengthwise or the cast bogie pivot pin not being true.

Whatever, I superglued a metal shim to the underside of  the chassis where it rests on  the bogie side bearer. This places the full weight squarely onto the bogie as it should be and all wheels now sit firmly on the mirror.

A simple fix, but it has completely solved the derailment problem and the second loco now  runs as well  as the first.

2 hours ago, Pteremy said:

 

I cannot claim to understand the precise nature of the problem you are experiencing. But, as has been noted in this thread before, the 15xx does seem to be good at highlighting layout imperfections. In the last week I have been running my 15xx, back and forth, with a 3 coach load. It stalled at 2 places that have sometimes caused issues before, particularly with short wheelbase locos - a Peco point and a section break. [This is on the DCC half of my layout, but with switched sections left over from when it was just DC.] I think that the issue in both cases was that the track was particularly uneven at one or more of the joints, of which there were several over a very short distance, but electrical connectivity could have been a factor. So i decided to do what I should have done ages ago, fix the track, reducing the number of track joints. Having done so the 15xx glides around as sweetly as I would want - and expect - it to do. 

It's a fair question, is it the loco, or  could the layout be at fault.

Effingham is a large layout, over 5 levels and is computer controlled.

A train failure anywhere on the layout is a major issue, both from the consideration of access to rescue it, which is non trivial, and for the chaos caused to the automatic timetable.

Consequently, there is a very stringent acceptance test before any train is added to the roster.

A new model must complete 3 continuous circumnavigations of the layout without stalling, derailing or parting of couplings.

One circuit of the layout at the specified test speed of 40 scale MPH takes 16 minutes and 10 seconds.

So far, 91 models have passed this test, from manufacturers including Accurascale, Bachmann, Dapol, DJ Models, EFE, Heljan, Hornby, Kernow, Lima, Rails, etc.

The 15xx fails miserably to travel even 20% of the first level without stalling and is unique in this.

I rest my case.

Hello Andy,

The decoder as fitted is a Rails of Sheffield own brand, as fitted by them. It does appear to magnify any power interruption, in as much as it will then reset which takes half a second or so.

 I have also tried a Gaugemaster decoder, which does not show the reset delay, but the loco still stalls repeatedly on the layout, as indeed it does on DC.

My curves are min R3, minimum point size peco medium radius. The stalling is most common on change of direction, but can also happen on plain track.

It is a large layout, with computer control, and reliable running is essential, and none of my numerous other locos exhibits these problems irrespective of brand or type of decoder. Unfortunately, the 15XX is currently unusable as a layout loco.

Well the saga of my 15XX rolls on...

Having been unreliable from day 1 with symptoms of intermittent pickup it went back to the retailer for rectification, only to come back to me with no improvement.

Consequently, it then went back to Rapido under warranty and they did warn me that it would take some time to come to the top of the queue for attention.

Well, it finally arrived back a couple of days ago, with the assessment that there is no fault, but the the retailer fitted DCC decoder is faulty.

I suspected that the apparent decoder fault was a symptom of intermittent power, rather than a fault per se, so as nobody else is going to properly investigate the matter, I have done so myself and these are my findings:-

All 3 axles have considerable side play and some vertical play, which makes for excellent track holding.

There are 6 pick up pins, one bearing on the back of each wheel. Of the 6, only 1 is actually in firm contact with the wheel throughout the range of articulation of the axle. 3 do not touch the wheel at all at the limits of sideplay, and 2 are only in very light contact.

The chances of reliable running thus appear somewhat remote.

It would appear that the pick ups have a more restricted range of movement than do the wheels.

the 15xx will either be going back to Rapido again for proper rectification or if that is not to be, it will go back to the unfortunate retailer for a refund.

For the moment, I will let my preorder stand for the 01, but my confidence in Rapido is not what it once was.

I always said you should be on the stage...

I suspect that some of the past stability and reliability problems have been related to issues with the 12 volt bus which have now been identified and can  be properly rectified after the quick fixes applied at Warley.