I purchased a lovely looking Bardon Agregates class 66 yesterday. For the asking price and being DCC fitted I was very happy with my purchase. I placed the loco onto my track next to my Farish 350-1 Desiro which runs absolutely beautiful.  I started her up in great anticipation as I have read a lot of good reports on how good Dapol were. loco ran lovely UNTIL running over turnouts. All my turnouts are long radius but the class 66 simply kept shorting out with tiny sparks emenating from the wheels, thus causing my DCC system to cut out and stopping my other trains dead. I have been scratching my head for the best part of today trying to think of a sure fast way to resolve this shorting issue. I tried placing a small piece of insulation tape at the frog end to prevent the rather wide Dapol wheels from touching both rails, this worked a little better but this then caused the loco to stutter worse than before. I don't have this problem with any of my other loco's which all run perfectly. so, as good as Dapol are, I will just stick with Farish. I'll be running the 66 on my branch line as that only has one set of points to worry about. Is this common with Dapol? Or is it just me having a run of bad luck.

Marcus

This is bad luck. I can only think that one or more of your axles might have a gauge problem. I don't think you are safe with Farish either as I bought a brand new class 66 from them a year ago. It ran for about 15 minutes or so before giving up the ghost.

Some locos are duds and rather than stop buying one brand or the other brand, I think the best bet is to return them to the vendor when something isn't right.

Webbo

Have to say I think it over-reacting to condemn an entire brand on the performance of one loco, particularly when it sounds like a relatively minor and easily fixable problem... 

The most likely cause if it just the one loco that has problems is that one wheelset is out of gauge (most likely the outer or middle set) That should be an easy fix with a back to back gauge.

It is also worth pointing out that the earliest produced Dapol locos did have wider wheels that the more recent ones (you don't say whether this one was new or second hand but as you describe it as having 'rather wide wheels' I'm guessing the latter).
Also out of gauge wheels is actually something Farish are more known for than Dapol, so if you write off everything Dapol on the basis of this one loco, it shouldn't be too long before you write off Farish for the same reason and are looking for another hobby...

Quote from: PLD on May 03, 2015, 12:07:50 AM
Have to say I think it over-reacting to condemn an entire brand on the performance of one loco, particularly when it sounds like a relatively minor and easily fixable problem... 

The most likely cause if it just the one loco that has problems is that one wheelset is out of gauge (most likely the outer or middle set) That should be an easy fix with a back to back gauge.

It is also worth pointing out that the earliest produced Dapol locos did have wider wheels that the more recent ones (you don't say whether this one was new or second hand but as you describe it as having 'rather wide wheels' I'm guessing the latter).
Also out of gauge wheels is actually something Farish are more known for than Dapol, so if you write off everything Dapol on the basis of this one loco, it shouldn't be too long before you write off Farish for the same reason and are looking for another hobby...

Not sure what exactly is meant when you say "back to back gauge" as I'm new to N gauge. If an easy fix as you say, how do I go about resolving the problem. The loco was purchased second hand, though in excellent condition. Looking at the width of the wheels in comparison to the Farish loco, I would say it's an earlier model.

Gauge is the distance between the insides of the rails on the track. Problems will occur if the separation of the wheel flanges on each axle are too narrow or too wide. Should be very easy to check whether all the flange separations on your problem loco are similar to the separations on your other locos. A fraction of a millimetre too wide or too narrow could be enough to cause major running problems.

I made a mistake in my post. My problem Farish loco was a class 55, not a class 66.

Webbo

If you google "n gauge back to back gauge" you will find a few suppliers of and pictures of back to back gauges.

They usually slide in between the back surfaces of the wheels and should be a tight fit.

You can also measure the distance between the wheels with a micrometer and adjust accordingly. The measurement should be 7.65mm according to one supplier.

I've never known the exact measurement because I bought a gauge from the N Gauge Society years ago, unfortunately they don't have them in stock at the moment.

The problem of wheels being out of gauge is common to all scales and makes of rolling stock. The result is usually derailments. I wonder how many locos get sent back for this reason alone?

This sort of thing is really frustrating but easily sorted out once you know what to do.

Quote from: silly moo on May 03, 2015, 04:28:05 AM
If you google "n gauge back to back gauge" you will find a few suppliers of and pictures of back to back gauges.

They usually slide in between the back surfaces of the wheels and should be a tight fit.

You can also measure the distance between the wheels with a micrometer and adjust accordingly. The measurement should be 7.65mm according to one supplier.

I've never known the exact measurement because I bought a gauge from the N Gauge Society years ago, unfortunately they don't have them in stock at the moment.

The problem of wheels being out of gauge is common to all scales and makes of rolling stock. The result is usually derailments. I wonder how many locos get sent back for this reason alone?

This sort of thing is really frustrating but easily sorted out once you know what to do.

Hi Silly Moo,

Sorry to butt into the thread but you say 'adjust accordingly' and 'easily sorted out once you know what to do'.

What would I do if had similar problem?

Thanks weave.

Quote from: Marcus Amison on May 03, 2015, 12:32:05 AM
Not sure what exactly is meant when you say "back to back gauge" as I'm new to N gauge. If an easy fix as you say, how do I go about resolving the problem. The loco was purchased second hand, though in excellent condition. Looking at the width of the wheels in comparison to the Farish loco, I would say it's an earlier model.

It may confuse you further, but try reading this recent thread... there was some useful discussion about back to back gauges (and the fact that not all are the same!!)

When I've had to adjust wheels it's usually just a case of easing the gauge between the wheels if they are too close together. My gauge which is one of the N Gauge Society ones is a block of brass milled to the right size.

If the wheels are too far apart you can usually push them closer together by hand or the gentle use of a pair of pliers or tweezers.

I must admit that I haven't done this to steam locomotive driving wheels, and I wouldn't recommend this   

The main culprits seem to be front bogie wheels, coach wheels and wagon wheels which in the case of wagon and coach wheels are easy to remove if needs be.

Here's a link to a very good tutorial on you tube.   
http://youtu.be/eezAYGyRmHU

You guys are making this far more complicated than it needs to be. I would just check to make sure than the wheels on all axles are pretty close to the same distance apart and that the separations are similar to those on other locos that perform OK. No need to buy wheel gauges. I've managed to get through life without a wheel gauge just fine and have faced a number of situations of locos and wagons of wheels being too close together or too far apart during my time on Earth.

Of course, we are assuming that it a wheel gauge issue that is causing the running problem which it may not be.

Webbo

As others have said, don't be too quick to write off Dapol. A lot of their more recent designs are truly excellent. Provided you don't get a duff specimen that slipped through what passes as quality control in China, then things like the D6300s, the 'Westerns', the Class 26s/27s and the Class 86s are widely regarded as reliable and well proportioned.

But some of their older stuff does have its flaws. The older 66s sound like boxes of rocks; the GWR 2-6-2s have just two speeds: zero and Usain Bolt; and the 9Fs look amazing but derail easily and aren't particularly strong (which causes problems with gradients, not just long trains).

Basically, unless it was going for an absolute song, I wouldn't buy one of the older Dapol locomotives. Stuff from the last 7 or 8 years seems to be the good stuff. More recent stuff is worth a flutter, but it's always worth trying it out or at least keeping the receipt so you can take it back if its faulty!

Cheers, NeMo

PS. Over the next year or two, Dave Jones will be producing his own line of models, promising few compromises at relatively moderate prices. He was the man behind a lot of "the best of Dapol" over the last few years, so expectations are high. One to watch if you're less than impressed with what's on the market at the moment.

If you are using insulfrog points it could well be where the two rails almost touch at the "V" in the plastic frog.
The wheels can make contact with both rails and no amount of back to back adjustment will cure it.

I had this problem and chainged all the Insulfrog for electrofrog.....no more sparks.
The Electrofrog can just replace the Insulfrog without any additional wiring.

Allan

Quote from: Bikeracer on May 03, 2015, 12:10:45 PM
If you are using insulfrog points it could well be where the two rails almost touch at the "V" in the plastic frog.
The wheels can make contact with both rails and no amount of back to back adjustment will cure it.

I had this problem and chainged all the Insulfrog for electrofrog.....no more sparks.
The Electrofrog can just replace the Insulfrog without any additional wiring.

Allan You say you can just replace Insulfrog to Electrofrog with no additional wiring? Did you not have any polarity issues? I have over 20 points on my layout, to change is going to cost an arm and leg but if it solves the shorting problem then I will replace over a period of time. Thx.

Hi guys,

Another idea would be to purchase a complete new wheel set from them!

One of the few things I did once my feet were under the table was to change wheel spec to RP25.72 standards with a 7.4 +/- mm back to back.

This alleviated this sort of shorting problem.

Hope this helps.
Cheers
Dave

Quote from: Bikeracer on May 03, 2015, 12:10:45 PM
If you are using insulfrog points it could well be where the two rails almost touch at the "V" in the plastic frog.
The wheels can make contact with both rails and no amount of back to back adjustment will cure it.

I had this problem and chainged all the Insulfrog for electrofrog.....no more sparks.
The Electrofrog can just replace the Insulfrog without any additional wiring.

Allan

Bikeracer has pinpointed the probable reason Marcus is getting shorting problems when his 66 runs through points. The following picture shows the polarity through insulfrog points and how two rails with opposite polarity come close together in the V of the the frog. If the wheel track covers both rails at once, a short will result.

[smg id=24609 type=preview align=center caption="Insulfrog points showing track polarity"]

However, how wheels run through points certainly depends on the wheel gauge and it may be possible to fix the problem by slightly narrowing or widening it on one or more axles of the 66. If the problem can't be fixed this way or with new wheel sets as suggested by Dave, then the following is another solution suggested by Railway Bob. Bob claims it to be a simple solution, but I would be inclined to try the simplest possible solution first i.e. modifying the wheel gauge. Changing all points to electrofrog would fix the problem if this is what it is, but this would be a big effort I'm sure. Wiring for electrofrog may require insulating track joiners to be fitted in some places as well. 

http://railwaybobsmodulebuildingtips.blogspot.ca/2011/06/fixing-short-in-peco-insulfrog.html

Webbo