Kernow Adams O2

[Ian J.]

You might find that dulling down or darkening the coupling rod could help?

[bertiedog]

I think the strange "quartering issue", (in the posted shot), or rod slop, is due to the illusion got because it is sitting on the curve where the front wheels are hard to the right and the trailing are to the left, this angles the rods, making any out of line more noticeable.

 

I checked mine and there is play, but no more than most makers allow. However I see your saying it is there and it must be a slight quartering issue as well.

 

The lining is a bit stand out, but this effect often shows more on smaller locos, the decoration overwhelms it a bit. The painting around the pump is a bit poor, needs attention later on to leave it accurate, but toned down.

The running has improved nicely with running in and attention to the bogie springing, plus added weight at the front. It hardly has to handle large trains, and no major inclines on my layout.

 

Stephen.

Edited April 7, 2016 by bertiedog

[No Decorum]

Very interesting comments, gentlemen. Yes, the engineering is clever and the provision for sound in such a small machine is exemplary. I have run mine on a friend’s layout as well as my own and he was very impressed by it. My eyebrows rose at the lack of sideplay of the bogie but the wheels themslves have plenty of sideplay without loosing contact with the pick ups and the arrangement seems to cause no trouble.

 

However, I do wonder if a good quality traditional motor would have delivered better running.

 

On my example, the cab roof is easy to pull off.

 

I don’t think the odd angle of the coupling rod is an illusion. I have seen it on many pictures and videos and my example is the same. The drive is through gears to both driving axles and I don’t think that’s a good idea, given that the model must have coupling rods. I suspect that the holes in the rods are a bit larger than the pins so that the rods do not interfere with the gearing but perhaps the quartering is out too.

 

I did try to take the body off to see if there was any way to remove the gear but gave up for fear of causing damage. In any case, even if I were able to remove the gear, replacement pins and rods would probably be necessary and any problem with the quartering would remain.

[bertiedog]

     A lot of makers have used the double or all gear coupled axles, mainly HO European models, and the idea is sound in that the rods do little work! But to function properly the wheels need to be as accurately quartered as usual, something German makes always did.

 

     I think the Chinese makers are slacker when using gears, and it shows with the oversize rod bearings. If the quartering is correct then the back of the rods can have a washer soldered on, with a smaller hole nearer the screw size. If the quartering is still a bit off, then tightening  the rods bearings may lead to binds. Even with perfect quartering, if the gears are not tightly meshed, then the play allows the axles to be out of sync with the rods

 

    The other way, (probably the best), is to remove one of the idler or final gears completely and rely on the quartering and rods alone. In this case new rods are worthwhile with wider bosses to give a better bearing area. It takes away the problem.

 

    My own example just about keeps the rods level, but there is slight play in the gears, and the rods are a tiny bit over scale in size. So the longer term plan is to de-gear, and fit new rods.

 

Stephen.

[john flann]

Thank you Stephen, it appears a well engineered solution but far beyond the capacities of me and I'm sure many others.

 

What riles me though is that the O2, for me at least, was an expensive purchase and I  would have expected at that cost, non drooping coupling rods.

[john flann]

 

I won't prolong these posts, but this shows the front end less the plumbing. But there remains the coupling rod droop. and it appears the loco down by the bows. That I agree is an optical illusion.

 

 

[phil-b259]

DSCN5406-1.jpg

 

I won't prolong these posts, but this shows the front end less the plumbing. But there remains the coupling rod droop. and it appears the loco down by the bows. That I agree is an optical illusion.

 

But the front end plumbing was on the real '207', so unless you are planning to renumber it as well then the model is now inaccurate - which is heresy in the eyes of some modellers

 

That said the removal of said plumbing does make the loco look more pleasing on the eye - and if Kernow were minded to make another Southern variant in olive without the PP equipment (possibly in the pre 1931 livery with an E prefix to the number) then I would be in market to increase my stud of O2s

Edited April 8, 2016 by phil-b259

[john flann]

Phil, glad you like the front end look and thanks for your observations. You know more about 207 than me; was the plumbing there from the very beginning? If not, when was it added?

 

My period for Hintock is 1937'ish.

 

In my own defence I did/do intend to renumber the loco 221 and got decals from Fox before I received the loco from Kernow. On arrival the decals were too large and I was so fed up with the loco and my first impressions I did no more about it. But now having got it in a viewable/runnable condition can you tell me please, of a source for the correct size numerals, please?

 

If I can't/don't renumber I'm content to commit heresy-it wouldn't be the first time in my modelling activities.

[ExPatBrit]

Phil, glad you like the front end look and thanks for your observations. You know more about 207 than me; was the plumbing there from the very beginning? If not, when was it added?

 

My period for Hintock is 1937'ish.

 

In my own defence I did/do intend to renumber the loco 221 and got decals from Fox before I received the loco from Kernow. On arrival the decals were too large and I was so fed up with the loco and my first impressions I did no more about it. But now having got it in a viewable/runnable condition can you tell me please, of a source for the correct size numerals, please?

 

If I can't/don't renumber I'm content to commit heresy-it wouldn't be the first time in my modelling activities.

According to Bradley, "Locomotives of the LSWR", #'s 182/3/7/207 & 255 were converted to pneumatic push pull between October 1931 and September 1933. So you're not that far out, but in any case it's your layout, your rules. Good luck finding transfers, HMRS Pressfix or Methfix maybe?

[john flann]

Thanks ExPat-another like myself I assume-as you say not far out and it will do for me.

 

I've had enough aggravation with the loco already, and what's an "incorrect" number between friends? It can stay 207.

 

I like to think that more will look at Hintock as a whole rather than the numbers individual locos carry. In any event, as my website http://www.hintockbranch.com/ makes clear, I model representionally not prototypically.

[trevor7598]

Something that John Flann mentioned in an earlier post was a comment on the ' chrome ' cab surround.

I am not sure where the idea for this piece of over decoration came from, I can only assume that Calbourne

had been specially bulled up on the day it was scanned. Any photo of an 02 in normal service would have 

shown that a ' chrome ' finish was hardly typical.

Perhaps any re-run of this model can have this overpowering error deleted. A fine model spoilt.

[Guest]

.....

The running has improved nicely with running in and attention to the bogie springing,.....Stephen.

What did you do to the bogie spring? I added weight into the boilers which helps keep both drivers flat on track. Lost the spring for 24, so lightly screwed in bogie, which actually seemed to help! 16 still has spring, but without boiler weight both locos out the box would tipp back slightly lifting front driver off. Edited April 9, 2016 by Guest

[t8hants]

Here's Calbourne as of last week, out shopped for the new season, the cab surround is not chromed, but it is polished.

[Bluebell Model Railway]

Burnished steel think we have been through this before regarding the cab opening and the straps on the pump it is in the condition of pristine if it's too bright weather it down...

[john flann]

I don't intend to get involved in any further discussion on this, I've done what I did and that will suffice for me.

 

My only further comment on the livery is to refer individuals to my post #1487.

 

But, I can't resist to remark that the coupling rods in post #1515 are horizontal and without the pronounced Kernow droop.

Edited April 9, 2016 by john flann

[NHY 581]

Thanks ExPat-another like myself I assume-as you say not far out and it will do for me.

 

I've had enough aggravation with the loco already, and what's an "incorrect" number between friends? It can stay 207.

 

I like to think that more will look at Hintock as a whole rather than the numbers individual locos carry. In any event, as my website http://www.hintockbranch.com/ makes clear, I model representionally not prototypically.

John, your philosophy is that of my own. I try to create an overall effect rather than an exact replica. I model to primarily keep myself happy and should my efforts appeal to others then I am both pleasantly supprised and flattered.

 

I know I am not alone in admiring Hintock and its 'spin offs', Hintock Town Quay and Port Bredy.

 

Rob

[billbedford]

     I think the Chinese makers are slacker when using gears, and it shows with the oversize rod bearings. If the quartering is correct then the back of the rods can have a washer soldered on, with a smaller hole nearer the screw size. If the quartering is still a bit off, then tightening  the rods bearings may lead to binds. Even with perfect quartering, if the gears are not tightly meshed, then the play allows the axles to be out of sync with the rods

 

    The other way, (probably the best), is to remove one of the idler or final gears completely and rely on the quartering and rods alone. In this case new rods are worthwhile with wider bosses to give a better bearing area. It takes away the problem.

 

 

The gears are not the problem. The rod are acting the way they do because the crankpin holes in the coupling rods are way over size. I can move the rods backwards and forwards about half a mill without the wheels turning. With this much slack on the crankpins any four coupled loco will have drunken coupling rods.

 

Unfortunately there is no easy solution short of replacing the wheels, which will open a whole new can of worms.

[bertiedog]

I have checked over the model very carefully, a near complete disassembly, and the rods displacement from level is due to the gears. With connecting gears, the rods go along for the ride supported by the crankpins. But even when perfectly quartered, the gears working play themselves allow the wheel sets to be driven slightly out of sync. The effect can be seen when the mechanism is moved from forward to reverse, the play in the gears allows the wheels to be at "different points on the clock" to each other, but running smoothly together due to the gears.

 

The slight rotational differences cause the pins to hold the rods out of the correct level position, they show it worse at "Quarter past" 90deg past the top and 270deg, where the rods can be about .75 degree out of true.

 

All of this can happen with perfect quartering, it is the working play between the gears that is the basic problem.

 

The only 100% cure is to remove the gear drive from one of the axles, and fit new rods with tighter bearings. Even the slack rods work well with the gear removed.

 

My only thought is that better gear meshing of higher quality gears would also cure it, but that's up to DJ Models and it would add to the cost greatly.

 

The other option is simply tighter rod bearings, but if the gears are left in place, you can't go too tight or binds may set in, with the rods fighting the gears as they rotate.

 

DJ and the designers and the Chinese producers must have been aware of the potential issue, otherwise why fit the over size rod holes?

 

Anyway at the moment it runs even better after re-assembly, and there are the various cures to the rods being out of level.

 

Stephen

[Izzy]

This effect is something that has been quite common in N gauge for many years with some steam locos using all-geared drive, a feature quite often used with continental models. It isn't so bad if the primary drive is to a central axle in a 6/8/10 coupled one as the gearing backlash/play tends to equal itself out with the outer axles, they are both behind the driven axle so keep some equalibrium within the coupling rods, but shows badly if the drive is at one end of the gear train. Generally, along with the usually oversized coupling rods, it's been accepted as part and parcel of modelling in the scale by most.

 

Not quite sure why the design has been used in 4mm. Traction for a 4-coupled loco (2-4-0/0-4-2/0-4-4/4-4-0) is produced by weight in the right place over the drivers and gearing both axles won't change or improve that aspect.

 

Izzy

[IWCR]

Several  people  have  commented  that  the  O2  model  looks "not  quite  right"  in  some  way.

I  think  this  is   inherent  in  the  fact  it  is  OO,  when  looking  at  a  3/4s  front  view  the  driving  wheels  are  obviously  further  inboard  than  reality,  this  then  makes  them  look  like  they  dont  align  with  the  splashers  (which  of  course  they  do  really)

Looking  square  from  the  side  it looks  fine

Comparing  with  an  M7  model  this  is  less  noticable  due  to  larger  wheels  with  less  of  them  visible.

 

Pete

[DJM Dave]

I rather nailed my colours to the mast with my post #1 on this thread, and still have the strongest wish to support the model, come what may. I have the first two in Southern livery. One (K2107) arrived (in February) with a defective smoke box door, I have now made three attempts to buy a replacement but to no avail, and I feel that my extreme brand loyalty is being taken for granted. Which is a shame because I had wished to populate my shunting plank with many more. John's photo (above) seems to say it all, with regard to the coupling rod droop. Does the engineering concept really make the droop inevitable? Round objects.

 

Come on Kernow chaps, you must do better.

 

PB

Hi Peter,

 

I think i've put this note on the thread already, but spares that were due from China with the original batches of models for Kernow were not produced and as such left us with egg on the face as i had promised there would be some at the release of the locomotive.

Even worse is that it may seem an easy thing to throw the tool onto the machine and squirt plastic, but only if there's a gap in production to do so.

However rest assured this is being worked n as i type this and spares will be available soon (fingers crossed) and i will only too gladly replace your defective smokebox door for you.

Cheers

Dave

[Graham_Muz]

My couple of O2s have left the paint and weathering workshop
 
First up 225 just weathered
 
 
Secondly 30193 repainted to SR black as 193, cab doors removed and weathered.


More information on the work done can be read here https://grahammuz.com/2016/04/23/workbench-witterings-5-o2-and-not-an-o2-is-this-more-weathering-i-see-before-me/

[ChrisG]

I have a question about DCC and the O2s. The two I have running at the moment have both been fitted with DCC Concepts Zen Decoders (I can't remember which ones they are exactly, but I don't think that is crucial to the answer.  One is a simple plug in, the other is hard-wired and has a Stay Alive (as supplied with the Decoder) added.

 

I cannot read back the CVs or even the address from these locos, using a Gaugemaster DCC Doctor. My other locos fitted with the same decoders and both with and without the stay-alive device can be read back quite happily. I am wondering if the difference is down to the motor used in the Kernow model. 

 

I have a hunch that the "stay alive" might also be affecting the loco's performance - it has a very slightly pulsing motion rather than the completely smooth running of the one without "stay alive".

 

I'm curious to know if anyone else has the same problem(s), or categorically doesn't have them, with these decoders in these locos.

 

Thanks

 

Chris

[Peter Bedding]

Hi Peter,

 

I think i've put this note on the thread already, but spares that were due from China with the original batches of models for Kernow were not produced and as such left us with egg on the face as i had promised there would be some at the release of the locomotive.

Even worse is that it may seem an easy thing to throw the tool onto the machine and squirt plastic, but only if there's a gap in production to do so.

However rest assured this is being worked n as i type this and spares will be available soon (fingers crossed) and i will only too gladly replace your defective smokebox door for you.

Cheers

Dave

 

Hello Dave,

 

I feel a tad embarrassed to ask further, however I should like to know if the spares in question are yet in view. My 207 is a lovely little mover, and it looks naked without a complete "face". 

I would welcome any solution at this point.

Be well,

Peter

[andyram]

Thought I would share this picture of my O2 at work on Skaleby West today. Very pleased with the model. It has run well since purchase and looks stunning. I have both Island 02's and hope more will be produced.