Kernow Model Rail Centre to produce GWR 1361 0-6-0 Saddle Tank

[Steamport Southport]

... and according to that thread ended up with a loco with valve gear that locks up (and some nasty looking wipers on the wheel backs as an aside).

 

You pays your money, you takes your choice......

 

Les

 

I could only see one comment about the valve gear locking up.

 

But how can a slight difference in wheel rim size and raising the running plate a tiny bit alter the working of the valve gear? It's surely the cranks and rods that would cause any problems. 

 

 

It's also a bit premature to say that the DJM model doesn't have any running problems since it's not been released yet. I'm also a bit wary of the drive train being used on an outside cylinder locomotive. The O2 and Class 71 threads had comments about poor running ISTR.

 

So isn't it worth waiting to see how well this thing runs?  If neither are good enough for my needs then one of the small suppliers will be getting my money. There's a very good looking kit of a 1361 due.

 

 

Jason

[sparaxis]

Does it make any sense at all to gear driving wheels together?

 

Good question. Some folks seem to think so, i.e Rapido with their new Canadian locos and of course, DJM.

 

Back in the good old days, when I was a boy, It was common practice amongst the "Good German Makes", I.e Fleischmann, Marklin and Trix. Fleischmann was the first to drop this followed by Marklin and lastly Trix, around the time they went out of business as an independent company and were swallowed up by Marklin. Something has to give. Gears have backlash, also known as "play" or "slop" or whatever you want to call it. So the good old answer was to have a huge amount of slop in the rods so they simply went along for the ride. The only reason to still do this is if you use fragile and flimsy plastic rods like Gutzold or Tillig which would disintegrate in a second if you actually expected them to transmit any force.

 

I have the Beattie, the O2, 14xx and the Austerity from DJM. The first three are fine, but the only way I could make the latter run acceptably was to remove the rods, carefully open out the holes in the rods and re-assemble everything.

 

Is it reasonable to spend hours of fiddling getting a brand new loco to run acceptably, or should it run well out of the box?

 

Based on my generally favorable experience with the DJM products I hope that my 1361 will run well. That being said, the general Heljan experience (as reported on this forum) starting with the Garratt, then the O2 and the L&B loco (which is still on order) with the disintegrating valve-gear has given me pause, and I have purchased none of them.

[Gerald Henriksen]

It would appear that Oxford weren't the first, this models incorrect CADS, 'with both the simple and rather amateurish mistakes which could, and should, have been corrected in any review of CADs' appeared in November 2014.

 

 

Sorry, but given that Oxford was using a 3D scan, and Kernow / DJM weren't, it means Oxford still gets to hold that distinction (well, that and the fact that adding non-existant rivets can't exactly be justified on the grounds that it is needed to allow the model to operate).

 

Besides, unless someone comes out and admits it was a mistake, there is certainly ample evidence that the splasher issue is likely a matter of compromise to allow the model to sit at the correct height (unlike the Heljan version), and not an "amateurish mistake".

[David Bigcheeseplant]

I don't understand why you need splashers if the footplate is thick as you are then adding same thickness to the splasher itself to overcome the issue.

 

The wheels are not sprung or compensated so no movement needed above the clearance for the wheels and some kind of recess could have been made if the footplate was cast Mazak.

 

Just seems such a shame that what was a really nice model as been spoilt by a adding something that's not there. 

[Gilbert]

I would like a clear comparison of the running qualities of both (including on DCC and particularly at slow speed) as that is one of the most important factors to me - has anyone done one yet?

 

Chris

[bill_schmidt1]

Sorry, but given that Oxford was using a 3D scan, and Kernow / DJM weren't, it means Oxford still gets to hold that distinction (well, that and the fact that adding non-existant rivets can't exactly be justified on the grounds that it is needed to allow the model to operate).

 

Besides, unless someone comes out and admits it was a mistake, there is certainly ample evidence that the splasher issue is likely a matter of compromise to allow the model to sit at the correct height (unlike the Heljan version), and not an "amateurish mistake".

I think PMP's point wasn't about who had used a 3D scan and made mistakes but the use of the phrase " with both the simple and rather amateurish mistakes which could, and should, have been corrected in any review of CADs".

It seems its all turned in to.. "this one might be wrong but so is this, this and this one".  Using other manufacturers mistakes still doesn't make the Kernow one right! 

[Roy Langridge]

I think PMP's point wasn't about who had used a 3D scan and made mistakes but the use of the phrase " with both the simple and rather amateurish mistakes which could, and should, have been corrected in any review of CADs".

It seems its all turned in to.. "this one might be wrong but so is this, this and this one".  Using other manufacturers mistakes still doesn't make the Kernow one right! 

 

Let's face it they (the manufacturers) have all made silly mistakes / decisions over the years - what we need to see if whether they learn from them.

 

Roy

 

Edit: I am unsure whether the decision made for the 1361 was a mistake, a silly decision, or neither. I don't like locos that ride too high, smaller wheels seem to get criticised a lot and having not seen a model in the flesh, I don't know if the running plate could have been shallowed.

 

Edited September 27, 2017 by Roy Langridge

[cctransuk]

I would like a clear comparison of the running qualities of both (including on DCC and particularly at slow speed) as that is one of the most important factors to me - has anyone done one yet?

 

Chris

 

Since the Kernow model has not yet been released, it's unlikely.

 

Regards,

John Isherwood.

[Gilbert]

Since the Kernow model has not yet been released, it's unlikely.

 

Regards,

John Isherwood.

I assumed they are not widely available but I thought I'd seen at least one photo - no rush anyway!

[cctransuk]

Of the two, anyone wishing to perfect it, will probably be easier to cut the splashers off than reduce the height of the Heljan one.

 

I have just taken delivery of the Heljan version.

 

The rail to top of footplate dimension is 16.5mm.; the rail to top of chimney dimension is 49.5mm. I have no idea what the scale dimensions should be - can anyone inform us?

 

Certainly, the buffer height matches the rest of my stock, and the model does not give the impression of being too high.

 

The build quality is excellent, and the level of detail more than adequate - there are some very fine (and vulnerable) separate moulding on there.

 

A lovely runner ...... and no splashers.

 

Regards,

John Isherwood.

[PMP]

Sorry, but given that Oxford was using a 3D scan, and Kernow / DJM weren't, it means Oxford still gets to hold that distinction (well, that and the fact that adding non-existant rivets can't exactly be justified on the grounds that it is needed to allow the model to operate).

 

Besides, unless someone comes out and admits it was a mistake, there is certainly ample evidence that the splasher issue is likely a matter of compromise to allow the model to sit at the correct height (unlike the Heljan version), and not an "amateurish mistake".

 

I'm not aware that Oxford scanned the Dean Goods, in my discussion with them at the ToyFair 2016 no mention was made of it, just reference to drawings, similar to my discussion with them re the N7 at this years event. Bear in mind the locomotive is part of a static display inside the works at Swindon, so scanning this would have meant the disassembly of that display https://www.flickr.com/photos/emdjt42/14310108113 to (presumably) allow in the round access to the engine. Whilst entirely possible that would mean that the loco may have been off display to allow that to happen, and interestingly Oxford to my recollection haven't made any comment regarding scanning prototypes, where other manufacturers and commissioners do.

Monday morning quarterbacking, if the splashers were added as a design compromise to allow the correct relationship between running plate and wheel diameter, I'd have thought that would have been mentioned early on, to offset exactly this discussion on release.

 

All the above however doesn't cover the incorrectly placed cab steps which have been there since day one of the CADS, regardless of the primary data source. Using the 'amateurish mistake' analogy applied to the team regarding the Dean Goods CAD detail reviews, surely the same comment is just as valid here? 

[UMinion]

Of the two, anyone wishing to perfect it, will probably be easier to cut the splashers off than reduce the height of the Heljan one.

Then what? I presume the splashers are there because of clearances. It's easy to say cut them off but then? Leave holes with potentially visible wheel edges or fill them in and apply the brakes? Just cutting them off is the easy bit but the 'perfect it' bit is a little bit more than that isn't it?

[Miss Prism]

I have just taken delivery of the Heljan version. The rail to top of footplate dimension is 16.5mm

 

That's pragmatically close enough in my view, John.

 

[JSpencer]

Then what? I presume the splashers are there because of clearances. It's easy to say cut them off but then? Leave holes with potentially visible wheel edges or fill them in and apply the brakes? Just cutting them off is the easy bit but the 'perfect it' bit is a little bit more than that isn't it?

 

Well some people have suggested very fine specialized tape on the Stirling thread to avoid having to lower the cylinders so the cranks can clear the splashers there!

 

All design is compromise. If we look at the Deltic and DP2 models we have:

Bachmann Class 55 - correct wheel dia but sits slightly high

Bachmann Deltic Prototype - small wheel diameter but sits at correct height

Heljan DP2 - narrow wheel profiles and under body cut outs, has correct wheel profile and sits at correct height. Not suited to certain point work.

 

The photos/images above are all far bigger than the actual models. So I really wonder how much is just psychological.

Me personally, I lived in bliss with my 10001 BR Early crest diesel model running on my southern-ish layout. Then it was pointed that, A/  with a full load of lamp irons it should have a smaller crest and B/ the lower end details correspond to 10000 than 10001. The superb Bachmann/Rails version in SR format never appeared.

Now when it runs on the layout, do I look at it in disdain thinking 'what a flawed model' I have?  No, but I would do if it performed badly!

Edited September 27, 2017 by JSpencer

[Ian Hargrave]

I would like a clear comparison of the running qualities of both (including on DCC and particularly at slow speed) as that is one of the most important factors to me - has anyone done one yet?

 

Chris

 

How is that currently possible ? The Kernow 1361 won't be available for such a comparative appraisal until it arrives . And no,the model rail press ( maybe other than BRM ?)  doesn't have any to conduct such a test. If it is of any value,the DJM coreless....described as "marmite" earlier on this thread....is particularly efficient for slow speed control,though it can be noisy .Go further up the range and it's entirely another matter as experience with the Class 71 demonstrates as it runs out of wind with a prototypical load above scale estimated speed 45-50 mph.This is on dc only btw.

 

The coreless motor drive appears understandably to be an issue once again but it's possibly an advantage with the 1361 with its small loco characteristics.I have no problem with it and accept the fact that there indeed appears to be a design flaw. I fully support Kernow and what they constantly achieve.Please let's not forget that this model is theirs and DJM the contracting agent. Some disparaging remarks have been posted about the latter.If there is,as has been suggested a cheerleading set of "groupies" who believe he can do no wrong,I am certainly not one of their number.I prefer to judge each emerging model on its respective merits whoever the manufacturer might be

[Gilbert]

How is that currently possible ? The Kernow 1361 won't be available for such a comparative appraisal until it arrives . And no,the model rail press ( maybe other than BRM ?)  doesn't have any to conduct such a test. If it is of any value,the DJM coreless....described as "marmite" earlier on this thread....is particularly efficient for slow speed control,though it can be noisy .Go further up the range and it's entirely another matter as experience with the Class 71 demonstrates as it runs out of wind with a prototypical load above scale estimated speed 45-50 mph.This is on dc only btw.

 

The coreless motor drive appears understandably to be an issue once again but it's possibly an advantage with the 1361 with its small loco characteristics.I have no problem with it and accept the fact that there indeed appears to be a design flaw. I fully support Kernow and what they constantly achieve.Please let's not forget that this model is theirs and DJM the contracting agent. Some disparaging remarks have been posted about the latter.If there is,as has been suggested a cheerleading set of "groupies" who believe he can do no wrong,I am certainly not one of their number.I prefer to judge each emerging model on its respective merits whoever the manufacturer might be

To repeat myself..

 

"I assumed they are not widely available but I thought I'd seen at least one photo - no rush anyway!"

 

I'll be grateful if and when anyone has seen both in action...

[Ian Hargrave]

To repeat myself..

 

"I assumed they are not widely available but I thought I'd seen at least one photo - no rush anyway!"

 

I'll be grateful if and when anyone has seen both in action...

 

Sorry....that's unclear in the post to which I replied.

[dibber25]

Does it make any sense at all to gear driving wheels together?

 

Good question. Some folks seem to think so, i.e Rapido with their new Canadian locos and of course, DJM.

 

Back in the good old days, when I was a boy, It was common practice amongst the "Good German Makes", I.e Fleischmann, Marklin and Trix. Fleischmann was the first to drop this followed by Marklin and lastly Trix, around the time they went out of business as an independent company and were swallowed up by Marklin. Something has to give. Gears have backlash, also known as "play" or "slop" or whatever you want to call it. So the good old answer was to have a huge amount of slop in the rods so they simply went along for the ride. The only reason to still do this is if you use fragile and flimsy plastic rods like Gutzold or Tillig which would disintegrate in a second if you actually expected them to transmit any force.

 

I have the Beattie, the O2, 14xx and the Austerity from DJM. The first three are fine, but the only way I could make the latter run acceptably was to remove the rods, carefully open out the holes in the rods and re-assemble everything.

 

Is it reasonable to spend hours of fiddling getting a brand new loco to run acceptably, or should it run well out of the box?

 

Based on my generally favorable experience with the DJM products I hope that my 1361 will run well. That being said, the general Heljan experience (as reported on this forum) starting with the Garratt, then the O2 and the L&B loco (which is still on order) with the disintegrating valve-gear has given me pause, and I have purchased none of them.

 

I'm not aware of Rapido doing this, except on diesels where it is standard practice among most manufacturers. Rapido hasn't yet produced any steam locos - British or Canadian - so we don't know how they'll be driven. The Stirling, I believe,  has gear drive to the rear axle, but it doesn't have coupling rods and the drive system is designed to overcome a different problem (lack of sufficient traction on the single wheel). Yes, a ready-to-run locomotive should run acceptably straight out of the box and should not require work of the kind that you describe. However, as far as I'm aware that problem does not exist across the range so it suggests to me that you were unlucky in receiving a 'rogue' model. I don't have any 'austerities' so I can't make a judgement about the six-coupled design but I do have all the four-coupled locomotives and, like yours, mine are all fine. Different manufacturers will use different design systems and we shouldn't expect everyone to use the time-honoured arrangements generally used by Hornby and Bachmann as that would stifle innovation. (CJL)

[The Stationmaster]

Except it's incorrectly detailed for every running number isn't it?

 

And I think you'll find the Heljan one is too, albeit in different respects.

[dibber25]

I have just taken delivery of the Heljan version.

 

The rail to top of footplate dimension is 16.5mm.; the rail to top of chimney dimension is 49.5mm. I have no idea what the scale dimensions should be - can anyone inform us?

 

 

Regards,

John Isherwood.

Model Rail data panel gives height as 11ft 115/8in (shown as 48mm). Of course, if there's an adjustment in height to overcome the interface between flange and running plate, do we want the overall height to be equally out, partially out, or adjusted  to make the overall height correct? In the latter instance body dimensions could be reduced to correct the height, thus altering the 'look' of the model. We're on the slippery slope with this......... If we still have the Heljan model I'll make some comparative checks to see exactly how they've overcome the problem - assuming, indeed, that it is a problem. (CJL)

[Ryde-on-time]

I'm not aware of Rapido doing this, except on diesels where it is standard practice among most manufacturers. Rapido hasn't yet produced any steam locos - British or Canadian - so we don't know how they'll be driven. The Stirling, I believe,  has gear drive to the rear axle, but it doesn't have coupling rods and the drive system is designed to overcome a different problem (lack of sufficient traction on the single wheel). Yes, a ready-to-run locomotive should run acceptably straight out of the box and should not require work of the kind that you describe. However, as far as I'm aware that problem does not exist across the range so it suggests to me that you were unlucky in receiving a 'rogue' model. I don't have any 'austerities' so I can't make a judgement about the six-coupled design but I do have all the four-coupled locomotives and, like yours, mine are all fine. Different manufacturers will use different design systems and we shouldn't expect everyone to use the time-honoured arrangements generally used by Hornby and Bachmann as that would stifle innovation. (CJL)

 

In the last Rapido News Vol 92 there is an update on the Royal Hudson steam loco where they confirm they are going for a geared drive to all driven axles

 

http://myemail.constantcontact.com/Rapido-News-Vol--92---New-Videos--deadlines-and-factory-updates-.html?soid=1101318906379&aid=lAXRjGa-Dq0

 

For a manufacturer of Rapidos reputation to take a fresh look at how to produce the best model steam loco at a premium price and to decide to do that type of drive system is interesting considering the negativity shown on this forum to it

[Andy Y]

A couple of shots to show that there is actually a recess for the rear wheels beneath the firebox/cab which indicates the factory designed a form of recess in for the wheel/flange clearance.

 

 

[dibber25]

In the last Rapido News Vol 92 there is an update on the Royal Hudson steam loco where they confirm they are going for a geared drive to all driven axles

 

http://myemail.constantcontact.com/Rapido-News-Vol--92---New-Videos--deadlines-and-factory-updates-.html?soid=1101318906379&aid=lAXRjGa-Dq0

 

For a manufacturer of Rapidos reputation to take a fresh look at how to produce the best model steam loco at a premium price and to decide to do that type of drive system is interesting considering the negativity shown on this forum to it

 

I wonder if it's a necessity of the particular assembly equipment/system? If you look back to movie of DJM's assembly of (IIRC) the Beattie, it shows how the chassis is assembled in a jig/press device. Maybe this equipment is specifically designed for assembling an all-geared diesel-type chassis. (CJL)

[34theletterbetweenB&D]

Does it make any sense at all to gear driving wheels together?

 

Good question. Some folks seem to think so, i.e Rapido with their new Canadian locos and of course, DJM.

 

Back in the good old days, when I was a boy, It was common practice amongst the "Good German Makes", I.e Fleischmann, Marklin and Trix. Fleischmann was the first to drop this followed by Marklin and lastly Trix, around the time they went out of business as an independent company and were swallowed up by Marklin. Something has to give. Gears have backlash, also known as "play" or "slop" or whatever you want to call it. So the good old answer was to have a huge amount of slop in the rods so they simply went along for the ride..

There are two current Bachmann steam products I am aware of with the 2nd and 3rd axles geared together, the 9F and G2A. No widely reported problems with their running that I am aware of, and the rods between the gear coupled wheelsets don't appear to have more 'slop' on the crankpins than is usual, nor do they take up any deviating angle from the general line of the coupling rods. (Having had the pleasure of watching these 9Fs in particular in very regular action on the layout over ten years, never seen anything to suggest a problem.) But that's only two axles that are both rod and gear coupled.

 

Ideally, if going with both rod and gear coupling of wheelsets, then the gear teeth should be phased coincident with the phasing the rods enforce, to avoid the requirement for excessive clearance 'somewhere': if on the crankpins, then with the resulting possibility of 'off-angle' rod positions as they are only going along for the ride. Simple enough in principle on a jig assembly tool, for each wheelset to have the axle with the gear on it presented at a consistent tooth position relative to the crankpins as the two wheels are pressed on quartered.

[PMP]

The big difference with those Bachmann products and the DJM design is the Bachmann models have jointed coupling rods, whereas the DJM versions are rigid rods. My 14xx has improved with a removed gear and replacement rods, however the J94 hasn't, though I have yet to try it with jointed rods. I'd heard though can't recall where that the G2 chassis had a reworking of the drive train to improve running quality but don't bet the farm on that.

 

(Edit) Assuming the Kernow/DJM chassis is of similar design to other DJM steam chassis, the wheels are automatically quartered fitting onto a square stub axle. Quartering issues should be in the highly unlikely camp, and I'd assume the axle drive gear will be in the same relative position for each driving wheel when set with a 90 degree offset.

Edited September 27, 2017 by PMP