!!

Not Registered?

Welcome!  Please register to view all of the new posts and forum boards - some of which are hidden to guests.  After registering and gaining 10 posts you will be able to sell and buy items on our N'porium.

If you have any problems registering, then please check your spam filter before emailing us.  Hotmail users seem to find their emails in the Junk folder.


Thanks for reading,
The NGF Staff.

Author Topic: Dapol A4  (Read 72171 times)

0 Members and 1 Guest are viewing this topic.

Online Dr Al

  • Trade Count: (+49)
  • Full Member
  • ***
  • Posts: 4878
  • Country: gb
  • Gender: Male
    • Awards
Re: Dapol A4
« Reply #60 on: March 28, 2012, 10:46:58 AM »
Didn't you mention previously that they are covering over A3 cylinders Al? If so, maybe that is why they are so overscale.

Yes, but I don't see that should be an excuse!

Cheers,
Alan
Quote from: Roy L S
If Dr Al is online he may be able to provide a more comprehensive answer.

“We have also arranged things so that almost no one understands science and technology. This is a prescription for disaster. We might get away with it for a while, but sooner or later this combustible mixture of ignorance and power is going to blow up in our faces.” – Dr. Carl Sagan

Offline Zunnan

  • Trade Count: (+7)
  • Full Member
  • ***
  • N Gauge Society Number: 17178
  • Posts: 336
  • Country: 00
  • Gender: Male
    • Facebook
    • Awards
Re: Dapol A4
« Reply #61 on: March 28, 2012, 02:21:05 PM »
I'm not an A4 fan to be honest, but I think you're right, the cylinders do look to be set too low by quite an amount. And the almost complete lack of curvature where the casing should wrap under the cylinder to the drain cocks is just plain wrong. The front valance also looks out, project a line from the bottom of the valance to the bottom of the cylinder and look at where this line sits across the front bogie wheels. Do the same with the model and its almost a scale foot out, either the body is sitting too low on the chassis, the bogie wheels are too large, or the valance is considerably out. Given that the cylinders sit too low by almost the same amount would suggest that the body sits too low, but the driving wheels are obscured at the top by about the right amount, so I think the whole lower front end is out.

That would bug the hell out of me now that I've noticed it because I don't think its easily fixable, if I wanted one. And it bodes poorly for a fully valanced model as a full valance will clearly show the discrepancy unless corrections were made. Maybe thats why they decided not to do a full valanced model yet, so that corrections can be made. I just love the stick on look of the chimney too, but thats fixable with filler, a file and some black paint.

edit ~

I've had a tinker with an image of the model and added in the parallel lines that the streamlining should take in relation to the cab floor and the approximate position in relation to the size of the bogie wheels.



Yellow line is the projection of the original valancing and lower limit of the cylinders of the prototype, the thin red line below that is where the cylinders and front valance of the model actually ends. From that quick scribble I'd say the cab floor sits a fraction too high as the vertical line projected forward from this point is too high in relation to the driver axle centers, but its only very slightly out here and could be down to assembly. However, the entire front cylinder and valve gear mounted to it is 2mm+ too low, the slide bar on the prototype is completely obscured by the side valancing. And the front valance is out by the same amount as the cylinders which also appears to drag the buffers too low and so presumably affects the shape and profile of the front end to make up the discrepancy in the valance and buffer height.

Compare the lines I've drawn with THIS profile photo of 'Dominion of Bittern'.
« Last Edit: March 28, 2012, 03:02:03 PM by Zunnan »
Like a Phoenix from the ashes...morelike a rotten old Dog Bone


Offline BernardTPM

  • Trade Count: (+1)
  • Full Member
  • ***
  • N Gauge Society Number: 3490
  • Posts: 694
    • Awards
Re: Dapol A4
« Reply #62 on: March 28, 2012, 03:09:09 PM »
Looking at those side-on shots, it looks as though the Dapol casing falls all the way from the front of the cab to the nose whereas the real loco climbs to about where the dome is (under the shrouding, of course), then falls.

Online Dr Al

  • Trade Count: (+49)
  • Full Member
  • ***
  • Posts: 4878
  • Country: gb
  • Gender: Male
    • Awards
Re: Dapol A4
« Reply #63 on: March 28, 2012, 03:28:25 PM »
Zunnan, thanks - and you've confirmed my worst fears - the whole front end is indeed wrong, not just the cylinders.  :thumbsdown: :thumbsdown: :thumbsdown:

Cheers,
Alan
Quote from: Roy L S
If Dr Al is online he may be able to provide a more comprehensive answer.

“We have also arranged things so that almost no one understands science and technology. This is a prescription for disaster. We might get away with it for a while, but sooner or later this combustible mixture of ignorance and power is going to blow up in our faces.” – Dr. Carl Sagan

Offline Zunnan

  • Trade Count: (+7)
  • Full Member
  • ***
  • N Gauge Society Number: 17178
  • Posts: 336
  • Country: 00
  • Gender: Male
    • Facebook
    • Awards
Re: Dapol A4
« Reply #64 on: March 28, 2012, 03:46:24 PM »
Looking and thinking about it more, I think they have the measurement from the chimney top to the cylinder bottom about right. The problem is that the whole front end is mounted too low, which results in the cylinders sitting too low. Pack up the body at the front of the chassis by the right amount and I think you'll improve it; the problem here is that the running plate appears to be correct in relation to the drivers. Factor in the missing bulge for the dome (as BernardTPM pointed out) that I hadn't noticed, it looks like the shell is wrong from the cab forwards to the dome instead of from the cylinders down as I had believed. If the tapering down of the front end started from the dome, as it should, then the whole front end would probably sit higher by the right amount as it wouldn't have as far to taper down.
« Last Edit: March 28, 2012, 03:53:30 PM by Zunnan »
Like a Phoenix from the ashes...morelike a rotten old Dog Bone


Offline Karhedron

  • Trade Count: (+1)
  • Full Member
  • ***
  • N Gauge Society Number: 19444
  • Posts: 2377
  • Country: 00
    • Awards
Re: Dapol A4
« Reply #65 on: March 28, 2012, 03:59:15 PM »
Dapol seem to have trouble with their steamers. The B1 apparently had errors in the cylinder area (not an LNER man so I cannot confirm). The Hall was reasonably accurate dimensionally but let down by careless detail errors.

Dapol seem to take great care with their diesels (witness the evolution of the Western on RMWeb) but then chuck out steam engines without any great effort. I cannot understand why as in most cases there are prototypes preserved for measuring (or even laser scanning).

Why do steam engines seem to merit second rate development?
Well, that's just not good enough. Some fount of all knowledge you are!  :no:  ;)

Online Dr Al

  • Trade Count: (+49)
  • Full Member
  • ***
  • Posts: 4878
  • Country: gb
  • Gender: Male
    • Awards
Re: Dapol A4
« Reply #66 on: March 28, 2012, 05:21:44 PM »
Oh dear....

I wonder if the Farish shell would fit the Dapol chassis....... ???
Quote from: Roy L S
If Dr Al is online he may be able to provide a more comprehensive answer.

“We have also arranged things so that almost no one understands science and technology. This is a prescription for disaster. We might get away with it for a while, but sooner or later this combustible mixture of ignorance and power is going to blow up in our faces.” – Dr. Carl Sagan

Online Dr Al

  • Trade Count: (+49)
  • Full Member
  • ***
  • Posts: 4878
  • Country: gb
  • Gender: Male
    • Awards
Re: Dapol A4
« Reply #67 on: March 28, 2012, 05:23:37 PM »
it looks like the shell is wrong from the cab forwards to the dome instead of from the cylinders down as I had believed.

To the eye the cylinders still look way too large as compared the prototype - I would need to measure and compare more to see what else is wrong (though the kink in the top of the boiler just behind the chimney *looks* odd also).

Cheers,
Alan
Quote from: Roy L S
If Dr Al is online he may be able to provide a more comprehensive answer.

“We have also arranged things so that almost no one understands science and technology. This is a prescription for disaster. We might get away with it for a while, but sooner or later this combustible mixture of ignorance and power is going to blow up in our faces.” – Dr. Carl Sagan

Offline BernardTPM

  • Trade Count: (+1)
  • Full Member
  • ***
  • N Gauge Society Number: 3490
  • Posts: 694
    • Awards
Re: Dapol A4
« Reply #68 on: March 28, 2012, 06:41:35 PM »
I wonder if the Farish shell would fit the Dapol chassis....... ???
What about the rather nice Foxhunter kit? That always cried out for larger wheels.

Offline Zunnan

  • Trade Count: (+7)
  • Full Member
  • ***
  • N Gauge Society Number: 17178
  • Posts: 336
  • Country: 00
  • Gender: Male
    • Facebook
    • Awards
Re: Dapol A4
« Reply #69 on: March 28, 2012, 06:55:07 PM »
I think its all down to the pitch of the boiler. If you project a horizontal line from the apex of the cab roof forwards, the dome is lower than it should be and the chimney is about as far below the roof height as the cylinders are mounted too low. I think the fix would be to remove the cab and tilt the whole front of the body and cylinders up by the correct amount and then refix the cab onto the shell at the correct angle. This won't fix the running plate, or the 'kink behind the chimney' (which suggests that the front wedge is raked back too far at the top?), but it will mean that the dome, cylinders and chimney are at the correct height.
Like a Phoenix from the ashes...morelike a rotten old Dog Bone


Offline Elvinley

  • Trade Count: (+1)
  • Full Member
  • ***
  • N Gauge Society Number: Lapsed
  • Posts: 1124
  • Country: gb
  • Gender: Male
    • YouTube
    • Elvinley YouTube
    • Awards
Re: Dapol A4
« Reply #70 on: March 28, 2012, 07:45:22 PM »
To be honest, none of this would matter too much to me if the loco runs well. My main concern is the running qualities as I have had some real problems with Dapol (and Ixion) steam so far. I have aslo had some winners, so it's not all bad by any means.

Offline Roy L S

  • Trade Count: (0)
  • Full Member
  • ***
  • Posts: 1865
  • Country: gb
  • Gender: Male
    • Awards
Re: Dapol A4
« Reply #71 on: March 28, 2012, 07:56:46 PM »
Got my Wild Swan today.

Credit to Dapol, a very nice model and as one would expect a massive improvement on the Farish one.

The loco has the right loping "gait" when it runs too, something the Farish one with it's undersize Drivers does not have. Also, have to say that the lubricator link and speedo drive are lovely touches.

It is a nice smooth runner, but so far slow running not in the B17/Ixion Manor league.

Not to like? Not much, the trailing truck is a little light and not very tolerant of less than perfect trackwork, and the nameplates are not especially vell defined, and not a patch on the Farish A1's.

It will just negotiate a 9 inch curve, but there is nothing to spare, second radius is much better - no problem at all.

Not sure the cylinder size issue is that noticable.

Roy

Offline Elvinley

  • Trade Count: (+1)
  • Full Member
  • ***
  • N Gauge Society Number: Lapsed
  • Posts: 1124
  • Country: gb
  • Gender: Male
    • YouTube
    • Elvinley YouTube
    • Awards
Re: Dapol A4
« Reply #72 on: March 28, 2012, 08:39:23 PM »
How about the temperature of the motor after a run?

Offline Stevie DC

  • Trade Count: (0)
  • Full Member
  • ***
  • Posts: 2101
  • Country: 00
    • Awards
Re: Dapol A4
« Reply #73 on: March 28, 2012, 09:04:05 PM »
I saw these at Ally Pally and thought they were very good 'in the flesh'. I can't say I noticed the cylinder issue when viewing the model, I think that this is one of those things that show up more in greatly enlarged photographs.

I haven't got one yet; finances and also I'm thinking of a fix for the lack of valances but most certainly will be buying one or two should Dapol manage to fit valances!

For me the Dapol A4 is a massive improvement on the Farish model as we're getting some great features such as:

- Closer to scale wheels with see through spokes.
- More correct wheelbase.
- Separate handrails.
- Choice of single or double chimney.
- Representation of brake gear.
- Refined valve gear.
- More refined rivet detail.
- Choice of corridor and non-corridor tender (also it doesn't have the cut outs which were only associated with the 1948 exchange locos).
- Couling hook.
- Speedo and lubricator drive linkages.

Yes, I'm sure that there are issues with the model (as people manage to find with Hornby and Bachmann products on 4mm as well...) but I have to say that I'm increasing finding myself disappointed with my older locos as they don't look as good against current productions.

My only concern is that Dapol seem to have a bit of a reputation for poor running. However, I own 6 Dapol locos and they've all run perfectly from the box - I might have been lucky here but once I've got some more funds (and valances!) I'll most certainly be seeing if my luck holds out!  ;D

Offline Newportnobby

  • Global Moderator
  • Trade Count: (+63)
  • Full Member
  • *****
  • N Gauge Society Number: 21962
  • Posts: 32153
  • Country: england
  • Gender: Male
    • Awards
Re: Dapol A4
« Reply #74 on: March 28, 2012, 09:06:20 PM »
In my case, it's 'ignorance is bliss'. If it looks like an A4 it is an A4
I don't have the knowledge to spot such mistakes, so would just say it's an improvement on the last Farish offering. I don't intend to get an A4 of any sort, and can appreciate that to those who know it must be very disappointing that the homework hasn't been done properly/compromise made.

 

Please Support Us!
September Goal: £55.00
Due Date: Sep 30
Total Receipts: £44.00
Below Goal: £11.00
Site Currency: GBP
80% 
September Donations

anything