!!

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: Connecting rods and valve gear  (Read 3957 times)

0 Members and 1 Guest are viewing this topic.

Online BobB

  • Trade Count: (0)
  • Full Member
  • ***
  • N Gauge Society Number: 27926
  • Posts: 485
  • Country: za
  • Gender: Male
    • Awards
Connecting rods and valve gear
« on: December 01, 2015, 04:46:01 pm »
A friend of mine has just received his pride and joy from TMC, a slightly weathered footballer numbered and labelled West Ham United. (Is a footballer a B1 or a B17 ?)

As a confirmed diesel fan, I don't normally get very excited about 'kettles' but my friend enthusiasm was infectious. He was so disappointed when he put it on his circuit and it didn't move so whilst not in tears he was rather subdued when he brought it round to me for attention.

A quick inspection revealed bent con rod and valve gear. After some work with the tweezers, and everything on the port side now looking almost as good as the starboard side, off ran the locomotive on its running in session as smooth as a singer sowing machine. After an hour, very quiet, very smooth and able to crawl very well.

Carefully packed away, I've now got a call from him, all the motion is broken and there was a definite catch in his voice.

I've read about how delicate these things are but flipping heck...... I'll try to repair it again but short of telling him not to touch the locomotive wheels under any circumstances I'm rather at a loss to stop it getting damaged again. Is there anything that can be done to make the model stronger ?

Offline MikeDunn

  • Trade Count: (0)
  • Full Member
  • ***
  • N Gauge Society Number: 21391
  • Posts: 3107
    • Awards
Re: Connecting rods and valve gear
« Reply #1 on: December 01, 2015, 05:02:14 pm »
A friend of mine has just received his pride and joy from TMC, a slightly weathered footballer numbered and labelled West Ham United. (Is a footballer a B1 or a B17 ?)
Strictly speaking, it's not a Footballer as it's a Sandringham ... this is the class name for the B17 (all sub-groups).  Now, the sub-group that are known as Footballers are the same locos as those not called Footballers; there was no actual build distinction ... unlike the pair of streamlined B17s that were B17/6.  The sole difference was the name of a football club instead of a country house.

Re the problems - I'd suggest this be taken up with TMC ... I don't think it should be that fragile !!!

Offline silly moo

  • Trade Count: (0)
  • Full Member
  • ***
  • N Gauge Society Number: Lapsed
  • Posts: 1532
  • Country: gb
  • Gender: Female
    • Awards
Re: Connecting rods and valve gear
« Reply #2 on: December 01, 2015, 05:33:23 pm »
I hope you manage to repair the motion. Even if strictly speaking it should probably go back to the UK it might incur more damage in transit both to the UK and back to SA again.

Our locos do a lot of traveling and this one has probably gone from China to Dapol (I'm assuming it's Dapol) lfrom Dapol to TMC from TMC to South Africa and has most likely been flung around by the Royal Mail and South African Post Office. Maybe some barely visible damage was done in the process.

Offline MikeDunn

  • Trade Count: (0)
  • Full Member
  • ***
  • N Gauge Society Number: 21391
  • Posts: 3107
    • Awards
Re: Connecting rods and valve gear
« Reply #3 on: December 01, 2015, 06:52:13 pm »
I hope you manage to repair the motion. Even if strictly speaking it should probably go back to the UK
Oh  :censored: - sorry, didn't realise you're in SA ...  :doh:

Good luck on the repair ...

Offline Atso

  • Advertiser
  • Trade Count: (0)
  • Full Member
  • ***
  • Posts: 1485
  • Country: 00
    • Awards
Re: Connecting rods and valve gear
« Reply #4 on: December 01, 2015, 06:54:01 pm »
Strictly speaking, it's not a Footballer as it's a Sandringham ... this is the class name for the B17 (all sub-groups).  Now, the sub-group that are known as Footballers are the same locos as those not called Footballers; there was no actual build distinction ... unlike the pair of streamlined B17s that were B17/6.  The sole difference was the name of a football club instead of a country house.

Just to correct you, the streamlined B17s were classified as B17/5, I believe the B17/6 referred to those engines rebuilt with dia 100A boilers during Thompson's reign and in BR days. The 'Footballer' class seem to fit into the B17/4 sub category as they were fitted with group standard tenders (the earlier batches were fitted with GER style tenders) and only vacuum brakes (a lot of the earlier batches were dual braked and had a pump on the right hand side of the smoke box), as well as some other refinements that had steadily been made to the design with each subsequent batch built. However, despite the subclass allocation, I believe the name 'Footballers' was not an official LNER designation while Sandringham, being named after the Royal residence, was.

Re the problems - I'd suggest this be taken up with TMC ... I don't think it should be that fragile !!!

Agreed, if TMC won't take it will DCC Supplies still honour the warranty despite the weathering? Might be the best option despite the postage...

Offline silly moo

  • Trade Count: (0)
  • Full Member
  • ***
  • N Gauge Society Number: Lapsed
  • Posts: 1532
  • Country: gb
  • Gender: Female
    • Awards
Re: Connecting rods and valve gear
« Reply #5 on: December 01, 2015, 07:05:49 pm »
Or perhaps DCC Supplies will send you replacement parts, they are generally very helpful.

Offline MikeDunn

  • Trade Count: (0)
  • Full Member
  • ***
  • N Gauge Society Number: 21391
  • Posts: 3107
    • Awards
Re: Connecting rods and valve gear
« Reply #6 on: December 01, 2015, 07:08:03 pm »
Just to correct you, the streamlined B17s were classified as B17/5
D'oh, typo ...  :doh:  As you say, the /6 was the boiler rebuild.

The 'Footballer' class seem to fit into the B17/4 sub category [...]  However, despite the subclass allocation, I believe the name 'Footballers' was not an official LNER designation while Sandringham, being named after the Royal residence, was.
The problem with saying Footballers are the /4, though, is that AFAIK some of the non-Footballers were also given this tender ... there isn't a point of distinction to give this naming other than the name.  At any rate, as you say, it's an unofficial categorisation.

Offline Atso

  • Advertiser
  • Trade Count: (0)
  • Full Member
  • ***
  • Posts: 1485
  • Country: 00
    • Awards
Re: Connecting rods and valve gear
« Reply #7 on: December 01, 2015, 07:14:31 pm »
The problem with saying Footballers are the /4, though, is that AFAIK some of the non-Footballers were also given this tender ... there isn't a point of distinction to give this naming other than the name.  At any rate, as you say, it's an unofficial categorisation.

I'm sure you're right although a very quick scan of my copy of Part 2B of the RCTS LNER green series doesn't seem to back this up. The main differences seem to revolve around the braking systems as well as modifications to the frames and springs of each subsequent batch (apparently these were weak aspects of the design). Visually the only real differences between the Dapol B17 and Sandringham as built would be the Westinghouse pump on the smokebox and GER tender - funnily enough I've had all the parts to build Sandringham for some time but it's yet another project in the 'to do' pile.

Anyway, I've digressed enough from the OP topic - hope you manage to get it sorted.

Offline MikeDunn

  • Trade Count: (0)
  • Full Member
  • ***
  • N Gauge Society Number: 21391
  • Posts: 3107
    • Awards
Re: Connecting rods and valve gear
« Reply #8 on: December 01, 2015, 09:10:43 pm »
The main differences seem to revolve around the braking systems as well as modifications to the frames and springs of each subsequent batch (apparently these were weak aspects of the design).
Done some more digging, found a new source, and have been able to map the various build groups to the locos ... you're right, the /4's all fall into the final batch (from 2 builders) and were named after the Clubs.  What seems to have caused the confusion is the renaming of two of the /2's when the Footballers were coming out after Clubs ...

So it seems we were both right  ::) - and wrong !

Online Webbo

  • Trade Count: (0)
  • Full Member
  • ***
  • Posts: 1627
  • Country: au
    • Awards
Re: Connecting rods and valve gear
« Reply #9 on: December 01, 2015, 11:21:43 pm »
A friend of mine has just received his pride and joy from TMC, a slightly weathered footballer numbered and labelled West Ham United. (Is a footballer a B1 or a B17 ?)

As a confirmed diesel fan, I don't normally get very excited about 'kettles' but my friend enthusiasm was infectious. He was so disappointed when he put it on his circuit and it didn't move so whilst not in tears he was rather subdued when he brought it round to me for attention.

A quick inspection revealed bent con rod and valve gear. After some work with the tweezers, and everything on the port side now looking almost as good as the starboard side, off ran the locomotive on its running in session as smooth as a singer sowing machine. After an hour, very quiet, very smooth and able to crawl very well.

Carefully packed away, I've now got a call from him, all the motion is broken and there was a definite catch in his voice.

I've read about how delicate these things are but flipping heck...... I'll try to repair it again but short of telling him not to touch the locomotive wheels under any circumstances I'm rather at a loss to stop it getting damaged again. Is there anything that can be done to make the model stronger ?

Back to the original question. A year or so ago I received a Dapol A4 from Rails which did a series of bunny hops when first run. It  turned out that the motion on one side was tangled with itself. I know I could have straightened it out, but relented as I imagined the very fine connecting pins to have possibly been stretched or otherwise misformed due to the forces imposed when it was not running properly. I could fix the connecting rods, but was unlikely to get the affected pins into the proper state. Back to Rails it went for a prompt replacement. I know this doesn't help you friend, but I suggest in future that it might not be the best strategy to try to fix these things yourself.

The price of good looks on these locos comes with fragility it seems. Beyond buying more robust locos like the old Minitrixs, I think all we can do is treat them with the utmost care.

Webbo

Offline Les1952

  • Trade Count: (0)
  • Full Member
  • ***
  • N Gauge Society Number: 9060
  • Posts: 636
  • Country: gb
    • Awards
Re: Connecting rods and valve gear
« Reply #10 on: December 02, 2015, 12:25:18 am »
This recalls a conversation I had with Dennis Lovatt of Bachmann at Spalding the other weekend about N-gauge locos (and A2s in particular).  He seemed to be of the opinion that most damage to N-gauge steamers is caused by people grabbing hold of them by the valve gear when picking them up.  I did point out to him (he reads these posts) that I always pick my tender locos up by the cab and tender together.

In the case of Dapol locos my main reason for picking them up like this is so the drive shaft doesn't pop out.  In the case of Farish it also stops any twisting of the drawbar.  In BOTH cases it makes sure that the valve gear doesn't get extra pressure on the rather delicate parts (which are just as delicate whatever the make....)

Les

Offline Elvinley

  • Trade Count: (+1)
  • Full Member
  • ***
  • N Gauge Society Number: Lapsed
  • Posts: 1124
  • Country: gb
  • Gender: Male
    • YouTube
    • Elvinley YouTube
    • Awards
Re: Connecting rods and valve gear
« Reply #11 on: December 02, 2015, 03:51:59 pm »
I think it is fair to say that Dapol valve gear is a lot more fragile than Farish. It is made from much thinner metal which bends easily. This is not to say that Farish valve gear never fails as it does from time to time.

Offline Atso

  • Advertiser
  • Trade Count: (0)
  • Full Member
  • ***
  • Posts: 1485
  • Country: 00
    • Awards
Re: Connecting rods and valve gear
« Reply #12 on: December 02, 2015, 07:58:06 pm »
I think it is fair to say that Dapol valve gear is a lot more fragile than Farish. It is made from much thinner metal which bends easily. This is not to say that Farish valve gear never fails as it does from time to time.

I agree with you here. When N-Stars built my J50 chassis (which is also compensated) I supplied the coupling rods as a 0.25mm nickel silver etch. The rods, while functional, are prone to bending and often need attention to ensure good running is maintained. In the longer term, I'll be replacing these rods with some etched in 0.5mm nickel silver. Looking at my Dapol A3s I'd guess that the coupling rods and valve gear have been etched in c. 0.25mm metal as well. Farish on the other hand seem to be nearer 0.5mm which greatly increases their resistance to bending.

Another weak point in Dapol's design (in my opinion) is their need to mount the valve gear onto the bottom of the running plate. While this may be somewhat prototypical, it doesn't help stripping the loco down and also makes for some difficult repairs if the hanger breaks (although it is doable).

Online BobB

  • Trade Count: (0)
  • Full Member
  • ***
  • N Gauge Society Number: 27926
  • Posts: 485
  • Country: za
  • Gender: Male
    • Awards
Re: Connecting rods and valve gear
« Reply #13 on: December 03, 2015, 05:49:53 am »
My mate brought the B17 around yesterday to see if I could fix it. There was no chance, the rod connecting piston and wheel was detached completely at the piston end. I advised him to send it back to TMC.

I've looked at some Farish steamers and some Dapol and agree with the comments about how fine Dapol's are compared to Farish. Definitely a lot better looking but if they're that fragile have Dapol gone too far in the looks department ? Maybe we need a big sign in the packaging that can't be ignored saying keep your hands away from the connecting rods ?

Offline Dr Al

  • Trade Count: (+49)
  • Full Member
  • ***
  • Posts: 4214
  • Country: gb
  • Gender: Male
    • Awards
Re: Connecting rods and valve gear
« Reply #14 on: December 04, 2015, 09:06:56 am »
They are fragile, but the B17 in particular (as well as the 9F) has a very fragile component that's prone to failure - that being the middle eccentric rod crank pin. These seem to be a casting and as such are weak to rough handling, commonly snapping off leaving a stubb in the wheel. Dapol don't seem to offer spares, so unless you have a scrap loco to pull them from it can mean the loco isn't easily repaired.

I don't know if an option would be to 3D print (in the newly rising 3D-printed metal) a replacement part?

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

 

Please Support Us!
August Goal: £65.00
Due Date: Aug 31
Total Receipts: £67.50
Above Goal: £2.50
Site Currency: GBP
104% 
August Donations


Advertise Here
anything