Commonality of mechanism parts

[34theletterbetweenB&D]

Following this comment by 'Cheesysmith' : "The piece you need is the bogie top retaining clip. Iirc all the Heljan locos use the same part, so don't be worried by the class 47 sprue not being in stock", as a relative newcomer to Heljan's product I have a follow on question.

 

It is very obvious from the exploded diagrams that the internal mechanism layout of the twin bogie traction follows a standardised format. Excluding those components that must have dimensions specific to a prototype, such as drive shaft lengths for correct bogie centres, and gear towers to provide correct ride height and wheelbase, are the generic mechanism parts generally interchangeable? (I have already swapped 14mm geared wheelsets into a unit with 12mm wheelsets with no trouble.)

 

 

[cheesysmith]

The only way of find out is to take them apart. There is different mod5 gears used internally, but having taken more than a few apart, the worms appear identical between all the versions. Same with the yoke (I think there is different ones for the Clayton) and other bits.

[Grizz]

Morning all. Did some investigating as to why one of my Heljan class 47s fail in traffic yesterday. Loco came to a halt and then wouldn't move. Removed the body, some what tight and took ten minutes, although no chassis rot etc. It appears that the top bogie tower retaining clips have shifted, oddly at both ends. 

 

Had a closer look and the three sided clips are both broken, snapped along the 90 degree angle down one side. Hence they no longer retain the bogies........thus followed an out break of 'them words'!!!

 

Anyone experiend this sort of thing before? I have a reasonable number of Heljan locos and this has not occurred to any of mine before. 

 

Howes appear to be out of spares for Class 47s, for this part anyway. 

 

Will a class 58 top bogie tower retaining clip fit it? It looks to be the same moulding.....

 

cheers all.

 

ATB Grizz

[34theletterbetweenB&D]

Exactly the style of question I have. Well, you need the part, so why not give it a whirl with an alternative and let us know one way or t'other in this thread?

[Allegheny1600]

I'd be very surprised if model manufacturers didn't use as many common parts as possible - it's just good sound engineering sense.

Seeing as most modern mechanisms are based upon the old 'blue box' Athearn (USA) mechanism anyway - I was not surprised to find that my LifeLike Proto 2000 (USA), Hornby (UK!) and Brawa (Germany) mechanisms were clearly all very closely related and apparently, interchangeable.

I've never had cause to swap and change any parts but I'm absolutely certain that I could if I wished.

No doubt this was due to the models all being assembled in the same factory?

Cheers,

John.

[pheaton]

13 hours ago, Grizz said:

Morning all. Did some investigating as to why one of my Heljan class 47s fail in traffic yesterday. Loco came to a halt and then wouldn't move. Removed the body, some what tight and took ten minutes, although no chassis rot etc. It appears that the top bogie tower retaining clips have shifted, oddly at both ends. 

 

Had a closer look and the three sided clips are both broken, snapped along the 90 degree angle down one side. Hence they no longer retain the bogies........thus followed an out break of 'them words'!!!

 

Anyone experiend this sort of thing before? I have a reasonable number of Heljan locos and this has not occurred to any of mine before. 

 

Howes appear to be out of spares for Class 47s, for this part anyway. 

 

Will a class 58 top bogie tower retaining clip fit it? It looks to be the same moulding.....

 

cheers all.

 

ATB Grizz

They appear to be a standard size, I've just extracted two from a class 33 scrapper to give to someone who needed them but they appear to be exactly the same as those fitted to a class 58 and since a 58 is a coco it's reasonable to assume they will fit a 47...

[Grizz]

Cheers Pheaton, sounds like a solution. Must have been a Friday afternoon batch of injection mouldings in my 47. I have never had any Heljan loco do this before. 

 

Hopefully this his was just a one off.......

 

 

 

 

[34theletterbetweenB&D]

4 hours ago, Grizz said:

... Must have been a Friday afternoon batch of injection mouldings in my 47. I have never had any Heljan loco do this before...

More likely start of week in my very limited* experience of injection moulded plastics part production. Mould not fully up to operating temperature, leaving significant residual stress in the components due to differentials in cooling rate.

 

(*I did a quick sidestep back into sensible metal based processes when it looked like there was a risk of being trapped in the nasty plastic squidging operations.)

[Grizz]

Just a quick progress report on the Heljan Class 47 broken bogie retaining clips. Finally got round to ordering them from Howes Models. The class 47 sprue they would have originally been fitted from was no longer available so I took a punt on £2.25 x 2 Hymek spures as they looked the same type. 

 

This is afternoon I fitted one on one of the bogies. It was a bit fiddly getting everything to line up but it clipped in fine and all looks ok. So the answer is that it would appear to be a common part, well common to 47s & 35s anyway.

 

Hopefully, if I don't have too much Harveys liquid anaesthetic this evening, I might get round to fitting the bogie at the other end. Who knows it may even get a test run.....probably not though as I have 12 Pints of 'Old Ale' fresh of the barrel....life's really tough some days....but this ain't one of em.