Wheel Counterweights

[Christopher]

Casting Service

In my wheel stock most main wheels come with counterweights of one sort or another. However in some sizes I have up to five different positions of weigh as well as a no weight option. Clearly this presents problem of cost and space.

I have suggested that we only stock the ones with no weights and provide the other to order only.

So far my canvasing of opinion shows that there are two clearly defined camps. Those that always add their own weights as it offers a neater finish and those who want the options because it offers a closer to scale result.

May I seek your reaction to my suggestion.

[Andy B]

I have suggested that we only stock the ones with no weights and provide the other to order only.

That sounds perfectly reasonable to me - allows the most flexibility in the usage of common castings for different classes of loco, at the best price.
Also means you can get new patterns into the foundry quicker if you only have 1 variant instead of 4 (or more) to get made.

Andy

[Andy B]

Request to webmaster - can this thread be moved to a more suitable area of the forum?
It's nothing to do with track construction.

Andy

[IanT]

Generally I'd be supportive of this move Christopher and I don't really see the issue as being either "neater" or "to scale". I see no real reason why they couldn't be both.

It does depend on the position/shape of the weight and how you intend to 'add' them I would think - but generally it should be possible to machine the weight in-situ using the wheel casting itself as a jig. Not too much different from machining cast-on ones really.

So - the "pro" is that you have more flexibility in being able to use a single wheel size (& number of spokes) across a variety of prototype locos vs the "con" of some extra work to add the required weights.

On balance I'd go for flexibility (especially if it helped to keep the cost of castings down!)

Regards,

Ian T

PS Agree this is in the wrong place currently!

[cabbage]

The type of locomotives that I like -don't need cast in weights. I am more the external flycrank user...
I does seem very logical to simply stock the non-weighted wheels and then add the weights yourself.
This would leave you with a more accurate weight, rather than trusting to luck -dependant on
the casting involved.

regards

ralph

[MikeWilliams]

Christopher,

I think your proposal is sensible, so long as the alternative versions continue to be available to order, please.

Mike

[Paul D Peterson]

I would cast my vote for wheels offered sans counterweights, as the several prototypes I hope to model either had no counterweights or very unusual designs that are not too difficult to add. It does seem to me that it is easier to add counterweights to a wheel that has none than to remove counterweights from a wheel that has them--in fact, I for one am too faint of heart to attempt the latter.

For what it's worth, the availability of appropriately sized wheels without counterweights is one of the main things that convinced me that gauge 3 would be worth a try. I would not be here without them.

Paul Peterson

[Christopher]

Many thanks for those comments - most helpfull

[Kalinowski]

Christopher, I must admit that I am split on this question. I have made 6 patterns over the past years - 2 with weights cast in and 4 without. 

Machining wheels with the weights already cast in is quick and easy and they look good.

By contrast the last lot that I turned for an 0-6-0 where I used a no weights pattern and then had to fix brass weights of 3 different types that were required, was a real pain in the backside and after hours of work still look no quite right.

The real question is this - What is the best means of adding weights to a no-weights wheel after it has been turned?      Brass sheet, car body metal epoxy, soft solder, cheese

Regards Peter

[IanT]

Interesting question Peter - and I supect it might depend on the type of wheel/weight combination. Never tried to add weights myself - but I have machined two part metal epoxy to a pretty good finish (filled in a damaged casting) although I was thinking more in terms of a screwed-on plate.

I've always assumed that in real life the balance weights were added after the wheel was turned and the tyres added - rather like the lead weights on a car wheel (after a tyre is changed). I don't think they would have had dynamic balancing as such but I must admit I have no idea of how they were engineered in practice.

But I'm sure someone knows....

Ian T

[MikeWilliams]

An interesting question Peter.

Where the balance weights are cast proud of the spokes on the real engines I have glued on brass shim and filled behind with epoxy, but its not easy to keep the shim flat.  Sometimes the weights are cast flush with, or even slightly recessed from the spokes and I don't know how you'd do that.

The LNWR iron wheels with H section spokes are easier.  I have an etch which sticks on the back of N2.6GA cast wheels, turning their T section spokes into a true H section, and separate etched weights which can be slotted in from the back between the spokes.

On all drawings I've seen the weights have been cast integral with the wheel centre.

Ian, they used dynamic balancing before the Grouping.  Later LNWR express engines had large bosses for the weights.  These were cast hollow, and lead weights inserted from the back as required.  However, so far as I am aware weights at the rim were usually cast solid and calculated before casting the wheel, with no dynamic checking afterwards.

Carriage wheels were also balanced dynamically (or at least Mansell ones were), but I'm not aware that they did the same for wagons.

Mike

[cabbage]

Rhodesia Rails bolted the counterweights onto the wheels, the SAR/SAS used cast in counterweights -despite the same type of locomotive being supplied by Messrs Beyer Peacock... My late father was always an exponent of adding weights to the wheel to get it dynamically balanced rather than drilling holes in the counterweight and / or packing them with lead. When the wheels for an MCR "spinner" came through the works in Derby I do know that he spent some time "sitting looking at them" while he "got the balance right" for machining them. It was one of the most difficult jobs that he ever had to do in his career.

regards

ralph

[bambuko]

...I've always assumed that in real life the balance weights were added after the wheel was turned and the tyres added - rather like the lead weights on a car wheel (after a tyre is changed). I don't think they would have had dynamic balancing as such but I must admit I have no idea of how they were engineered in practice...

In my collection of original/production drawings for American(PRR), German(KPEV), Polish(PKP) and British(Vulcan) steam locomotives, balance weights were always cast integral with wheels. In some the weights were cast hollow to be filled with lead later. I do not doubt that in some designs they were added/bolted on after casting, but no examples in my collection - and I would guess that "cast integral" was preferred option.

Chris