Wagon Suspension Systems Discussion

[Brian T]

Hi All,
I have a number of Parkside Dundas Wagon kits that are long overdue for constructing, so with xmas approaching I'd like to get some bits on order in able to receive them in time.
Rather than a simple "I use product X", I wondered what are the current thoughts regarding what wagon suspension system products are available and also advantages/disadvantages of each - everything from fixed W-Irons through to rocking 3-point units and springing systems.
It would also be useful to understand how to select the correct pattern of W-Iron (e.g. BR, RCH etc.) where appropriate.
Many thanks!
Brian

[jim s-w]

Hi Brian

Does this help at all?

http://www.p4newstreet.com/welcome-to-spring.html

Jim

[Guy Rixon]

There was previously some discussion in another thread:http://www.scalefour.org/forum/viewtopic.php?f=39&t=4353

Among the sprung systems, I've tried the following.

Bill Bedford axleguards, sold as a separate product. Very simple, and very flexible, but you have to set up many of the critical alignments yourself; see the thread noted above for some details. The spacing between the axleguards for one axle is set slightly over-scale (should be 24mm between centres for the RCH 1907 spec, 25mm for the 1923 spec, actually 25.5mm) such that the axle end-float comes out about right with typical (e.g. Gibson) bearings.

Bill Bedford suspension in his recent mixed-media kits. As above, but the axleguards are etched in one piece with the wagon floor so the alignment is done for you. The distance between solebars, and therefore between axleguards, is to scale and therefore you need bearings with deeper coning than typical; the Markits bearings are reckoned to be good here.

Prickly Pear suspension. Seems fairly simple to set up. Will L. tested it and found dubious stability with heavy wagons. I tried it and found the axleguards to be so tall that they couldn't be fitted to an open wagon while retaining the right buffer height.

Exactoscale FASS (Weller & Cross era, no longer in production). My favourite in terms of ease of construction; pity it's out of production. It uses parallel bearings for the axles, so the stock is not as free running as with pin-points bearings. The axleguards were typically supplied etched in pairs to set the wheelbase, and the end-float on the axles could be controlled with washers, so the spacing between solebars became less critical. Jigs were needed, and sold by Exactoscale, to set the axles square. The Exactoscale wheels sold by C&L suit this system if you buy the right axles.

Exactoscale FASS Mk2 (currently sold by C&L). The evolved version of the FASS, with the axleguards folding down from a floor piece such that they are automatically in alignment. A highly-engineered system, it works well if you follow the instructions carefully; the details matter!

Ambis sprung axleguards. Very similar to the Bedford ones, but you have a lot more preparation to do on each axleguard and you have to fit the deep-coned bearings to get them to work at all.

Other brands exist: I have some Craig Welsh and some Morgan Design parts in stock to try.

[barhamd]

Whichever system you go for (personally I like the Bill Bedford ones from Eileen) get yourself one of the Brassmaster's spacing jigs. Sticking the etched W irons to the bottom of a wagon KNOWING it is square is half the battle.

David

[Will L]

...Other brands exist: I have some Craig Welsh and some Morgan Design parts in stock to try.

Not forgetting the Masokits who do both the now "traditional" guitar wire type units and his original etched stainless steel spring.

[grovenor-2685]

Whilst 3 point suspension compensation systems are still on offer I would avoid them for kit building. Either Bill Bedford or Masokits sprung versions do a good job if you are happy using the brakes etc supplied with the Parkside kits. The Craig Welsh underframes are in another league for complete detailing but if you have a pile of kits there you need a hefty budget.
So far as the style of W-iron goes you need to check what the prototype used, most if not all of the Parkside kits will be covered in either the BIll B or the Masokits range, many in both.
If you need help with that list out the kits and someone is bound to know.
Regards

[Ian Everett]

Given that the combination of Parkside kit and etched W irons is the de facto standard for fine scale wagon building, it should be in the manufacturers' interests to cross refer kit to suspension type in a web-accessible table. That way we'd spend less time on researching and more on buying and building kits.

How about it, Bill? (Other suspension manufacturers are available...)

Or maybe that is the sort of thing we could all contribute to and keep up-to-date if there was a Scalefour Society Wiki?

Ian

[dal-t]

Given that the combination of Parkside kit and etched W irons is the de facto standard for fine scale wagon building, it should be in the manufacturers' interests to cross refer kit to suspension type in a web-accessible table. That way we'd spend less time on researching and more on buying and building kits.

Yes, but for some people research is half the enjoyment of a build - and you never know what it is going to turn up. Checking axleboxes may lead to reviewing buffers, doorstops, brake gear, perhaps even picking up details of loading/unloading and operating patterns. But personally, I do often slip into the 'press on and build' frame of mind, particularly if I seem to have hit a research dead-end, so there are times when I would very much welcome such a list.

How about it, Bill? (Other suspension manufacturers are available...)

Oh come on, you know Bill's response to that - if you don't have such detail by heart, you shouldn't be buying his bits!

Or maybe that is the sort of thing we could all contribute to and keep up-to-date if there was a Scalefour Society Wiki?

Big 'Hear, Hear' to that - but what has happened to the Wiki? Will has gone off and done his 'Everything you could possibly (not) want to know about CSBs' opus (and, ribbing aside, I applaud him for it) but where does the rest of the Wiki idea reside?

[grovenor-2685]

Big 'Hear, Hear' to that - but what has happened to the Wiki? Will has gone off and done his 'Everything you could possibly (not) want to know about CSBs' opus (and, ribbing aside, I applaud him for it) but where does the rest of the Wiki idea reside?

By Will's opus I assume you mean this topic http://www.scalefour.org/forum/viewtopic.php?f=96&t=3605&hilit=CSB
It is not currently a Wiki but i agree it could be used as content for one. As could this wagon suspension topic.
Perhaps John can find a bit of time to set one up.
Regards

[Mike Garwood]

If we're talking about Parkside wagons, then you'd be hard pressed to better with sprung under frames than Justin Newitts range of sprung bits. Providing that he does one suitable for your wagon.

http://rumneymodels.co.uk/index.html

No messing about setting anything up, a straight forward build. My only gripe is the 0.3mm holes he insists on using (which I open out to 0.4, I can see that)...this is probably where failing eyesight doesn't help. And he knows I'm kidding!

Totally recommended.

Mike

[Paul Willis]

Big 'Hear, Hear' to that - but what has happened to the Wiki? Will has gone off and done his 'Everything you could possibly (not) want to know about CSBs' opus (and, ribbing aside, I applaud him for it) but where does the rest of the Wiki idea reside?

I'm afraid that's with me. And time taken up on other matters has rather pushed it down the list of priorities.

However now that you mention it, it is sufficient kick up the a**e to renew my efforts on it.

Just to be absolutely clear, WebmasterJohn has done a superb job in finding and setting up a suitable tool. It's primarily up to me to take that to the point that it can go live. And my apologies that it has taken longer than I expected.

Cheers
Paul Willis
Deputy Chairman

[billbedford]

Given that the combination of Parkside kit and etched W irons is the de facto standard for fine scale wagon building, it should be in the manufacturers' interests to cross refer kit to suspension type in a web-accessible table. That way we'd spend less time on researching and more on buying and building kits.

How about it, Bill? (Other suspension manufacturers are available...)

I see that you don't quite understand how marketing works...

What modeller should be doing is buying a stock ( half a dozen sound like a nice round number) of each of the w-irons available an then they can pick the best choice simply by matching the picture on the front of the kit.

[dal-t]

What modeller should be doing is buying a stock (half a dozen sound like a nice round number) of each of the w-irons available an then they can pick the best choice simply by matching the picture on the front of the kit.

Strangely enough (and proving that I do agree with Bill from time to time) that's pretty much what I have been doing - although I tend to match from photos before i actually acquire the kit, and I'm not sure I've stuck to the half a dozen bit. However, Bill will be pleased to know there are still one or two variants of his w-irons I haven't acquired yet which are definitely on my 'to get' list (even though I suspect they're the ones I'll never have a real use for!) - so minor bump to the cash-flow forecast for next year sometime ...

[Noel]

Note that all options mentioned have cost implications, which no-one has mentioned. If you are on a limited budget there are cheaper options, which may be adequate for your purposes [and easier to use, sometimes], even if not so good in theory.

Noel

[jim s-w]

I don't agree that brass w irons are defacto for p4 wagons. Anything bigger than a grampus is my rule. Smaller doesn't need it.

Cheers

Jim

[Mike Garwood]

I don't agree that brass w irons are defacto for p4 wagons. Anything bigger than a grampus is my rule. Smaller doesn't need it.

Cheers

Jim

Interesting...do add any additional weight to your smaller wagons?

Mike

[jim s-w]

Hi mike

I just use 2 x 10 gram wheel weights on the small ones. Seems fine

HTH

Jim

[Philip Hall]

I agree with Jim that a rigid (but true) short wheelbase vehicle with a bit of weight runs just fine. There is a caveat, though, and that is that the wheels should be absolutely concentric, otherwise the thing will sway around like a fishing boat in a Force 10. I usually add weight to bring a wagon up to the standard 50 grams, maybe a touch more, and as the wheelbase increases a bit more still. For example, I am just finishing off a conversion of the lovely Hornby LMS horsebox, and that weighs in at 63 grams. I used Ultrascale wheels and it runs very well, probably not a silky as a sprung vehicle but then didn't have to spend a lot of hacking the underframe about! And there's a lot of very nice detail in that underframe...

I often do the same for a kit built short wheelbase wagon, but only when I am sure it's true and square.

Philip

[martin goodall]

A variation on the rigid suspension idea for wagons that I have used successfully for many years is to build in a bit of 'slop', so that the pin-points of the axles are not held rigidly in their bearings, but can move around a bit.

No doubt there are all sorts of theoretical objections to this, but in practice (which is what really counts) it seems to have the effect of a very crude form of compensated suspension, and produces a very sure-footed model.

[Guy Rixon]

A variation on the rigid suspension idea for wagons that I have used successfully for many years is to build in a bit of 'slop', so that the pin-points of the axles are not held rigidly in their bearings, but can move around a bit.

No doubt there are all sorts of theoretical objections to this, but in practice (which is what really counts) it seems to have the effect of a very crude form of compensated suspension, and produces a very sure-footed model.

And this is possibly why you need the big flanges. A wheel-set that is loose in its bearing carries no weight when it runs over a dip in the track. In this state, it will be very prone to flange climbing; full-size trains have this problem too. However, if the flange is deep enough, the wheel-set will rise to the top of the slack bearing as the flange starts to climb over the railhead. It will then be carrying weight again and the weight will stop the climbing.

Effectively, the weight is transferred automatically onto the wheel that's about to climb off the track. You'd get the same effect with a rigid axle. This, presumably, is why coarse-scale models stay on the track, even the Dublo trains with no wheel-coning and tramway curves.

If the flange is very small and the slack in the bearing is very great, the flange may clear the railhead before the wheel picks up its load. This, IMHO, is why the EM flanges help. I predict that they don't help as much in stock that is properly sprung or compensated such that all wheels are loaded for all track conditions.

[martin goodall]

Actually, I did it with P4 wheels, and found it totally effective and reliable.

When using EM wheels, I find it is unnecesary to add any slop, because the extra depth of flange gives you just that bit more lateral guidance and support.

[jim s-w]

Hold on to your hats, I agree with Martin and have added a smidge of slop at one end for 20 years. It works absolutely fine. There's no point comparing the theory to the real thing as the real thing doesn't have pin pont axles.

Cheers

Jim