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Chassis for a 6 wheel carriage help please


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I want to build some six wheeled GCR carriages, but who does the best chassis to go with them? MJT / Brassmasters or someoneelse?

I have the sides and ends already but will need to build up the chassis, MJT is a third the price of brassmasters but does it work as well?

Help/ advice please,

Richard

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There is also the comet axle guards set for 6wheelers. This has three axle guards that are compensated, the centre one being able to have a (supplied) centre bearing fitted which, when the pinpoints have been removed from the axle ends, allows side play. From memory they are comet part c7.

Bargin at less than a tenner too!

 

Andy g

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The Brassmasters Cleminson can cause problems if the underframe is very full, it sometimes fouls things like gas tanks. As an alternative to these, I've made a few where one axle is fixed, one rocks and the centre one just floats about. The only photo I can find is from a Roger Chivers LMS 6 wheel fish van:

 

lms6w.jpg

 

This one has fixed axles both ends, but you get the idea. The centre axle runs on one of those Comet fold up cradles mentioned above, attached on the end of a length of .45 wire.

 

There are several ways to set up the centre axle - Bill's website has an idea with sliding tubes which would work just as well - but I can recommend the Comet bits.

Edited by jwealleans
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Didn't you read and understand Alan Austin's piece in Snooze 196?

 

I've calculated that in P4 with 1mm end float in the centre axle, models with a 11' x 11' wheelbase will go round 30in curves.

Edited by billbedford
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Good morning all

 

The Brassmasters Cleminson chassis is a beautiful piece of work. I have fitted one to a six wheel passenger brake van, and it runs very smoothly, even over bad joints on my test track.

 

I recently tried the tube method on the chassis for a six wheel GER 20T brake van.

 

I didn't have any 1mm axles, so used a spare Gibson pinpoint axle from Gibson tender wheels. I used brass tubing a fraction over 2mm so it slides easily.

 

The pics shows the centre wheels pushed as far left a possible.

 

Earlswood nob

 

 

post-3118-0-99355300-1462264163_thumb.jpg

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I tried sliding centre wheelset in EM and it wouldn't go round 750mm curves. I even made the outer wheels pivot and it still wouldn't go round. I was using MJT inside bearing pedestals, using a 00 one would have given more swing on the centre axle but I haven't done any more on it as I plan to build a new underframe of better appearance and  hopefully better function! 

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Didn't you read and understand Alan Austin's piece in Snooze 196?

 

I've calculated that in P4 with 1mm end float in the centre axle, models with a 11' x 11' wheelbase will go round 30in curves.

Yes and yes, but it didn't change my views on taking a pragmatic approachto P4 to modelling.

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Yes and yes, but it didn't change my views on taking a pragmatic approachto P4 to modelling.

 

 

So what happened when you tried It?

 

As far as I can see there are two ways of dealing with long wheelbase six wheelers. One is to have the wheel sets slide on the axles. This gives about ± 1 mm side play on the middle axle in P4 and EM or about ± 2.5 mm in OO. The other is to have someway of moving the middle w-iron across the floor. This will give around ± 1.5 mm side play in all three gauges, unless the solebars are moved outwards.

 

Of course this doesn't apply to short wheelbase stock, such as brake vans or tenders, as the rail/wheel slop is big enough to accommodate fixed axles in all three gauges.

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So what happened when you tried It?

 

As far as I can see tanhere are two ways of dealing with long wheelbase six wheelers. One is to have the wheel sets slide on the axles. This gives about ± 1 mm side play on the middle axle in P4 and EM or about ± 2.5 mm in OO. The other is to have someway of moving the middle w-iron across the floor. This will give around ± 1.5 mm side play in all three gauges, unless the solebars are moved outwards.

 

Of course this doesn't apply to short wheelbase stock, such as brake vans or tenders, as the rail/wheel slop is big enough to accommodate fixed axles in all three gauges.

The first six wheeler I built -other than a misguide attempt at a K's kit - was a Mallard Models LNWR/WCJS six wheel fish van which has a  fixed axle at one end and what is effectively a inside bearing bogie at the other. It was made about thirty years ago and used Mike Sharman's "Flexichas" ideas on compensation. The theorists would probably poo-poo Mike's approach nowadays but it still runs very well on London Road.

 

I've also built several six wheelers with D&S/Microrail underframes but those aren't very good. When John Redrup wanted to introduce the LRM the LNWR six wheel carriages, he asked me to design a Cleminson underframe for them as it was likely that a number of customers would want them to go round fairly tight  curves. Many modellers don't have the luxury of a lot of space and in OO in particular 24" radius or less is not uncommon, especially on "hidden" sections. In those circumstances a Cleminson chassis, rather than one with a long "fixed" overall wheelbase offer advantages.

 

Of course we can bat around various theories and experiences, but the "best" answer will depend on a number of variable for each model and model maker.

 

Jol

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Whilst on the subject of six wheelers does anybody know if the Hornby body is actually to scale or not? I have heard it's not!  I don't have any scale drawings for it and considering it's not likely to go anywhere other than where it currently squats it shouldn't really matter but curiosity still gets the better of me! I am told that the Comet example is OK but I don't have one available to compare with the Hornby version. Photographs tell me nothing.  Advice would be greatly appreciated.Regards. Serron.

Opinion in the WMRC is that it is overwide. Cuttng down the centre line brings it more to scale width

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There's a whole thread on it somewhere on here - search for 'Dapol Stove R', I think.

 

I like the look of mine, but I'm not an LMS expert and haven't measured it. My recollection of the thread was that the body was OK but the undersize wheels ruined it, so I did as you have and replaced with correctly sized wheels and Comet bits - which brings this little deviation nicely back to the OP's original question.

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Good morning all

 

I purchased some thin-wall brass tubing and brass rod when visiting the model shop on wednesday.

 

The tubing was 2mm OD with 0.225mm walls. The rod was 1.5mm.

 

The tubing is an interference fit to Gibson wagon wheels.

 

I cut a 26mm length of the brass rod and made pin-point ends by putting the rod in my Dremel and using a needle file.

 

I had to use a small broach to clear the tubing of swarf etc, so tube slid easily along the rod.

 

The result was a replacement wheel set for middle axle of six wheeled vehicles, which runs well and is simple to make.

 

The camera battery is flat, so a pic will be taken later.

 

Earlswood Nob

 

Earlswo

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Here's a pic of the 8-wheel chassis for a GNR brake van.

 

The central two axles are allowed to slide sideways. The pic shows one at extreme left movement and the other at extreme right.

 

The end two axles are fixed pinpoint axles.

 

Earlswood nob

post-3118-0-44329600-1462524012_thumb.jpg

Edited by Earlswood Nob
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I've found a pic of a large horsebox under construction.

I've used Brassmasters Cleminson chassis. The chassis is a beautiful piece of work and it runs very smoothly. It is quite difficult to photograph as it rolls so freely, that it finds slopes at places that  I think are level. In fact shortly after the pic was taken it ran away and fell onto the floor suffering damage.

 

Earlswood nob

post-3118-0-23581000-1463127824_thumb.jpg

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