Completing the 4mm NER 6 wheel coach

[MikeTrice]

Having produced the end drawing time to start adding some detail. As part of my guesswork I am assuming that the end steps should be 9" wide by 6" deep, totally unfounded of course  . For strength my preference is to use a moulded angle as the basis for making them.

 

Take a piece of Evergreen 2mm x 2mm angle (Ref 292). Unfortunately they do not do an 'L' section so we are going to create one:

 

Now take two steel rulers and clamp one of the angles of the styrene then using a knife run it along against the edge and trim off the unwanted bit. Sorry if the photo is not clear. I staggered the rulers to try and show up what I mean, probably unsuccessfully:

 

Now take a piece of prepared angle and cut off sections 3mm wide:

 

You now end up with a small step, here rested on its shallow side:

 

Carefully pare down the corner of the shallow side forming a rough curve:

 

Repeat the process until you have enough steps:

 

The two lower steps are solvented in place, making sure you are using the right end panel:

 

In this instance I used d-Limonene which gave me a little more time to get them positioned and aligned correctly.

 

A pair of dividers were then set to measure the position of the top step from the base of the coach:

 

This was then transferred to the coach and the point on the beading scribed:

 

Using a knife a section of the panelling can now be removed:

 

The top step can now be fixed in place:

 

Repeat the process for the remaining steps, sit back and pat yourself on the back that it went OK:

[MikeTrice]

Sorry, lost the final image:

 

Hmm, that central step looks off centre. Not obvious looking at it directly.

[richbrummitt]

Is the alarm on the same end as the steps? I'm used to seeing it on the other end to the steps, because I'm used to studying GWR.

[MikeOxon]

....

 

Hmm, that central step looks off centre. Not obvious looking at it directly.

Photographs can be painful!  I make something that I'm really pleased with and then take a photo and see all the mis-alignments,out-of-square bits, etc   

 

Fortunately, it seems that other people's eyes are more like mine than like my camera

 

Mike

[MikeTrice]

Is the alarm on the same end as the steps? I'm used to seeing it on the other end to the steps, because I'm used to studying GWR.

Some photos suggest so. T'other end has the valve for the gas lamp feed so I guess they deemed it safer to have people climbing up away from the gas supply.

[MikeTrice]

This is what you get with the Brassmasters Cleminson chassis kit, in this case MC002. You also get quite comprehensive instructions although I think the illustrations could be better:

 

Here are the main parts broken out and the tabs cleaned off:

 

I started as I usually do, and folded up the w-irons:

 

The instructions state: "It may be necessary to trim the width of the ends to enable the w-irons to fold correctly". This is an understatement and should read "It will be necessary" due to an obvious mistake in the artwork. Unfortunately having bent up the w-irons first I could not easily get to the ends to make them narrower:

 

In the end I managed to get a jeweller's saw in and as you can see have managed to trim back the nearest corner:

 

After treating the remaining corners the sides can now also be folded:

 

Here are all the main components folded:

 

To allow various different wheelbases to be built there are various tabs, arrow, numbers and letters that need to be assembled in a particular way. These are very clearly stated in the instructions. Here the pivot plates are soldered in place (after clamping with a clothes peg):

 

What you are left with on t'other side are these overlong tabs:

 

These need trimming back, thus:

 

The main parts all assembled. I should add that at this point I realised that the holes were all undersized and needed opening up, something not mentioned in the instructions. Perhaps it is deemed too obvious:

 

One of the pivot screws is soldered in place. Unfortunately the recess for it is also slightly undersized:

 

The tabs for the strengthening ribs also need filing back as has been done on the end ones. Note the three sets of stabilizing domes:

 

Only the pair that correspond with the pivot point should be left:

 

Fitted Romford Mansell wheels using the bearing provided by Brassmasters and ARGHHHH the w-irons splay alarmingly:

 

Now totally cheesed off

[MikeOxon]

I didn't hit your problem with the W-irons, since I folded the long tabs first and, when I subsequently folded the sides, they seemed to mate up quite well. They also ended up slightly further apart, so not as splayed as yours but still not parallel. 

 

I agree about the under-size holes but, from comments I received on my blog, I was given to understand that this is pretty usual -still annoying, especially since opening out the holes in the very fragile brake shoe assemblies is b....  awkward.  On the second chassis I made, I opened out all the holes while still on the fret, which was very much easier - see my diagram at http://www.rmweb.co.uk/community/index.php?/blog/1405/entry-13324-six-wheelers-wip/

 

I also agree about the screw heads not fitting in their recesses - the instructions say they are cheese-head screws but those supplied with mine were CS, that didn't fit as described.

 

If you've not found out already, you'll also need to open out the slot in the centre carrier for the 0.9mm rods from the end units to pass through - not easy, either, and should not be necessary! (the slot is in the foreground in your last photo)

 

I gave the kit a 'thumbs up' because it does its job (when completed) very well, and covers a wide range of different wheelbases (which I needed).  I do, however, empathise with your irritations over the fit of some of the parts.  I came to this kit from a 'Scale Link' horse bus, which was extremely fiddly to build, so this kit seemed very straight-forward, in comparison!

 

Mike

 

EDIT: corrected name of source of horse bus

Edited March 3, 2014 by MikeOxon

[richbrummitt]

Some photos suggest so. T'other end has the valve for the gas lamp feed so I guess they deemed it safer to have people climbing up away from the gas supply.

 

Are the mouldings the same both ends then? If not you appear to have the steps on the end where the mouldings suggest that the alarm gear should be?

[MikeTrice]

No the ends are different and you are correct that the steps do go on the alarm gear end as suggested by a couple of photographs.

[MikeTrice]

To resolve the splayed w-irons I have a number of options:

 

1. Throw them in the bin
2. Increase the distance between the w-iron faces somehow
3. Recess the bearings more
4. Shorten the axle.

After some thought I decided to try shortening the axles.

 

The existing axle was cut through with a slitting disk in a rotary tool and the ends dressed up with a file:

 

The wheels were then moved out by gripping the stub axle in a pair of pliers and the wheel twisted outwards. A new sleeve was cut from a piece of 2mm bore styrene tube, 14mm in length and the wheels adjusted to gauge when fitted to the sleeve. The stub axles have then been glued in with UHU solvent free:

 

The axle length has now been reduced to just under 25mm. When fitted to the etched w-irons the sides are now virtually straight:

 

One down, two more to go!

 

Mike, bear in mind that Brassmasters produce two versions of the Cleminson. The version I used was the RCH version.

 

 

Edited March 3, 2014 by MikeTrice

[micklner]

Any reason why you didnt simply grind the end down and then file the axle to a point using a drill if no lathe ?

[MikeTrice]

Yes, I thought it would be easier to cut and rejoin from the middle rather than having to re-engineer the points. In hindsight I still believe this to be the case.

 

Mark II version using K&S #9833 2.5mm brass tube assembled with cyano:

 

More than happy with these.

 

[Jol Wilkinson]

The issue of axle lengths, bearing depths, etc. can be found http://www.clag.org.uk/bearing-interface.html. It goes some way to explaining why w--irons get splayed or axles are a loose fit in bearings. An article based on this was recently published in Scalefour News. The author emphasised the need to carefully match the bearings to suit the w-iron and axle, if it is possible.

[Marbelup]

It looks like you have some damaged pinpoints too, which doesn't help the wheels to run true.  I found they can be restored to some extent with careful filing to remove the squashed bits which are outside the theoretical conical shape.

 

I have also been battling the issue of axle lengths and bearing depths with respect some 3D-printed bogies I designed.  The most recent batch of bearings I obtained was a different depth (deeper), and I ended up modifying the bogie design to accommodate the deeper bearings as they are more easily obtainable than the original ones for which I designed the bogies.  I didn't waste any bogies as I had enough of the original bearings for bogies I had, but changed the design for the latest batch I ordered.

 

After analysing the dimensions of W-irons and bearings, based on 2 types of each, I found one combination which is exactly right for 26 mm axles despite neither the W-irons nor the bearings complying with the "standard" referred to in the CLAG document.  At least I know what is going on now and I have a workable solution resulting in vertical W-irons.

[t-b-g]

I had the same problem with bearings in the Brassmasters W irons. I was advised by a certain Roy Jackson that if I got Markits bearings, they have a deeper hole for the axle to go in. It seems that all bearings are not alike and other makes have a shallower hole, which is what caused the problem.

 

The information on the CLAG site backs this up but at least I can confirm that the combination of Brassmasters W irons and Markits bearings works. At least it did a few years ago when I did mine, manufacturing new batches of bearings may have altered things over the years.

 

New bearings and problem solved, although the solution outlined above has also cured it, new bearings may be the simpler option for future builds.

 

Tony

[MikeTrice]

You might have noticed someone's name appearing in that CLAG reference ;-)

 

The problem with the Brassmasters etch is the distance between w-irons is 23mm which is below the normal recommendations, so even using Romford/Markit bearings is not enough, they do help, but do not completely cure. As stated previously the options are to increase distance between the w-irons, reduce axle length or increase bearing depth somehow. Shortening the axles seemed the simplest, least risky approach.

 

As far as I am aware the pinpoints on the modified axles are unchanged as all modification was carried out in the centre of the axle. The modified wheelsets do still appear to run true (which is one reason I did not try and shorten the axle by regrinding the pinpoints) and they do solve the problem.

 

I must admit I am tending towards trying the Exactoscale parallel axle approach, however they are currently out of stock of the bearings.

[Brassey]

In P4 I doubt we have the luxury of being able to reduce the axle length as the wheels are pretty much on the limits when set to the correct back to back.

 

I have built a couple of the Brassmasters Cleminson underframes and a few of their bogies too in P4.  IIRC they come with tophat bearings supplied and when I used these, i had no problem with 26mm axles.

 

Thanks to Jol for reminding about the article in the latest S4 news about inconsistencies between different manufacturers of bearings; must re-read that one as it's more relevant than I thought!

 

Cheers

 

Peter

 

Edit:  looking again at the images on the thread Mike, you don't appear to have used the bearings supplied which are more cone shaped than the ones you fitted.  You can see them in the first shot of all the components.  Peter

Edited March 5, 2014 by Brassey

[MikeTrice]

Trust me, I did use the supplied bearings. I did later replace the ones in the centre with Romfords and they were slightly better. I accept that you would have issues with shortening the axles for P4, the only real option being to increase the distance between w-irons. It should also be possible to tweak the w-irons by careful bending at the base:

 

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[JCL]

I can send you a Cleminson Inkscape file...

[MikeTrice]

Thanks Jason. I have actually got the Brassmasters' unit to work, but am also tempted to try springing. Currently in experimenting mode.

[micklner]

In P4 I doubt we have the luxury of being able to reduce the axle length as the wheels are pretty much on the limits when set to the correct back to back.

 

I have built a couple of the Brassmasters Cleminson underframes and a few of their bogies too in P4.  IIRC they come with tophat bearings supplied and when I used these, i had no problem with 26mm axles.

 

Thanks to Jol for reminding about the article in the latest S4 news about inconsistencies between different manufacturers of bearings; must re-read that one as it's more relevant than I thought!

 

Cheers

 

Peter

 

Edit:  looking again at the images on the thread Mike, you don't appear to have used the bearings supplied which are more cone shaped than the ones you fitted.  You can see them in the first shot of all the components.  Peter

Could the W irons be fitted/designed wider on the P4 chassis ? design error on the OO version ?

[MikeTrice]

Could the W irons be fitted/designed wider on the P4 chassis ? design error on the OO version ?

I don't think there are specific versions of the chassis available, they are supposed to suit all. There are OO, EM and P4 internal bearing centre units supplied with the etchings, but in this instance are not used. I believe it is just a design error.

 

As a very slight diversion here is a Bill Bedford unit folded up and fitted with Bachmann 3 hole disc and Romford bearings. No drilling of holes required and more importantly no splaying of the w-irons. Unlike the Brassmasters' unit which is designed with 23mm between w-iron faces, Bill's are the more universal 24mm:

 

Likewise the original wheels I used with the bearings did not have a problem in the Bill Bedford unit albeit being too large.

 

These units are obviously not intended for OO wheelsets as the cut outs are not wide enough and the flange bottoms too easily:

Edited March 5, 2014 by MikeTrice

[micklner]

I have had width problems with some D&S and 51L kits in the past inc whitemetal kits so not that unusual. 

 

 

Nice coach Mike, well done.

[MikeTrice]

Why oh why oh why did I choose a 6 wheel coach? Life would have been so much easier with conventional bogies.

 

Having placed the completed Cleminson on a piece of curved track I could not help noticing how much the various trucks stuck out from the centre line. Concerned I mocked up a sample underframe to the correct dimensions and added solebars of 30 thou to provide maximum clearance for the various trucks to rotate. Placing the completed Cleminson in it and offsetting the wheels thus:

 

A quick estimate tells me it might manage 6' radius curves if I am lucky!

 

I need another option.

[micklner]

Flattened flange on fixed centre wheel set aka Chivers Fish Van .