The plan is to build a model of 76010 picking up on the errors made on 76009.

There are some differences. 76009 was based on a Comet Chassis, this is based on a Branchlines chassis.

This blog will record my progress both good and bad. Your comments and suggestions are welcome. Hopefully this will help anyone who wants to see how this chassis goes together or even want to see how to put together an etched chassis /kit. This is how I do it...this time around. It is neither right nor entirely wrong.

So here is the starting point...Define the problem

This will be a model of 76010 built in EM gauge as she was in May/June 1960. The target is to have this running at the Chatham show in June. But that looks really too close so lets set a more realistic target...the plan is to get the chassis rolling around the EMGS test track at ExpoEM in May. For the record I broke the seals of the pack during the Christmas holidays* so this is progress up to the end of January.

Branchlines sell several packs for the Class 4. I will only be using two of them as the complete pack contains parts to make an OO chassis.

The first pack is a chassis pack while the second is the detail pack. For the moment the latter will be put to one side.

Here are the contents of the chassis pack.

The next task is to read through the instructions which include a nice exploded diagram. Now we identify the parts on the fret and bag.

Then it’s time for a little maths.

Frame width!

The etch is .018†(0,46mm) thick Nickel Silver.

The frame spacers provided are;

OO = 10,7mm

EM= 13mm

P4=14,6mm

The spacers are tabbed and fit into slots on the frame.

The calculated overall frame width for each gauge is therefore.

OO = 11,62mm

EM = 13,92mm

P4 = 15,52mm

Including the heads of the Romford bushes (0,8mm) that gives total width at the axle of

OO = 13,22

EM = 15,52

P4 = 17,12

If I was using sprung horn guides then I could use the P4 spacers, however I am using the shouldered bushes so I will use the EM spacer.

The next picture shows the frames cut out and cleaned up, the frame spacers (err these are the wrong ones...I told you to identify the correct parts and these are the P4 spacers), the coupling rods and the extra strapping for the firebox. (one side fitted)

Another important thing to remember is that the half etch line goes on the inside of the bend. I forgot on some of the spacers. This is not a tragedy as I just have to fettle the tabs to get them to fit into the slots on the frames.

The coupling rods are now made up as a matched pair. The centres are then measured and the driving wheel centres are checked to make sure that they are also at the same distance.

In this case the centres are spot on so I go ahead and open up the holes for the axle bearings.

Then the whole lot is set up on the building jig for assembly.

This is a construction taken from the Ian Rice book on Loco Chassis construction. It is made from MDF. On the surface sits two sine bars. These are two steel bars that are square, flat and the same height. On top of these sit three 1/8†silver steel bars that are 12 inches long. These are threaded through the axle bearings that are loosely fitted into the frames. The 1/8†bars are held in place with Blue Tack and at the extreme ends of the bars rest the coupling rods.

The chassis is then soldered together to produce this.

I have soldered on a few of the nuts (but ran out of 2mm) and have also started on the pony truck.

The tabs fitted nicely and after fixing the uprights I removed the small lip. I don’t think that you would need to do this for P4 and I have no idea for OO as to have to use the inner slots for the uprights and reduce the frame width.

The next task is to purchase the extra nuts and the axle bushes. That will be at this weekend’s show in Southampton. I think that Eileen’s will be there.

I will also have to order the wheels and various boiler fittings from Alan Gibson.

Plus and I guess that this might be important...an Airfix/Dapol kit.

Until next time...

If you are at Southampton, say hello.

Andy

*Holidays being when RMweb went off line and we all had to find something to do.

Aplos to AY