LB&SCR E2 00 chassis in 4mm 00
Due to the large wheelbase, this is reliably suitable for 3rd radius curves and greater. Test builds show that the assembled chassis will sometimes go around 2nd radius curves and points (small Hornby types) but not always. Springing will help but this chassis is primaraly designed to be built fixed, a different version designed for brass Hornblock springing is in the pipeline for the future.
If building the original / standard E2 then 1mm of material will have to be filed off the front of the chassis frames as the later versions were 3 inches longer here.
The axle holes will need 1/8th / 3mm 'top hat' bearings glued in place. Either side of the holes are slight 'etched' indented holes to help guide a saw to cut away the whole area away should you wish to add sprung hornblocks or compensation etc.
The brake pads are already in position for the wheels, the brake rodding is sprue joined on the top and needs to be carefully cut off and added after the engine is running nice. To make this easier very carefully hand drilling the holes in the brake pads will make locating and dislocating the brake rigging much easier.
At the front and back of the chassis are 'T' shaped 'legs' that are there purely to make printing easier, you can cut these off as they arn't needed. A spacer is sprue joined to the side of the chassis and needs to be added inside the frames where ever you choose. The choice depends on what gearbox you are using and the sapace it takes up and you can cut it to size. If using a gearbox thinner than the space provided then thickening the frames with some thin plastic will make everything flush. The insides of the frames may need thinning out a bit to provide room for your gearbox but this purely depends on which model you use as there are many options out there. For test builds a Roadrunner+ from High Level kits was used with the frames thinned slightly.
The chassis joines to the body by slotting the rear protrusion into the space on the body then angling the whole chassis upwards, if it is a little tight then filing in the recesses will alleviate this. The hole at the front is for fitting to the body, a 10 or 11BA 'cheese head' bolt is reccomended, you don't need to add a nut to the top as it will self tap easily in both WSF and FUD and can easily take repeated handelling, however, a space inside the smokebox saddle on the body is provided should you wish to add a nut. If the hole is a little tight then drilling or reaming it out to a wider diametre is fine.
Assemble motor, gearbox, wheels etc as per most locomotive kits.
Some builds have shown that a London Road Models GB4 Single stage Motor Mount (Gearbox) fits and is cheaper and quicker to build than most. As with all loco kits the choice is entirely yours though.
For wheels, axles, crankpins etc
Alan Gibson is a great resource
...as is Markits
For Motors and Gearboxes, High Level are recommended.
For crank pins, hand rail rod/wire and pillars, washers, bearings and other small sundry items Mainly Trains is a good website to visit.
But of course you can use whatever suits your needs and preference best,
the above has been typed out to hopefully aid you should you be new to kit building. The advantage of these 3D printed kits is 90% of the work is done for you, both on the body and the chassis.