The original chassis was to take Slaters sprung axle boxes and when reduced to 4mm the slots were not the same size as any commercial 4mm hornblocks so I have turned my own  bearings to fit 1/8th for the drivers and 2mm for the trailing wheel

 

Edited September 25, 2022 by Jeremy Suter

Have I missed something here or have you not told us what the loco is?

13 hours ago, mike morley said:

Have I missed something here or have you not told us what the loco is?

North Staffs NEW L originally built to 7mm now building two in 4mm one in OO and one in Scalefour

Edited July 11, 2021 by Jeremy Suter

The patterns are made from 30 thou Plasticard and glued onto another piece of 30 though plasticard. They are more than the basic shape all the holes needed for later are put in now as pin points so when I cut them out I can use the correct size cutter to make the correct size hole In the right place.

 

Cutting out the footplate, its useful to try and use some of the waist material instead of tossing it in the scrap box. So I have got the patterns for the buffer beam and steps inside the the footplate. and they will be cut out first. There are pin point holes for the buffers and a line of 3 pinpoint holes for the coupling hook. I will use a piecing saw to join them up later.

 

I have put a line of 1mm holes on both sides of the cut out these are so I can screw the tanks and bunker to the footplate.

 

I am cutting 10 though nickel silver sheet at a 3.5:1 ratio the cutter is a1.5mm D cutter and I am using a 5.25mm runner to go round the plastic pattern.

On the internal cut I go round in a clockwise direction and the outside I go round in a anticlockwise direction. This is so that the cutter does not wander and clings to the edge that is being cut.

The depth of cut varies as its only held down by hand and I try to go round 10 thou material twice but as you can see I have gone through in a couple of places.

 

The material is only clamped to a piece of Perspex and gripped in the jaws of the machine and the patterns are clamped to the work plate

 

 

 

 

 

 

 

Edited July 11, 2021 by Jeremy Suter

Chassis frames put together and rods for the brake hangers fitted OO chassis here

 

 

Foot plate and the tank bases cut out and cleaned up.

 

 

Now attached to the foot plate with 14ba screws and the foot plate attached to the chassis with 12ba screws.

 

The nuts are now soldered to the yank base without the use of flux. I just put the iron where I wanted it and offered the cored solder to the heat so it only joins the nut to the base. I want the tanks removeable to make it easier to paint later.

 

Now screwed to the P4 chassis and the frames fit perfectly in the gap without any filing. I used the frame spacers pattern which I used on the 7mm version. Using 22 thou for the chassis frames in 4mm and 32 thou on the original 7mm model.

 

 

 

Beautiful work Jeremy, not that I expect anything less from you. Watching with interest!

 

Checking the mail every day for the SRM

 

Regards,

 

Craig W

Been making buffers for the locos this weekend.

Starting with short lengths of 4mm Square section brass rod cut to about 8mm fitted in the 4 jaw self centring chuck then milled the base to 1.5mm.

 

 

This is a watch makers mill for making pivots and spigots.

 

 

They come in .1mm sizes from .4mm to 2.4mm or at least they're the sizes I have although I have lost the 1.1.mm.

 

Just run over the section all done in 10 seconds.

 

 

4 jaw chuck off. Buffer turned round now mounted in a 1.5mm collet and first part off the excess.

 

 

Excess cut off Find the centre with a 2mm ball bur this will give me a good start later.

 

 

Now I have turned down the shank.

 

 

Next drill out the centre to fit the buffer head I drill only as deep as the base of the buffer.

 

 

Now change drill for a .6mm and drill the rest of the way through the shank it has a bit of spit on the drill to prevent the drill sticking and snapping.

 

 

Buffers ready for the bolt holes to be put in.

 

Edited July 19, 2021 by Jeremy Suter