Today we are making the fixed sleeves for both the 1/6th and 1/12th scale engines. The starting point it to create a constructional drawing, showing the parts from which they are going to be made. On the drawing the black are the measurements for the 1/6th scale engine
, the red are for the 1/12th scale
, you will note that not all the measurements are halved:
Starting with the body, turn to profile:
Bore to suit the spindle diameter:
Now we slit the end to take the arm hanger. You can use a slot drill if you want but I prefer a slitting saw and to take multiple cuts:
Which gives us this:
That?s it for the body, now for the arm hanger. This took a while as I first had to hack some suitable material out of an off cut. Once to overall size these have been coordinate drilled. Note the holes in the top these are smaller than the spindle diameter (the arms are the width of the spindle diameter so this assembly hole must be smaller).
We now need to profile the arms, yes you can use a mill and a rotary table but these were hand filed using my collection of various buttons superglued to the blocks as shown:
Next we check the fit of the arms in the slots:
Now we need to make our assembly piece it is simply a brass sleeve part the diameter to suite the spindle diameter, part the reduced size in the arms:
Now we use the assembly tubes to keep the two parts aligned whilst we silver solder them together.
You want as little silver solder as possible and flux only where you want silver solder. This is what they looked like after:
Remember if you put too much silver solder on you will only have to remove it later. These are now cleaned up whilst they are still on the parent metal. It gives you something to hold in the vice. Now its is off to the lathe, drill and ream for the spindle diameter.
You should find that the assembly piece will come out with the drill meaning there is little to ream. Once the bore is to size each can be parted off, leaving us with two sleeves.
The second sleeve tomorrow. (I should be working on the DTC
).
I have been thinking about balls and sadly I have not got the right sized ones so cannot cheat for the larger engine, so it looks like I will have to make them.
Jo