E4um resources

These are draft instructions subject to revision. those interested should contact Gordon Ashton for further details. Gordon estimates that the price including MJT bearings will be approx. Ł1.50 per axle.
Click for larger image.		Click for larger image.

The Springing units applied to a Comet GWR 28xx chassis using Puffers bearings, click images for larger version.
Further Pieces : a) Square Bearings – MJT or Puffers b) A piece of card – from a cereal packet . c) Spring steel wire 10 – 12 thou – solid drawn guitar string . 1) First decide which length spring you wish to use and check that it will fit in the chassis without being obstructed by any frame spacers . Try to allow a couple of millimetres either end of the spring . In most cases I would use the shorter spring mount , however I am aware that some loco builders prefer a longer spring . With some forethought and a few judicious holes in the frame spacers it should be possible to slide the springs out so that the wheelsets can be dropped out for chassis painting – brake rigging allowing. 2) Take your piece of card and a) cut a square hole 6mm x 8mm approx . b) cut a T shape approx 15 mm horizontal and 8 mm vertical, removing approx 1 mm width of material. 3) Remove any burrs from the top edge of the outer etch . 4) Remove item 2, fold top through 90 degrees and fit to item 1 still in etch . Check that the longer vertical face is vertical using square referenced to the top outer edge of the outer etches . Place assembly on T shape cut out in card , with the vertical tabs in the vertical cut-out ( etc) , and solder . Remove assembly from etch . 5) Prepare square bearing . Fold and mount spring anchor to top of bearing . Lightly smear oil on the side faces and slot of bearing . This will stop the solder gumming the works up . Fit bearing to the assembly . Check that the bearing only runs against part 2 . These hornblocks are designed to work in a similar way as the prototype 6) Fold and fit part 3 with the bearing in place . This part should be fitted with the horizontal section to the top , and underneath that one that is already in place a snug fit against the square bearing . Solder the longer vertical face first then the horizontal . The bearing should be a good sliding fit without any slop. Please note that because of production tolerances , the square bearings must remain matched to their etched hornblock assembly . 7) Fit retaining wire at bottom of horn guide faces . 8) Spring Mounts . First check that spring wire will go through the holes in your bearing anchor and the 4 holes in each of the outer spring anchors . The four holes are for final height adjustment . Bend up the required outer spring mounts , cut off surplus if short chosen . Cut a suitable length of spring wire . I find it useful to bend approx 3 mm to 90 to act as a "handle" , and debur the other end. I find it helpful to thread the wire through and grip it in a pin vice . Slide spring wire through the outer mounts and bearing anchor . The assembled units are mounted in exactly the same way as the MJT and Puffers units .
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	Scalefour Society Resources
	updated 30 October 2001
G.A Models – Sprung Axle Box Units