User:DrRob/Belt anchors

Parts list
Per belt anchor, so x4 for each ShapeOko:


 * 3x M5 x 8mm bolts
 * 3x M5 washers
 * 1x M5 nut
 * ~50mm length of aluminium right-angle section, sides ~10-12mm
 * 1/4" x 3/4" x 2-1/2" steel strip with two holes, supplied with the ShapeOko kit

Tools required

 * Drill
 * 4.5mm drill bit
 * 5mm drill bit
 * 5mm thread tap
 * hacksaw or jigsaw to cut the aluminium

How to make them

 * 1) Cut two ~25mm lengths of aluminium right-angle section
 * 2) * Actually the top piece doesn't need to be right-angle section - you can use a flat strip of a similar width instead
 * 3) Hold one piece against the steel strip as shown in diagram 1 below, so that the tops are flush, and mark the position of the hole with a pencil
 * 4) Centre-punch the centre of the hole
 * 5) Drill through with a 5mm drill bit
 * 6) Now take the other piece of right-angle section, and centre punch roughly in the centre of the left-most third, and the right-most third, as shown in diagram 2 below
 * 7) Clamp the two sections together as shown in diagram 3 below
 * 8) Drill through the unclamped side with a 4.5mm bit
 * 9) Tap the 4.5mm hole to 5mm
 * 10) Remove the clamp
 * 11) Drill out the hole in the top piece ONLY to 5mm, removing the thread
 * 12) Put the sections back together, and screw in one of the bolts to clamp them back together
 * 13) Repeat for the other side, as shown in Diagram 4
 * 14) Using a 5mm bolt, nut and washer, fit the bottom section to the steel strip
 * 15) Place the end of the belt across the top, between the two threaded holes, then loop it back on itself, teeth to teeth.
 * 16) Put the other section on top, and screw two bolts through into the lower section.  Don't do it up tight yet.
 * 17) Using the loop of belt as a handle, pull the belt tight, using your precisely calibrated muscles to pull with 6lbs of tension, and while holding that tension, tighten the two bolts to clamp the belt in place.
 * 18) * Obviously you only need to apply the tension while doing the second side of each belt.