INTRO

The assembly of the belly space frame (parts 23 to 32) was shown in the previous page. This page presents parts 33 to 40 which are the ‘shoulders’, ‘breast bone’ and associated components. These items complete the space frame assembly.

These are located approximately where the arrows are indicating below.

When completed it will look like this:

Nb. the attachment of the vertical neck sections (55 & 56, to be added later) is very straight-forward but is easier if some of the parts shown on this page are moved out of the way. You may therefore wish to make and attach the vertical neck sections before attaching the parts on this page. If so see page 11.

PARTS

List of components presented in this page:

• Front Y-frame, left (33)
• Left shoulder (34)
• Right shoulder (34a)
• Shoulder link, left (35)
• Triangle (36)
• Breast bone (37)
• Shoulder link, right (38)
• Front link (39)
• Front Y-frame, right (40)
• M4 socket screws, 22mm (x4)
• M4 nuts (x4)
• M3 socket screws 10mm (x4)
• M3 socket screws, 6mm (x5)
• M3 nuts (x9)
• M3 washer (x11)

(New parts are coloured blue below).

And with the fasteners added:

Exploded views….

ASSEMBLY

The parts are shown below as they are assembled, starting with the front y-frame, left:

This is added as shown below:

Three M3 x 6mm socket screws plus a washer each and 3x M3 nuts are used. The nuts are captive in the recesses behind.

At this point of course, only the top right captive nut lug will be attached from the previous pages, so attach to this one and just tighten it slightly (‘finger tight’) until the other parts are added. Don’t tighten anything until they are all in place.

At this stage the parts are quite vulnerable, especially the points where the lugs join the rods so take care.

The front Y-frame, right (#40) is a mirror image of the left one so just do the same.

The next are the ‘shoulders’ (34 & 34a).

As can be seen the shoulders have four holes. The top ones are dia’ 4mm and are to secure the front legs. The lower ones are for securing the vertical neck sections and are dia’ 5mm.

The left shoulder above has recesses for the heads of M5 socket screws (red arrows below):

The right shoulder is a mirror image of the left one except that instead of a round recess for the screw head there is a hexagonal recess for the M5 locknut (red arrow below; Nb these are added later so not listed in the parts list above).

Both shoulders have hexagonal recesses on the reverse side of the 4mm lugs to house M4 nuts as shown below.

Attach the shoulders to the forwards facing lugs of the left and right Y-frames using M4 socket screws (x22mm) (15 & 16) that were attached previously (page 4), as shown below (red, yellow arrows below). Do not tighten these fully yet.

The next item to add is the ‘breast bone’ (37) and the front link (39).

The end lug on the ‘belly rod’ sandwiches between the lower end of the front link (no captive nut recess) and the central hole in the ‘breast bone’ (orange arrow below).

These three lugs are fastened with an M3 socket screws 10mm long plus a washer and the captive nut mentioned above (in the central recess of part 37). As mentioned above, do not tighten until all the parts are in place.

The outer lugs on the breast bone are secured to the lower lugs on the left and right front Y-frames (33 & 40) using M3 x 6mm socket screws with a washer and captive nut as shown above (green arrow).

Next, attach the shoulder links, left (35) and right (38).

These are attached as shown below (red arrow):

The top lug has an M4 hole and is connected to the left shoulder with an M4 socket screw (22mm long) and captive M4 nut in the recess on the shoulder (as shown previously). The middle lug attaches to the left Y-brace lug with an M3 x 6mm socket screw plus washer (and a captive nut -see green arrow below).

The lower lug attaches to the top right lug of the ‘triangle using an M3 x 10mm socket screw and M3 nut and two washers i.e, not a captive nut (orange arrow below).

The right shoulder link (38) is a mirror image of the left one as is attached in the same way (orange arrow below).

The triangle (36) is shown below and attaches to the shoulder links and the front link with two more M3 x 10mm socket screws with nuts and washers.

The fasteners can now be tightened but gently -never over-tighten. The M4 screws to remain loose for the legs=.

The assembly should now look like this (Nb. as mentioned above the cross-head or Phillip’s screws shown are temporary and M4 x 2mm socket screws are used)….

The next step is to attach the front legs, motor-gearboxes and claws.