There are 2 jigs, a simple one for determining where the C/L of HS602 is

and an assy jig.  



The C/L Jig consists of 4 off straight dressed 2*1 wooden blocks

screwwed to a customwood base.  the blocks are located by sitting a

HS602 on the base and locating each block hard up against the HS602, and

I mean hard aginst, a real tight fit.  I made the long pieces slightly

shorter than the spar length which enables a screwdiriver to fit under

the spar at each corner for prising it out.  The inner edges of the long

blocks are projected onto the shorter ones and midway between these

projected lines is the spar C/L at the end. repeat for each end and mark

the spar C/L on the Jig and on the spars.  I use a very fine felt tip

pen for marking the wood, and lightly scribe the C/L on the spar, the

surface mark wont hurt at these locations.



My assy jig is mounted on a piece of laminated bean purchased for the

fuselage jig, but any flat surface loke a bench will do.  Two blocks of

dressed ex 1 inch wood are aligned across the jig at exactly 97 5/8 inch

apart, these form the end spacer blocks. the two spars sit on three ex 2

*1 inch dressed wooden blocks, one towards each end and one approx 18

inches long at located at midway between the end blocks.



Two additional blocks are used to locate the HS610 and HS614 the correct

distance apart and the correct distance from the spar c/l.  The location

of these blocks is the tricky part, and they are in turn mounted on two

blocks about 3.75 inches apart so that they are at the correct height

for the HS610 and HS614 to butt up against.  make these blocks the same

length as the HS610 and HS614.

To locate these blocks, and the HS602 I strung a coloured nylon fishing

line betwen two nails along the jig length approx on jig c/l.  this line

becomes the spar c/l.

the HS602's were sat in place with two 0.125 inch alloy spacers betwen

them either side of spar c/l so as not to foul the nylon line.  The

previously marked spar c/ls were aligned under the nylon, and the H602's

clamped in place.  At this point I realised that the HS602 outbd flange

is deeper than the longitudinal flanges so I should have used marginally

thicker blocks under the spar, but the affect was small.

Then I marked the empennage C/L (as opposed to spar C/L) on the jig and

marked the spanwise locations of the HS610 and HS614 locating blocks.

Next clamp these blocks  in position tight enough so they can be moved b

gentle tapping with a hammer. 

Adjust their location until they are 3.25 inches apart, both parrallel

to the spar c/l, and equidistant either side of spar C/L.  Firmly clamp

and recheck their location.   readjust, recheck repeat n times until

satisfied.  drill screw holes and clamp them in place, recheck before

finally tightening screws, and again after.  

Mine ended up 0.032 inches further apart in one direction than I wanted

so I used a 0.032 inch alloy packer between the errant block and the

HS610 or HS614.



i forgot to mention my way of locating the HS602's in place once

aligned.  Whislt they are clamped drill 0.125 inch thru the HS602 web

and 3 support blocks approx 0.5 inch off c/l, and drop an AN470AD4 rivet

into each hole it works.  Off c/l so as not to foul the nylon line.  



when measuring from the line to a surface put the ruler under the line

withone end butted up against the surface being located that way it is

easy to read the spacing.  DO NOT let the ruler touch the line.  i

located the longer block off the nylon line first then screwd it down

and then located the second block off the first.



For using the jig do NOT trim the HS 602's prior to using it.

When the jig is ready locate the HS602's using the rivets, and clamp the

HS610 and HS614 to their blocks. RECHECK EVERYTHING AGAIN.  Then match

drill the HS602's to the HS610 and HS614.  That easy.  My HS610 to HS614

spacing was 0.020 inch over the drg figure of 3.25 inch which I suspect

is good enough.



If anybody wants a drg of the jig email me at jgmurphy@xtra.co.nz