Stearman build

Prepared all the parts for the 4 wing spar boxes and finished both lower units

Will you be putting lightening holes in the aluminium joiner Kevin?

JRI wrote: Will you be putting lightening holes in the aluminium joiner Kevin?

Ive thought about it but this 89" Flair version is reputed to build at least 5 LBS lighter than a Nick Zirrolli 87" so i'll see what the finished weight is

Last night i built the first of the upper wing spar boxes IAW the plan but found a major problem. The tapered furings created an offset causing a mismatch to the centre section. So I had to carefully cut out the spars and remake the box parts.

This time I cut a groove in one spar which allowed the alloy spar to exit centrally.

spar box now aligns with centre section

Finally getting progress underway.

Small diversion as the rudder hinging has been bugging me. The design uses Robart H/D pin hinges which are fine but they would protrude almost 1/2 their length.

So reworked using paxolin stub hinges and removable wire pin

Hi Kevin, how thick is the paxolin plate, what diameter is the hinge (I assume it is hollow brass) and does it need lubricating?

JRI wrote: Hi Kevin, how thick is the paxolin plate, what diameter is the hinge (I assume it is hollow brass) and does it need lubricating?

could

the pax plate is approx 1/8. with 1.7mm holes for 16swg piano wire. The brass tube is a sliding fit at approx 1.9mm bore. but you've just stirred my ageing brain. I was going to fix the wire to the rudder and allow the wire to turn in the paxolin. (then if wear occurs i could bush the paxolin Perhaps i could bend the wire 90deg and locate in the rudder sternpost and grease the wire to turn in the brass tube

kevinross wrote: the pax plate is approx 1/8. with 1.7mm holes for 16swg piano wire.

Youve got to love this metric world we live in