Cashmoor warbird fleet size increase

4Pedalsfly wrote: Kevin - Interesting solution but would it not be simpler to epoxy a cast lead billet into the front of the cowl ?
What size & length of socket screws do you need - I'll have a look in my stock, worked for many years in
the fastener industry. ?

Colin.

As my fastener supplier is closed until Monday - do you have any threaded to head m5 HT machine screws x 100mm long or just m5 HT studding ?

My $0.02. I wouldn't put any weight on the cowl. The extra weight would really pull on the securing screws and tear the fibreglass.

Kevin - Cannot find anything to help you out, hopefully you'll get sorted Monday.

Colin.

kevinross wrote: Thought about compressing the lead and will post the solution

Now completed re-configuring the nose ballast. Made secondary stand-offs then mounted the weight on rubber bushes (in an attempt to minimise any vibration / resonance from the weight. This has improved the effective moment which will allow reducing the unnecessary 1.5 lbs battery weight which has a less effective moment.
The motor drive hub protrudes the cowl but this is compensated by a special spinner.

A neat job Kevin, but I am convinced that you will also need diagonal cross-bracing between the top of each brass standoff and the bottom of an adjacent one, otherwise a resonant vibration in the weight could cause all of the load to be focused on the bottom of one of the brass standoffs causing the stud or the engine mounting lug to fracture.
I see it a bit like doing a dance on a slightly wobbly table, get the rhythm right and each gyration cumulatively adds to the motiion applied to the joints until one of the legs fails ! Diagonal cross-bracing limits the rocking motion (and potential twisting moments). Apparently the diagram below is how legged structures are made earthquake proof (presumably also allowing for some rocking movement to dissipate the energy).

Diag bracing will be difficult. Need to re-assemble everything and run the engine to investigate.