Thanks Ian
The bolted option sounds like good engineering if done properly.
One other idea I have heard suggested, (by Tony Kay) is that a snug
fitting inner tube is assembled, eg with Bearing Fit /retainer grade
Loctite, into the torque tube, basically to make the whole thing
thicker-walled and therefore to reduce the contact stress of the pin/
tube contact areas. I think it would be a machine shop job to get the
drilling and reaming done accurately so obviously the torque tube
would have to come out.
The other option might be simply to junk the existing torque tube and
substitute something beefier (thicker walled and or harder). Not sure
how the CofG works out for a mono but most trigears seem to have a
hefty lump of lead in the tail so they could presumably take the
extra weight of a reinforced or beefier torque tube with a
corresponding reduction in the ballast weight.
By the way, I think it is highly enlightened of Francis to invite
ideas from owner/builders. Most of us know from uncomfortable
experience what practical implications are put on any solution by
the access issue, to say nothing of being "stakeholders" in the
success of the outcome.
Thanks for your good work.
Willie Harrison
On 24 Jun 2007, at 11:13, G-IANI wrote:
> William
>
> The idea of the bolt option is that it does two things. a) It
> clamps the two parts together. b) to ensure the tubes stay round a
> cross drilled spacer is fitted inside the TP4 tube. This is
> Loctited in. So you have both clamping and a glue joint but retain
> the ability to dismantle.
>
> This is not PFA approved at present but has been discussed with
> Andy Draper in 2005.
>
> Francis Donaldson asked me on Friday to pool any ideas we have on
> eliminating slop in this area. He wants to address this as part of
> any solution to the present problems. I will have a document ready
> for him, by tonight, summarising all the options (existing pins,
> big pins, taper pins, Bobs blocks and bolts). If anyone can think
> of anything else I will be glad to hear from them.
>
> If the PFA decides that bolts is the way to go, then we will have
> it documented and approved very quickly.
>
>
> Ian Rickard #505 G-IANI XS Trigear
> Europa Club Mods Rep (Trigear)
> e-mail mods@europaclub.org.uk
> or direct g-iani@ntlworld.com
>
>
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