There are two issues with using those pultruded tubes:
They have no smooth surface which can act as pivot.
Secondly, because of their smaller diameter and larger wall thickness they
are considerably less stiff for the same weight.
Kevin
Op 2 mrt. 2013 07:53 schreef "Kevin Lamers" <kevin.lamers_at_gmail.com> het
volgende:
> Hi,
> Here another picture of an older prototype wherein the pivot is visable.
> The outer carbon tubes have an OD of 1.7mm so the aluminium tubes are very
> thin. This runs extremely smooth.
> Correct! Sharp eye ;-) The slots will be closed with a small loop of
> kevlar thread.
> Btw the base pitch is adjusted by turning the balsa prop spar with respect
> to the outer tubes.
>
> Kevin
> Op 2 mrt. 2013 06:23 schreef "Tapio Linkosalo" <tapio.linkosalo_at_iki.fi>
> het volgende:
>
>> On 1.3.2013 22:49, Kevin Lamers wrote:
>> > [Attachment(s) <#TopText> from Kevin Lamers included below]
>> >
>> > Here a carbon hub I'm working on currently. The main tube weighs 15mg
>> > including the bracket for the screws. The tube is 2mm ID and has a
>> > 0.05mm wall thickness (2 layers 17 gsm prepreg).
>> > I hope the attachment gets through.
>>
>> Yes, it came out fine. I have two questions: first, you have the prop
>> blade hinge as the two carbon tubes pivoting within each other? how much
>> friction is there to that hinge? I was discussing component weight with
>> Kang several months ago, tried his setup to use a small carbon rod as
>> the blade holder pivoting inside the (0.3mm ID) pultruded tube, but it
>> felt to me to have quite a lot of friction. I'm slowly coming towards a
>> conclusion that these blade hinges should be very free to help adjusting
>> the hub... The second question is shorter: what keeps the blade holder
>> from pulling out of the hub (when centrifugal force of rotation is
>> applied)? Your pitch arm has a slot, so the pitch setting wire cannot
>> second as a blade holder.
>>
>>
>>
>> -Tapio-
>>
>>
>>
>> ------------------------------------
>>
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>>
>>
>>
>>
Received on Fri Mar 01 2013 - 22:59:57 CET
This archive was generated by Yannick on Sat Dec 14 2019 - 19:13:47 CET