Re: Re: Exact Builder of Model Rule

From: Jake Palmer <82.jake_at_gmail.com>
Date: Thu, 30 Jan 2014 14:53:15 -0800

I should also clarify that I would not use any of my current motor tubes if
I was flying in Slanic. I would likely build new tubes with .014 or .015
wood. The extra weight is unimportant because of the weight savings in the
prop. If it is indeed possible to make a strong carbon fiber tube under
200mg, that could also be a good option for the mine.


On Thu, Jan 30, 2014 at 12:33 PM, Jake Palmer <82.jake_at_gmail.com> wrote:

> Kang,
>
> I don't have my notes in front of me, but I know my lightest tube was
> ~100mg before gluing the seam. My seams only weigh 6 or 7mg. Add in 2
> boron and I have a finished tube weight of ~115mg. Assuming your tube is
> 10.25" long and weighed 130 before gluing the seam, that means you're using
> ~4.7# wood. I'm using 3.8# wood. I've loaded my models with a motor wound
> to .42 in/oz before without a problem (at least not a problem for the motor
> tube, but I've had motors break on the model).
>
> For reference, back in the days of 65cm models we used 14.5" long motor
> tubes made from 3.8-4.0# wood and they worked. By comparison the 10.25"
> sticks of 55cm models are quite robust.
>
>
> On Thu, Jan 30, 2014 at 12:06 PM, <ykleetx_at_gmail.com> wrote:
>
>>
>>
>> Jake,
>>
>>
>> If your 10" F1D motor tube is really 100 mg, then you would have
>> collapsed it for sure, even if you wound the motor modestly.
>>
>>
>> My tube with glue is 138 mg, with 2 borons, 146 mg, with 4 borons, 154 mg.
>>
>>
>> If a carbon tube can be built to 180 mg, that's a 30 mg penalty, not 100
>> to 150 mg.
>>
>>
>> -Kang
>>
>>
>>
>
>
Received on Thu Jan 30 2014 - 14:53:16 CET