Gene Fuller wrote:
> There are planetary gear systems and then there are planetary gear systems.
> Granted that probably there are present day boxes that you can turn by hand,
> but thern I believe that technically speaking the gear box on the propitch
> motors is also planetary and you sure can't turn that one back
> Gene / W2LU
>
I should have rephrased that as I meant spur gears such as are used in
most rotators like the Ham M family, rather than planetary. OTOH it
still takes a very high gear ratio in a planetary to provide enough
resistance to prevent free wheeling.
Yes, the prop pitch motors use a planetary gear system but with a fairly
powerful motor and a very high gear ratio as well. As they were designed
the output was over quite a short range of rotation (slightly less than
90 degrees) and there was a lot of resistance to turning from those big
prop blades bring turned by around 1800 to 2400 hp it took a lot of
torque to turn them
73
Roger (K8RI).
> .
> ----- Original Message -----
> From: "Roger (K8RI)" <K8RI-on-TowerTalk@tm.net>
> To: "Tower and HF antenna construction topics." <towertalk@contesting.com>
> Sent: Thursday, April 15, 2010 5:52 PM
> Subject: Re: [TowerTalk] Rotor on the verge of failure? - Follow up
>
>
>
>> Tony wrote:
>>
>>> On 4/13/2010 8:05 PM, ronald schmid wrote:
>>>
>>>
>>>> Get up their and make sure the bolts are all tight. Mabe it will make
>>>> the noise while your up their Ron / N6DCN
>>>>
>>>>
>>>>
>>> Ron,
>>>
>>> Ive been on the tower several times (see link below). Tower / rotator
>>> bolts are tight. The noise seems to be coming directly from the rotator
>>> itself and some say it's normal, others say it's not. I'm hoping that if
>>> it does fail, it will freeze and not free-spin. Not sure what to expect
>>> with Yaesu's planetary gear rotators.
>>>
>>>
>> I've not seen any rotators using planetary gear trains that offered much
>> resistance to rotation. IOW you can probably turn most any of them by
>> hand when the wedge is disengaged, which is the reason I went to
>> rotators that use double worm gear drives.
>>
>> 73
>>
>> Roger (K8RI)
>>
>>> http://www25.zippyshare.com/v/53201444/file.html
>>>
>>> Thanks,
>>>
>>> Tony -K2MO
>>>
>>> _______________________________________________
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>>>
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