[TowerTalk] Prop Pitch Motor

[GALE STEWARD]

George is dead on with his comments. I used a "modified" PP for many years. It worked fine but needed to be fixed about every two years. The standard "modification" consisted of cutting off the top-most gear from the output shaft. This output shaft was then drilled and bolted to the planetary gear cluster buy drilling/tapping corresponding holes in it. The bolts can sheer or work loose at the very least (I've had both). I had custom-made brass pieces installed in mine and even with helicoil inserts, loktite, and hardened bolts it would all loosen up over time. BTW, I'm turning a TH6 and a 40-2CD - nothing really big.

Luckily, I obtained another PP (unmodified) And used the parts from it to return mine to stock configuration. It takes about a minute & 45 seconds to rotate a full 360 degrees now but you can turn just about anything you want even in high winds. I'm VERY happy that I returned mine to the unmodified configuration.

I would not recommend turning anything big with a modified PP unless you like doing repairs.

73, Stew K3ND




--- On Mon, 3/15/10, Dubovsky, George <George.Dubovsky at andrew.com> wrote:

> From: Dubovsky, George <George.Dubovsky at andrew.com>
> Subject: Re: [TowerTalk] Prop Pitch Motor
> To: "Tower and HF antenna construction topics." <towertalk at contesting.com>
> Date: Monday, March 15, 2010, 9:51 AM
> It's worth noting that these
> "modified" pp gearboxes are no longer capable of doing the
> antenna rotation tasks usually asked of prop pitches. They
> trade off torque and braking capability (holding in the
> wind) for an increase in rotational speed. Please don't do
> this to a pp.
> 
> 73,
> 
> geo - n4ua
>