Thanks, Paul, Dan, Skip, both Daves and Roger.
To answer several questions, I had recently changed to a new belt,
applied grease to the drum via the fitting and changed the gearbox oil.
Frankly, I may have been a little lax about oiling the pulley bearings
on one tower, but I know I had done it recently on the other tower. I
really don't think the issue is the pulleys or obstructions to the
movement of sections.
Usually, I can get things to work properly by simply retightening the
belt. In fact, I got it running yesterday and while it was going up
sprayed Belt Dressing on the pulleys. The slippage immediately began
again. I think that Belt Dressing is more of a lubricant and seems to
make the problem worse. The can says it is for the elimination of squeaks.
The idea of reducing the belt size by a half inch makes a lot of sense.
In the past I had blindly replaced the belts with the identical size
that came with the towers. I bought a shorter belt yesterday and will
try it out on Friday.
Frankly, I had no idea that there was some kind of clutch mechanism
associated with the large pulley. I knew that the mounting hardware was
unusual, but that information was a revelation. I'll pay more attention
to it in the future.
I'll let you know how the shorter belt works tomorrow.
73, Joe
k0dan wrote:
>Paul...
>
>Interesting. I'm gonna send a photo to your email address, would like to see
>if you can steer me to what you mean by "hub of the driven pulley is a
>clutch". I either have no clutch, or it is corroded into non-existence, or
>maybe tightened beyond functionality.
>
>I -have- snapped a cable before....under unusual circumstances (excess slack
>caused pull-up or pull-down cable (I forget which) to slip of the pulley on
>the top tower section, it got pinched and the motor had enough torque to
>snap it). Not sure a clutch would have helped, but might have added a little
>extra margin (or noise) to warn me before the failure.
>As it is now, the motor starts, there is no clutch slippage, maybe the belt
>slips a tad but this is not apparent, and the tower instantly begins to go
>up or down. No big problem. But a little extra "momentum buffering" would
>probably be a good idea.
>
>I have replaced the tower motor twice before (Leeson makes a fairly
>inexpensive "washdown motor" which is right size, HP, and bolt pattern for
>the LM470 application), however I think you are referring to the clutch
>being in the gearbox which is kind of a mystery and certainly a bigger
>production to replace than the electric motor.
>
>There is also an odd flange with unexplained bolts on the shaft of the
>pulley which comes oout of the gearbox. I think this is what you're
>referring to as "clutch" but I want to send you a phot (picture is worth
>1000 words).
>
>Thanks and 73
>
>Dan
>K0DAN
>
>
>----- Original Message -----
>From: <paul@w8aef.com>
>To: "Tower Talk" <TOWERTALK@contesting.com>; "k0dan" <k0dan@comcast.net>
>Sent: Wednesday, November 23, 2005 11:56 AM
>Subject: Re: [TowerTalk] Belt Slippage on LM-470 Towers
>
>
>
>
>>The hub of the driven pulley is a clutch. This is true on my LM-470 and
>>
>>
>was
>
>
>>true on my HZN-354. (Not true on my Tristao TX-455).
>>
>>What I call the driven pulley hub is mounted on the keyed worm gear the
>>drive shaft and the pulley fits over the tapered hub with a plate and 2
>>bolts that secure the pulley to the hub.
>>
>>It's been a long time since I made this adjustment on my HZN-354 but I
>>recall I inserted a two by four through the lowered tower (so it would not
>>destroy itself if the cable broke), removed the drive belt, loosened the
>>
>>
>two
>
>
>>bolts until the pulley turned freely on the hub, then tightened the two
>>bolts until I could still move the tower up and down by turning the pulley
>>by hand (no motor) but when the tower was against the stop (2x4) the
>>
>>
>clutch
>
>
>>would slip.
>>
>>There is no procedure for this in the manual. It's the procedure I used
>>because when I obtained my HZN-354 tower (used) the driven pulley was not
>>
>>
>on
>
>
>>the hub.
>>
>>The ususal weasel clause(s) apply in this case. Just as the manufacture
>>
>>
>is
>
>
>>not responsible so am I not responsible for any misfortune you may suffer
>>
>>
>by
>
>
>>you or anyone else by following what I did.
>>
>>de Paul, W8AEF
>>
>>----- Original Message -----
>>From: "k0dan" <k0dan@comcast.net>
>>To: <paul@w8aef.com>
>>Sent: Wednesday, November 23, 2005 6:34 AM
>>Subject: Re: [TowerTalk] Belt Slippage on LM-470 Towers
>>
>>
>>
>>
>>>What clutch? What clutch adjustment?
>>>
>>>The "optional" (but should be "mandatory") limit switches should shut
>>>
>>>
>the
>
>
>>>motor off just before max up & down positions.
>>>
>>>I have never been aware of any clutch action on my motor or gearbox, nor
>>>is
>>>it mentioned in the manual.
>>>
>>>73
>>>
>>>Dan
>>>K0DAN
>>>
>>>
>>
>>
>
>_______________________________________________
>
>See: http://www.mscomputer.com for "Self Supporting Towers", "Wireless
>Weather Stations", and lot's more. Call Toll Free, 1-800-333-9041 with any
>questions and ask for Sherman, W2FLA.
>
>_______________________________________________
>TowerTalk mailing list
>TowerTalk@contesting.com
>http://lists.contesting.com/mailman/listinfo/towertalk
>
>
>
_______________________________________________
See: http://www.mscomputer.com for "Self Supporting Towers", "Wireless Weather
Stations", and lot's more. Call Toll Free, 1-800-333-9041 with any questions
and ask for Sherman, W2FLA.
_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
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