[TowerTalk] Fwd: Lockwasher Comparison

[Grant Saviers]

They are commonly available as distorted thread nuts
http://www.mcmaster.com/#hex-nuts/=13hjsuv

They are one time use, and most make the bolt a one time use as well.

One way, if not the cheapest way, to make a locking nut.

Grant KZ1W

On 7/28/2016 21:09 PM, Hans Hammarquist via TowerTalk wrote:
> When I put up my tower, the sections were bolted together with a special self locking nut. The nuts had three dents in them and there were friction that made it necessary to use a wrench to put them in place. The tower doesn't shake or vibrate that much but I have a tough time to imagine these nut will unscrew themselves.
>
>
> Anyone else with experience with these kind of lock nuts?
>
>
> Hans - N2JFS
>
>
>
> -----Original Message-----
> From: Roger (K8RI) on TT <K8RI-on-TowerTalk at tm.net>
> To: towertalk <towertalk at contesting.com>
> Sent: Thu, Jul 28, 2016 10:31 pm
> Subject: Re: [TowerTalk] Lockwasher Comparison
>
> There are Helicoil steel thread replacement inserts that work really
> well and were inexpensive the last time I used them.
>
> Others like Nordlocks, while I've had very bad luck with them.  We are
> nowhere near being downwind from industrial centers with the Chicago
> area at near 200 miles, but the Nylon inserts just seem to dissolve away
> in a year or two. None have made it past two years. I'd like them if
> they'd last, but here? They are short term only. If the threads are shot
> a bolt through from the inside with the head epoxied in place has worked
> for me as a stud. The mount to accessory plate is not precision and
> there are usually enough threads left to screw the bolt through.
>
> I can find no reason for their short life. I thought it was IR as nylon
> rope breaks down and gets stiff out in the weather, but others in areas
> with far more sunshine than we have said they had no problems.
>
> I'd advise drilling a small drain hole, but not large enough for
> Muddobbers to get in. They ruined the matching network on an AV640 for me.
>
> The SS bolt with NordLock nuts would be ideal if I could get them to last.
>
> 73
>
> Roger (K8RI)
>
>
>
> On 7/28/2016 Thursday 3:48 AM, Ian White wrote:
>> Grant KZ1W wrote:
>>
>>> Another place I use Nordlocks is for rotator base bolts.  Since
>> aluminum
>>> has about 2x the expansion per degree F as steel (alloys and temper
>> make
>>> big differences), there is temperature cycling of the bolt load.  It is
>>> also the case that I don't want to mess with Loctited bolts when on the
>>> tower, but with the cautions, it works. Used rotators I've bought
>> always
>>> seem to have roughed up base threads, and a Helicoil insert is the
>>> ultimate fix, since they are stronger than the raw aluminum threads.
>>>
>> If the threads in aluminium rotator castings aren't too badly damaged, a
>> simple alternative is to use RED Loctite to fix short threaded studs
>> permanently into the rotator base. (Even better, insert set-screws from
>> inside the base casting to leave protruding studs, and again use Red
>> Loctite.) During installation, the studs pass through the holes in the
>> tower plate, locating the rotator safely in its correct position even
>> before you add the nuts and washers.
>>
>>> Nylocks everywhere else.
>> Make that NEW Nylocs, every time.
>>
>> Threaded studding can also be used to rescue damaged threads in the bell
>> casting on Ham-IV and similar rotators. Again, clean out the threads and
>> insert stainless steel studs, fixed permanently in place using Red
>> Loctite. Then use Nyloc nuts to secure the two castings together.
>> (Because the original self-tapping screws cause corrosion damage in the
>> aluminium casting, you may need to re-tap the holes to a slightly larger
>> size. Although you may lose some thread engagement, the Red Loctite will
>> help fill the gaps.)
>>
>>
>> 73 from Ian GM3SEK
>>
>>
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>