Re: [AFMUG] Gtek Communications deploys PMP 450

[Adam Moffett]

I have replaced just the nut.  The seizing is from stainless on 
stainless.  If you take out one stainless piece the problem goes away.

We can get by with just zinc plated in our environment I suppose but 
again replace just the nut or both the nut and the bolt?

Best regards,

Brandon Yuchasz

GogebicRange.net

www.gogebicrange.net <http://www.gogebicrange.net/>

*From:*Af [mailto:af-boun...@afmug.com] *On Behalf Of *Ken Hohhof
*Sent:* Friday, June 19, 2015 10:19 PM
*To:* af@afmug.com
*Subject:* Re: [AFMUG] Gtek Communications deploys PMP 450

So where can you buy a galvanized M8x1.25 nut?  In any case, I would 
think you would have to replace both because galvanized nuts are 
usually tapped oversize to accommodate the extra thickness of the 
galvanizing on the bolts.

I was able to find a bronze hex nut, it doesn’t specifically say 
silicon bronze:

http://www.mcmaster.com/#91776a102/=xp6t4f

Would it be so bad to just use a zinc plated nut? Otherwise, replace 
both the nut and bolt with galvanized 5/16”.  A 13mm wrench might 
still work.

The other thing I’m wondering is whether you could get away with using 
some kind of grease on the threads instead of actual anti-seize.  
Something you have anyway like dielectric grease or O-ring grease. 
Otherwise, I think the nickel anti-seize is what you’re supposed to 
use with stainless steel:

http://www.oreillyauto.com/site/c/detail/PER0/77124/N0490.oap

*From:*Brandon Yuchasz <mailto:li...@gogebicrange.net>

*Sent:*Friday, June 19, 2015 9:49 PM

*To:*af@afmug.com <mailto:af@afmug.com>

*Subject:*Re: [AFMUG] Gtek Communications deploys PMP 450

Okay so clarify for me. Are you guys leaving the stainless steel bolt 
in place and just using a none stainless steel nut ( galvanized for 
example) to avoid the seizing problem?  Let say for example on a force 
110 dish. Or are you replacing both the bolt and the nut with galvanized.

I am asking since I have had this on the force 110 dishes and also 
just had three stainless U-bolt clams seize today when removing some 
older antennas from a tower site. We had to cut them off.

Best regards,

Brandon Yuchasz

GogebicRange.net

www.gogebicrange.net <http://www.gogebicrange.net/>

*From:*Af [mailto:af-boun...@afmug.com] *On Behalf Of *Ken Hohhof
*Sent:* Friday, June 19, 2015 7:28 PM
*To:* af@afmug.com <mailto:af@afmug.com>
*Subject:* Re: [AFMUG] Gtek Communications deploys PMP 450

The worst had to be the special axle-like bolt on the first version 
430 sectors, I think those were made by PCTel?  If you cranked the 
nuts down even moderately hard to keep it from slipping, it would 
snap.  I don’t think seizing was even the problem, it looked like the 
inside of the bolt was crystalline and just asking to break when you 
torqued it.  And it was not something you could buy at the hardware 
store or McMaster, and Motorola support was absolutely unhelpful about 
getting a replacement, I ended up having to MacGyver something.

*From:*George Skorup <mailto:geo...@cbcast.com>

*Sent:*Friday, June 19, 2015 7:13 PM

*To:*af@afmug.com <mailto:af@afmug.com>

*Subject:*Re: [AFMUG] Gtek Communications deploys PMP 450

Oh, sorry, forgot to mention that. Yes, I'm talking about the long 
mounting bolts and nuts. Haven't had a problem with the short hex head 
bolts that mate the mounts to the antenna itself. Except you really 
need to crank down on those. I tightened them to what I thought was 
good, but then I could still give them a slight push or pull and they 
moved. So I'm trying to tell the guys to make sure those are really 
nice and snug, but try not to wrench too tight on the mast clamp nuts. 
They did that.. and they still seized.

On 6/19/2015 7:04 PM, Ken Hohhof wrote:

    OK, on the 450 sectors, my recollection is the elevation
    adjustments are short hex head bolts that go into threaded
    inserts.  If those are seizing on people, I think I will just
    apply anti-seize goop (the good stuff with nickel dust in it) to
    them before assembly since I do that on the ground and there’s no
    need to touch the threads afterward.

    The ones that clamp it to the pipe are wiz nuts on long threaded
    bolts, those would be harder to use anti-seize on, and would be
    the best candidates to swap out for bronze nuts.

    *From:*George Skorup <mailto:geo...@cbcast.com>

    *Sent:*Friday, June 19, 2015 6:13 PM

    *To:*af@afmug.com <mailto:af@afmug.com>

    *Subject:*Re: [AFMUG] Gtek Communications deploys PMP 450

    Yup, same here. Had to peak out a Force110 link and couldn't break
    the elevation nut loose, so we had to leave it a few dB off
    instead of breaking it off completely and/or bending the mounting
    plate.

    On 6/19/2015 5:56 PM, Mathew Howard wrote:

        I've had several of the SS nuts seize on the ePMP
        Force110's... which appear to be the exact same nuts as on the
        slightly-less-than-half a ton 3.65 sector I just put up.

        I would very much like to see Cambium switch to a different
        kind of nuts.

        On Fri, Jun 19, 2015 at 5:05 PM, Ken Hohhof <af...@kwisp.com
        <mailto:af...@kwisp.com>> wrote:

        Have you actually experienced the SS nuts seizing? Maybe I’ve
        been lucky, but I have not had trouble with that even after
        years.  I guess I should be putting anti-seize compound on
        them, but it’s so messy.

        Metric silicon bronze nuts look to be expensive, like in the
        $1 each range, to swap them out yourself.  Which of the many
        nuts would you want to be silicon bronze?  Just the 4 that
        hold it to the pipe?  Or also all the ones involved in the
        elevation adjustment?

        *From:*George Skorup <mailto:geo...@cbcast.com>

        *Sent:*Friday, June 19, 2015 4:42 PM

        *To:*af@afmug.com <mailto:af@afmug.com>

        *Subject:*Re: [AFMUG] Gtek Communications deploys PMP 450

        I've pulled two up the tower by hand at once and the tower
        guys didn't complain, so they can't be that heavy.

        What I really wish Cambium would do, or talk Laird into doing,
        is replacing the nuts with silicon-bronze like LMG uses on
        their stuff. Or just go to galvanized. The stainless on
        stainless sucks. They're $500 antennas and I shouldn't have to
        go buy extra shit for them.

        On 6/19/2015 3:45 PM, Josh Luthman wrote:

            I bet it's less than half a ton...don't be so dramatic =P

            Josh Luthman
            Office: 937-552-2340 <tel:937-552-2340>
            Direct: 937-552-2343 <tel:937-552-2343>
            1100 Wayne St
            Suite 1337
            Troy, OH 45373

            On Fri, Jun 19, 2015 at 4:44 PM, Matt
            <matt.mailingli...@gmail.com
            <mailto:matt.mailingli...@gmail.com>> wrote:

            > 3GHz and 5GHz I've only used the Cambium/Laird sectors. The
            patterns and
            > null-fill is excellent. So Matt, your new integrated AP
            antenna better be
            > good. :)

            Wish they made the sector mounting hardware out of
            aluminum.  You get
            4 of them together and they weigh a ton.