My second K2 is working great after occupying my free time during hurricane
Rita (I'm in Houston, Texas). I ordered the pre-built coils this time around and that sure helped speed things up for me. I'm actually going to order another set of coils and retrofit my first K2 because it seems like 5119 is hearing about 10db better than 4687 and I didn't think was possible. I'll go through the troubleshooting process first to see if I have a problem, but I never would have thought I had a problem if I didn't have a second K2 to compare with. I also felt like everything fit (hardware, case, etc.) better this time around. I thought it was great on the first one, so I was very surprised to find things even better on the second one. Maybe it was just the familiarity from building the first one. Now I can finish building out my SO2R station in preparation for November's Sweepstakes contest. The only possible weakness I have found is in the chassis screw/ 2-D fastener interface. My shack is literally a cubbyhole room built in my garage. It is only climate controlled when I'm operating, so it sees high humidity and heat regularly (100F at 100% humidity.yes, Houstonians have gills). After 6 months, I'm finding the chassis screws are getting stuck in the 2-D mounts from corrosion or galling between the aluminum mounts and the steel (I guess) screws. I now have 2 screws that I've not been able to remove before striping out the heads. Any suggestions (both for screw removal and long term protection)? See you all on the bands! Bob K5WA K2s 4687 and 5119 _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
Hi Bob:
>The only possible weakness I have found is in the chassis screw/ 2-D >fastener interface. My shack is literally a cubbyhole room built in my >garage. It is only climate controlled when I'm operating, so it sees high >humidity and heat regularly (100F at 100% humidity.yes, Houstonians have >gills). After 6 months, I'm finding the chassis screws are getting stuck in >the 2-D mounts from corrosion or galling between the aluminum mounts and the >steel (I guess) screws. I now have 2 screws that I've not been able to >remove before striping out the heads. Any suggestions (both for screw >removal and long term protection)? Long ago, I found that the ONLY case screws which I really TIGHTEN down are those I don't intend to remove often. My shack is always climate controlled and although I don't SEE any deterioration of the screws, I HAVE certainly found that the screws do NOT want to be removed if you really tighten them down. Nowadays, I just 'snug' down the screws I remove frequently. They stay tight, and won't voluntarily back themselves out, yet they can be readily removed by the right-sized screwdriver. One other thing I've found is the absolute need to use the properly sized Phillips screwdriver. We Americans tend to use Phillips screwdrivers which are generally too small for the head of the screw we're working with. I use a #1 Phillips screwdriver in the Elecraft screws and it fits nicely. For what little it might be worth, here's how I determine which size Phillips screwdriver to use - If I put the tip of the screwdriver into the screw head and if I can rotate the screwdriver (in the head of the screw) AT ALL, the screwdriver tip is too small...! If I cannot get the tip of the screwdriver to fit SNUGGLY into the screw head WITH ADEQUATE DEPTH, then it's too large. The right size tip has NO SLACK SPACE when rotated and fits deeply into the screw head. WATCH OUT TOO... some American Phillips screwdrivers are made with too much 'nose' on them... the heavily-pointed tip won't allow the blade to drop down into the screw head deeply enough for you to obtain a snug fit... this is a prescription for a rounded-off screw head... and eventually a damaged screwdriver as well. 73, Tom N0SS _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
In reply to this post by Bob Evans-5
Bob,
Congratulations on your 2nd K2. On the screw thing, yes steel screws in aluminum can be difficult in some circumstances - the aluminum conforms very well to the steel screw threads. The best preventative measure I have found is to put a drop of oil (NOT WD40!!! - it is NOT a long term lubricant and will cause additional galling) on the screw threads before mating the parts - a small bit of light grease would do just as well. Another product that will work great, but is a bit more messy is the anti-sieze compound that is normally used when installing spark plugs - it is designed specifically for the steel/aluminum siezure problem when aluminum heads first appeared in automobiles. As for getting the screws out - use a GOOD #1 Phillips screwdriver (look for nice sharp corners on the edges of the tip, if the corners look shiny, get a good new one), and use a lot of force straight down onto the screwhead before attempting to rotate it - sometimes a drop of oil (WD40 is OK for this part) right under the screwhead with several minutes of wait time after that treatment will help. As for choice in screwdrivers, the bargain counter types just don't cut it, this is one place where being a 'frugal ham' is not desirable IMHO, buy good tools, they are cheaper in the long run. If the screw breaks, the best recourse is to remove the 2-D connector and order a new one from Elecraft along with some chassis screws if you don't have spares. 73, Don W3FPR > -----Original Message----- > > The only possible weakness I have found is in the chassis screw/ 2-D > fastener interface. My shack is literally a cubbyhole room built in my > garage. It is only climate controlled when I'm operating, so it sees high > humidity and heat regularly (100F at 100% humidity.yes, Houstonians have > gills). After 6 months, I'm finding the chassis screws are > getting stuck in > the 2-D mounts from corrosion or galling between the aluminum > mounts and the > steel (I guess) screws. I now have 2 screws that I've not been able to > remove before striping out the heads. Any suggestions (both for screw > removal and long term protection)? > > No virus found in this outgoing message. Checked by AVG Anti-Virus. Version: 7.0.344 / Virus Database: 267.11.8/113 - Release Date: 9/27/2005 _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
In reply to this post by Bob Evans-5
For long term protection Brownells Firearms Tools and Supplies offers some great Anti-Galling compounds.
http://tinyurl.com/7h5e3 http://tinyurl.com/7kqpw 73 KI4DGH Chuck G. > > From: "Bob Evans" <[hidden email]> > Date: 2005/09/28 Wed AM 10:42:08 CDT > To: <[hidden email]> > Subject: [Elecraft] 5119 is alive! > > My second K2 is working great after occupying my free time during hurricane > Rita (I'm in Houston, Texas). I ordered the pre-built coils this time > around and that sure helped speed things up for me. I'm actually going to > order another set of coils and retrofit my first K2 because it seems like > 5119 is hearing about 10db better than 4687 and I didn't think was possible. > I'll go through the troubleshooting process first to see if I have a > problem, but I never would have thought I had a problem if I didn't have a > second K2 to compare with. I also felt like everything fit (hardware, case, > etc.) better this time around. I thought it was great on the first one, so > I was very surprised to find things even better on the second one. Maybe it > was just the familiarity from building the first one. Now I can finish > building out my SO2R station in preparation for November's Sweepstakes > contest. > > > > The only possible weakness I have found is in the chassis screw/ 2-D > fastener interface. My shack is literally a cubbyhole room built in my > garage. It is only climate controlled when I'm operating, so it sees high > humidity and heat regularly (100F at 100% humidity.yes, Houstonians have > gills). After 6 months, I'm finding the chassis screws are getting stuck in > the 2-D mounts from corrosion or galling between the aluminum mounts and the > steel (I guess) screws. I now have 2 screws that I've not been able to > remove before striping out the heads. Any suggestions (both for screw > removal and long term protection)? > > > > See you all on the bands! > > > > Bob K5WA > > K2s 4687 and 5119 > > _______________________________________________ > Elecraft mailing list > Post to: [hidden email] > You must be a subscriber to post to the list. > Subscriber Info (Addr. Change, sub, unsub etc.): > http://mailman.qth.net/mailman/listinfo/elecraft > > Help: http://mailman.qth.net/subscribers.htm > Elecraft web page: http://www.elecraft.com > Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
In reply to this post by Bob Evans-5
In a message dated 28/09/05 16:43:04 GMT Daylight Time, [hidden email] writes: After 6 months, I'm finding the chassis screws are getting stuck in the 2-D mounts from corrosion or galling between the aluminum mounts and the steel (I guess) screws. :--------------------------------------------------------------- Hi Bob, As I understand it in certain climates there is a problem with electrolytic corrosion between disimilar metals, with some combinations worse than others. For use in my motorcycles the use of Copperslip or some similar anti-seize compound is essential for this purpose. Also use this for stainless to stainless steel bolts/nuts to prevent what you termed as galling. Had a near disaster with this very subject about five years back where our work airstrip Southern Avionics non directional beacon antenna was damaged in a violent sandstorm. The technicians decided to impress me by getting the new antenna assembled before I arrived on site. Alas they had assembled the upper loading coil part of it upside down and try as we might the bolts on stainless steel straps retaining the loading coils would not come apart. Eventually after some hours work managed to loosen the straps enough to get it assembled correctly. This was a warning to me at least of the problems that can arise with stainless steel bolts. All it needs is a little oil, grease or preferably anti-seize compound on assembly to prevent the problem. Bob, G3VVT _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
In reply to this post by Tom Hammond-3
Tom, N0SS, wrote:
My shack is always climate controlled and although I don't SEE any deterioration of the screws, I HAVE certainly found that the screws do NOT want to be removed if you really tighten them down. Nowadays, I just 'snug' down the screws I remove frequently. They stay tight, and won't voluntarily back themselves out, yet they can be readily removed by the right-sized screwdriver. ----------------------------------------- One of those "Aha!" moments one gets sitting in a class that sticks in the mind for a lifetime is this: A screw is a SPRING! A screw "tightens" because it is a spring. I watched a demonstration of just how important that is. The demonstration consisted of trying to tighten a screw made from frozen Mercury (which is not elastic or "springy"). One can put hundreds of inch-pounds of torque on the darn thing tightening it in a frozen Mercury nut, then remove it with nothing more than your (heavily gloved against the cold) fingers. When a normal screw (or bolt) is tightened, it stretches. That's the "spring action". The threads bind against the mating threads and the head is held secure by whatever is being "fastened" and the whole thing stretches slightly. No stretch, no tightening action. Any action, corrosion, dissimilar metal action, etc., that takes place where those threads are hard-pressed against the mating surfaces will increase the friction enormously. Consider just how long that mating surface is on the screw - it's the entire length of the thread winding around and around the screw that it touching the mating threaded surface. It doesn't take a huge increase in the friction to make the torque required to free it exceed the strength of the shaft, and suddenly you have a broken-off screw. The screws in things like my K2 case are just gently "snugged" down with the proper size screwdriver. Nothing I'd call "tight", and not a single one has ever been found loose the next time I opened it up. A little snugness provides plenty of spring tension to hold the assembly together. How tight do I mean? Well, I've never managed to strip the threads in the slots on the sides of my KPA100 heat sink using the normal Elecraft screws, even though I've removed it dozens of times, at least, over the past few years. Ron AC7AC _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
In reply to this post by Bob Evans-5
Along with the other fine discussion here about why screws bind/gall
and what to do to prevent it, I'll toss in a couple of brand names that I have found useful both in my automotive and (mechanical) instrument hobbies: Kroil and Microil, both from Kano Labs. http://www.kanolabs.com/ Kroil (and its cousin, Silikroil) are wonderful for taking apart something that no longer wants to come apart. Microil is wonderful for putting together fine instruments that you want to keep moving or to disassemble later. I think that a drop of Microil would keep the alu/steel interface from galling, without the possible mess involved in applying a more traditional anti-seize (I'm fond of the silvery stuff from Permatex/Loctite, myself). And for the ones that won't come apart any more, a short shot of Kroil will free them right up. 73 de chris K6DBG _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
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