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General control line discussion => Open Forum => Topic started by: Paul Taylor on June 30, 2017, 08:37:55 PM
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I need a few washers and nuts for my LA 46s.
No biggie just order from tower right?
3 nuts and 3 washers. $22.74 !!!
Are you kidding me???
Anyone have a better source?
Thanks
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The nuts are 1/4-28 thread and can be found at hardware stores and auto parts stores. You may have to fish around for a washer that fits close to the shaft like an OEM prop washer does. Find something that is tight and drill it out. You may try Fastenall stores and see what they have for close fitting ID washers.
Type at you later,
Dan McEntee
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I threw a prop nut a couple of weeks ago and had to borrow a replacement from someone at the field. After flying, I went straight to Ace Hardware and bought four extra SS nuts for 45 cents each and four washers for something less.
Mark
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Prop nuts are easy to come by. Hardened prop washers are much harder to come by.
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Hey Paul. I'll look tonight. I did have some extra prop washers at one time.
JIm
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You can also source a non serrated flange nut in that size and forego the washer. I do this so that I don't lose the washer in the grass.
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nuts are 1/4-28 (OS uses a metric crankshaft and then cut the 1/4-28 threads in the front). Any grade 8 1/4-28 nut will work on them.
Use a USS grade 8 flat washer as it has a bigger diameter than the SAE ones and will work better to clamp the prop. the 1/4" USS flat washers can be obtained from www.boltandnut.com they show them for on line order at $.07 each.
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The prop nuts less than grade 8 are usable because any wear will be in the nut and not in the crank threads and are easily replaced. The washers are another story. Most hardened washers are too small to use with wood props, they won't spread the load. So called OD washers are dead soft and deform easily. Proper washers are hard to come by.
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My Standard Operating Procedure has been to chuck out the stock OS prop nut immediately, because the hex is made for French wrenches. To have a piece of hardware that uses both French and SAE systems makes no sense & should be illegal. I got some Gr.8 1/4-28 nuts at the LHS (Local Hardware Store) to keep in stock.
I haven't got a great solution for the washer, but would consider looking at McMaster-Carr or even MECOA. Might also check Dave Brown and Tru-Turn websites. D>K Steve
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I just checked McMaster & found nothing useful -- the only extra-thick washers had 0.281" holes.
A 5/32" to 3/16" thick washer made from 6061-T6 works great -- basically, make it a bit thicker than the stock steel washer so it won't deform under pressure, with a hole that just barely clears the threads. You can make buttloads if you're not afraid of using a cutoff tool. But, it's absolutely not worth the lathe time unless you enjoy that sort of thing.
Oh -- any old grade 8 1/4-28 nut should work, but I would hesitate to use a grade 5 nut. A grade 8 SAE washer may work OK -- anyone want to try?
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Oh -- any old grade 8 1/4-28 nut should work, but I would hesitate to use a grade 5 nut. A grade 8 SAE washer may work OK -- anyone want to try?
I managed a few thousand flights with an ungraded 1/4-28 nut I got from a central Kentucky hardware store.
I am not sure why anyone is so worried about this. We used to hold the entire engines on with dead soft 4-40 slotted screws from the "Perfect" rack and you could easily bend those with your fingers. I know people whose names you would recognize that used round-head #4 *wood screws* to hold the engine, and others who did (and probably still do) thread 4-40 screws directly into the motor mount with no nut, no nut plate, nothing, just screw it into the wood.
None of that is recommended but being scared of a hardened steel Grade 5 nut seems a little much by comparison.
Brett
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I rely on the hardware from ACE Hardware as I have in the past stripped a prop nut on a couple of engines.
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I prefer to have the extra safety margin good hardware can give me.
MM
Yup. And with a grade-8 nut costing an extra $0.10 or so at the feed store, you can puff off your high-dollar habits, too.