Gotta_Fly

My Feedback: (2)

Hey guys
I was wondering about something, The other day I was putting a new prop on my DA-100 and I always screw my bolts down in a cross way pattern, but anyway when I was done I put my 4!QUOT! tru-turn spinner on and I was just wanted to get the radio and engine settings right, so anyway I was by myself so I tied the tail to a try and fired it up and it started the first crank, but I had to turn it off because I used the wrong radio, OK before you say you dumb SOB I have two radios that I have the same plane on the same freq that I use for a backup so that wasn't the problem but that was my 9C and I wanted to work with my 9Z, so I fired it back up, I'll be damn if the dog next door came over and was trying to play with the prop with his nose and I new if he hit that there would be one headless dog and a ole gray headed women burning down my house, So I stop it again, Well since that was a new blade and also I make it a habit to check my tru-turn and prop bolts just to make sure there on as tight as I put them on, Well come to find out there were two bolts that I could have unloosen with my fingers with some back bone, well what I wanted to know is this has happen to me a few times before and iv been very lucky not to lose anything YET, but I'm tighten the prop down right I even have a very large wrench that size to give me plenty of cranking down power and of coarse I use plenty of back bone to it also, but what I wanted to know from you giant scale pros is, could I use some of those(I don't know the name but i'll describe) round washers that have the the cut in them and there slightly bent and also maybe some blue lock tight, I maybe can see me using the washers but I don't know about the lock tight, or do you guys use both, or is there any other tricks that you guys know about, and last on the tru-turn spinner, same there would it be a bad idea to put just a tiny winy tad bit of blue lock tight just where the screw starts inside the spinner right in the middle of all the bolts????

Thanks a lot guys I really appreciate it

airega1

My Feedback: (204)

If it was a wood prop you will encounter wood compression after the intial tightening, you probably will need to retighten the bolts after the first couple of runs until the wood reaches enough solid mat'l and won't furthur compress. If it is a composite prop you should tighten around after sequencing the bolt pattern, so use your cross pattern and finally tighten clear around the bolts.

Ragz

good topic. What abt using loctite thread lock compound on the prop bolts as well as the spinner bolts? Is this a good idea? i am paranoid abt these things coming off!!!

islandflyer

I use lock-washers (I don't know the name of those washers either: they are not split washers, but have kind of a "star" pattern), and Locktite on my DA 100. You might think that this is a paranoid over-kill, but I have a lot of respect for the possible dammage from a loose 28x10 CF prop; never loosened so far.
Today, I have just installed the 30x10 break-in prop on my DA 150. I have not run it yet, but I trust that it will not come loose ( I will check closely, because of the possible compression of this wood break-in prop).

Diablo-RCU

My Feedback: (1)

Loctite or lockwashers are not the answer. They will not help the problem. If you use a wood prop, it will compress over time and remove the tension on the bolts. Without tension, the bolts will fail from fatigue. The only solution is to check and tighten the bolts frequently with a wood prop. If you use loctite on a bolt and leave it alone, the bolt will still lose tension over time as the wood compresses - the bolt will eventually break from fatigue. Now you've got a broken off bolt held in place with loctite.

RTK

My Feedback: (1)

DIABLO is 100% correct, follow what he has recommended and you will be fine.

Rockyaged

As a normal practice, priop to the first flight of any flying session, the group I fly with
will remove the spinner, loosen and re-tighten the prop bolts/screws. I use standard
lock washers on my prop bolts and no Locktite. Material of prop is not important if
you follow this procedure. We have not had any kind of prop mishap due to the prop
bolts coming loose.

Gerald

BALSA BANDIT

Diable is 100% on the money. No one needs broken prop screws installed with loctite. The only other loose nuts at our field are behind the transmitters,,,,

Duane Cox

My Feedback: (1)

I found the use of a torque wrench to be a good piece of mind. I go over the bolts in a criss-cross with a torque setting of 45 in/ozs. I continue the pattern until I hear the click without any bolt rotation. I check my bolts on a newly installed prop after the first flight. And then before each flight session.

Duane

Gotta_Fly

My Feedback: (2)

OK I guess using lock tight is not good to use, But lets just say for the heck of it(by the way I don't ever remember using the word heck) anyway lets say I check the prop and its fine , what would it hurt to use washers as a safety measure, I mean what can it hurt, if anything it seems like it wood keep the prop on long enough till you checked again,, but I understood Diablo that makes since about the lock tight, but he never really said why or what would it hurt to use some washers......

Randy

mikenlapaz

Gotta_Fly
Checking /inspecting and retension is good. I use Locktite RED on the prop hub. I feel better and a little judicious use of a sodering iror will soften the red for easy removal. I do brush the old locktite off bolt and will chase bore threads with tap frequently. If it is on the engine I want it to stay in place!!

Duane Cox

My Feedback: (1)

On new CF props it takes a while for the spinner back plate to get fully seated, and wooden props will always expand and contract due to the environment. I don't think there is a problem with washers as I have seen them used to balance a prop and spinner. But as for lock tight I would not use. As a CF prop works its self into the back plate grooves it will slightly loosen the bolts, if you have lock tight on these slightly loose bolts you will not see it. JMO

Duane

pizza

My Feedback: (24)

been flying my da100 every weekend for 3 years many diff props, I use da drill jig then re drill holes oversize to prevent any side pressure on bolts from prop expand/retract. I never use any type of washers but do put on very small amount of locktight on all bolts and spinner bolt, never have had a problem.

epc

My Feedback: (33)

Gene Payson @ www.troybuiltmodels.com has a nice article about this.

epc.

Gotta_Fly

My Feedback: (2)

Hey Fellows
I know I started this thread and it seems that everyone has there own way that works for each person, I thank all of you for giving me a lot of different ideas on this subject, But instead of starting a whole new thread I'll just ask this question here because the props did get brought up,, I have two Carbon Fiber props 28x10 27x10, but what I wanted to know was I was talking to a very well known RC pilot which I will not announce his name but he told me that its not a good idea to use those props, number 1 there only a few inches of the ground and number 2 if you hit the ground with it just a tad bit you will ruin your engine, Now all you guys know that hitting the prop or nicking it on the run specially a hard service runway will happy sooner or later, But then again I might be wrong about that because I don't have the time most of these great pilots so maybe you guys don't hit, but anyway I just want to know if it would do massive destruction on my engine..

Thanks again Guys
Randy

JohnVH

My Feedback: (38)

Hey Randy, there is nothing wrong with those props, I have hit the ground on my 100 with a CF prop, and nothing happened to the engine, does that mean its good for it? NO, but its not the end of the world. Go to a 3 blade, that will give you more clearance.

Flyfalcons

I agree, a normal prop strike with a CF prop shouldn't damage the engine at all (though the prop might be history). A hard crash with a carbon prop might be a different story, but then you'll have other things to worry about . My DA performs well with the Mejzlik 28-10, though I have seen them turn Mejzlik 27-10s with similar performance (and slightly better prop clearance).