Holding screws in

[Tony j]

Good morning All

I have a canopy that is located with two peg at the front and then two M3 screws screw into the sides . Now I was flying the other day and returned with one screw missing. So is there away that I can stop them from coming loose in flight. I thought about thread loc but thought this may not suit as they need to go in and out on a regular basis so any suggestions please .

Many thanks in advance.

Kind regards.

Tony J

[Former Member]

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[Peter Miller]

Use stiff nuts inside

[Former Member]

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[Former Member]

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[trebor]

I gave up using locktite as even the kindest stuff used to strip fine Chinese threads made of China's best metal, instead I use Uho por which is very sticky and shake ressistant. Even the other half's old nail varnish comes in handy and it looks good too

[Manish Chandrayan]

I am assuming that canopy needs to be removed frequently, either to change the batteries or access equipment inside.

I am also assuming that the original screws that were on the model and one of which bailed out was metal M3.

This is a common occurrence and Locktite, nail varnish etc do not work in this situation. My way of avoiding the screws bailing out is to use nylon screws instead of the provided metal ones. Once snugged in they remain snug.

Other option is to remove the existing blind nut and epoxy a nyloc nut. This will allow you to use metal screws but the torque required to loosen or tighten the screw may dislodge the nyloc nut

[kc]

Any sort of rubbery adhesive works well to lock screws. I used Evostik impact or Thixofix to hold silencer screws in - never came loose until needed to unscrew.

Of course shakeproof washers as found on lots of electrical items ( dozens in an old washing machine ) could be used in this instance if they are small enough sizes.

[Ronaldo]

I solder steel nyloc nuts onto captive 'T' nuts. Sounds impossible I know, but it does work if you can set the soldering iron temperature just hot enough to melt the solder and not the nyloc insert.

I've used this method for all kind of fixings where vibration is an issue.

[Former Member]

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[Nigel Dell]

I found that just changing the metal bolts to nylon stopped this, if they are suitable for purpose that is, It was just to hold a canopy section access hatch on the fuz in my case, the Seagull models iSport has the exact same set up.

[Capt Kremen]

Where the screw hole already exists and the screw is loose, take a small piece of 'soft wood' e.g. match stick. Break off enough to insert as filler in the hole, using a spot of glue to stop it coming out. Re-insert the screw. The screw will then cut a new tighter thread fit. (This is a common remedy for musical instrument loose screw strap buttons which are subject to constant wear and tear).

[Bob Cotsford]

I try to replace screw retention on hatches with a spring latch, either a single central latch or one each side mounted in the fuselage side mounted so that the sprung pin locates into a notch in the edge of the hatch tab. As I'm all electric now I want quick access to the battery so screwed on hatches are out.

[Peter Jenkins]

I slip a bit of fuel tubing over the bolt but with a washer between the bolt head and fuel tubing. When tightened, the fuel tubing provides sufficient pressure to stop the bolt loosening and falling out. I've used this to retain the canopy on a Capiche 140 with what has to be the roughest 4 stroke 180 made - Saito! The bolts stayed tight all day. Cheap and very effective.

[Tony j]

Hi

Thank you all for your replies lots of interesting ways of dealing with the issue , its good to know that I am not alone with the problem.

Kind regards

Tony J

[Jon Laughton]

A small collar of silicone fuel tubing between the head of the M3 bolt and the fuselage side may do the trick - just tighten it up well before flying. Alternatively fir the both toa Seacraft cup washer and a spring washer for the same kind of effect

[FlyinBrian]

Small "O" rings on the M3 bolts or as abve slivers of silicon fuel tube.

[ken anderson.]

try a rubber washer under the bolt head.....

ken anderson...ne...1...rubber washer dept.

[Cuban8]

A cut down servo grommet works well, the round type rather than rectangular Futaba ones. Full grommets hold cowls in place without losing screws as well.

[Bruce Collinson]

Modelfixings sell small O-ring grommets, included in their socket-head servo screw packs (which I endorse unreservedly, five get used for every one that secures a servo) and are great for cowls and canopies upto say 10cc in old money. I'm sure they're sold seperately, although much better value in the assortment pack.

BTC

[Steve Balaam]

I used to have this problem until I changed to plastic screws similar material to wing retention bolts .

The plastic screw thread expands a little as you screw it in and provides a solid hold, never had a problem since.

Steve B

[Mike T]

It's an obvious question (so obvious in fact that nobody has yet thought to ask it), but what material are you trying to fix into? I think I'd need to know that before offering any advice on stopping a screw from working out of it...

[Tony j]

Hello Mike

thank you for your reply I am using metal screws through a wooden side screwing into a steel captive nut

Kind Regards

Tony J

[SR 71]

Is that a screw or a bolt ? If it's into a captive but i would say bolt

I always cut 3mm off the end of a piece of full tube put it over the bolt

When it's tight the tube squashes up and stops the bolt turning

Tony

[Nigel R]

Any threaded fastener into a nut, is a bolt, whereas, any threaded fastener into a threaded piece of material, is a screw, I believe. And thus a hair is split.