DUCATIKID

The heat sheild material can also be bought from aftermarket auto parts oulets, i used some a year or 2 ago to shield the fuel tank from the muffler on a large water blaster, it was a silver flexible gasket like material that was quite cheap and i charged the customer an arm and a leg to fit

mikes68charger

My Feedback: (34)

Hey guys my Top Flite Gaint made it through last year flying season

So going over it for this year , I had to buy a new front cowl set as I lost the rear cover as it hides my switchs etc

Anyway I have 4 screw holes on the left side holding the front cowl on that have vibrated throw.!

Im useing washers with the rubber backs so no metal to fiberglass rubbing

Anyone have any ways to fix this?

Thanks

Lifer

My Feedback: (1)

One option is to use threaded brass inserts. I think Dubro sells them in various sizes. Another option is to drill the holes a little bit larger and then glue in the appropriate size wooden dowel rod then re-drill for your mounting screws. Also, you could go for a larger screw or bolt for what you are currently using.

I'm sure someone else will chime in with more options.

n8622t

My Feedback: (8)

Strip and glass is coming

mikes68charger

My Feedback: (34)

Well guys. I pulled the cowl off to check everything before this flying season and found out my jtec muffler is broken almost ready to fall off.

Anyone else?

To be fair it was rewelded by them after a belly land

donddsms

My Feedback: (1)

Mike,
Did the screws vibrate through the fiberglass, or vibrate out of the holes in the fuse? I am wondering if I should reinforce the fiberglass around the screw holes.
Also, do you know how the rear cover failed? I liked your idea and also mounted my switches and my fuel dot under the rear cover, trying to duplicate what you did. I have two magnets and also Velcro. I wonder if that is going to be enough to hold it in place.
Sorry about the muffler, I hope it can be fixed.

donddsms

My Feedback: (1)

I am having a problem with the rudder servo setup. The pull-pull clevises jam up against each other, and the lock nuts also cause interference. Has anyone else encountered this problem? Any ideas? When they jam, the rudder is deflected hard to one side, no way I can fly like this.
Thanks.
Don

mikes68charger

My Feedback: (34)

It ended vibrating off as the main front cowl came lose so the front part was not tight

So I just redid it. I found a rally strong magnet and lightly taped it into a dubro blind nut (the one's with the 3 or 4 prongs to hold in place)

Then just ca (for now) a bolt that fit nice onto the little cover

This way there is no way it could vibrant back out. It seems a lot better. The other way lasted 10 flights

I used #6 cap screws with the rubber washers

The fiberglass fail around the screws. So im going to add a little carbon fiber mat behind the screws

mikes68charger

My Feedback: (34)

I used tiny little rubber bands (my daughters) to pull them apart when gear retracted

Lifer

My Feedback: (1)

To stop the clevis from migrating, I laced a small tie wrap between the clevis, left it very loose, and it prevents them jamming into each other.

As far as the cowl is concerned, I thought you meant the wood had worked away from vibration. It seems you were referring to the glass itself eroding from vibration. I prevent that from the beginning by cutting some 1/32nd inch plywood discs and after drilling a clearance hole for the mounting screw, I then glue them on the inside of the cowl surface. That seems to prevent the problem you describe. As a fix, you could make them a little larger, glue them on the inside of the cowl and then place fiberglass or carbon fiber in the hole and seal with some resin and then touch up the paint.

Also, do you balance your props? Some are really way off. The only ones I have found balanced from the factory are Xoars, but I'm sure other premium brands are pre-balanced as well.

DUCATIKID

I had the same problem, i did not use locknuts on the tailwheel clevis to , and locktited them instead,

Starfighter

My Feedback: (78)

Hi. There are two things to do that will fix this, and keep it from happening again. Take a piece of Great Planes or any other CA hinge and cut it in a round shape and approx 1in overall dia. (thats why use the Great Planes material as it comes in one large sheet). Roughen the inner surface of the screw hole approx 2in overall with 150 grit sandpaper and remove dust. Take a piece of Blue masking tape and stretch over the hole on the outside of cowl. This to keep the CA from wicking out to the outside of the cowl. Glue CA hinge in place but don't use too much glue, and don't use kicker. Then take 3/4 in. glass cloth and cut into 2 in.dia. round shape. Cut as round as possible and glue into place over the CA hinge using thin CA or thin layer of 5min epoxy. Done this way, and the screw holes will generally not deform and the cowl will stay in good shape. After all is dry, drill your attaching holes using a piece of scrap wood against inside of cowl as you drill. This will keep the fiberglass from splintering too. You could also use carbon fiber too, but more expensive, and may still crack. The CA hinge material will not crack.
"Try it, you'll like it."
Ken (Starfighter)

SWORDSN

My Feedback: (13)

I did mostly the same but used left over pieces of the cowl that were cut out for the muffler.I have a little over 100 flights and I hope That I have to do it again at 200
Mike,
As for the J-tec muffler I had the same problem with muffler cracking and coming loose.on both my P47 and P40. I finally went to a Slimline in the P40 and the stock DLE55 on the P47. There was no crash or belly landing involved in my cracked mufflers. This also happened to two other club members using these mufflers.

dasintex

My Feedback: (10)

Cowl Mounting

For those that have had Cowl Mounting Screws vibrating loose, wallowing out the mounting hole or stripping the thread out; the suggestions given will all work well, I have one other suggestion that I use that is different and maybe others use this method as well.

I use Rubber-Insulated Rivet Nuts; Keleo Creations sells a Cowl Mounting Kit that uses these http://www.keleo-creations.com/index...ex&cPath=74_89 or you can get the actual Rubber Rivet Nuts from McMaster-Carr scroll down to Rubber-Insulated Rivet Nuts http://www.mcmaster.com/#standard-rivet-nuts/=qx5ldl

Basically these Rubber Rivet Nuts are a rubber inserts about 3/8" diameter 1/2" long (depending on the size used), with a Nut embedded in one end of the insert and on the other end is a Rubber shoulder that is larger in diameter than the insert with the thickness of the shoulder about 1/8". To use them, you drill a hole in a hardwood mounting block the diameter of the insert, the blocks are mounted on the Firewall and are placed or recessed about 1/16" to 1/8" in from the edge of the fuselage/firewall, to allow for the thickness of the rubber insert shoulder.

Make your Cowl mounting holes to line up or match the holes of the inserts that are placed in the mounting blocks; use a rubber washer under a button head or phillips screws; place the screws through the cowl mounting holes and into the rubber inserts; tighten the screws, the nut in the inserts draws up the rubber insert which expands inside the holes the inserts are placed. The Cowl mounting screws are held tight, the cowl is snugged up tight against the rubber insert shoulder and the rubber washer under the mounting screw further hold things tight and isolates or dampens any vibration; the cowl is sandwiched between the rubber shoulder of the insert and the rubber washer under the mounting screw.

Works great.

donddsms

My Feedback: (1)

Thanks for the advice on rudder clevises. This is how I solved it, so far it seems to work:

I placed silicone tubing both on the servo side of the nut and also on the other end of the nut. Seems to keep everything from hanging up.

lomcevac540T

My Feedback: (1)

I never heard of spraying the wood with hair spray.

SWORDSN

My Feedback: (13)

Another way is to use heat shrink tubing.

donddsms

My Feedback: (1)

Also, in response to Mike's missing cowl extension/switch cover problem, I added another magnet to the cowl extension. Now I have three. One is buried under the sheeting and isn't visible. These are strong magnets and I hope I don't lose it. I think Mike's idea is a great way to conceal these switches and lines.

DUCATIKID

I don't have a huge amount of experience with glassing although using the hair spray does seem to help stop the wood absorbing too much resin, at the very least it makes my shed smell nice, and i can take it to the field on a windy day to keep my hair looking good

lomcevac540T

My Feedback: (1)

Lol, Sounds like a good idea!

dasintex

My Feedback: (10)

I may be wrong; but I thought that using Hair Spray was to hold the cloth in place while you apply the resin, espeacially on verticle surfaces; although, I would think that if you used enough hairspray some of the resin would not soak in, but I always thought you wanted the resin to soak into the wood, at least a little bit to fully bond the cloth to the wood.

Unless you are using Water Based Polyurethane (WBPU) as your resin and you don't want excessive water from the WBPU to soak in, then you would use a Sanding or Wood Sealer first like 'Deft' then Hairspray to hold the glass in place.

mikes68charger

My Feedback: (34)

I think you should add the wood off the fire wall with a little velcro on the nose just to help prevent your cover from vibration ing back off the magnets

SWORDSN

My Feedback: (13)

Mike,It looks like that you modified the area in front of the cockpit.What did you do there?

mikes68charger

My Feedback: (34)

What do you mean infront of the copit?

I added the bolt with the little magnet inside but the fact it the bolt going into the slot will prevent the peace from vibrating back off the magnets. As that's how I lost my first one

The velcro up front will help keep the front part secure if the cowl comes lose

I did the ca hinges and fiberglass behind the bolt holes last night. Thanks for the tip

DUCATIKID

You may well be right, i read about the hair spray being used to seal the wood and it seemed to make sense but i am far from an expert