johnnychimpo

Should I remove the metal wing bolts and put some 1/4 20's in there place?
Anyone recomend that I do this or not?

Same for the v-tail?

js3

My Feedback: (3)

Scott,

Yes, that's a good thing to do. It's not so much the metal bolts as the metal blind nuts that causes the problem. Metal screws in metal blind nuts can vibrate loose.

You can use plastic 1/4 X 20s. Metal bolts going into tapped wood works well too.

[email protected]

Yes, replace the steel ones because they will viabrate loose- mine certainly did. Use a long knife and flick out the blind nuts- I use 6mm because we are metric but 1/4 will suffice. I use countersunk nylon bolts , Countersink the wing accordingly and after tightening up the nylon bolts with the wing mounted to the fuselage then place some 3m 845 tape 2 inchs wide over the heads and onto the adjacent wing area- this is only a backup.........I carry this tape in my toolbox all the time and am not scared to use it anywhere. ...its the stufvf that I use to hld my FAI pylon model cowling in place with, regards Trevor H, nz

Ed Smith

The screws that most use to hold the wings in is usually huge overkill. I use 8-32 flat head screws into maple blocks for the wings and 6-32 screws into blind nuts for my detachable Vee tail. The strength is not in the screw. The wing attachment is no stronger than the glue holding whatever hardpoint there is that the screw goes through to the foam core.

If there are doubts about this consider this. A Nelson engine revving at 19,000+ generates nearly three HP. It pulls an at least a 3 1/2# airplane along at 150mph+. And what holds this engine to the airframe? Four little 5-40 backplate screws!

Ed S

splatt

I've had the same Viper now for 2 years, only because its only been in 1 race. It's not as fast as a composite. Plus it's a little chubby.

I run it with a Nelson the whole time and guess I've got over 50 flights on it. It was this winters "winter beater". Flys nice. I balanced it with 2 quarters taped to the left outer wing tip.

I removed the metal blind nuts on it and drilled and plugged each hole in the fuse with some 1/4" dowel. Now I did this ONE HOLE AT A TIME, using the other holes to keep the wing on and aligned, while I redrilled the plugged hole and retapped it for 1/4-20 nylon bolts.

Maybe a little retentive... but

The covering blows, my next one I'll just peel off the saggy covering off versus hammering it back on with a torch.

It is a nice flying model, and a step in the right direction. Just give me a RTC version.

That dreamy look is just a smuge on the lens

johnnychimpo

My main question is for survivability on landing mishaps.

splatt

I myself go over my ARF's with a bottle of glue and build up some fillets along all the interior corners where the landing gear blocks are and practice landing somewhere smooth.

The wheels that come with a Viper, while looking like the real thing, manage to create a point of failure in it's design.

The rubber comes off the rim, a rim that does not exist if you get some "real" pizza cutter wheels.

A work around is to use thin CA to hold the rubber to the rim, anyways, have fun with your Vipers.

splatt

In comparison to any other quickie, the landing gear block for a Viper is the same as any. Just be nice to your models.

I have a fair degree a elevator travel on high rate for landing. It milks out when necessary, also can do the famous tail up and slide on the muffler trick when asked too.

diggs_74

Here's proof the muffler drag thing does work....

daven

My Feedback: (1)

Yeah Lee, you would have never heard the end of it, had you crashed into my plane on the ground with the plane that I had sold to you

Dave

diggs_74

I can't even begin to imagine the ribbing I would still be enduring if that had happened... I guess it wouldn't have been an issue had I taken notice of the change in the wind before shutting down the engine. I'm sure Spatt would have been just a quick to get out there with the camera had it not worked out this way.

daven

My Feedback: (1)

I still don't know what possessed me to cover a racing plane in blue and silver. That was a tricky plane to see in certain skies.

diggs_74

That's ok... It's not really an issue anymore

splatt

I had twice as much fun as you

diggs_74

Yeah, that was definately a rough first race for you... Just remember around the pylons not through them

johnnychimpo

Check these bolts out

[link=http://www.plasticnutsandbolts.com/metalcore.html]CLICK HERE[/link]

I think these would work out perfect with out modyfying the viper blind nuts.

Ed Smith

Now why did we not know this before?. Prevention of cathodic or thermal transfer, is an absolute must for wing screws!

Ed S

johnnychimpo

Obviously Ed they can be used for other applications. Im sure that Q500 racing is not their target audience.

Well, if not go back one page to [link=http://www.plasticnutsandbolts.com/screws.html]Click here you know you want to[/link] where you can find every type of nylon screw for hatch doors/ fuel doors, wing bolts, etc...

johnnychimpo

Ed are you using nylong or steel bolts?

Ed Smith

I use 8-32 flat head steel screws with tapped holes in maple blocks. If a 1/4 screw is used the block has to be fairly large so there is enough wood around the hole. For the hard point on the wing I glue in a full depth dowel. A 1/4 flat head screw has a head dia of 1/2", so the dowel has to be at least 3/4" dia. any less and the screw head will split the dowel as it is tightened. By using smaller screws the sizes of the blocks etc can be reduced. I use 6-32 socket head cap screws to attach the tail. Smaller screws, smaller bits of wood means less weight. Now a huge amount of weight may not be saved just on wing attachments. However if the same philosophy is applied to the whole airplane it is quite easy to remove 4 ounces of unnecessary weight.

For the record, the tensile strength of a standard high quality 1/4 UNC screw is 6,050 pounds. For 6-32 screws the tensile strength is 1,730 pounds. A little overkill in a model airplane don't you think?

Ed S

PS That went over my head,what did it mean? I am sometimes acronym challenged.

[email protected]

Ed, you are right, but when you have removed the metal tee nut from under the 'viper' wing blocks then short of filling those holes and redrilling, then the best method for a NZer is to put a TAP thru that hole to create a thread- it so happens that a 6mm tap is very appropriate for that circumstance..........check your mail box ( snailmail) in about a fortnight. Will I be seeing you in France at the F3d w/c?
regards Trevor H.

Ed Smith

Hi Trevor,

Unfortunately I will not be competing in France. I got so far behind technology wise that I decided I could achieve nothing this year. However if the event does go to Muncie in the US in 2007 I may compete there. It will be my last kick at the cat as they say. If I do not compete I will be there anyway, it is just an eight hour drive.

Ed S

garys

Ed, so you are saying that if the 2007 World's are in Muncie, and you don't fly, you'll be the starter?
GS

DHG

My Feedback: (7)

Q: Why did you decide to compete in F3D?

A: I was too happy, and I had too much money.



Duane Gall
RCPRO

Ed Smith

Gary,

If invited, gladly. I come cheap as well. However I would think the AMA will assemble a good crew.

Duane,

The only answer I can offer is the same as when people ask me why I emigrated to North America. "IT SEEMED A GOOD IDEA AT THE TIME"!!

Ed S