Boggers rotax rig

[Bogger2]

Hey Buster,
Your technique sounds simalar to what I heared before. My question is did you fill the tubes with sand before bending? If not did tubes colapse?
Thanks for the tip.
Bogger
By the way I might try to salvage the main hoops because they are already the correct demension. Just have to do a bit more grinding.

[buster]

Bogger,

No I never even thought about filling the tubes with sand. Sounds like a lot more work! My tubes did not collapse at all. I think 1/2" emt would bend up even easier than what I used.

Dave

[airhead]

Bogger,

I checked the suspended ceiling wire and it is .105 and we all know that 1/8 inch is .125. I haven't checked the 4x4 wire but i think it is a lot smaller. The welding rods probably cost a great deal more and are 3ft. I think the ceiling wire is 10 or 12 ft.? Just info for thought. Let us know what you decide. I have decided to use the ceiling wire because i have it.

Jim

[chuckitt]

I have never used the ceiling wire and never even though of it. I think it will work good. Let me know how it welds. It has got to be cheap compared to the ss we use. See, the more read, the more we learn.
Thanks, Chuck

[buster]

I remember the gas welding rods cost me about one third what the SS rod would have cost.

Dave

[chuckitt]

We sell the ss 1/8 inch rod X 12 ft for .18 cents per ft or $ 2.16 per pcs. It takes about 17 to 20 pcs to do a full mini cage on 4 x 4 centers.
Thanks, Chuck

[Papee]

Not SS but concrete mesh comes in 4x4 square about the same thickness. It may save some welding.

[airhead]

Papee,

I agree, but all the concrete wire around here is rusty whene you buy it.

[Wildfowl]

This is all good and I am glad the full moon is over for now. You all know I could go on here but I will give it a break.

When it comes right down to it, imho, it is all about keeping the prop from striking something.

From there it comes down to keeping brush out of the prop and people from loosing their balance and falling into the cage. The cage can brush off the brush easy enough but will it keep someone who looses their balance from falling into the prop. That is what it is all about.

[Cajun_Ag]

Just a suggestion but you can use utility panel. You can find it at the farm store like tractor supply co. I believe it's 4X4 and comes in 4X16' sheet. Here's a pic of it on my bowfishing rig fan. It's easy to weld, galvanized, and can take a beating. My rings are 3/4" so you can get an idea of the rod dia.

[Bogger2]

Thanks every one for your reply's. I have desided to go with 1/8 inch wire. it seems it will be stong enough to keep people and objects out. the ceiling wire is not a bad idea and it's cheep but like chuck asked , I'm not sure how it welds up. So 1/8 inch rod it is. I'll post some pictures to let you see the diffrence from the original pancake set up to the traditional cone shape, I plan to design.
Thanks all,
Bogger

[Duane Scarborough]

Bogger,

Rule 1: The most important thing is that YOU need to be happy with YOUR boat.

Having said that, if it was me, I'd stick with the pancake style cage, but get rid of the expanded metal, and go with 1/8 wire on 3" or 4" centers.

The bigggest advantage that I see to the pancake style cage is being able to get to the engine easily. I like to tinker. And I like to maintain my stuff.

A pancake cage puts the really dangerous part (the prop) inside the cage, but leaves what you may want to tinker with and maintain within reasonable reach.

That's just MY opinion. See Rule 1 above.

Duane

[Bogger2]

Hey guys,
I'm getting close to finishing most the welding on my new cage.
Has any one ever tried putting sheet metal around the out side of the cage?
I put it on the out side but I'm not sure if I will keep it there yet. It so thin that I don't have the welding skill to tack it in with out burning holes in it.
I'm hoping it will keep the tip noise down and direct the air a little bit.All a guess on my part.
What do you think? Think it will help the performance?
. The old cage I cut out weighed 15 lbs All the new metal I added is 13 lbs. So I'm not to unhappy with the weight. I been on my wife's bathroom scale doing a little math.
I also manged to tuck the muffler " expansion chamber", in a little bit with out having to punch a hole through the new cage. I thing It will help the performance a bit also since it not blocking the prop as much as before.
I will be putting wrap on it on final assembly.
Keep a builden
Bogger

[Bogger2]

Here's another picture of the muffler setup. I can't seem to get four pictures to post at once.
Bogger

[Flathead]

So my guess would be: sound reduction, Yes, performance increase: No. Just echoing what I have read about ducted fans...no personal experience to speak from. I like the look however.....

Bruce

[Papee]

Nice build! I'm going to move this thread into the builds section. To weld that thin metal just start on on the cage not touching the metal and move toward the thin metal as needed until you can get the weld to just flow across the two. You will have to just put spot welds every few inches to hold it.

[airhead]

Hey Bogger,

I don't know enough about the sheet metal to comment but it looks neat to me. What i decided while building my cage was if i liked it that was the most important thing. Mine wasn't planned it just kinda evolved or something. Actually that was the whole build which isn't finished, i should add. So my point is do what you like and if you change your mind later you can always redo it.

Keep on buildin

Jim

[Bogger2]

Thanks Papee,
I think this thred would be good under the buids section. Also thanks for the tip on the welding. I'll give it a try again if I can't get it I will admit defeat and get a pro to handle it. $$$I don't want to spend if I don't have to.
Airhead,
I to like the look,besides that it will give me some surface to paint camo on beside my rudders.
Thanks guys,
Bogger

[Papee]

I always say it's like welding toilet paper to a tank. Just get out some scraps of each material and try it. You want to heat up the heavier metal first so the weld sticks then move closer to the thin metal. You won't even have to touch the thin metal, the weld will flow across. Sort of like soldering or brazing.

[chuckitt]

Hey Bogger, Many people have tried the sheet metal on the cage and lost thrust. A propeller blade pulls more air in from the sides than from the middle. It only works when the metal is real close to the tips of the blades and forces the blades to act like a fan.
Chuck