3.5 foot dia. tsr 6 blade mold

[willib]

below is a close up of the last half which i finished last night.(file size is 66 kb )

http://www.otherpower.com/images/scimages/2965/IM002142.JPG 66Kb

below is looking into each half of the soon to be mold

below is a perspective pic of the two mold halves next to the blade

next step is to build an enclosure for the mold

[theTinker]

they look very nicely done. i get the impression that kinda of blade making takes alot of precision and patience. how long does it take you to make a full blade? been hollow they must be light as feathers comparing to wood.

[willib]

this is a mold for blades , that i'm going to make

i'm going to fill the hole with canned foam and glass and epoxy .

i found the perfect foam ,it dries hard as a rock yet is very light , and strong..

its taken weeks to get this far.

, but after i get the mold done i should be able to make a set of three in a several  hours depending on the temp , and the curing time needed for the foam..

[oztules]

You got an A for perseverance Willib.... well done.

..........oztules

[coldspot]

Very Very Nice work!!!

So.......

We should be able oder us, (your friends here @ otherpower)

some  "3.5' Dia tsr 6" Foam blades .

In maybe a couple more months?

lol

When and What

Let us know

[willib]

granted i've been working on foam blades for some time , but its been just 4 weeks & 4 days since these blades were potential wall insulation on the store shelf ( till i rescued them).

[SamoaPower]

Congrats! Looks like you've had some success.

There is a point I have trouble understanding. You claim a TSR of 6 and yet your own measurements of an unloaded RPM of 285 in 13-15 mph of wind doesn't jive.

Those measurements indicate an unloaded TSR of 2.5. It's likely that when loaded with a matched load the TSR will drop to less than 2.

Am I missing something here?

[willib]

the ones i was referring to in this post were the larger ones

http://www.fieldlines.com/comments/2006/5/14/84437/3687?pid=11#13

which are just shy of 8 feet dia at the  moment.

the photo at the beginning of the thread

http://www.otherpower.com/images/scimages/2965/IM002082.JPG

is an old one i've since added 30 inches to the dia.

i have one more 5 inch section to add to all three blades

[willib]

i've been doing a lot of thinking since my last post , not much work has gotten done .

but i think the best way to accomplish what i need to do is , to do each half separately , this way i would be able assemble it, rather than have it as a mold (top and bottom ).

my first job after high school was making plastic bottle molds and trimmer machines for plastic bottles, anyway i can envision what will happen if for some reason i cant get the mold apart, after i've layed in the epoxy and glass and the foam.

lots o' cursing , and a destroyed mold in the end.

so i think i'm going to lay the epoxy & the glass to each half and assemble the two halves afterward. the safe way is usually the best i think..

[willib]

I've got the leading side curing at the moment .





What you are looking at is the inside of the leading side .

the outside of the leading side is going to be a lot smoother .

i spent days thinking of how i was going to hold the mold , and i even made a cradle for it , but as you can see i didnt use it.

the convienence of being able to move it around while i was applying epoxy won out over the mold holder..

[willib]

i think it came out real nice!!

[oztules]

Is that the airfoil (convex top half of the wing) or is it a pic of the complete wing from the convex side.

If it doesn't work, at least it'll look good (after a haircut)............oztules

[willib]

Hi Oztules, its the outside of the leading half ,that faces the wind.

No its not complete yet , hence the strands..

it is just a shell of its future self

[willib]

i did another one of the outside of the leading side , but this time i used polyester resin. it came out ok , but the poly resin is not as clear as the epoxy resin.

and i'm soo glad i made the mold like i did , because i think there is no way the mold would have come apart if i had made it as one piece .

the above airfoil half  is really a little more yellowish looking without the camera flash .and not as professional looking as the epoxy resin. i hav'nt tried a gel coat yet hmmm that might look nice, with a white jel coat, and a red jel coat on the tips..