Day # 1

[goatherder]

I guess the clock is ticking now.

 

FYI - 4" wider, 4" deeper. These bulkheads are plywood - not that rediculously overpriced red foam. Lloyds of London rated structural Oukume. Hey - at least I didn't use OSB!

 

Tomorrow I start whackin. (Foam)

 

Glass and glue (Pro-Set 125/226) is in the mail.

 

7715 UNI and 7781 BID...which is 13.3333333333333333% stronger than 7725 according to this chart:

http://www.hexcel.com/Products/Downloads/Fabrics+Data+Sheets.htm?map=P1&t=Fiberglass+Data+Sheets should be here soon

 

And yes, I bought the 7715 from ASS because hardly anybody carries it, ASS has a cool name and the price wasn't that bad.

 

So what do I call this thing...the Goatherder Special?

[Kent Ashton]

7715 UNI and 7781 BID...which is 13.3333333333333333% stronger than 7725 according to this chart

7781 ought to work OK--I'm using it for cowls at the moment--but I've found it a little harder to work with than 7725. You ought to order some 7725 and compare. 7781 is more difficult to pull out bumps and wrinkles. The tightness of the weave also makes it harder wet out and to get air bubbles out of it. There isn't much of a problem on flat surfaces but 7725 is easier to work with on curved surfaces. I'm using E-Z Poxy. Perhaps you'll have better wet-out results with Pro-set.

[goatherder]

Ok...I'll order a few yards of the 7725 for the tough spots.

 

Thanks

[TMann]

I guess the clock is ticking now.

 

FYI - 4" wider, 4" deeper. These bulkheads are plywood - not that rediculously overpriced red foam.

....so what do you plan to use for a canopy bubble?

If the red foam is overpriced, perhaps now would be a good point to stop.

[mfryer]

....so what do you plan to use for a canopy bubble?

If the red foam is overpriced, perhaps now would be a good point to stop.

In one of the cp issues, they discuss the temporary unavailibility of the 250 lb 1/4" foam. They did approve 1/4" plywood as a substitute.

[Edge 513]

Goatman. Contact Todd Silver for you custom canopy. You might want to ask him rgarding size and tallness. The taller it is the more abrupt the front of the bubble...so you should make it taller so you can lower the front and get a nice swoopy transition. IMHO.

Btw..seems we could just as well say "fish-man" as goatman

[Lynn Erickson]

7715 UNI and 7781 BID...which is 13.3333333333333333% stronger than 7725 according to this chart:

http://www.hexcel.com/Products/Downloads/Fabrics+Data+Sheets.htm?map=P1&t=Fiberglass+Data+Sheets should be here soon

 

 

 

So what do I call this thing...the Goatherder Special?

Why do you think that because it is stronger as a fabric it will be stronger when used with a matrix. that chart is giving you breaking strength of the fabric and does not relate directly to the strength of a composite structure that uses this fabric. the weave is completely different and that is only one property that will effect the strength of a composite structure. you are comparing apples and oranges and saying one is better then the other. but better, how is the question?

[goatherder]

....so what do you plan to use for a canopy bubble?

Will definitely contact Todd re: canopy but may be able to order a Limo-EZ canopy and recontour the top of the firewall to fit.

 

If the red foam is overpriced, perhaps now would be a good point to stop.

Why should I buy the red foam at a hundred bucks for a firewall-sized piece when I can get a whole sheet of this plywood for the same price and make all the bulkheads out of it. ALso - it is stronger and more rigid and foam. Yes there is a weight penalty but most of these bulkheads end up being cut away, so any weight penalty is negligable and not worth the price you pay to aviod it. I hate being bent over. Its the principle.

 

Btw..seems we could just as well say "fish-man" as goatman

The Goatherder thing is a reference to how I feel sometimes in my supervisory role aboard the fishing boats I work on. Some of these boats have 60-80 people on board...and not too many rocket surgeons among them.

Sometimes we get alot of short-bus riders, and trying to keep them all going to same direction and not dragging their asses is about how I imagine herding goats would be.

 

Goats might be easier though. You can give a goat a good kick in the ass when he needs it...and he probably won't go and get a lawyer.

[TMann]

Why should I buy the red foam at a hundred bucks for a firewall-sized piece when I can get a whole sheet of this plywood for the same price and make all the bulkheads out of it. ALso - it is stronger and more rigid and foam.

For the sake of argument, let's say that 1/4 inch aircraft grade birch is an acceptable substitution.

 

That said, is that what you are using?

What I mean here is I hope you're not getting materials from your local 'Big Box' store.

 

The problem is that somewhere down the line, someone else's @ss will be on the line. Either as a passenger, purchaser of the completed (or partially completed) aircraft or whatever. There have been many deviations from the prescribed materials that have resulted in a completed/flying aircraft being cut up and thrown in a dumpster for multiple reasons. (the Cozy IV "Viper" comes to mind.)

 

You have to manage the scope of your modifications. Materials is not a place to start (in my opinion.)

 

The comments you have received represent a concern for your safety, that of your passengers, others who follow your lead and the reputation of the design.

 

That said ..... enjoy the build.

[Edge 513]

 

 

 

The Goatherder thing is a reference to how I feel sometimes in my supervisory role aboard the fishing boats I work on. Some of these boats have 60-80 people on board...and not too many rocket surgeons among them.

Sometimes we get alot of short-bus riders, and trying to keep them all going to same direction and not dragging their asses is about how I imagine herding goats would be.

 

Goats might be easier though. You can give a goat a good kick in

the ass when he needs it...and he probably won't go and get a lawyer.

Sounds like herding cats...maybe you should change your name

First I have herd of (sorry, had to use that word) using plywood for bulkheads....kinds puts the word bulk in bulkhead...but hey who am I to say anything...I've got a 110# heavier engine....

[Kent Ashton]

Will definitely contact Todd re: canopy but may be able to order a Limo-EZ canopy and recontour the top of the firewall to fit.

Below is a wide canopy from Todd. I don't know if he calls it his Limo-EZ canopy. I asked for one like Steve Velovsek used. The one I got seems even bigger than Steve's. It's really a bit too large for a regular LEZ. Might work well on a wider LEZ. I had to build the canopy frame inside it which I did not expect, and recontour the firewall, which was not hard to do. (But then I needed a custom cowl. Changes snowball.)

[goatherder]

I just talked to Todd and he says he can make it 4" wider no problem. 4" longer is another story. He claims it ended up costing him 3 grand to make the limo canopy so he could sell it for $500...and he doesn't like to lose money, so max canopy stretch is about 2". I'm sending him a pic of my firewall template so he can give me some firm details and pricing info.

 

I'll end up making the firewall and canopy frame fit the canopy. No big deal.

[Bruce]

I just talked to Todd and he says he can make it 4" wider no problem. 4" longer is another story. He claims it ended up costing him 3 grand to make the limo canopy so he could sell it for $500...and he doesn't like to lose money, so max canopy stretch is about 2". I'm sending him a pic of my firewall template so he can give me some firm details and pricing info.

 

I'll end up making the firewall and canopy frame fit the canopy. No big deal.

Another possibility is the Berkut style of canopy(2 pieces), unless you're really married to the one piece. It'll give you a lot more flexibility in making parts larger.

[goatherder]

Yeah, I was talking to Todd about that today and he mentioned that the hoop in between the two canopies really restricts the passenger's view.

 

So I guess its a one piece canopy. Maybe I have to make the turtle deck a bit longer.

[Neverquit]

the hoop in between the two canopies really restricts the passenger's view

Don't worry about the dogs or the luggage in the back. You'll be putting in a roll bar or something anyway, right? I read a lot about the big bubble expanding and contracting with the weather. I think a split in the middle helps control that. Either way, I put a bit larger rear windows in the back and there's lots of view. My kids will be playing on their laptops anyway.