Long EZ Mold Construction - Question

[Apollo]

It is massively more work to use molds. First make a plug and finish it to the quality of a finished Long-ez. Then use the plug to make your molds. Then use the molds to make the actual skins. Along the way add foam or honeycomb to the skins in the mold.

Kent's got it right. The only reason to use molds is if you plan to build more than one. That's the only way the extra work pays off.

 

[cheapracer]

Kent's got it right. The only reason to use molds is if you plan to build more than one. That's the only way the extra work pays off.

No. That's just his and other's preferred method, it's not mine or other's.

Making bucks and molds gives one all sorts of scope for mods and changes and stuff-ups, and what's more, I find it creative fun.

Nims, steer yourself away from thinking that foam is the only way to reinforce fiberglass skins, start looking around how plenty of other fiberglass products are made with strength.

 

[kent Ashton]

Making bucks and molds gives one all sorts of scope for mods and changes and stuff-ups, and what's more, I find it creative fun.

What!? You can't modify or change a moldless design?

Why are there no plans for scratch-built aircraft that specify using molds, eh?

I would guess that only about 1/3 of homebuilt starts ever get to the flying stage. In the Cozy world, about 1600 sets of plans sold, maybe 300-400 flying. Don't make it harder than it is.

 

[Turd Ferguson]

His concern was that it takes too long to finish the surface of a moldless composite airplane.

Building molds and making significant structural changes just to reduce the time to finish the surface seems over the top. A large number of these planes have been built and flown by hand finishing the surface. Many of them have a finished look equal to a factory plane.

I still suggest getting firsthand experience with what it takes to finish a moldless composite airplane, then decide if it's the right kind of project. If not, just move on to something else that better fits vs trying to extensively modify.

 

[Nims11]

Why are there no plans for scratch-built aircraft that specify using molds, eh?

Perhaps that is because CNC routers and 3D Printers have not really been around for more than the pas several years or so, at least not cheaply.
[/QUOTE]

His concern was that it takes too long to finish the surface of a moldless composite airplane.

I really like the Long EZ and would love to build one. I simply do not have the time to spare for such a time consuming project.

 

[Turd Ferguson]

I really like the Long EZ and would love to build one. I simply do not have the time to spare for such a time consuming project.

Have you considered just buying one that is already flying? Can probably find one for little more than what it will cost to build one.

Unless you opt for a quick build or "two week to taxi" option I don't think it will be any more time consuming than building a Glasair Sportsman, RV-x, Super Cub replica, Barracuda, or (insert any full size, 2 place airplane).

Some of the aluminum tube fabric covered airplanes advertise relatively low build times (400-700 hrs). One of my friends bought a partially built Quickie and finished it in about a yr (600ish hrs?) but they are pretty small. I also know a guy that built a Long-EZ in a little over a yr. He worked on it every day even if it was just cleaning up his shop, which is apparently the key to success.

 

[cheapracer]

Don't make it harder than it is.

Oh the irony. :gig:


From Cozyaircraft.com,

Q. How long does it take to build a Cozy from plans?

A. We estimate a good worker can build a Cozy in 2500 hours. These are working hours, not time spent reading plans, drinking coffee, etc.

... seems that 4000 hrs may be fact for some who do drink coffee and actually read the plans.

If a plans or kit doesn't get completed in 6 months time, the chances of it ever being completed are dramatically reduced.

Perhaps that is because CNC routers and 3D Printers have not really been around for more than the pas several years or so, at least not cheaply.

For pure plans build, moldless is the simplest process for low skillz set builders.

 

[bmcj]

From Cozyaircraft.com,

Originally Posted by Cozycraft.com

Q. How long does it take to build a Cozy from plans?

A. We estimate a good worker can build a Cozy in 2500 hours. These are working hours, not time spent reading plans, drinking coffee, etc.

... seems that 4000 hrs may be fact for some who do drink coffee and actually read the plans.

Surely you're not suggesting that we read the plans?!? :gig:

 

[kent Ashton]

No molds, no CNC router B.S.

A flat work table, a bandsaw, a digital epoxy scale and a few handtools and you will have a Long-ez in 2000 hours or less.

Mess around with molds and porting things to CNC, add an additional 2000 hours.

Both airplanes will fly within 5 knots of each other.

 

[Turd Ferguson]

For pure plans build, moldless is the simplest process for low skillz set builders.

Which was the designers intent and likely the reason the design enjoyed so much popularity when it was marketed. Like the name says "E - Z"

 

[autoreply]

No molds, no CNC router B.S.

A flat work table, a bandsaw, a digital epoxy scale and a few handtools and you will have a Long-ez in 2000 hours or less.

Mess around with molds and porting things to CNC, add an additional 2000 hours.

Both airplanes will fly within 5 knots of each other.

Sometimes making molds can be as quick as a moldless method. Highly dependent on the part in question, weight and finish requirements etc. To a reasonably good finish, I wouldn't except making molds adds considerable work compared to moldless.

In reality, a big part of the time is spent on all the details. Hard points, controls, systems.