[randomtask]

I'm going to start my Ziroli B-18 soon. I was thinking of making some changes to the construction. Mainly using some foam. I'm not sure if it can be done yet, I have to really study the plans to what I can do. The main question is does anyone know where to buy foam that I can cut parts from.

I was looking around and found a forum where a guy enlarged the same plans and discovered that the Ziroli plans specified a method of construction that was inherently heavy. I'm think it said the use of allot plywood was to be used. I don't wish to redesign the airplane but if I could do away with some of the plywood is less critical areas i could save allot of weight. I really think I can shed 5lbs.

I plan to use the new robart electric retracts which will eliminate the need for the air tank, air lines, and fittings. I figured I could beef up the firewalls a bit and use foam for the rest of the nacelles. Possibly the remainder of the wings outboard of the engines. I've even seen pictures of a full foam fuselage.

I would like to think that in this new age of smaller, lighter, stronger servos, that I can unload some weight there as well. Although that scares me a bit, I would hate to get the thing in the air to discover that was a really bad idea. Perhaps I'll stick with the heavy duty giant scale servos. Is there a new lighter alternative to the fiberglass cloth that was common when these plans were designed? I think I can go with a thinner sheeting too. If anyone has good ideas to shed weight I'd love to hear them

Thanks.

[Trumpetman]

Nick Ziroli is a master designer and from what I have heard and seen on DVD, his designs, including the Beech 18, fly great. So, my tip would be this, why mess with success?? Especially on your first large build? If Nick designed a plywood former there was a reason for it being plywood. Fiberglass cloth does not have to be heavy and when done right it provides a great base for the finish coat of paint. I would certainly use the new electric retract technology, new digital servos etc. but until you have more experience in building large scale models why would you try to re-engineer the structure of a proven winner? No offence, but if it were me I would build it as Nick designed it....

[randomtask]

excellent point. The more I think of it, the more I think of keeping it was originally designed. Perhaps my problem is I think too much. Nick Ziroli is known around the world as an excellent designer. Perhaps I should do more research on finishing. I really want to have an airplane that looks amazing and flys the same too. Thanks for the insight

[Trumpetman]

No problem! If you can find a copy of the DVD series that Dave Platt has out it contains great information on how to do a fibreglass cloth finish that works well and is really light!

[wymbly1971]

I'm with the previous posters (and I have a bit of experience with Ziroli models; Beech 18 included).

They tend to be a little heavy but they do fly well. They're proven designs.

If you're concerned about weight, think like a race car builder.

Weight can be managed EVERYWHERE! Use strong glue (like anaphalic) and use only what is necessary, take it easy with the epoxy, use lighter servos of same strength, lighter engines, Golden Rods or Pull-Pull instead of hardwood dowels for control rods, do sheeting well; wet bending, with no gaps and you'll need less filler, FG with the least resin you can get away with. Sand, sand, sand, select lighter covering, take it easy with the paint.

Make sure every single part serves a purpose. There's hardly any point in using a heavy engine (for whatever reason), but then have to balance it with a whole bunch of tail lead (and vice versa). Batteries/servos have weight and their placement works wonders for balancing.

The list goes on and on. Being conscious of it helps a lot! Craftsmanship and hardware selection are the primary causes/opportunities to manage weight.

And I think for the Beech 18, try to keep the hardware, servos etc toward the front. Engines are on wings near C of G. You'll need stuff up front to balance that beautiful tail

[randomtask]

I have yet to decide which engines I'm going to use, there are so many options now. I'm thinking of DLE's possibly OS or Evo's. If I can find something that a friend already owns I don't have to worry about buying engines before I start the center section. There has been a pile of new products that have come along since this design was released. Electronics are lighter, stronger and faster, There are so many more options for engines too. Not just Zenoah, and Quadra anymore. It's just weighing out the options, such as weight, power output, and of course quality. There are alot of Chinese engines on the market. They don't cost much, but they may only last for a couple seasons. I found a really nice scale cockpit the other day. I've found what I want for the most part. It's just a matter of ordering all the goodies and keeping things hidden from the wife. Finishing is going to be the biggest hurdle I think. I like the idea of panel lines and rivets. I'd just want to find an easy method to do it. I'm also kicking around the idea of functioning cowl flaps. I think that would be pretty neat.