Hobby King's Nutball

If you're into scratch building little foam RC planes you know what a Nutball is. For the uninitiated the Nutball is arguably the most significant design to come out of our branch of the hobby. Goldguy knocked it out of the park with this design.

The support thread over at RC Groups is on page 834 and counting for good reason; this is the perfect first build. You don't have to worry about elevons, it has very few steps in its construction, and its polyhedral tips give it a huge amount of stability and thus make it easy to fly. Dial up the rates and you can do silly things with it. A pilot who is bored with Nutballs is a pilot who is bored with life. These things don't get old.

I first encountered the design at Flitetest:

I've made several. Some I've crashed because I wanted to see how far I could push them, and some just plain wore out. I've passed 3 of them along to newbie pilots to use as their first planes. Every one of them has flown great.

Say you're new to the hobby don't want to scratch build it? Getting the new plug and fly version from Hobby King might be a good option. Like scratch Nutballs all of the components are exposed; you can see how everything is put together and what everything does. Even if you didn't build it from scratch you still get some experience learning about what makes an RC plane work. Just glue on the tips, attach your receiver and you're in business. Also consider the fact that HK's version only weighs 100 grams ready to fly (3.5 ounces!) and it's made of EPP, which means it will be crash resistant.

$50. It doesn't get a whole lot cheaper than that, folks. I haven't bought it, so I can't review it, but I like it. I might have to get one for the sheer novelty of ordering an ARF Nutball. It's also smaller than the Nutballs I have known, having a span of just over 18 inches. The original design calls for 20, and that's the only size I've ever flown, but the way this one flies seems very familiar to me.

Here I am with my buddy Albert in some Nutball versus Pizza Box Flyer combat (my Nutball is squarish... I haven't found that the shape matters very much). With the rates up this thing is very agile; with the rates dialed down it's a sweetheart.

So build a Nutball, or buy one. Everybody should have one.

Model Plane Foam

Time flies! It has been too long. Life gets busy.

I just got a load of Model Plane Foam's A-grade stuff, 16 sheets for $60 shipped, and I'm very happy with it.

Lets compare it to Dollar Tree's Adams Redi Board:

Surface Area: Adams =  600 square inches  per 20x30 inch sheet, while MPF has a surface area of 1152 square inches per 24x48 inch sheet. For all practical purposes MPF sheets are equivalent to two sheets of Adams.

Price: Adams costs $1 per sheet, while MPF costs $1.88 for an equivalent sheet if you buy the A-grade stuff ($60/32).

The Foam Itself: At first blush I like MPF better. It's maybe not quite as stiff as some depron I've ordered, and it certainly isn't as stiff as Adams, but there's no paper on it.

Thickness: Both are 6mm thick, so plans designed for Adams ought to work with MPF.

Weight: Adams weighs .19 grams per square inch (source), while MPF weighs .14 grams per square inch.

To calculate MPF's weight we take the retailer's figure of 2 pounds per square foot of density (a 12x12x12 inch cube) and divide by the total number of 1 inch square cubes in that large cube, which is 1728. Then we divide that by 4, because the stuff is 1/4 inch thick. We get a weight in ounces of .005 per square inch of material. This converts to .14 grams per square inch.

Conclusion: MPF has no paper to deal with, it's strong but not as stiff, and it's about 25% lighter. I'm liking it so far... I'll build a plane with it and report back.