Video Cassutt

[CRG]

Ok guys, thought I'd start this forum off with some information about my recently completed Video Cassutt. The full size aircraft was flown by Dave Morss in the late 80's, it was a modified Cassutt IIIM with a high aspect ratio wing and tall tail. Was not spectacular on the course, but respectable. It later became Frenzy, flown by David Hoover, and flies today as Outrageous in the hands of Scott Crandlemire though it's difficult to say how much of the original airframe remains.

A couple of years ago Chris Justus and Tom Keating designed and built a 42% version of the Video Cassutt, having decided that the layout of the airframe had some potential to be competitive. The big factor is the high aspect ratio wing, which scales to around 118" span, second only to the GR7 at the time which is nearer 130". More AR means good things in the turns, and that's a big factor in the two pylon course we fly.

A little over a year ago Pete Goldsmith convinced me that I needed to go racing and Chris was kind enough to send me the plans and some parts for the Cassutt. I've built a few models, and the Cassutt is of conventional construction, but it was a long project. Part of the problem I encountered was that it was my first giant scale racer and I just didn't know what standard techniques were being used for various parts, and how much was too much (or enough) with regard to structure. Fortunately lots of help was available and things worked out easily enough.

Fuselage: all balsa and lite ply construction, with aircraft ply in a couple of places, cowl and wheel pants are fiberglass. There is a 1/4" lite ply subframe, to which attach the 1/8" ply bulkheads and 3/16" balsa sides. I glassed the whole fuselage with light cloth and thinned resin.

Tail: The stabilizer is 3/32" balsa over foam with a .060" carbon rod laid into the core top and bottom to serve as a spar. Elevators were cut out, faced and hinged after sheeting the cores. Fin and rudder are built up and sheeted.

Wing. Cores are CNC cut 1lb. white foam, with a ply, basswood and carbon spar inserted into the core. Sheeting is 3/32" contest balsa bagged onto the cores with 1.4oz. S-glass cloth both sides of the balsa. The wings are fairly labor intensive to build and took at least as long as the fuselage.

The Ziroli "Ole Tiger' cowl is not a great fit to the fuselage and rather than have to fair it to the fuselage I cut it apart and put it back together over the firewall bulkhead, then filled in the gaps and surfaced it to use as a plug for a new cowl mold. The new cowl fits a lot better.

Wheel pants and gear legs are stock Ziroli, though I rebent the gear to narrow the track, and will shorten them a little eventually also. It stands pretty tall right now and being a little lower won't hurt it, plus will save some weight.

The concept behind this build was to save some money over the purchase of a molded kit. I probably did save quite a lot of money, but at the expense of time. There's also a lot of satisfaction from scratch building then seeing it fly, and it flies great which makes it even better.

That's it for the first installment, will add more pictures and details of more specific areas later.

[Fearless Flyer]

Very nice work. I like the look of the plane also

[RobertV]

Craig,

It's great to see that you have the Video Cassutt ready to fly. Your detailed descriptions of the structure are very interesting and informative. And I love to see something different! That design has some features that can make it fast as you have described so we can't wait to hear about the flight tests. Is your buddy going to race it at Parker as you had intended?

[Stainless Skills]

How on earth did the word VIDEO get put in front of the Cassutt? That really messes with me but oh well...

Its awsome how you wait untill you get it maidened to apply paint. What engine is in it?

[Toro]

I had a friend who had a REAL one of those based out of KCNO. I couldnt even fit in that thing, my head hit the top of the hatch, and my knees were up in my chest. IM 6'2 " He's about 5'8"... Very cool little airplane...

[CRG]

The full size that Dave raced was sponsored by a video store, the name is a play on 'video cassette'.

The model being 42% gives you an idea how small the full size Cassutt's are. I'm 6'1" and it's very tight.

Robert,
I flew it three times last Saturday morning, and am extremely happy with it. It turns well and feels very locked in when running a simulated course. Speed appears ok for a new motor, we'll see how it compares in a heat. Gives a up a little to the other designs in wetted area but should make it up in the turns. Has a fair amount of room for aero cleanup also, it was a rush to get it done enough to fly and get reasonably tuned for Parker.

Travis Flynn is confirmed as the pilot, he sent in his entry today and is really looking forward to the event. Very sharp stick too, so if the airplane does ok he will give some people a run.

Craig.

[CRG]

Stainless,

I was in a rush to get it done so have skipped most of the prime and paint steps, just did enough to get it fuelproofed.

Engine is a box stock Zenoah GT80, this model will run in the F1-GT class which means any 42% F1 airframe that qualified at Reno or Cleveland, stock GT80 powerplant, and the race organizer supplies the prop and fuel. At the moment this class has the largest entry numbers as it's relatively affordable and the racing is close.

Same airframe with an alcohol motor (usually GT80 conversion) can run in the F1 class. Speeds are higher, pilots run their own props and fuel.

	Quote: Originally Posted by Stainless Skills
	How on earth did the word VIDEO get put in front of the Cassutt? That really messes with me but oh well... Its awsome how you wait untill you get it maidened to apply paint. What engine is in it?

[CRG]

Fuselage. part 1.

As noted above, the fuselage is based around a frame made of 1/4" poplar ply. It's tied together at the front end by the firewall (birch ply), and by balsa spacers for width at the aft end. It also carries the wing and landing gear mount plates (birch ply).
The full fuselage width is made up at the wing saddle area by bulkheads attached to the subframe, then the full length 3/16" balsa fusleage sides are attached. Now there's something to add the aft bulkheads to. At this point it's a very flexible assembly and it's good to have accurate lines marked for bulkhead placement.

Once all the bulkheads are in place the fuselage bottom was planked, and the cross grain sheeting added between the wing trailing edge and the stabilizer on top of the lower fuselage side. In hindsight this sheeting, though lightweight, is perhaps not necessary. It adds a lot of stiffness to the fuselage but the upper sides and turtledeck spine is probably enough. The Cassutt builds a little tail heavy so every few grams aft of the CG makes a difference.

Hopefully the pictures give the idea. More tomorrow.

[KennyMac]

Man....that's a lot of work! Hat's off to you Craig. I think you know why I stick with composite airfrrames now! Can't wait to see it fly this Saturday...and get to see Travis' face after he flies it!

You made a good point about one of the things that makes Giant Scale Racing (GSR) so challenging from an aero standpoint, and that's the race course. It is a two pylon course with 1600' straights. The turns are 20+ G and favor high aspect ratio wings with high lift airfoil sections, while the straights favor minimal wetted area and lower lift sections. Some designs optimize for the straights and get great speed, while others hedge towards turn performance. Most have had success to some degree, but racers are paying more attention now to designs that are optimized for overall performance. I've heard it said that 90' base paths ended up being the perfect length for baseball, and it really was just an arbitrary number...well I feel the same way about the 1600' two pylon course that we race on...it just works well. Love to hear Robert Vess' comments on that. Maybe we could get him to describe his design philosophy for his racing models too!

KMac

[timlime]

Craig,
It's looking good, I cant wait to se SuperT in the Gold

[Cole Thornton]

SUPER-T! SUPER-T! SUPER-T!!!

the airplane looks great...brings alot more meaning when you put all that time into an airplane and then you see it in the air...its awesome..great work!

[CRG]

Next was sheeting the bottom of the fuselage with 3/16" cross grain balsa, and adding the turtledeck spine and side sheeting. The gear mount plate was drilled and tapped for the aluminum landing gear (Ziroli) and a tail wheel mount added (Ohio R/C). Third photo shows the fuselage on the gear and trial fitting of the tail surfaces for fit and alignment.
Before the bottom sheeting is glued I had to finalise the rudder and elevator servo locations and add the mounting rails, as these would be difficult to install later.

[CRG]

Yesterday I took the Cassutt back out for more test flying, Travis Flynn and KMac were there also. I wanted Kenny to fly it and give me some feedback from somebody who had a more neutral standpoint, and Travis was to get his first flights on it in preparation for Parker.

Everything went well, Travis did great and we got him some simulated start dives and race turns. On the second or third flight the motor quit, we thought due to being out of fuel but when it wouldn't restart next flight it was found to be a short to ground in the electronic switch/wiring. We cut the wires to the switch and it fired right up. Bench tests show the switch to be good so am not sure what's going on yet. Will rewire it and check it again.

Ended up with another six or seven flights and got it inspected, is now USRA legal and has a logbook and ID stickers.

[KennyMac]

What a nice flying racer!....All of the F-1 racers that I have flown handle nicely, but this one is especially locked in. Very stable, it's hands off on the straights. The tall vertical gives it an arrow straight track. The roll rate is perfect for racing with no signs of adverse yaw. It turns very well with the higher aspect ratio wing and holds it's line well with no yaw or roll during the pitch up. The CG is set great as it has a very neutral feel and doesn't drop it's tail at all in the turn. Take offs are very friendly, with only minimal rudder necessesary on initial rollout. The stance on the ground is just right as it shows no tendency to lift the tail excessively and nose over. Landings are nice too as you can just set up a nice rate of descent and let it land itself with just a small flair and then easing the up elevator off at the point of touchdown. The landing gear location is perfect as the plane shows no sign of wanting to bounce back in the air and the gear spreads and absorbs the touchdown energy just enough to cushion and dampen the landing. The angle of the landing gear spread even looks "just right" when it's on final....

Nicely done Craig. Tip of the cap to Fred Sattler too who designed the laminar flow airfoil on the bird. Craig did it justice by having the cores CNC cut, and then bagging the wood and glass on. Craig put a quick coat of paint on the wings for test flights, and the paint is a little dusty and I'm sure it's disturbing the airflow some. Some color sanding is on the "to-do" list and I'm sure this will improve the top speed.

Travis Flynn had never flown a large airplane like this before and was impressed with the handling. He intended to fly it around plenty high and was surprised to find himself down on the deck banking and yanking....He said it felt so good that he just fell right into the low line without even thinking about it.

Very nice airplane.

KennyMac

[Matchless]

Awesome to see a scratch GSR! I spent the winter scratching a QM40 sport plane, so the work you've put in is even more impressive to me.

Can't wait to see it painted and on the course!