Binder Design Excel Plus (38mm)

Binder Design - Excel Plus 38mm {Kit}

Contributed by Shelly Hattan

Manufacturer: Binder Design
Rating
(Contributed - by Shelly Hattan - 11/25/00)

Picture courtesy of Binder DesignRocket Pic

Brief:
A tall 3FNC single-stager with a large payload section, a 38mm motor mount, and a 36-inch parachute.

Construction:
The kit comes with two tubes, a main body tube and a payload section. The payload section is what differentiates the kit from the standard Excel. The Excel Plus comes with 3 pre-cut fins, two centering rings, and two eyebolts --one for the payload section and one for attaching the recovery harness.

The biggest "pro" for this kit are the instructions. As opposed to the one-pagers you get from LOC or PML, the Binder instructions are several pages long and document every step of construction with pictures. The assembly is logical and very easy to follow for a first-timer. This is a great kit for a first-time HPR flyer.

Fit was very good. The only "gotcha" is that you need to cut your own fin-slots. It's a cardboard tube and the fin locations are already marked, so it's really not much of a problem.

At first I was worried of the construction of the ACE "bleach bottle" nose cone, but after over 30 flights, my worries have ceased. It's been more than tough enough to handle any motor I've thrown at it.

Two parts that need to be added are a motor retainer and a parachute protector, but these seem to be left out of most kits. I'm a big fan of Giant Leap Rocketry's MotorHolder motor clip. It only costs about $6, and it works as well as anything I've seen out there. You can't add it later, so make sure you install it during construction of your kit. As for chute protectors, the Pratt protector works wonderfully. After dozens of flights, my pink chute hasn't even gotten cooked once.

Finishing:
Nothing special to know about finishing. It's a standard cardboard tube with a plastic cone and plywood fins, so it's really no different to finish from any other kit. The only thing I would've changed about building mine would be to have added a ring of sheet aluminum or two more layers of cardboard to the inside of the aft-end of the rocket. I've gotten a couple of dents in the end, and beefing up the end of the tube would've made it a bit tougher for landings. The rocket comes with a large nice vinyl decal with "EXCEL PLUS" and the Binder logo. I didn't use it, as I'd rather decorate 'em up the way I want. I painted my rocket black and bright pink, which makes the guys at the launch roll their eyes.

Construction Rating: 4 out of 5

Flight:
Flying is the best part of this rocket. It's super-stable, and it's flown beautifully on every motor I've used (and I've flown this thing over 30 times). The fins aren't too big, so it flies straight even on windy days. My preferred motors are blackjacks, because I love to see that plume of black smoke. My current favorites are the Aerotech I154 and the Kosdon I255. It flies very nicely on both motors (quite a bit higher on the Kosdon).

Motor retention is important, as this rocket doesn't have a thrust ring. As I mentioned before, I've got a Giant Leap MotorHolder on it, so motor retention is quite simple. I just slide in the motor, tighten two bolts, and the motor is as secure as can be. The Kosdon 38mm casing doesn't have an aft closure, so I used a hose-clamp on the aft end. It's worked just fine for a half-dozen flights, so I just leave the clamp in place.

For wadding, I use the Pratt protector. It's a large piece of Nomex® (about 12" diameter), which works well for the 4" rocket. I just bundle up my chute, place the protector over the tube, making a little "cup" to hold the chute, and tuck the whole thing down into the tube. The diameter of the rocket is big enough that things don't have to be packed tightly. I've never had a problem with a cooked chute or a tangled chute using this method.

Recovery:
The shock-cord is about 12 feet of elastic. It's nice and long, so even if the ejection charge is late it doesn't hurt anything. The chute is a standard octagon of pink rip-stop with nylon shroud lines. It's fairly lightweight and light-duty, but the rocket's not very heavy for its size, so the descent rate is just fine.

Flight Rating: 4 out of 5

Summary:
Main pro: Flying! This is the best flyer in my collection, and one that I never fail to bring out at a launch. I've flown it dozens of times. It's stable as all get-out, and it just makes the whole thing look easy. Other pros are the instructions. Cons: You've gotta cut your own fin-slots. I wish they'd at least give some tips on beefing up the aft end. Rockets do tend to get dinged when they land, but there are plenty of ways to get around that.

Overall Rating: 4 out of 5

Flights

Comments:

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E.S. (January 1, 2001)
I have had a Excel Plus for my years. It was one of my first high powered rocket kits that I have owned. I used this rocket for my level one cert on an I-284. What a flight. A real head snapper. This rocket is capable of flying on anything from a G-125 short (about a thousand foot flight) to a J motor. I have used this kit for my level two flight last summer. The last that I put on the kit was on a J-570. Nice fast lift off too about five hundred feet until the nose cone A.C.E. Decided to cave in. It looked like snow up there in the sky! The info given here was very accurate. The only con this kit was that the motor tube was about one millimeter too small. The casing would not fit. Always pre-test tube before gluing into the rocket!
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S.C. (November 4, 2007)
My Excel Plus has become the 38mm workhorse in my fleet - I fly it at every launch I attend. It's easy to prep, looks good, and flies great! I've found that it turns in the best flights on the red, white, and blue loads for the AT 38/480 case (the I300T is my favorite.) Built entirely using wood glue, this rocket is durable and sturdy. A great value and just plain fun.

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