The Obscure and Amazing
Groover 4 Sport/Pattern Plane

Designed by Nathan Bast

 

Text by Dave Swanson, SPA L27, Rockford, IL
w9eu@hotmail.com

 

The Groover 4-60 was approved for SPA competition on March 1, 2017

 

The Groover 4-60 is one of the most obscure pattern planes in existence. It is a plane that, to me, has almost mystical qualities. The Groover was designed and refined from the mid 1960's to the early 1970's by my local RC modeling mentor Nathan Bast (deceased). The Groover had 4 generations, each one a refinement of the prior generation. All of the Groovers were good flyers, but the 4th and final configuration was, and still is, an amazing airplane; fast, very aerobatic, and it tracked (grooved) like it was on rails! Knife edge performance was very important to Nathan. The Groover 4 was and is capable of consecutive knife edge loops with a good engine.

The Groover was known to only a small enclave of enthusiastic devotees. I was among them and will always remember the day Nathan felt confident enough in my flying ability to let me fly his Groover. What an amazing experience that was! Pure RC nirvana! The Groover remained virtually unknown outside our immediate circle of fliers. Nathan never joined the local clubs, but chose instead to fly from more private remote areas, therefore creating the limited audience. Nathan was kind enough to share his plans with a few of us and 35 years ago during the Groover's heyday there would be 2 or 3 Groovers at the field. Nathan is on the right in the photo below giving his signature hand signal as if to say "having a great time"!

I am the proud owner of what may be the only Groover 4 - 60 size in existence today.  It was built by Nathan himself, making it even more special to me. Nathan had given me a fuselage that had been crash damaged but was meticulously repaired by him. The next winter he needed help clearing snow from his driveway and I volunteered to keep it clear for him. At the end of the snow clearing season he gave me a brand new wing he had built over the winter unbeknownst to me. I was on cloud 9!

The focus on knife edge performance can be seen in these 2 photos.

1) The wonderful airfoil shape of the fuselage

And 2) the substantial tail sub fin and rudder. Note Nathan's stylized initials on the vertical fin.

Knife edge performance was also enhanced by Nathan's building techniques that kept it light. The total weight with all gear (less fuel) is 6 lbs. 2 ozs...

Only Nathan and I were at the field on the day the photos below was taken. I took Nat's Groover up and was putting it through the paces when I heard a brief flutter and saw half of the stab and elevator separate and float down! The Groover was still quite flyable in spite of the fact that the elevator control horn was on the side that flew off!! I eased the Groover back to the field and landed without incident. Here is Nathan pointing to the stab and doing the circling "crazy" gesture with the other hand. A testimony to a well balanced plane if there ever was one!

I recently returned to RC after a 30 year absence, but I had carefully stored away my precious Groovers for all those years. Now that I am comfortable with my flying skills again I have been busy getting my Groover 4 -60 ready to fly. I have gone through it with a fine tooth comb. It has a new Spektrum 6 channel receiver, Hitec high voltage digital servos, and a 2s 1300 Lipo receiver battery. I will be using my Kraft Signature Series transmitter converted to 2.4 GHz by Cal Orr, and power comes from a vintage 1982 OS 61FSR ABC with a Macs flow thru muffler. Truly a sweet setup!

I went to the field this morning (9/28/16). It was perfect weather and it brought a record crowd out to the field. The 3D planes were out there making their deafening noise, the foamies were flitting around like houseflies. In other words a good day at the field, but all the activity was messing with my Zen!

I went back to the field about 5 pm and no one else was around. I am happy to report I had 5 successful flights! My knees were knocking on the first flight, but the Groover was back in the air! It only needed a click or two of trim and all was good. The OS 61FSR was running super strong and perfect! By the third flight I was back to doing knife edge loops - so easy to do it's intoxicating! Nathan would be proud. Thanks old buddy for all the great memories and a most amazing plane!

Here's a wonderful inflight photo taken by Dave's son Kristian. Love that rainbow!!

More information and some nice videos can found on
Dave's Groover thread on RCGroups.com.

Groover 4 -60 stats
Wingspan - 61.5 inches          Ready To Fly Weight (less fuel) 6.1 lbs.
Wing Area - 561 sq. inches          Wing Aspect Ratio - 6.74 to 1
Wing Weight (with servo) 1.75 lbs.          Engine 1982 vintage OS 61 FSR ABC
   
Download the Groover 4 - 60 Plans
The plans are very basic and leave a lot to the imagination,
so feel free to contact Dave at the email address above
for any questions or clarifications.
Fuselage Plan             Wing Plan