A blast from the past -An ARC Black Widow Build Thead

[JackC]

Steve Shannon sold me a rocket antique. ARC, the precursor to Dynacom, produced a version of its Black Widow rocket before Dynacom existed. This kit does not provide an aluminum tail cone for the rocket.

I plan to modify the rocket from 1988 into a super sports flyer in 2022 by lengthening the airframe and converting one of the eldest fiberglass rockets for dual deployment.

I will start construction soon on one of the earliest produced fiberglass rockets (a rocket older than my marriage!

 

[Steve Shannon]

I’m really looking forward to seeing this built. I’ve had it since it was just old, not an antique.

 

[jmasterj]

Does it have an airframe that matches modern FG airframe sizes? I thought the Dynacom tubes were non-standard compared to what's available today.

 

[tsmith1315]

the rocket from 1998

Oh, it's older than that if it's ARC.

 

[Steve Shannon]

Oh, it's older than that if it's ARC.

The original shipping label is on it, so it’s easy to tell. I don’t remember what the shipping date was. It was a very nice kit, which I bought from someone who hadn’t built it. Then I didn’t build it. I’m delighted Jack is building it.

 

[JackC]

Does it have an airframe that matches modern FG airframe sizes? I thought the Dynacom tubes were non-standard compared to what's available today.

Actually, the Black Widow’s tubes matchup almost exactly with Composite Warehouse tubes.

 

[JackC]

Oh, it's older than that if it's ARC.

You are correct! The shipping label on the box states 12/30/88. I was in my first year of law school at that time! Man, is that old!

 

[JackC]

Actually, the Black Widow’s tubes matchup almost exactly with Composite Warehouse tubes.

Except for the color of the old tubes (a parchment color) vs the new tubes the coupler and airframe tubes fit like a dream!

 

[Wally Ferrer]

Why no picture(s)? I'm not familiar with this kit and you're making me go do a search for it...

 

[JackC]

Why no picture(s)? I'm not familiar with this kit and you're making me go do a search for it...

Pictures are coming soon.

 

[JackC]

Pictures are coming soon.

As promised here are the photos.
The first photo shows the parts of the original kit. There are three small and short all threads installed at the aft of the rocket with three nuts to hold the fiberglass centering ring that acts as a motor retainer. The smaller airframe tube is designed to hold your altimeter and recovery system. The nose cone is gel coat fiberglass. The reason you don’t see a motor mount tube is that it is installed in the sustainer at the factory.

The second photo shows the new nose cone and tubing from Composite Warehouse that will allow me to stretch the rocket a bit to make it conventional dual deployment. The CW tubes are lighter than the ARC tubing but fit exactly the same.

The third photo shows the long fins. The fins are original but do not come beveled. So, I had Mike Fisher bevel them.

Finally, we focus on the filament wound nosecone with the aluminum tip. The new nosecone is stronger than the gel coat original.

 

[StreuB1]

In 1988, we had no altimeters so to speak. There were "some" but they were home made. This was before the Alt and g-wiz.

Some of the only electronics at that time were timers which at that time were generally Radio Shack digital egg timers converted to fire a single output.

Electronics were EXTREMELY limited at that time.

There was Microbrick but I think they only made a few timers but I don't think they went back into the 80's......

 

[JackC]

Well…I tried to slide a 54mm motor case to check the fit of the motor mount tube and the glue on the rear centering ring failed.
But I am not defeated!

I will install a new motor tube and place a Slimline retainer on the business end. I have ordered the parts and should receive them shortly. The build will continue!

 

[Steve Shannon]

Well…I tried to slide a 54mm motor case to check the fit of the motor mount tube and the glue on the rear centering ring failed.
But I am not defeated!

I will install a new motor tube and place a Slimline retainer on the business end. I have ordered the parts and should receive them shortly. The build will continue!

That must have been surprising. I’m really glad modern parts fit and you’re undaunted.

 

[JackC]

Okay! I have started the build (rebuild in some areas) of the Widow. I will have pictures in the next post but I wanted to explain some of the choices I made.
The original motor mount tube had an engine block about 25 inches inside the tube. It also had a steel cord with a loop to anchor the shock cord. The engine block would stop a CSR 54mm 6GXL or the long 54mm Loki motor from fitting in the rocket. The steel cable also can be a problem. My friend built the Air-X Delamar which had a similar cable. The steel snapped and tore up the inside of his sustainer. So, I chose to get rid of them both.

Next, I decided to dump the fiberglass motor mount and replace it with a PML phenolic tube to save some weight because the original airframe tube is very heavy.

Finally, I will join a 6.5 inch section of the original airframe with a 23 inch section of the airframe with the fin slots. When I add the anti-zipper coupler, the rocket will have enough room for nearly every 54mm commercial motor.

 

[Rocketjunkie]

I built a Black Widow in 1989. This when Tom Blazanin was running it. Still have it in flyable condition although I haven't flown it since early 1990. Cat for scale

 

[JackC]

I built a Black Widow in 1989. This when Tom Blazanin was running it. Still have it in flyable condition although I haven't flown it since early 1990. Cat for scale
View attachment 515526

Yes!

Dynacom also offered a slightly stretched Black Widow that was 67 inches long as opposed to the stock version which was 60 inches long.

My modification should be 80 inches long, full dual deployment.

As for the Black Widow kit, I just love the extremely long fin root chord!

 

[JackC]

Okay! I have started the build (rebuild in some areas) of the Widow. I will have pictures in the next post but I wanted to explain some of the choices I made.
The original motor mount tube had an engine block about 25 inches inside the tube. It also had a steel cord with a loop to anchor the shock cord. The engine block would stop a CSR 54mm 6GXL or the long 54mm Loki motor from fitting in the rocket. The steel cable also can be a problem. My friend built the Dynacom Delamar which had a similar cable. The steel snapped and tore up the inside of his sustainer. So, I chose to get rid of them both.

Next, I decided to dump the fiberglass motor mount and replace it with a PML phenolic tube to save some weight because the original airframe tube is very heavy.

Finally, I will join a 6.5 inch section of the original airframe with a 23 inch section of the airframe with the fin slots. When I add the anti-zipper coupler, the rocket will have enough room for nearly every 54mm commercial motor.

Here are the new photos.

The first shows the old motor block removed from the motor tube.

The second is the new motor mount made from PML phenolic tubing and a pair of plywood centering rings. The rings fit inside the airframe tube perfectly. Also the airframe feels much lighter with the phenolic motor mount!

The last photo shows the newly joined airframe tubes. A Composite Warehouse coupler tube joins the pieces of the original airframe tubing.

The third photo shows the Composite Warehouse nosecone with the shoulder. I had to do some significant sanding to get the shoulder to fit the nosecone.

None of these items have been epoxied yet. I am waiting for the Slimline motor retainer to arrive to ensure my measurements are correct.

 

[JackC]

I built a Black Widow in 1989. This when Tom Blazanin was running it. Still have it in flyable condition although I haven't flown it since early 1990. Cat for scale
View attachment 515526

Hey, man, thoroughbreds are meant to run, Black Widows are meant to fly! Launch that rocket into the wild blue yonder!

 

[Rocketjunkie]

I still have one of the motors I used to fly it on. An early version of Warp-9. 54 mm OD, 5" long. Clear flame, no smoke. It is a PITA to prep but will take up to a Vulcan K420SS.

 

[Rocketjunkie]

Yes!
As for the Black Widow kit, I just love the extremely long fin root chord!

It's good for high performance rockets. I used a short span, long root fin design in my Cloudbuster series. Later in 1990 I flew 2 at the Black Rock II launch on Vulcan O1500 motors. These motors were 4-5/16" diameter and 40" long moon burners. Fins (surface mount), Test flight on J700, completed rocket again cat for scale.

 

[JackC]

I still have one of the motors I used to fly it on. An early version of Warp-9. 54 mm OD, 5" long. Clear flame, no smoke. It is a PITA to prep but will take up to a Vulcan K420SS.
View attachment 515578 View attachment 515579

Did you cut the rear of your fin slots to build the fin can outside of the airframe for your Widow?

 

[Rocketjunkie]

Did you cut the rear of your fin slots to build the fin can outside of the airframe for your Widow?

No. Thoroughly sanded the motor tube and installed it. Then buttered the fin roots well and installed them through the slots. External fillets only.

 

[JackC]

No. Thoroughly sanded the motor tube and installed it. Then buttered the fin roots well and installed them through the slots. External fillets only.

Nice! Thanks!

 

[JackC]

I just remembered I had a Slimline retainer for my carbon fiber two stage that was a project my son (the “boy”) and I were supposed to construct during his senior year in high school. He is now finishing his freshman year in college. <Sigh> Well, waste not, want not!

So construction on the Widow continues.

The first photo shows the two sections of airframe joined with West System 105/205 epoxy. The nice thing is that even with the epoxy, the weight of the tubes and the coupler equals the weight of the sum of the separate components.

The second photo shows the phenolic motor mount with both plywood centering rings epoxied in place. Unlike the original kit, the rings will sandwich the fins between them and stabilize them in the slots.

The last photo shows the awesome fins of the rocket. I used the Dremel sanding drum to remove the sheen from the root chord up to .125 inch for the external fillets.

 

[JackC]

It's good for high performance rockets. I used a short span, long root fin design in my Cloudbuster series. Later in 1990 I flew 2 at the Black Rock II launch on Vulcan O1500 motors. These motors were 4-5/16" diameter and 40" long moon burners. Fins (surface mount), Test flight on J700, completed rocket again cat for scale.
View attachment 515584 View attachment 515582 View attachment 515583

How high did the O motors go?

 

[Rocketjunkie]

How high did the O motors go?

Back then it was motor ejection, no electronics. Chuck Rogers program (now RasAero) indicated 40-50K. Nobody knew about the problems with poor burning of BP at altitude or even delays burn quite a bit slower at these altitudes. Altitude was determined with a measured base line and tracking powder for a cloud at ejection. (5 lb. in my rockets.) Here's the first one

 

[JackC]

Back then it was motor ejection, no electronics. Chuck Rogers program (now RasAero) indicated 40-50K. Nobody knew about the problems with poor burning of BP at altitude or even delays burn quite a bit slower at these altitudes. Altitude was determined with a measured base line and tracking powder for a cloud at ejection. (5 lb. in my rockets.) Here's the first one

That was awesome!

 

[JackC]

Construction of the fin can is complete! I just have to wait six to seven hours or so for the JB Weld to cure. I used JB Weld to tack the fins to the motor tube because of its high temperature capability. I spread JB on the motor tube where the fins would go. Then I spread West epoxy inside the airframe where the centering rings will be installed. Then I slid the entire motor mount assembly into the airframe.

Next, I coat each fin edge with a left over batch of JB. Then I place each fin in the slot, pull the fin back out and reset the fin back into the slot. After that, I slide the handy-dandy ******/Badass Rocketry fin jig over the fins’ leading edges. These jigs are awesome and do a great job aligning the fins. You just order a jig based on the number of fins and the diameter of your rocket.

The second and third images shows the Slimline retainer. This model fits a 54mm motor tube and has a screw on/off retainer ring. Very handy on the field.

Finally, the completed fin can awaiting its fillets. A nice thing about the Badass jig is you can set the rocket on its tail while you wait for the internal attachment points to cure.

 

[JackC]

The external fillets are complete. They look great! I also used a technique from RocketGeek 101 to ensure the fillets don’t drip by using a level to keep the fins level. Works like a charm!