SNARKY by Dyna Star (Apogee Components) Build Log

[JoeFilgas]

Tonight I started on the SNARKY project. First I used 400 grit to sand the “Balsa” more like Basswood fin pieces before removing from their laser cut housing. Quality laser cutting here by the way! Then I layed out the left and right wing sections and top fin pieces making sure I had all the angles right. Then I used t pins and wood glue to create the sections. I will sand in airfoils to all fins and will cover with 3/4 oz fiberglass cloth and thin CA glue. Next I moved onto the motor mount. Since I’m using a motor retainer (Estes 24mm) I don’t need to use any hooks or blocks. I dry fit the entire mount to fit the retainer and also made the shock cord mount in a loop fashion dividing the strain to both sides of the rocket. Next I started by gluing the Aft CR in place and went ahead and glued in a green CR to add more strength to the joint. I moved to the front CRs using the same procedure. The front CRs each had notches cut for the shock cord to become captured. Then I knotted the shock cord down and secured with more wood glue. Finally, using JB Weld high heat epoxy I glued the engine retainer to the aft portion of the motor mount. I had to add about two wraps of regular masking tape around the MMT so the slightly larger retainer diameter would fit better on the MMT.

 

[JoeFilgas]

Today was all about getting the fins ready! I started by pulling the t-pins and freeing up both wings and vertical stab. All fins were then surface sanded with 220 grit to clean up the glue joints. All fins were then air foiled with 150 grit sandpaper. Once I was happy with that they all received a 220 grit clean up sanding. Next it was onto strengthening and sealing all the fins using 3/4 oz fiberglass cloth. I first sprayed side one of each fin with Elmer’s spray adhesive though not very much as it only has to tack down the fiberglass cloth. Each was fitted with one layer of cloth, smoothed down and then glued down with thin CA glue. Each fin then had the excess glass removed with some 220 grit sand paper. The same procedure was followed to the other side of all fins. Finally they all were finish sanded with 220 grit sandpaper being careful not cut through the fiberglass. They are now in a finish ready state awaiting installation to the BT.

 

[JoeFilgas]

SNARKY rocket build: well today started at 4:30am to watch the Starship 2 launch live and WOW! Congrats to SpaceX and Elon! Anyway Snarky moved along just a little bit tonight. First I had to finish making the main Kevlar shock cord connection before glueing the motor mount in to the BT. I layed the motor mount outside the BT and added approximately another section of Kevlar cord about six feet long. I made the looped portion attached to the motor mount fall well below the top end of the BT to allow for the addition. The new six foot section was then added via loop attachment to the main so only a single width of cord would extend past the top end of the BT. I added a little wood glue to the knot loop on the six foot section just for safety purposes. With that complete I shoved the entire shock cord down through the aft end of the MMT in preparation of glueing the motor mount in permanently. A 3/4” or so swath of thin CA glue was placed on the top inside of the BT to help prevent any zippering followed by a light sanding of the area CA’d. Next it was on to installing the motor mount. I used the 3” measurement for glue placement on the upper CR. I inserted the MMT partially and then added the rear glue section at the end of the BT followed by quickly inserting the full MMT to its final position leaving about 1/16” of a lip from the aft BT to allow for a good bottom glue fillet. Looking down from the top of the BT it was clear I have a decent glue fillet on the top so nothing more is needed there. I’ve set this assembly aside, standing vertically (allowing the top internal glue fillets to form) to dry and then I’ll add the glue fillet to the bottom.

 

[JoeFilgas]

The SNARKY rocket came further along today! The glue fillet on the bottom of the rocket was done with TB II and set aside to dry. Next I cut out the four paper marking guides. The BT was still drying so I moved onto the scoop tube making all the required marks and lines. Then the two ends were cut according to the marked pattern with a new Xacto blade. Many, many light pressure runs were made slowly cutting through the tubing. Once both were removed I used a sanding block with 220 grit sandpaper to clean up the cuts. Next it was time to cut out the upper section of the scoop tube and they mean it when they say go slow and use an angle to score both line cuts BEFORE you cut all the way through. This is because the this tube will no longer be a tube when finished and is easily damaged if you use too much pressure in both cutting and sanding. Once the top portion was removed I proceeded to carefully and slowly sand the last two cuts, again with a 220 grit sanding block. I also used a small piece of hand held 220 grit to clean up all the cut edges. By now the glue fillet had dried enough so the last tube marking guide was used and all lines drawn on those marks with an aluminum angle. That’s it for today!

 

[Bruiser]

So just thin CA used to attach the fiberglass and fill the weave? I've never tried that before. Sounds interesting. I wouldn't think it would fill the weave.

Build is coming along great. Even though I don't have one I like these style rockets.

-Bob

 

[JoeFilgas]

So just thin CA used to attach the fiberglass and fill the weave? I've never tried that before. Sounds interesting. I wouldn't think it would fill the weave.

Build is coming along great. Even though I don't have one I like these style rockets.

-Bob

Thanks. I probably should have said “helps” fill the weave depending how much of the CA you don’t wipe off. The surface will indeed need finish fill work.

 

[JoeFilgas]

Back on the Snarky build tonight/this morning now. I used the two kit included cardboard guides and dry fit the scoop tube to the BT. I am impressed with this incredible tool to hold the scoop tube in place while being glued. I did a couple of other things while gluing this piece. First the directions say you may need to slide the guides while gluing. They really don’t help much on the aft end where the scoop tube pieces are long and really don’t have much there. So first I used some metal T-pins to push the edge of the scoop tube and keep them in place on the line. I went ahead and placed pins along the entire length the the scoop/BT joint on both sides. Next I first secured both ends of the joint down with a dab of gap filling CA and a hit of accelerator on the internal side. This really helped in making sure the joint was being held together well while only doing the outside this bead or fillet for now. As the glue dried I removed the pins and ran additional fillets in the pinned areas on both sides. After more drying time I removed the cardboard guides and finished filling in those remaining areas of the joint. Although the directions don’t call for an internal fillet I decided I wanted to do that. So I went ahead and glued in the internal launch lug first and let that dry a bit. Next, using two coffee stir sticks glued end to end I ran small internal fillets along both sides with TB II. I also did additional fillet work around the launch lug and set all aside to dry.

 

[JoeFilgas]

The SNARKY build jumped forward today! With both cardboard jigs attached to the BD/Scoop tube assembly I dry fitted one of the wings. Turns out the root of the wing attaches to the BT only and kind of sits against the Scoop tube joint. To make sure I had a good purchase for the wing joint I used a small file to rough up the BT and the existing small glue fillets on both sides. I made front and back reference marks on the BT and then proceeded to glue the first wing to the BT. After that dried for a bit I went ahead and did the glue fillets to both sides of the wing since they are fairly large pieces and I didn’t want to damage them while installing the remaining wing and fins. I used this same process, one fin at a time, with some drying time in between each installation which took all afternoon to complete. Finally I glued in the rear scoop tube fin and did some more glue fillet work on it as well as the launch lug. Basic construction is now complete. Tomorrow I want to do the epoxy fillets on all joints. I’ll be using West Systems epoxy again with colloidal filler to form the final fillets. Then it’s on to some sanding, filling and the first round of primer!

 

[JoeFilgas]

Today I sanded the areas of the SNARKY to prepare for the epoxy fillets. After a wipe down the areas were masked off. I mixed up a batch of the West Systems epoxy and colloidal filler followed by applying the fillets. One batch of epoxy was a perfect amount for all the fillets. I let it sit for about half an hour and then removed all the tape and set it aside to dry and cure overnight.

 

[JoeFilgas]

Got the epoxy fillets all sanded down. I also reinforced the inside of the scoop tube with thin CA both for and aft. Next I ran auto glazing putty in all the fillet areas with my finger to even everything out and also long the visible inside of the scoop tube both fore and aft. Once this is dry and sanded I’ll go back and fill the tube spirals with glazing putty and a razor blade. It was just to crowded with wet putty to handle trying to do the spirals right now. Finally I sanded down the seams on the nose cone with some 150 grit and then overall with 220 grit. I’ve put this all aside to dry overnight. On a side note Lorrena did a test vinyl decal she had printed and after letting it dry well overnight I shot it with multiple coats of Matte clear to see how it would handle it. Turned out great so she’ll be making all my multi-color decals for this project!

 

[JoeFilgas]

Today’s SNARKY Flying Tigers update: today I sanded down all the fillets that I applied the glazing putty to. Then it was time to glaze fill all the spirals!

 

[JoeFilgas]

So on the Snarky Flying Tigers build I did a final sanding with 220 grit. I used a small piece of 3/16” hardwood dowel as a hard anchor for any epoxy and BB weight that may go into the nose. I used thin CA followed by some gap filling CA on the dowel and sanded flush. I haven’t yet decided, but I may cut the majority the nosecone shoulder off and install a plywood bulkhead and eyebolt. My only concern there is will there be enough shoulder that sits inside the BT (only about 1” or so) to hold up to a launch. I taped off both sections and readied them for the first round of primer (always fun because it always shows all the areas you missed with the prior fill work.) I used my go to grey primer, Iron Armor Filler Primer to coat both pieces. Not sure when the next round of primer will go on as the rain is coming tonight!

 

[JoeFilgas]

Rain, rain go away I’m not done with this yet!

 

[JoeFilgas]

Today’s SNARKY Flying Tigers had the first round of primer wet sanded for the most part with 400 grit then thin layers of more glazing putty inserted where needed. I let that dry for a couple of hours then dry sanded those areas with 150/220-400 grit and wiped clean. It’s ready for round 2 of filler primer when the weather permits.

 

[JoeFilgas]

Well still waiting for better weather to move the SNARKY Flying Tigers rocket painting along so I pulled the trigger on a modification I like to do on most of my rockets and that’s not to trust the molded plastic anchor on the nosecones. That necessitated cutting off the base of the shoulder with the Dremel cutoff wheel and sanding smooth. Now access to the inside of the nosecone is obtained for a few reasons. First a rat tail file is used to toughen up the inside surface down near the tip where the BB and epoxy nose weight mixture will go. Secondly I roughened up the inside as well where I will be epoxying the 1/4” eyelet plywood bulkhead in. I put a slight bevel on the edge of the bulkhead to get a better gluing surface to the NC. The screw is just temporary allowing me to insert and move around for initial fitting. Tomorrow I’ll acquire the eyelet hardware plus a 1/2” plug for the 1/2” access hole I’m going to drill in the bulkhead to allow the BB and epoxy nose weight mixture to be inserted through. I’ll also add some medium weight fiberglass cloth to further reinforce the bulkhead from moving aft upon ejection and deployment.

 

[JoeFilgas]

Made a run to the hardware store and acquired the pieces I needed to complete the SNARKY Flying Tigers rocket nosecone modification. I epoxied the bulkhead in with 30 minute with some colloidal filler added. Then I cut out some short strips of medium weight fiberglass and brushed on some epoxy to the aft face of the BH and about 1/2” up the inside of the NC. Then, with tweezers, I placed the strips on the wood to plastic joint and gently tapped them down into the epoxy with the end of the brush. I always cut about half the bristles off so I have a stiffer brush. Finally I brushed more epoxy over these areas and set it aside to dry. Also while at the hardware store I picked up the two colors for this project. Finally I worked on sizing our custom decals and sent the files off to Lorrena to work on the vinyl.

 

[JoeFilgas]

Thank you to my wife Lorrena for producing these vinyl decals for the SNARKY Flying Tigers rocket! These are printed vinyl so they will be matte clear coated along with the rest of the rocket when done.

 

[JoeFilgas]

Yay a break in the rain today allowed me to get the second round of primer done on the SNARKY Flying Tigers rocket!

 

[JoeFilgas]

Kept forgetting to sand and primer the motor retainer ring for the SNARKY Flying Tigers rocket, but I got it done!

 

[JoeFilgas]

Did the final wet sanding today with 400 grit on my SNARKY Flying Tigers rocket. Now we wait for a paint day!

 

[AfterBurners]

Looking good! It's a great kit!

 

[JoeFilgas]

Looking good! It's a great kit!

Thanks! It sure is I love it!

 

[Adam3836]

Nice work here
I certainly love the snarky also

 

[JoeFilgas]

Nice work here
I certainly love the snarky also

Thank you!

 

[bcook7135]

Nice job. I love my Snarky. It is one of my faves. But, I really built mine heavy it seems. So after many dubious flights I finally found an engine that would actually launch it upward instead of sideways - the E18-4.
Beautiful flight! But, now I call it the Sparky Snarky

 

[JoeFilgas]

Nice job. I love my Snarky. It is one of my faves. But, I really built mine heavy it seems. So after many dubious flights I finally found an engine that would actually launch it upward instead of sideways - the E18-4.
Beautiful flight! But, now I call it the Sparky Snarky View attachment 618780View attachment 618786

Thanks! Oh my gosh we’re you able to retrieve it? Beautiful launch pic!

 

[JoeFilgas]

Well after a nightmare day with the original paint (2 defective) I was able to return and go for a different color and got it on the SNARKY Flying Tigers rocket just after 4pm today! Also changed to a different shade of green. Hopefully we’ll get a decent day in the next week or two so I can get the green and red on!

 

[bcook7135]

Thanks! Oh my gosh we’re you able to retrieve it? Beautiful launch pic!

I had to call the power company to come cut it down.

 

[JoeFilgas]

I had to call the power company to come cut it down.

Wowsa glad you got it back!

 

[Capt. Eric]

Love the Snarky kit. After my first one was lost to a tree, I got another and this time made it in silver, just to do something a little different. A friend set up his go-pro and got one of my favorite rocket pictures of Snarky lifting off.