Article – The Tragedy of the Archer

On November 23, 2017, I was able to complete my North Coast Rocketry SA-14 Archer.

Final Build of my NCR SA-14 Archer
Final Build of my NCR SA-14 Archer completed 11/23/17

Sorry for the terrible picture.  I usually have better lighting.  Here is the IG link.

His maiden flight was with his brothers on January 7th, 2018.  You can see he’s the class clown as he’s the only one standing like a weirdo.  What a guy!

Launch Crew of the CRASH Launch on 1/7/18

This day turned out pretty good.  I was able to launch this kit on a F50-6T Estes PSII Composite Motor.  I’ll provide a video of this at a later date.

When the rocket landed, it showed no sign of any issues.  That’s usually the case right? When I picked it up, I noted the following damage.

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What appeared to be a Broken Fin upon maiden flight landing 1/7/18

If you look at the above picture, you’ll be able to tell that the fin itself did NOT break, but that the epoxy mended area cracked almost completely off.  The OTHER side did not look like this at all, which in turn ripped the tube on the bottom.

So at this point, we think about the future of our rockets that we spent around $60 to buy.  This kit is available directly from North Coast Rocketry and a few other places such as Apogee Components (my personal go to), eRockets.biz, eBay and Amazon sellers.

First thing we think about is time spent on creating the masterpiece.  I would like to think that I put some pride in my builds and try to go for flash appearances as much as possible to the box or card insert in the bag with the kit.  I was literally torn by what to do next, so I asked my friends on Facebook on the Model Rocketry Fanatics group.

Follow the link to see what my peers had to say! Also feel free to join the group if you’re not part of it already!

We decided that trying to take the fin OFF, was the best move.  I would like to thank Paul Wolaver for confirming my idea of doing the exploratory surgery on Mr Archer here.  Here was my process.

First… Cut the fin OFF, since its broken off at the joint line on the opposite side.

Hobby Saw cut line!
Use of a hobby saw to remove the epoxy to the opposite side that was not damaged.

So here is the thing.  This is embarrassing to admit, but here it goes…

This was assembled incorrectly.

For most mid powered and high powered kits, the whole reason a kit has TTW Fins (Through the Wall), is for strength and durability.  Well… if you DON’T use some type of adhesive reinforcement on the INSIDE of the body tube… this is what happens when your rocket lands perfectly on the TIP of the swept wing.

This fin came out pretty easy as a result of NOT reinforcing the inner joints with epoxy or even wood glue!

We can talk about how to do the reinforcement of the internal joints at a later time.

This isn’t a proud moment for me.  However, we all learn, and that’s the purpose of this post.  Moving on…

Taking a look at the tube damage after the fin is removed reveals a MESS of work.  Time to whip out some sandpaper and make this worthwhile.

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Damage to the fin can area noted after fin removal

Reshaping this was not too difficult. I was more focused on giving new epoxy a place to adhere to rather than worrying about the aesthetics at this point.  Decals are copies from the originals, so it was easy to scrape and sand them off as needed.  After cleanup of the affected area, I wound up with these results for the tube and bottom fin can.

Where the crinkle is… I’m not worried about… that’s nothing some model putty or even FixIt Epoxy Clay can’t help remold.  We will look at the re-finishing of this on a later post.

Next process was the fin itself.  I only took the below pic of me “sawing” off the old epoxy and paint from the fin.  I left it pretty clean, took it all the way passed the primer to the ply.

Cutting the epoxy and paint away from the fin itself!
Cutting the epoxy and paint away from the fin itself!

This photo below shows some accomplishment.  The fin now sits correctly in its location after sanding INSIDE and outside of the body tube/fin can!

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I decided NOT to glue this in just yet.  As per Paul’s advice per the Facebook Post on the Model Rocket Fanatics group, we are going to DRILL next to the fin tang on each side on the bottom centering ring, making an access.  I am using a 3/8″ drill bit so I have enough room to get a smaller wooden dowel in there to smooth out the fillet for internal reinforcement.

I did dry fit this fin AFTER I drilled the holes… just to make sure the fin tang would be able to be reinforced after the fact.  Below pics show that the fin will FIT in its original spot correctly.  Last photo is the fin glued in place with Wood Glue to the MMT (Motor Mount Tube).  This will hold it in place till I am able to get some epoxy in there.

I let this sit for approx 8 hours… the wood glue was dry at his point, so took the liberty of using my holes drilled and “pouring” epoxy from a wood stick into the opening.  I didn’t take a photo, but after this, I took a small wooden dowel and smoothed the epoxy where the fin connects to the MMT and the inside of the fin can.

Here… you can see the epoxy after it has dried a bit, shining through the fin can on the seam.  We are now ready to epoxy the fin on the outside.  I like to use 30 minute epoxy myself.

The clear epoxy peeking out between the fin and the body.
The clear epoxy peeking out between the fin and the body.

It’s these small victories we have to cherish and appreciate.  The fact that something literally comes back together.  I am 90% confident that the finishing of the damage will be almost as good as it was when it was completed in Nov 2017.

More to come on this! Thanks very much for reading.  Feel free to send me an email or leave me a message!