Mini Tempest

[Bruiser]

Back in June 2019 I designed and built the Tempest, a two stage pseudo scale Navy missile. I've flown it several times and it is a hoot to watch.

Now that I am building some 13mm rockets I decided a down scale was in order. The original was 24mm to 18 mm and while I thought about 18mm to 13mm I was afraid the fins would break off the booster so this one is 13mm to 13mm.

Here we go with my build documentation.

So it begins with the motor mounts. A BT-5 with some Estes centering rings. Both motor mounts were the same. There is a engine block in each one as well


Then I moved on to the booster. Here I show the interstage coupler being positioned


Next was adding fins to the booster. They are 1/32 bass but next time I will use something a little thicker I believe. I did taper the leading edge and yo can see where this CA was used to strengthen the sanded area.


Moving on to the sustainer, here it is with the fin jug from payloadbay.com I just print them out on paper, 3M77 them to a piece of cardboard and cut them out with a hobby knife and ruler


Decided to do the strakes next. Again, 1/32 basswood.


Can't forget the launch lug which looks huge!


Here's a view of the business end of the sustainer


Back to the booster. The original Tempest booster featured vent holes and it has worked great so far. I decided to add them to this booster also


Here's the trial fitting after primer


Here she is in full color with decals. No clear coat yet because there was a malfunction when I clear coated the decals. The can kept spraying when I released the nozzle. I tried depressing and releasing the nozzle several times, tried a different nozzle, tried tapping the can and combinations of all that to no avail. It was a new can of Krylon Crystal Clear gloss.


Here she is with the original


The primer is Rustoleum 2 in 1 filler/primer. The white is Krylon Acyrli-Quik. The red is Duplicolor Perfect Match. The decals are made by me and I got to say these went on better than any others before. There must be a learning curve

I did have a problem with the fins splaying out when I left the rocket laying on it's side for a few hours. This happened several days after I had glued them on with Elmer's Glue-All and applied the fillets with Titebond Quick and Thick. It was just a few hours after I had sprayed the fins red though. I was able to "flex" each fin back in place except one. It came loose on one side so I ended up removing it, cleaning the bonding surfaces and gluing it back on. All the fins are solid today. I'll make note if anything happens when I clear coat.

First launch would have been on the 20th but I'll be off to dogs shows so she's gonna have to wait a bit. By June, there might be another ready for a maiden also. I am thinking of building an Xtreme with a 13mm mount or building a 13mm powered D-Region Tomahawk next. I have been thinking that the nose cone of the Xtreme does look a lot like the nose cone on the upcoming So Long release. Maybe a downscale???

Thanks for reading,
-Bob

 

[mh9162013]

Looks good. You should consider doing away with launch lugs on these smaller rockets and use fly/fall away launch lugs instead. As you already observed, a launch lug on a BT-20 or similar sized rocket really stands out.

 

[BABAR]

Looks good. You should consider doing away with launch lugs on these smaller rockets and use fly/fall away launch lugs instead. As you already observed, a launch lug on a BT-20 or similar sized rocket really stands out.

Micro buttons is another option.

 

[Bruiser]

I launched the Mini Tempest on 20 May. It was a very strange launch.

I flew a A10-0T to A3-4T and it staged very quickly like pfft-pfft, maybe a nano-second between. It must have staged right off the rod as I did not even see the booster separate. The booster sustained heat damage and is a loss.


The sustainer had a normal flight. The streamer deployed at apogee and it came down at a nice descent rate but one fin did get knocked lose. I'll just flex it, clean the gap up a bit and re-glue it.

The sustainer will be a full rebuild. I think I will go 18mm this time like I originally had planned. The original Tempest is a 24mm to 18mm so going 18mm to 13mm will be more like the original. I just need to play around with the fins in OR. I'm concerned that they are a little on the small side for a nice tumble recovery.

My one experience with 13mm to 13mm has me questioning the concept. I have a Checkmate kit and I don't want the booster getting torched on it. Anybody else have extremely short boost with the A10-0T motors?

-Bob

 

[kuririn]

Sounds like you had a booster motor CATO.

 

[Bruiser]

Never had a CATO or seen one in person but now that you mentioned it I can see that's a possibility. At first I was thinking that a CATO would have blown the whole thing apart but with it being a two-stage the explosion blew the sustainer off and ignited the motor at the same time.

My eye was on the sustainer so I did not see where the booster went. I walk out after the sustainer and when I got back somebody had put the booster on a table for me.

Thanks,
-Bob

 

[kuririn]

Check your date codes:

Demon seed.... Estes 13mm motors

I've had numerous catos with 13mm motors recently, in particular the A10s. 3 out of 4 in one afternoon. Got warranty replacements, but, get this, with the same date code as the failed motors. So I just received this: Dear Valued Customer, Estes has identified a potential manufacturing issue...

www.rocketryforum.com

Those mini engines make for spectacular pics though


After numerous CATOs I only use my older A10s in open ended saucers and spools now.
Newer motors might be OK.

 

[Bruiser]

I just saw a message on Facebook this morning stating there is a potential motor casing issue for mini engines with a lot code that begins with H21.

Guess what lot code the booster I used had?

Gonna have to contact Estes now. The message says they will replace the motors. I wonder if they'll do anything about the destroyed booster... I'll post back when I hear from them

-Bob

 

[kuririn]

I just saw a message on Facebook this morning stating there is a potential motor casing issue for mini engines with a lot code that begins with H21.

Guess what lot code the booster I used had?

Gonna have to contact Estes now. The message says they will replace the motors. I wonder if they'll do anything about the destroyed booster... I'll post back when I hear from them

-Bob

If the motor destroyed an Estes rocket, they'll replace both.
For a scratch built, probably just the motor.
Hoping they give you some kind of credit for the rocket, though.

 

[Bruiser]

I received a package yesterday from Estes. I had two packs of A10-0T motors in it to replace the recalled motors and an Epic II kit. I had explained that the rocket booster that got destroyed by the bad motor was actually a bashed Epic II and they sent me a replacement.

How awesome that is!

-Bob