ACE 4X18 Mini-Allegro
 

Thanks to Jason Blatzheim for sharing his plans for the ACE Mini-Allegro. I decided to clone it using parts obtained from Semroc. I've compiled the plans into PDF format if anyone is interested. Scott, my FTP program is on my crashed computer so I'm going to have to email them to you. PM me with the email address since I purged all my contacts when I had a malware attack. Some changes I made from the original plans....…….

I replaced the single 23” BT-18 with an 18” and 9” #18 tubes. The plans call for the upper baffle plate to be installed 8” from the forward end of the BT. Instead of building baffles using the templates in the plans, I’m using an EB-18 from Semroc. I've built the EB-18 and installed it into a #18 tube coupler. This will place the forward bulkhead of the baffle 8” from the forward end of the rocket, as the plans called for. I cut 4” from the 18” #18 to maintain the overall length of 23” for the #18 tubing. In retrospect, I should have asked Sheryl to cut the 18” #18 for me. The rear bulkhead of the EB-18 was sanded to fit inside the #18 coupler.

I didn’t want to have to special order a nose cone so I went with a BC-1892 from Semroc. It’s about 1.5” shorter than the original nose cone but, again, its close enough to suit my purposes.

I also ordered four 18” #7 tubes. Instead of cutting them down to 17”, I plan to just recess them one inch further into the #18 tube. Have you noticed? I don’t particularly care for cutting body tubes.

I already have launch lugs, shock cords and a parachute so I didn’t have to order any. Fin material will be bought from Hobby Lobby using a 40% off coupon. It’s not indicated on the plans but for those of you who might care, the ¼” launch lugs are 1.25 inches long. Here is a list of what I bought from Semroc for the clone.

4 ea ST-7180 body tubes @ $1.60 ea $6.40
1 ea ST-1890 body tube @ $1.80 ea $1.80
1 ea ST-18180 body tube @ $2.70 ea $2.70
1 ea BC-1892 nose cone @ $10.45 ea $10.45
1 ea EB-18 ejection baffle @ $1.75 ea $1.75
1 ea HTC-18 coupler @ $0.70 ea $0.70

Total cost: $23.80

Below are the kit fin patterns and nose cone.....

Kit Parts
 

And here are the parts I ordered from Semroc.....

Fins....
 

I was actually able to pick up the fin material at Hobby Lobby as part of a 50% off sale. I didn’t buy the ply because I didn’t want to think about trying to cut it. Instead I bought 3/32” balsa and laminated it with card stock.......

Below is the adhesive I used to glue the card stock to the fins......

FIns
 

And here are the fins before and after the card stock lamination......

Baffle
 

Next I assembled the ejection baffle.......

Baffle
 

I had to sand the rear bulkhead of the baffle so it would fit inside the hollow tube connector......

I placed a line of glue about an inch inside the baffle to set the rear bulkhead as well as a thin layer of glue on the forward edge of the HTC to hold the forward ejection baffle bulkhead.....




Then applied a fillet of glue around the aft ejection baffle bulkhead......

I then cut the 18" #18 tube to 14" and glued the ejection baffle assembly into the forward end. Once the glue set (I waited till the next day), I glued the forward portion of the ejection baffle into the 9" #18. This completed the build of the payload section of the rocket.

I then glued the #7 tubes together per plans. Fin assembly was easy since your can use the spaces between the tubes for guides. Since I already had the ejection baffle installed in the payload section, used a conglomorate of tissue and glue to seal the hole between the tubes at the forward end.

I used a generous amount (5') of shock cord to attach to the kevlar that came with the ejection baffle. The other end was attached to a large screw eye installed in the nose cone. The only remaining task is to glue the fin can to the payload tube. I'm delaying this portion until I get some good painting weather. The fin can and payload tube are two different colors and will be easier to paint separately. Since the top 3.5" of #7 tube will be inside the payload tube, I'll just mask the glue surfaces to avoid painting.

The 4X18 Mini-Allegro instructions recommend that the fin can and motor tubes be painted flat black and the payload section fluorescent red with a black nose cone.

I'll post the final product when I get it complete. The way the weather has been around here, that's probably right before NARAM....lol.

And, I'll try not to forget to put the launch lugs on...... ;)

I never once saw Korey use laminated paper sheets on fins. Plywood baby!

Jerry