Build thread for this years Airfest

[SDramstad]

So I finished up a few things in the last day or 2. Glued the rail guides in place.



Used JB Weld for that. While that set up I worked on the motor retention set up. This consists of 2 1/4 inch thick bulkheads glued together because 1 just looked flimsy to me.... I drilled out a 7/16ths hole for the T-nut and hammered it in place. 75mm hardware uses a 3/8ths inch bolt for retention. Then installed a U-Bolt for attachment of the shock cord.



Now when I first started thinking about this kind of retention I was concerned about what would happen if when you were removing the motor the forward closure came off? How would you get it out? If you just used a bolt or an eye bolt to hold it in then trying to turn either of those would just rotate the closure and nothing would come apart. On a previous build I tried installing and removing the motor a few times before the bulkhead was glued in and sure enough the forward closure came off inside the air frame. I finally installed a T Nut on the motor side of the bulkhead. Now if the closure comes off I can unscrew the bolt, the T-nut will stop the forward closure from turning and the closure will come loose.

Next is gluing in the bulkhead. I scuffed up the inside of the tube with some sandpaper. Then mounted the bulkhead on top of the biggest motor casing I will be using.



Attached a 20foot long 3/16th inch One Badhawk harness to the Ubolt and slid the motor into place. Used a short piece of air frame under the fins to lower the motor in the tube and applied a couple grams of rocket poxy to the inside of the airframe just above the bulkhead. Then inserted the motor all the way in while turning it to spread the glue around. With the motor all the way in I hammered 3 small brads into the bulkhead to hold it in place while it sets then removed the motor case. I didnt want the motor case glued into the airframe in case the glue dripped down that far. Will remove the brads and fill the holes after it sets up.

 

[SDramstad]

Well I was planning on 3 builds for airfest and flying the best of the builds. Unfortunately life and death happens and progress slowed way down..... So on to plan B. I am going to continue this build with a name change since calling it Larry without flying Moe and Curly just doesn't make much sense..... Will take suggestions for names. Anyway.

Looking at one minor change. I am concerned about using a tracker that is partially in a carbon fiber tube. Ground tests didnt show any problems but not having a chance to test fly it makes me nervous. Anyway I am going to install a fiberglass switch band on the ebay. That will put the tracker completely out of the body tube. The ebay is quite long and will still have over 1 caliber inserted into the body tube. So next move is to roll a fiberglass tube that I can cut to size for the band. Will do that later this week.

 

[SDramstad]

Too much work going on to spend time in the workshop. However starting Thursday I should have 4 mostly free days to finish up this build. Since Larry didn’t make sense without Moe and Curly the new name is “Prairie Fire”. Seems semi appropriate since it’s flying in Argonia. Should be posting more around Thursday.

 

[SDramstad]

So got a little more done. Mounted the Feather weight tracker in the AV bay. Most of it stuck out above the carbon fiber body tube but I wasnt going to take chances with it. Went ahead and rolled another fiberglass 3 inch tube and cut a 2.5 inch section of it to act as a switch band. With it in place both the circuit board and antenna stick up above the carbon fiber tube so shouldnt have any issues with the GPS signal dropping out.
Installed the main parachute and One Bad Hawk harness into the nose cone. Using head end deployment on this build and the chute and harness fit perfectly in the nose cone. My earlier attempts at this were way tighter then this one. Almost needed 2 people to install the shear pins. Should not be a problem this time.

 

[SDramstad]

Airfest is a week away!!! I havent been updating this like I should but have been working on it a little at a time. Finished the Av bay and recovery. Got a few coats of primer on it. Its ready to fly but still need sanding and paint. Should be able to do this this weekend along with charge testing. After that clean out and load the rocket trailer and after that, road trip! Looking forward to meeting all of you and setting a new personal altitude record for myself. Simms to 28k or so.

 

[SDramstad]

And ready to fly.

 

[WILDMANRS]

Hi Tim! It’s Jack from Oregon!

Hi Jack
Been a long time.
Are
You coming to Airfest?

 

[JackC]

Hi Jack
Been a long time.
Are
You coming to Airfest?

Nope. That’s a long way to go for me!

 

[SDramstad]

And a successful flight! Nice straight boost and maxed out at 23125 feet. I was hoping for more but due to things outside of my control I wasnt able to do the fine tuning that would have maxed out the altitude. Overall pretty happy. A little mach rash, one part of the tip to tip started to peel. That probably took a couple thousand feet off of the flight. Will fix it up and see what it will do next year. Have more rockets with me and will see what I can do with them the next couple days.

 

[Jacktango22]

This has been a great thread to follow. I am retired and getting back into the hobby with gusto and learned a great deal from what was posted. Thanks for doing this.

 

[Hobie1dog]

wow, that's up there.