Falcon 54 extreme minimum diameter build

dhbarr said:

Some of the things outgassing from composites are pretty nasty is all.

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I will wear a respirstor as always. im sure fire isnt a risk because it is rated to 600 degrees and I will be watching netflix on the kitchen table while it is curing. I will look into building the oven, but I have very little left in the budget for this project.

I think they’re more concerned about the smell permeating your house afterwards. Depending on your marital status things could get chilly. [emoji948]

dhbarr said:

Some of the things outgassing from composites are pretty nasty is all.

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This is what I was getting at. Then if you have some drips in the oven every time you use it you get more of it. Not sure I want that in my lungs or food.

Steve Shannon said:

I think they’re more concerned about the smell permeating your house afterwards. Depending on your marital status things could get chilly. [emoji948]

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Not just the smell- the chemicals might not be so good for breathing. There have been people in the hobby who have developed serious allergies to epoxy. Allergies to the point they have had to quit. Was it Dangerous Dave or the Microbrick guy? For those who have not been around they were two of the early composite rocket manufacturers along with Dynacom.

sooooooo....

It turns out I am SOL. I used JB weld to install my minimum diameter retainer and I have it about .25" in too far and I can't get it out. I will have to get a new body tube and grind away the fiberglass and JB weld from the retainer. I cut off the charge well on the L935 and drilled the top hole out to 1/4". I only went in about .125" into the smoke grain, which shouldn't be an issue. I have filled the hole with epoxy and put the threaded CTI adapter into the forward closure of the motor.

I don’t understand why .25” is an issue? Are you saying the motor sticks out an 1/4” an inch? Just cut a 1/4” length of body tube to fill the gap. Slide it over the motor before sliding it into the main body tube. It may take a bit of work to get a clean seam but a lot less than starting over.


Tony

Can you get the threaded adapter out, cut a little off, and reinsert?

manixFan said:

I don’t understand why .25” is an issue? Are you saying the motor sticks out an 1/4” an inch? Just cut a 1/4” length of body tube to fill the gap. Slide it over the motor before sliding it into the main body tube. It may take a bit of work to get a clean seam but a lot less than starting over.


Tony

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markkoelsch said:

Can you get the threaded adapter out, cut a little off, and reinsert?

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Yeah, you guys are right. I was feeling a little hopeless towards the project at the moment I wrote that. I am in the process of working on that spacer to try and get it to work. I will have to take the extra length off the front to make the rocket the same length to keep the maximum performance possible. It is more like .5"

mperegrinefalcon said:

Yeah, you guys are right. I was feeling a little hopeless towards the project at the moment I wrote that. I am in the process of working on that spacer to try and get it to work. I will have to take the extra length off the front to make the rocket the same length to keep the maximum performance possible. It is more like .5"

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Make a spacer body tube, and cover with aluminum tape.

markkoelsch said:

Make a spacer body tube, and cover with aluminum tape.

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Why the aluminum tape? Also I have ordered a threaded FW closure from wildman. I will also be extending the CF to the end to make sure it holds up.

Here is my thinking on how to solve this a couple different ways, and I will also comment on the tape.

1) as I mentioned initially, can you get the threaded adapter from the Aeropack out of the rocket? If so, you could throw a nut on it, cut the needed length off of the threads, and take the nut off of the threads to clean up the threads.

2) To expand on the tape and added 1/4" section on body tube to fill the gap. My thinking is to cut the spacer section of body tube and square the ends with the main body tube. When prepping for flight slide the filler section of tubing over the motor, insert the motor into the rocket, and then apply the aluminum tape over the main body tube coving the end of the main tube, the filler section and overlapping the end of the motor. This would keep you from having to fill the seams and keep things in place.

To expand further, if you use masking tape to friction fit a motor and then put a wrap of aluminum tape over the body tube and wrapped over the end of the motor it can make very effective motor retention. This was a very common method in days passed. I used it last year a couple of times and it worked perfectly.

markkoelsch said:

Here is my thinking on how to solve this a couple different ways, and I will also comment on the tape.

1) as I mentioned initially, can you get the threaded adapter from the Aeropack out of the rocket? If so, you could throw a nut on it, cut the needed length off of the threads, and take the nut off of the threads to clean up the threads.

2) To expand on the tape and added 1/4" section on body tube to fill the gap. My thinking is to cut the spacer section of body tube and square the ends with the main body tube. When prepping for flight slide the filler section of tubing over the motor, insert the motor into the rocket, and then apply the aluminum tape over the main body tube coving the end of the main tube, the filler section and overlapping the end of the motor. This would keep you from having to fill the seams and keep things in place.

To expand further, if you use masking tape to friction fit a motor and then put a wrap of aluminum tape over the body tube and wrapped over the end of the motor it can make very effective motor retention. This was a very common method in days passed. I used it last year a couple of times and it worked perfectly.

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I just cut the length of the body tube from the spare payload section I have. I will cut about .5" off the tip of the tube to shorten it in front. I have just epoxied the extension to the base of the tube. I don't mind filling the seem, besides it would add unnecessary drag to the airframe if I just left the seem in and the spacer loose. Pictures will be posted soon. I will just use the retainer already epoxied into the airframe. I have tried removing it, but it is JB welded in. I can't heat the fiberglass to the temp needed to remove it. It is 8" into the airframe so it is pretty much impossible to get to.

I would not bother cutting the .5" off the front unless you are record hunting.

So, I have made some progress,
The slight crisis has been averted. I epoxied a .5" tube to the end of the body tube, and filled the seem.


This is it with the tailcone closure.


I just need the Duralco 4460 to arrive so I can make fillets and laminate it.

I received my TeleMetrum today, and I am trying to figure out how to connect it to my computer to configure it. If anyone has experience with this product, then please help me out. I can't get the AltOS to connect to the altimeter through the USB cord.

mperegrinefalcon said:

I received my TeleMetrum today, and I am trying to figure out how to connect it to my computer to configure it. If anyone has experience with this product, then please help me out. I can't get the AltOS to connect to the altimeter through the USB cord.

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Is it beeping? Have you connected the "Switch" pins on the pyro header? If the pins are not connected, LEDs connected to the charger will come on but the rest of the altimeter wont get powered.

Reinhard

Reinhard said:

Is it beeping? Have you connected the "Switch" pins on the pyro header? If the pins are not connected, LEDs connected to the charger will come on but the rest of the altimeter wont get powered.

Reinhard

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I have connected the switch pins and turned it on. It is beeping. I managed to change it through radio connection, but it wont change the callsign.

To configure your Telemetrum via USB on your laptop you should do the following steps.

1) connect switch to the Telemetrum.
2) connect up Lipo and USB cable to Telemetrum.
3) fire up AltOS
4) power on the Telemetrum
5) plug the USB cable into your laptop, you should hear the device connect to the PC as it's a serial interface
6) Click the "configure Altimeter" button in AltOS.
7) Select the TeleMetrum serial com port interface.
8) Click connect.

That should open the "configure Altimeter" window for the TeleMetrum and allow you to change all the user configurable values on the device.

I received the Duralco 4460 epoxy yesterday. The last set of fillets is curing right now. I made on oven out of a large cardboard box, some aluminium foil, and fiberglass insulation. I am using a space heater, and a ceramic heat emitter lamp for temperature and it is easily getting to the 250 degrees I need it to be at. This epoxy does not cure at room temperature, so I just wrapped the mix in plastic and left it out. It doesn't even thicken overnight. I added fumed silica and fiberglass to the mix. Pictures coming after the epoxy is cured.

You got a fire extinguisher or a bucket of water standing by? Any pics of the DIY oven? ( this is on my ever-longer todo list )

dhbarr said:

You got a fire extinguisher or a bucket of water standing by? Any pics of the DIY oven? ( this is on my ever-longer todo list )

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Yeah, when I post the proper build update. It is just cobbled together. The box is lined on the inside with aluminum foil, and it has the fiberglass insulation wrapped around the outside. I have a 150 watt ceramic heat emitter bulb and lamp on top. The heater is a 1500 watt heater that I have the hot air being piped via more cardboard and insulation. I have a cooking thermometer I simply stick through the material where the fins go.

On the fire extinguisher:
I have one I specifically keep in my basement work space.

dhbarr said:

You got a fire extinguisher or a bucket of water standing by? Any pics of the DIY oven? ( this is on my ever-longer todo list )

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I found this article on making an oven, and I think it is much better than what I have. You don't need nearly all that heating, but I want to build one. It is basically what I have but better, and safer.

I found filing cabinet on craigslist for $15 and I'll be picking it up.

https://www.homediystuff.com/building-a-diy-oven-from-filing-cabinet/

Apologies for not updating this thread. I have been extremely busy. You should expect an update either today or tomorrow. The build is mostly complete, I just need to finish up with the JB weld on the fin leading edges and get some paint and polish on her.

Did this fly last month?

Edward

Steve Shannon said:

For breather you could probably use any kind of quilting or even absorbent mats intended for health care spills, but you need some kind of release film or peel ply and as far as I know there’s no substitute for the real thing. I got mine from Aircraft Spruce.

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Steve; I've had surprisingly good results using cut off/scraps from my umbrella based parachutes (1.5 oz Ripstop) as peel ply and multiple layers of paper towels for breather. Next time you need to laminate something and don't have time to wait for the UPS man, give it a shot..

really? 1.5oz Ripstop?

I've never done any bagging and I always just kind of assumed whatever went against the actually layup had to be special so it didn't adhere.

That's kinda cool.

I did not invent the concept. Just had some layup to do and no materials. I remembered reading somewhere that ripstop nylon would work. Surprisingly well at that. Left a nice bondable texture for follow on layers. I only needed a vail so I sanded it smooth.

Apologies for the lateness, I have been extremely busy and this just kind of fell through. So, Update on the build. I have no pictures at the moment, but I should be able to post shortly. This rocket was not able to fly. I had some issues at work and did not get the time I needed to finish it up and fly it, plus I ran into some last minute issues with pretty much everything, so the lack of time made it impossible to finish.

Issue 1:
The Av-bay. I had to build it the night before the launch, so I was rushing and made a mistake on the terminal block on my Telemetrum. The screw came all the way out of the block, and would not screw back in so I had no way to connect the E-match. I soldered a lead wire directly to the pad and fixed this. The Telemetrum is fine. I will be seeing if Bdale can replace the terminal block, and I or he solder it on.

Issue 2:
The sled. This just did not want to work. It would bind and catch and do all sorts of craziness. I had to make some serious modifications to get it to fit. Eventually it did, but it was fiddly and took my precious time.

Issue 3:
The motor spacing. As you peeps know, I messed up early in this build and it has bit me in the ass still. The spacer I attached fell off, and after I assembled the motor I realized it was wayyyyy too short, so I had to make another one that was about 1.5" longer than I had previously made.

Issue 4:
Deployment. I was unable to do a deployment test because I was too busy fixing everything else that had gone wrong. By the time I had gotten to this point I was worn out because I had been at work since 6 am and finished at 5 pm, and it was already 2 am. I did not feel comfortable not doing a deployment test and this caused some doubt in the back of my mind.

Issue 5:
Fins. Upon an inspection I found that one of the fins was warped slightly. I have no clue how, but it was. On a rocket going over 2,000 mph I do not feel comfortable having a fin warped, even as slightly as this. I do not know where this happened.

Issue 6:
CG. Even with all of this, I went and checked the CG location, and it seems that the spacer I added cause there the be a weight shift back, which means it is now in a negative stability margin. And it was 2am of the day of the launch, with the site being a 2.5 hour drive away.

I know a lot of this stuff is easily overcome, but the point of this build is to push the limit of this rocket, not cut corners. With all the issues of this rocket I do not feel comfortable with flying it, and in fact plan on re-building a fincan for it. All the margins on this rocket are thin. I want to get as much as I can from this rocket, and that means it needs to be built perfectly. The extra length of the spacer causes extra skin friction, as well as it sticks out farther in diameter causing extra drag. I did not feel comfortable with not having tested the electronics, and I did not feel comfortable driving to a launch on no sleep.

The point of this project is to push the limit of the rocket and my building skills. My building skills have been thoroughly tested and I have learned many new things from this failed build. I have been humbled by it, and I will be starting anew with a new body tube and fins and this time do it right. I feel I may have succumbed to launchitis a little bit towards the end. I want this rocket to have the best possible chance of surviving the flight, and of reaching my goal. To me, that means I need to build it as well as I possibly can. I have no clue when I will be able to launch Falcon 30k v2, but I want to do so as soon as it is finished.

Looks to me like you've made the most sound decision possible given the circumstances. Everybody gets go fever now and then, it's not easily overcome.

You did the right thing.