"Starship" - L3 Build Thread

The Rocketry Forum

Help Support The Rocketry Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.
Not being argumentative here but nylon bolts are a lot stronger then most people realize. Ask any R/C pilot. I have seen nylon bolts used to hold down wings of 1/4~1/3 scale aerobatic planes like the Cap 21 and Christian Eagle.
I'm just saying in relationship to stainless steel all thread of the same size. I'm designing all components to survive 2000lb+ forces for worst case deployment. I just don't think nylon all thread by itself is up to the task, rather not risk it. So I am going with the nylon all thread and the ring (epoxied into shoulder) to support the bulkhead load.
 
Has anyone had an issue with noseweight (bbs and epoxy) interfering with the GPS transmitter? I imagine this is another thing to consider and why it would probably be a good idea to have the antenna mounted through the bulkplate. From what I have been reading is that I should not use metal in the nosecone besides the ubolt on the bulkplate, but I suppose the best way to test would to be to actually build it and physically test it. Just wanting to get some input before I make any permanent changes.
 
Update #22:

Photo #1: Top view of the support ring for the nosecone bulkhead. I will be using 4 #6 screws epoxied into the ring with 4 wing nuts to secure the bulkhead to the ring.

upload_2019-5-19_17-8-52.png

Photo #2: Bottom view of the support ring. The #6 screws and washers will be epoxied to the ring.
upload_2019-5-19_17-9-20.png
 
As a general rule of thumb, it's generally taken that one should be concerned about conductive objects in an antenna's near field if they are greater than a quarter wavelength in size. If the are not just under but well under then they're probably not a concern. A long threaded rod very well could cause problems. BBs, if they are reasonably well isolated from one another by the epoxy, are probably not.

Which are you concerned about, the GPS signal or the signal you're transmitting? GPS uses three carriers, all within the L-band region, with wavelengths of about 19 cm, 24.5 cm, and 25.5 cm. The one link IO found does not state whether you need to receive all three or just one (or two out of three, but I doubt that) for a fix. So, the quarter-wave size is from a bit under 5 cm to a bit over 6. So BBs might be an issue, but I'd still bet not.

As for your transmission, I don't know the wavelengths involved.

I repeat others: test it.

Aesthetically, I like the idea of an external antenna. A stripe down the side that's actually functional just seems cool.
 
As a general rule of thumb, it's generally taken that one should be concerned about conductive objects in an antenna's near field if they are greater than a quarter wavelength in size. If the are not just under but well under then they're probably not a concern. A long threaded rod very well could cause problems. BBs, if they are reasonably well isolated from one another by the epoxy, are probably not.

Which are you concerned about, the GPS signal or the signal you're transmitting? GPS uses three carriers, all within the L-band region, with wavelengths of about 19 cm, 24.5 cm, and 25.5 cm. The one link IO found does not state whether you need to receive all three or just one (or two out of three, but I doubt that) for a fix. So, the quarter-wave size is from a bit under 5 cm to a bit over 6. So BBs might be an issue, but I'd still bet not.

As for your transmission, I don't know the wavelengths involved.

I repeat others: test it.

Aesthetically, I like the idea of an external antenna. A stripe down the side that's actually functional just seems cool.

Would having the antenna mounted through the nosecone bulk plate solve this issue or would the threaded rod and the ubolt still cause considerable interference? Just asking around before I make any permanent changes.
 
I have not had issues with putting trackers/gps in bays with threaded rods [2 double]. Or NC I just wrap in bubble wrap, place under sled in av-bay or stick in empty cone. TeleMega and Missleworks Rtx.
To be sure of your setup, simple put all the crap in place [even temporarily] and set 6-8ft off the ground. Drive as far away as you can while checking every so often for signal strength.
Then remove metal you are worried about and check again for how far away you get signal.
Simple fool proof method, an hour or so of test time and YOU will know...matters not what forum tells ya.:cool:
 
To be absolutely sure, drive not just away but around, as interference from conductors in the near field, if it is an issue at all, is directional. And let me repeat that what I posted earlier were general rules of thumb, and testing is the way to go.
 
Update #23:

Photo #1: Installed the 1515 airfoiled rail buttons I got from Apogee.

Photo #2: Shows the mounting hardware. I decided that nylon locking nuts would be the best choice as it allows for the rail guides to be replaced if they are damaged. I will be epoxying the nuts to the airframe to secure them.

Photo #3: Received 100 ematches.

The rocket is ready for flight, just need to locate black powder from a local ground shop and do ejection charge tests. I tested the connections using a lightbulb and the Stratologger software. All terminals worked as expected and the altimeters passed all the tests. IMG_20190706_004230.jpegIMG_20190706_004232.jpegIMG_20190706_004506.jpeg
 
Hey guys i just went back to begenning of this thread did he not wash any of the fiberglass before bonding anything ? Or did i miss it somewhere

I didn't include the bubble bath picture on this thread as it was started after I washed the parts. The picture is on the "what did you do today' thread I believe. I washed the parts in my bathtub with dawn dish soap and then cleaned it again (with dawn) after it dried. I then used alcohol (91%) to clean the surface before and after sanding. Another option was to use denatured alcohol but it seemed like nasty stuff for a rocket I was building at the end of my residence hall.
 
Was just checking :)
I didn't include the bubble bath picture on this thread as it was started after I washed the parts. The picture is on the "what did you do today' thread I believe. I washed the parts in my bathtub with dawn dish soap and then cleaned it again (with dawn) after it dried. I then used alcohol (91%) to clean the surface before and after sanding. Another option was to use denatured alcohol but it seemed like nasty stuff for a rocket I was building at the end of my residence hall.
 
Once again, I'm late, but can you make a video of the ground testing because it's something I've been curious abot for a while, and I couldn't find any good video. Alsp, when will you be flying this
 
Once again, I'm late, but can you make a video of the ground testing because it's something I've been curious abot for a while, and I couldn't find any good video. Alsp, when will you be flying this

Should be ground testing in a week or so, the first flight will be either this month or next. I'll record ground testing but I'm certainly not an expert as this is my first-time ground testing, going off some information I found on the forum.
 
For my level 3 I taped up all but one of my static pressure ports and then taped a piece of foam over the last hole. Then I used a vacuum cleaner and tested each output to make sure they worked through the primary altimeter since it was a brand new altimeter. The back up was a tried and proven Adept 22.
 
I've done the vacuum deploy test. Major hassle. Now I use e-match and an estes launch controller for deployment tests, and I'll vacuum indoors with LEDs to indicate events and test the altimeter.

Level 2 testing

 
I've done the vacuum deploy test. Major hassle. Now I use e-match and an estes launch controller for deployment tests, and I'll vacuum indoors with LEDs to indicate events and test the altimeter.

I agree it was a hassle. In the case of my L3 rocket I didn’t have any switch holes (Egg Timer WiFi switches) only the static pressure holes and no real good way to get wires out to a launch controller. But it was good to know that my altimeter worked properly.
 
Update #24:

Photo #1: Laid out the vinyl/paint design in OpenRocket. Uses black Rustoleum 2X paint and stainless steel vinyl.

Photo #2: Painted fins and nosecone. This is not the final product as it will be wet sanded and recoated after the first flight to fix some overspray. I'm sure Houston humidity didn't help either.

Photo #3: Wrapped the booster in vinyl.

Photo #4: Finished result with the payload bay and switch band wrapped. I'm happy with how it turned out.

Photo #5: Another angle of finished paint job/vinyl.

Photo #6: Preview of name vinyl that will be manufactured and installed next week.

First flight should be next month pending ground testing. IMG_20190821_180436.jpeg20190825_232843.jpegIMG_20190825_233236.jpegIMG_20190825_233502.jpegIMG_20190825_233504.jpegScreenshot_20190825-233901_Ai%20Viewer.jpeg
 
Nice. It looks awesome. I'm excited to see it fly.
I just finished all the preparations for deployment charge testing and the first flight. The first flight should be in 2 weeks. I will be testing the charges an hour or two before the flight and if all checks out it will be ready to go.
 
I just finished all the preparations for deployment charge testing and the first flight. The first flight should be in 2 weeks. I will be testing the charges an hour or two before the flight and if all checks out it will be ready to go.

You're not going to test prior to going to fly?
 
You're not going to test prior to going to fly?
No time this weekend and I'll be in college until the weekend of the launch so no testing until then. I'll be testing the ejection charges multiple times prior to launch to ensure they are sized appropriately. If everything does not check out, I will launch a different rocket and re-run tests on the deployment charges in the following weeks. I've spent a long time on this project so I'll make sure to take my time when it comes to testing to ensure a successful first flight.
 
Back
Top