LOC 4" Phoenix Payload Bay Options

[Private]

Been trying to post this question for a week now, but I keep get side track down the rocketry forum rabbit (or is that rabid?) hole of other threads recently purchased a LOC 4" Phoenix. I plan on building it for a L1 cert attempt at LDRS 42. At least that is the current plan. This is my first step into a rocket of this diameter and with a payload bay to boot.

My version of the phoenix has three sections. Nose cone, payload bay and fin body tube. I understand that previous versions were 2 sections: Nose cone and one body tube (no payload bay). I also understand that this rocket will require some nose weight depending on the engine installed to shift the center of gravity forward more. I was thinking of acquiring the RNWS from LOC that came with the previous model but not with this one. It is my understanding that this is installed in the nose cone and take up that space. I have also been reading other posts in here about installing cross pieces / screws / expanding foam as positive retention methods for the nose weight. As a result I feel well informed what I can do with that area of the rocket.

In the instructions they completely skip over the connection of the nose cone to the rest of the rocket. I am assuming this is because there are multiple options from friction fit, shear pins, screws, printed parts to plain old gluing it in place. Depending on what you plan to do with your payload bay will rule out some options. Obviously a glued connection permanently seals off the payload permanently and basically turns the Phoenix into a two section rocket with an elongated nose cone.

When I did my dry fit the other night, I noticed that the couple tube butts up with the forward fin root where it barely protrudes through the wall. and the other end of the coupler tube butts up with the the bottom of the nose cone. This results in a total gap between 4" payload bay tube and adjacent section of 1/16" to 1/8" total. This can easily trimmed / sanded down for a proper fit, but was also a bit of an eye opener to actually how little space is available in the pay load bay section.

So that long window intro brings me to my question (I heard something say finally!):

What do people with this particular version of the phoenix missile (4" with payload bay) tend to use the pay load bay for?

Or conversely how do most people with this configuration of the phoenix tend to set up their rocket?

I have been considering the following:

Nose Options:

1. Fixed weight to move CoG forward and permanently attach payload bay.
2. LOC removable nose weight system to move CoG forward.
3. Turn it into an ebay (altimeter, tracker/locator, Dual deployment electronics)

Payload bay:

1. Turn it into an ebay with Altimeter, tacker/locator
2. Turn it into a recovery system bay for the parachute and second shock cord (loose nose cone). Essentially turning it almost into a cylinder ejection system
3. Turn it into a dual deployment zone with ebay in the nose
4. A smoke / chaff dispenser to highlight deployment
5. secondary parachute
6. Some other idea that I have not thought from the minds of the rocketry forum

For L1 cert, plan on keeping it simple student! No dual deploy for that flight, however a secondary back up parachute sounds like a great idea.

 

[Ronz Rocketz]

I flew the LOC 4in Patriot for my L1 last September. I chose it so I could fit the small fin booster into a large suitcase and fly it over from Hawaii to Reno. Plenty of room in the payload so sorry I'm not much help to you in that. Later I flew it on an I280DM. The 356mm didn't leave a lot of room in the booster for the laundry but the Nomex blanket did it's job.

The main problem was ensuring the CG was 4in in front of the CP. The only thing I had on the playa was dirt, so I packed the NC with sand and covered the hole with duct tape. I knew the sand wouldn't stay at the tip so added enough to move the CG five inches from the CP. Worked like a charm. Later, I removed the sand and replaced it with lead beads and epoxy.



Earlier, I flew the rocket on an I285GR and added a dash of extra BP in the ejection like some do but was a mistake. It separated the payload and blew off my chute. Just stick to the prescribed BP charge and you'll do fine.

 

[KenECoyote]

Been trying to post this question for a week now, but I keep get side track down the rocketry forum rabbit (or is that rabid?) hole of other threads recently purchased a LOC 4" Phoenix. I plan on building it for a L1 cert attempt at LDRS 42. At least that is the current plan. This is my first step into a rocket of this diameter and with a payload bay to boot.

My version of the phoenix has three sections. Nose cone, payload bay and fin body tube. I understand that previous versions were 2 sections: Nose cone and one body tube (no payload bay). I also understand that this rocket will require some nose weight depending on the engine installed to shift the center of gravity forward more. I was thinking of acquiring the RNWS from LOC that came with the previous model but not with this one. It is my understanding that this is installed in the nose cone and take up that space. I have also been reading other posts in here about installing cross pieces / screws / expanding foam as positive retention methods for the nose weight. As a result I feel well informed what I can do with that area of the rocket.

In the instructions they completely skip over the connection of the nose cone to the rest of the rocket. I am assuming this is because there are multiple options from friction fit, shear pins, screws, printed parts to plain old gluing it in place. Depending on what you plan to do with your payload bay will rule out some options. Obviously a glued connection permanently seals off the payload permanently and basically turns the Phoenix into a two section rocket with an elongated nose cone.

When I did my dry fit the other night, I noticed that the couple tube butts up with the forward fin root where it barely protrudes through the wall. and the other end of the coupler tube butts up with the the bottom of the nose cone. This results in a total gap between 4" payload bay tube and adjacent section of 1/16" to 1/8" total. This can easily trimmed / sanded down for a proper fit, but was also a bit of an eye opener to actually how little space is available in the pay load bay section.

So that long window intro brings me to my question (I heard something say finally!):

What do people with this particular version of the phoenix missile (4" with payload bay) tend to use the pay load bay for?

Or conversely how do most people with this configuration of the phoenix tend to set up their rocket?

I have been considering the following:

Nose Options:

1. Fixed weight to move CoG forward and permanently attach payload bay.
2. LOC removable nose weight system to move CoG forward.
3. Turn it into an ebay (altimeter, tracker/locator, Dual deployment electronics)

Payload bay:

1. Turn it into an ebay with Altimeter, tacker/locator
2. Turn it into a recovery system bay for the parachute and second shock cord (loose nose cone). Essentially turning it almost into a cylinder ejection system
3. Turn it into a dual deployment zone with ebay in the nose
4. A smoke / chaff dispenser to highlight deployment
5. secondary parachute
6. Some other idea that I have not thought from the minds of the rocketry forum

For L1 cert, plan on keeping it simple student! No dual deploy for that flight, however a secondary back up parachute sounds like a great idea.

I have a 4" Madcow Phoenix, which I believe should be very similar, but actually 2" shorter. I've recently converted it to dual deploy, so I can understand what your dilemma is because I had to figure out how to do it with so little space myself.

In my case, I ended up doing a conventional e-bay, but shortened by maybe an inch. I did this after measuring the free space available on both ends and estimating how much space I would need for either side.

I have a post about my 4" Madcow Phoenix which I'll update this weekend with details of my dd modifications.

Imho you chose a very challenging one for cert, but also a very cool one!

Regarding the options of using the bay for a second chute or powder, etc., (unless I'm misunderstanding) I myself wouldn't recommend it unless you're using dd with electronic deployment of the forward section. Trying to get it loose enough to come out by itself could very likely lead to drag separation from the heavy weighted nose cone, leading to a bad zipper.

Can you provide drawings of each of your ideas/iterations? That would be very helpful.

BTW I'm planning to be at LDRS 42 as well!

 

[KenECoyote]

Also please post pics of the parts in your version? I couldn't find the newer version you're talking about and I'm curious. Did you buy it new?

 

[Tractionengines]

Here is a build thread I did l
For a 4" LOC Phoenix I got at Christmas last year. It is NOT a "typical" build, but compare your parts.

I lengthend it to get room for standard dual deploy. Also added optional RNWS to nosecone.

Thread 'LOC 4" Phoenix, extended, w/ 38mm MMT, Dual Deploy, & RNWS' https://www.rocketryforum.com/threads/loc-4-phoenix-extended-w-38mm-mmt-dual-deploy-rnws.180117/

Ask any questions I have lots more photos, and I can send you a "Corrected -Stock" OpenRocket sim file. The one on their site is very outdated, and weight overrides are way off.

 

[Private]

Also please post pics of the parts in your version? I couldn't find the newer version you're talking about and I'm curious. Did you buy it new?

I did buy new. will work on getting some pics or doing some drawings in CAD. Oddly enough I have my Bomarc laid out right beside it for a parts inventory, which I also did for the phoenix. I have photos of the Bomarc, but not the phoenix.

 

[Private]

Here is a build thread I did l
For a 4" LOC Phoenix I got at Christmas last year. It is NOT a "typical" build, but compare your parts.

I lengthend it to get room for standard dual deploy. Also added optional RNWS to nosecone.

Thread 'LOC 4" Phoenix, extended, w/ 38mm MMT, Dual Deploy, & RNWS' https://www.rocketryforum.com/threads/loc-4-phoenix-extended-w-38mm-mmt-dual-deploy-rnws.180117/

Ask any questions I have lots more photos, and I can send you a "Corrected -Stock" OpenRocket sim file. The one on their site is very outdated, and weight overrides are way off.

I have read your build thread several times. The pre-finishing vinyl was an interesting approach. I am not up and up on my filleting skills, so I am also not about to attempt this approach. Your finished product looks great though.

I plan on doing the LOC method of building I think it is which someone also made a build thread in here of building the fin can first and then sliding it into the body. Though its still a debate. The other part of me is thinking of doing the standard through wall installation but with the added challenge of only epoxying in the leading centering ring on the MMT leaving both sides of the centering ring available for perimeter epoxy fillets. Then installing the leading fins and epoxying them with fillets to both the MMT and the inside of the BT or some other method where I could fillet the fins to the inside of the BT. But I am not there yet. Still in the thinking about it stages and making sure I have all the pieces and they generally fit part.

Did your Phoenix come with the RNWS or did you need to buy that separately?

 

[Tractionengines]

LOC now has the "internals" of the RNWS available separately. If your ok with cutting off the bottom of the cone, its a lot less expensive than buying a whole RNWS with the already cutoff nosecone. That is what I bought to "add the RNWS" to the kit.

I usually do the externally built fin/motor mount assembly; that slides into the body tube. BUT I didn't want to slot the body tube all the way to the front "tab" of the forward fins. I don't know if you can build the whole fin/motor assembly, and slide it in for this model... maybe build the assembly with only the back fins, and put the front ones in after...as a hybrid build approach.

 

[Tractionengines]

How many centering rings do you have, I can't remember if I added to the kit or not, but I built with 4. So each fin is captured.

 

[Art Upton]

I built a LOC ISP 3" Kit with 54mm motor mount. I planed to use a Motor that did not have motor ejection it was plugged. So I used an Altimeter in the payload bay for Apogee deployment and a Jolly Chute Release for the main that was in the main body tube.

 

[Private]

Also please post pics of the parts in your version? I couldn't find the newer version you're talking about and I'm curious. Did you buy it new?

Below is a picture of the components from the LOC web site. The only 2 things missing from the photo are a solid ring for the bottom of the coupler tube and the coupler tube. Note there are no notches in the centering rings like there were in previous versions.

 

[Rschub]

I don't think that it has a payload bay, that is just an extension to make it look correct. You would use the copler to attach the 2 body tubes together. The result would be a one piece body and a nosecone.

 

[bobbyg23]

I don't think that it has a payload bay, that is just an extension to make it look correct. You would use the copler to attach the 2 body tubes together. The result would be a one piece body and a nosecone.

This right here

 

[David Schwantz]

Rschub is correct, there is no payload bay in this rocket. I built my fin can outside of the tube. Slid it in when done. Built very strong. Probably too much.
If you did want to build a payload bay, could be done easily. There is plenty of room on top of where the avbay would come for a main chute for a rocket of this size. it would just fit partially into the NC.

 

[Private]

Below is a rough sketch of a section taken through the 2023 Version of the LOC 4" Phoenix. Some of the wall thickness are kind of thin so it may be hard to differentiate between various tubes. The cyan is supposed to be the 4" dia payload tube. The orangish is the 3.9" coupler tube. The white / grey is the 4" Slotted Airframe tube. When built as per the LOC instructions for the 2023 version (no clue when they changed) there are two main differences between this version and previous version in reference to PAYLOAD BAY. The are other differences as but relatively minor.

1. The main body is delivered in two piece and is itemized in the bill of materials in the LOC instructions as: 7" Payload Section and 23" Slotted Airframe
2. While not listed in the bill of materials and absent from the photo in the previous post, there is a 1/4" Dia solid bulkhead that, according to the instructions, is recessed 1/8" into the coupler tube and come complete with eye bolt.

In the image below, the orangish section in the middle sandwiched between the black nose cone and the blue bulk head is the available area for a payload bay. The white/grey area to the right of the blue bulkhead and to the left of the 1/4" centering ring is the space allocated for shock cord and parachute.




So having said that, I completely agree with what you gentlemen are eluding to that the rocket would not have a payload bay IF the instructions were not followed, the bulkhead was not installed, and the coupler tube was glued to the 7" Payload Section and 23" Slotted Airframe.

From the LOC website there is also this photo that shows the missing bulkhead and eye bolt:



and from the instructions there is step 6 that shows the end of the payload section complete with bulkhead:





So based on this information, I really do believe that the 2023 version of the LOC 4" Phoenix has a payload bay (but I could still be wrong). Hopefully its not an issue with terminology of payload bay vs avionics bay versus electronics etc. Right now I am viewing the empty space (orangish in the CAD sketch) as generic payload bay with space that could be used for various options including turning it into an electronics bay. One thing I am sure of is: I currently have no desire to add any video imaging.

 

[Private]

LOC now has the "internals" of the RNWS available separately. If your ok with cutting off the bottom of the cone, its a lot less expensive than buying a whole RNWS with the already cutoff nosecone. That is what I bought to "add the RNWS" to the kit.

I usually do the externally built fin/motor mount assembly; that slides into the body tube. BUT I didn't want to slot the body tube all the way to the front "tab" of the forward fins. I don't know if you can build the whole fin/motor assembly, and slide it in for this model... maybe build the assembly with only the back fins, and put the front ones in after...as a hybrid build approach.

I was not sure how the RNWS actually got delivered in terms of parts. I never even thought a pre cut nose cone was part of the purchase. As a result of this information I will definitely be looking at just the weight parts as an alternative option to permanent lead BB epoxied and doweled into the nose cone.

Your memory serves you right, there are 4 centering rings, but there is also a bulkhead plate for the bottom of the coupler tube for the 2023 version of the phoenix.

My original plans were to slice between the fwd and aft fins and from the aft fins to the bottom of the tube. I was assuming there were be enough flex / wiggle room to get the leading tabs to pop into their pre cut slots

 

[Tractionengines]

I was not sure how the RNWS actually got delivered in terms of parts. I never even thought a pre cut nose cone was part of the purchase.

Here is a cross-section I did as a layered PDF file. Turn the layers visible, or hidden, to see how the RNWS goes together. (Works best on a bigger screen, than a phone or small tablet.)
Thread 'LOC Precision Removable Nose Weight System (RNWS)' https://www.rocketryforum.com/threads/loc-precision-removable-nose-weight-system-rnws.177098/

there is also a bulkhead plate for the bottom of the coupler tube for the 2023 version of the phoenix.

Correct, IT IS THERE AS OPTION. the original kits had a single long body tube. But they could signifficanly reduce packaging size, and therefore shipping charges, by making the packaging shorter. The payload tube and nosecone are about equal in length to the main tube. Then they added the coupler and bulkhead, which gives you 3 options for building:

1) Permanently glue the coupler onto both the Main and Payload tubes. Do NOT use the bulkhead. Then blow the nosecone to deploy recovery. Like the original version of the kit. Just with a spliced Main body tube.

2) Permanantly (or with rivets etc) afix the nosecone to the payload tube. Permanently glue the payload tube to the coupler WITH the Bulkhead installed. Now you attach your recovery to the Bulkhead eyebolt. And eject the whole forward assembly of nosecone, payload, coupler, and Bulkhead as a unit. This reduces the volume your pressurizing, and gives the ejected part more mass to help "pull out" the recovery gear.

3) Add another Bulkhead, hardware, sled, etc. (Not part of kit.) And make the coupler a AV Bay for traditional Dual Deploy.

My original plans were to slice between the fwd and aft fins and from the aft fins to the bottom of the tube. I was assuming there were be enough flex / wiggle room to get the leading tabs to pop into their pre cut slots

It DOES sound like others have done this, so it can be done this way. I did not, so can't say how easily it worked.

 

[David Schwantz]

The easiest thing to do is just call Jason and ask. LOC CS is some of the best out there!!!

 

[b.wieting]

I really like LOC's RNWS and payload bays, having them on my Mini- and Mega-Maggs (well, I retrofit the Mini myself with LOC tubes and CR). Though I'm not sure about the nose volume available on the 4" frame, you might be able to add a Eggfinder mini just for fun.