LOC-IV BASIC avionics for basic dual deploy recommendations

[Lt72884]

If you can handle a soldering iron, then for single deployment the Eggtimer Apogee is probably the cheapest at $15.
http://eggtimerrocketry.com/apogee_faqs/For dual deployment, the ET Quark or Quantum kits.

Chute Release
https://jollylogic.com/products/chuterelease/

here is a question for you about these egg-timers. Lets say i get the quark kit. I set the altitude for 500 feet for the main to go off. What tells the egg-timer not to go off at 500 feet as the rocekt is in lift off? is it the amount of acceleration sensed?

Second, if i do go with the quark, how many should i purchase?
can i make my own e-match? IE, take a small amount of steel wool and put it between the wires and use that to ignite the BP? i used to do this as a kid with my small estees launch controller to set off firecrackers from my room

 

[boatgeek]

here is a question for you about these egg-timers. Lets say i get the quark kit. I set the altitude for 500 feet for the main to go off. What tells the egg-timer not to go off at 500 feet as the rocekt is in lift off? is it the amount of acceleration sensed?

All modern commercial altimeters have logic in them to keep them from setting off charges on the way up. It's a software issue that you don't have to worry about unless you're building your own.

Second, if i do go with the quark, how many should i purchase?
can i make my own e-match? IE, take a small amount of steel wool and put it between the wires and use that to ignite the BP? i used to do this as a kid with my small estees launch controller to set off firecrackers from my room

Don't bother. Spend a few bucks and get real ematches. You need a consistent product to have consistent results, and consistency is your goal with deployment.

 

[Lt72884]

All modern commercial altimeters have logic in them to keep them from setting off charges on the way up. It's a software issue that you don't have to worry about unless you're building your own.

Don't bother. Spend a few bucks and get real ematches. You need a consistent product to have consistent results, and consistency is your goal with deployment.

ok, ill just order some or see if the school has any extra. They may have ordered plenty of them.

 

[Voyager1]

here is a question for you about these egg-timers. Lets say i get the quark kit. I set the altitude for 500 feet for the main to go off. What tells the egg-timer not to go off at 500 feet as the rocekt is in lift off? is it the amount of acceleration sensed?

Second, if i do go with the quark, how many should i purchase?
can i make my own e-match? IE, take a small amount of steel wool and put it between the wires and use that to ignite the BP? i used to do this as a kid with my small estees launch controller to set off firecrackers from my room

The rocket has to pass the apogee event before the main will deploy at the specified altitude on descent.

You could buy two so you have a spare if you use one, or use both if you want a redundant deployment system. As boatgeek suggested, buy the proper ematches for consistent results.

 

[waltr]

Exactly, there is quit a bit of logic that detects various flight states before arming functions.
First is LDA (Launch Detect Altitude which is 200' for the Quark). This means the Quark MUST measure a change of altitude exceeding 200' for ANY channel to fire.

Then the Apogee detection: Altitude deceasing for 1 second. which fires the Drogue channel.
After apogee it waits for the Main deploy altitude.

Download and READ the manuals for the Eggtimers. These are freely available on the Eggtimer web site.

 

[Sailfish1957]

Ok, for my second L2 flight i would really really like to learn the bare basic setup for a dual deploy. I have never done this so i have no idea what electronics to get for my rocket or how to set it up.
I may have messed up during construction of the LOC-IV. I glued the coupler to the upper airframe (probably should not have done that), BUT i did not glue the nosecone in. Its held in with some screws so i can access the upper airframe tube. This leads to my questions:

1. Do i need another coupler to make the bay? If so, would a 3d printed one work?
2. What are some good easy basic starting electronic kits i can buy with good documentation for a dual deploy? or what electronics in general should i get?
3. Im on a small budget so not to fancy is nice. I do not need GPS since this will be a J270 or lower launch
4. Anyway to remove the epoxy on the coupler or whats the best way to re-add an e-bay?
5. Since im using aj270, or so. im guessing the ejection charge will pop the drogue and the av bay will pop the main?
6. Are the av bays friction fit or are they held in with screws, removable rivots and or shear pins?

Below is my upper airframe. I removed the nosecone to make sure my bag of powdered sugar was still intact after the first launch haha... yes, its powdered sugar, 358 grams to be exact. It is sitting on top of the epoxied bulkhead.
I am looking for some guidance and recommendations. I have never setup electronics before like this before, and any help and complete guidance is much appreciated.

thank you much for any help
This will be for my first L2 electronic flight


View attachment 570017
View attachment 570019
The last photo is how it currently is setup for single deployment
View attachment 570020

I will take your questions in the order asked:

1. Do i need another coupler to make the bay? If so, would a 3d printed one work?
No 3-D on a coupler. Not strong enough. I would cut just across the coupler and remove any bottom bulkhead installed off the coupler that's glued in; then glue on a length of BT to accommodate the Av-Bay insert. (Don't try to remove the coupler or scrape it out - what a mess and terrible idea). You will end up with a rocket that's only about 4 inches longer if you do it right. The Av-Bay with a switch band would now be the "coupler" between the bottom and top of the rocket. The ejection charges go on each end, top end with the nose cone going out with the Main laundry; bottom end with the main airframe/fin can going out with the Drogue. Do not rely solely on the motor ejection charge for the drogue, that is a back-up in the DD world. Set the delay on the motor to be well past apogee. The altimeter will fire at apogee.

2. What are some good easy basic starting electronic kits i can buy with good documentation for a dual deploy? or what electronics in general should i get?
Missle Works RRC3 makes a great, inexpensive DD altimeter. And...they sell a dongle for linking to software on your PC to configure the unit; and they have a blue tooth capability for Android.

3. Im on a small budget so not to fancy is nice. I do not need GPS since this will be a J270 or lower launch.
No GPS needed for the use you have in mind. The whole idea of using Dual Deployment is to have the rocket recovery be close to the launch site - that is why the drogue comes out first, followed by the main at a much lower altitude - to limit wind drift.

4. Anyway to remove the epoxy on the coupler or whats the best way to re-add an e-bay?
As I stated above, cut the coupler off just above the bulkhead. If you have not installed a bulkhead then add a BT to accomodate the Av-Bay. You will end up with a rocket that's only about 4 inches longer if you do it right.

5. Since im using aj270, or so. im guessing the ejection charge will pop the drogue and the av bay will pop the main?
No, full redundancy is best - still use an ejection charge to go off at apogee, then adjust the motor ejection to several seconds later.

6. Are the av bays friction fit or are they held in with screws, removable rivots and or shear pins?
Theav-bay would be shear pinned to the bottom end, or friction fit if you can get it right (watch out for drag separation). The top is connected to the av-bay with either removable rivets, screws etc. It MUST stay connect, the nose cone is going off, so attach it with shear pins.

The DD av-bays are not hard to assemble at all. Good Luck - Sailfish out

 

[Lt72884]

I will take your questions in the order asked:

1. Do i need another coupler to make the bay? If so, would a 3d printed one work?
No 3-D on a coupler. Not strong enough. I would cut just across the coupler and remove any bottom bulkhead installed off the coupler that's glued in; then glue on a length of BT to accommodate the Av-Bay insert. (Don't try to remove the coupler or scrape it out - what a mess and terrible idea). You will end up with a rocket that's only about 4 inches longer if you do it right. The Av-Bay with a switch band would now be the "coupler" between the bottom and top of the rocket. The ejection charges go on each end, top end with the nose cone going out with the Main laundry; bottom end with the main airframe/fin can going out with the Drogue. Do not rely solely on the motor ejection charge for the drogue, that is a back-up in the DD world. Set the delay on the motor to be well past apogee. The altimeter will fire at apogee.

2. What are some good easy basic starting electronic kits i can buy with good documentation for a dual deploy? or what electronics in general should i get?
Missle Works RRC3 makes a great, inexpensive DD altimeter. And...they sell a dongle for linking to software on your PC to configure the unit; and they have a blue tooth capability for Android.

3. Im on a small budget so not to fancy is nice. I do not need GPS since this will be a J270 or lower launch.
No GPS needed for the use you have in mind. The whole idea of using Dual Deployment is to have the rocket recovery be close to the launch site - that is why the drogue comes out first, followed by the main at a much lower altitude - to limit wind drift.

4. Anyway to remove the epoxy on the coupler or whats the best way to re-add an e-bay?
As I stated above, cut the coupler off just above the bulkhead. If you have not installed a bulkhead then add a BT to accomodate the Av-Bay. You will end up with a rocket that's only about 4 inches longer if you do it right.

5. Since im using aj270, or so. im guessing the ejection charge will pop the drogue and the av bay will pop the main?
No, full redundancy is best - still use an ejection charge to go off at apogee, then adjust the motor ejection to several seconds later.

6. Are the av bays friction fit or are they held in with screws, removable rivots and or shear pins?
Theav-bay would be shear pinned to the bottom end, or friction fit if you can get it right (watch out for drag separation). The top is connected to the av-bay with either removable rivets, screws etc. It MUST stay connect, the nose cone is going off, so attach it with shear pins.

The DD av-bays are not hard to assemble at all. Good Luck - Sailfish out

Thank you very much for this information. It ahs helped greatly. I will look into the missle works RRc3 altimieter as well as how to remove the epoxied coupler haha.

For the RRC3, do i need to solder anything or is it prebuilt?
thank you again for the help

 

[David_Stack]

Thank you very much for this information. It ahs helped greatly. I will look into the missle works RRc3 altimieter as well as how to remove the epoxied coupler haha.

For the RRC3, do i need to solder anything or is it prebuilt?
thank you again for the help

Missile Works products are already assembled and ready for configuration by the flier... https://www.missileworks.com/products/

 

[Banzai88]

Thank you very much for this information. It ahs helped greatly. I will look into the missle works RRc3 altimieter as well as how to remove the epoxied coupler haha.

For the RRC3, do i need to solder anything or is it prebuilt?
thank you again for the help

It's pre built. Works very well. I suggest getting the attachment that lets you interface your computer with it since it's a very useful utility and provides some interesting data about your flights

 

[Sailfish1957]

Thank you very much for this information. It ahs helped greatly. I will look into the missle works RRc3 altimieter as well as how to remove the epoxied coupler haha.

For the RRC3, do i need to solder anything or is it prebuilt?
thank you again for the help

The great thing about the RRC3 is that it is pretty much plug n' play. Attached is picture of an av-bay I'm working on. The Christmas lights are a means to test continuity, and in a vacuum chamber you can check actual altimeter settings for drogue and main release altitudes. The batter is a 9v on the back side out of the photo. The object to the right side is a screw switch mounted on its side so that I can turn the unit on and off through the switch band, from outside the rocket. Note that the RRC3 has terminals for all connections.

 

[Lt72884]

The great thing about the RRC3 is that it is pretty much plug n' play. Attached is picture of an av-bay I'm working on. The Christmas lights are a means to test continuity, and in a vacuum chamber you can check actual altimeter settings for drogue and main release altitudes. The batter is a 9v on the back side out of the photo. The object to the right side is a screw switch mounted on its side so that I can turn the unit on and off through the switch band, from outside the rocket. Note that the RRC3 has terminals for all connections.

i really like that. I may have to get this. I do have a couple of eggtimer quantum's i ordered last week but have not put them together yet. I do need the experience of soldering but i may get the RRC3 anyway to get up and running for a larger rocket build. I even got a jolly logic for some smaller builds. I want to gain as much experience as i can.

 

[Sailfish1957]

Get a good soldering set, with a set of tips; make sure you have a fine point tip. Always flux and tin the soldering tip.
You can use a Jolly Logic in the vacuum chamber to keep an eye on the altitude that you are simulating.

 

[tsmith1315]

For the Eggtimer kits, read the instructions prior to buying an iron. Follow Cris’s recommendations, you’ll be glad you did.

 

[Buster]

Thank you very much for this information. It ahs helped greatly. I will look into the missle works RRc3 altimieter as well as how to remove the epoxied coupler haha.

For the RRC3, do i need to solder anything or is it prebuilt?
thank you again for the help

Might look at the RRC2L they are in stock and cheaper than the RRC3. The Stratologgers are NIS.

 

[Lt72884]

Might look at the RRC2L they are in stock and cheaper than the RRC3. The Stratologgers are NIS.

that is a nice altimeter. I might have to do this. For 54$, thats not a bad price at all.

 

[Sailfish1957]

Go for the better unit. The RCCL3 has blue tooth capability (this module was underdevelopment but is now available and is excellent) and interfaces with mDACS software (free download to PC or Android). The mDACS software alone is worth the price of admission. The BT module is a permanent resident on this av-bay - lower right side.