Spent shotgun shells for ejection charge well?

[RocketSquirrel]

I drive alot, and have LOTS of time to daydream. Todays thought was using a spend shotgun shell to hold your black powder ejection charge. Not the worst idea, maybe its been done before.

What are some daydreaming ideas you've had?

 

[dhbarr]

If you keep an eye out for high brass, should work fine I'd think. People trim down spent handgun casings from time to time.

 

[cwbullet]

I drive alot, and have LOTS of time to daydream. Todays thought was using a spend shotgun shell to hold your black powder ejection charge. Not the worst idea, maybe its been done before.

What are some daydreaming ideas you've had?

Brass or plastic will work.

 

[KenECoyote]

Great idea and it recycles a bit of the many shells one can find at some ranges (especially skeet and trap of course). I may try it myself instead of the usual PVC pipe caps I use.

 

[Rob Campbell]

I drive alot, and have LOTS of time to daydream. Todays thought was using a spend shotgun shell to hold your black powder ejection charge. Not the worst idea, maybe its been done before.

What are some daydreaming ideas you've had?

Sounds like a great idea.

 

[Handeman]

Will probably work fine for a few flights. I used .45 cal brass on one of my av-bay and ended up switching it out for a 1/2" copper pipe cap because the brass on the drogue side of the av-bay kept getting damaged when that part of the payload section hit the ground first.
I've found that 1/2" copper pipe caps can hold about 4g of BP, the 3/4" caps hold about 6g of BP. Not sure what the 1"caps will hold, but expect they would be somewhere around 10g.
I've had a few of the copper pipe caps that were retired after 50 flights, but I'm positive they would have been good for +150 more. They just work and never seem to get damaged, just dirty. Just use a SST screw to attach them so it doesn't degrade either. They may cost a $1 or $2, but they will last longer than the rocket. Saving money is fine, but having to bother with replacing damaged, cheap wells, is false economy to my way of thinking.

 

[thequick]

It works fine. I’ve been using the same 20 gauge plastic shells for 20+ flights over maybe 5 years. I typically use about 2-3g of 4f powder along with igniter contained in a glove finger wrapped in tape, all secured inside the shell.

I use this set up in several cardboard and fiberglass rockets, with and without shear pins as needed

 

[manixFan]

I use both .38 special and .45 Long Colt cartridges for BP holders. I designed and printed holders for them that use the case rim to hold them in place, and caps that slide over the top with an opening on the side for the ematch leads. The screws that attach the holder to the bulkhead are also used as binding posts for the leads. They are only suitable for up to about 54mm diameter due to their limited capacity, but they are easy to make up in advance. I print the caps with white filament so I can write the charge size right on it. They are easy to replace so it makes flying the same rocket more than once a day a lot easier.


Tony.

 

[teepot]

I tried 45 Long Colt cases for a very brief time. When the charge would go off it must have been like a cannon because I collapsed 3 Av Bay lids. Two of the Av Bays had both bulkheads collapsed. I would put a little dog barf in and a couple pieces of tape. I used the BP holder that comes with a motor to put the same amount of BP as a charge. After the first two I reduced the BP and didn't use as much tape and it still happened. I gave up on that and changed the way the end caps are seated. No more having the cap sit on a ring of coupler. Now I use stepped lids and glove fingers not attached to the end cap..

 

[KenECoyote]

I have spent 50 caliber shell casings from a Desert Eagle that I may use just to surprise people lol

 

[ejpyle.mgb]

I have used cut-down .45-70 cases which, because they are tapered a bit they fit well into holes, and because the extractor rim of the casing is wider than the case itself, you can retain the case easily with a pan-head screw. Drilling out the primer hole allows for wires to pass through, but make sure the igniter does not touch the inside of the casing. I also use 3fg BP - 4fg makes for some interesting...distortions.

 

[twoxsheds]

I have used cut-down .45-70 cases which, because they are tapered a bit fit well into holes, and be cause the extractor rim of the casing is wider than the case itself, you can retain the case easily with a pan-head screw. Drilling out the primer hole allows for wires to pass through, but make sure the igniter does not touch the inside of the casing. I also use 3fg BP - 4fg makes for some interesting...distortions.

I’m going to try that.

 

[thequick]

 

[manixFan]

I tried 45 Long Colt cases for a very brief time. When the charge would go off it must have been like a cannon because I collapsed 3 Av Bay lids. Two of the Av Bays had both bulkheads collapsed. I would put a little dog barf in and a couple pieces of tape. I used the BP holder that comes with a motor to put the same amount of BP as a charge. After the first two I reduced the BP and didn't use as much tape and it still happened. I gave up on that and changed the way the end caps are seated. No more having the cap sit on a ring of coupler. Now I use stepped lids and glove fingers not attached to the end cap..

Wow, I’ve been using the .45 Long Colt cartridges in my 54mm rockets for a couple of years without any issues.

It sounds like you didn’t use a charge calculator or do any ground testing? A .45 LC is just a straight walled case, it would not increase the pressure of the charge any more than any other similar sized charge holder.

Bummer about your results, but I don’t think the case is at fault.


Tony

 

[RocketSquirrel]

Will probably work fine for a few flights. I used .45 cal brass on one of my av-bay and ended up switching it out for a 1/2" copper pipe cap because the brass on the drogue side of the av-bay kept getting damaged when that part of the payload section hit the ground first.
I've found that 1/2" copper pipe caps can hold about 4g of BP, the 3/4" caps hold about 6g of BP. Not sure what the 1"caps will hold, but expect they would be somewhere around 10g.
I've had a few of the copper pipe caps that were retired after 50 flights, but I'm positive they would have been good for +150 more. They just work and never seem to get damaged, just dirty. Just use a SST screw to attach them so it doesn't degrade either. They may cost a $1 or $2, but they will last longer than the rocket. Saving money is fine, but having to bother with replacing damaged, cheap wells, is false economy to my way of thinking.

I think the copper pipe idea better. This will be my first ebay in a 4" LOC IV, it doesn't have to be perfect i just want to get dual deploy down a few flights before i build my L2. Still debating on setting it up for dual deploy or just using a jolly logic chute release. I used a chute release for the L1 flight and i dont think i got the strap tight enough and the parachute opened at apogee. Luckily i was able to find it unharmed. If im going to be strapping expensive electronics to my $200 rocket i want it all back in once piece haha

 

[RocketSquirrel]

View attachment 618536View attachment 618537

Very nice! Looks like its seen a few flights. Do you have to replace it after a couple?

 

[cwbullet]

I think the copper pipe idea better. This will be my first ebay in a 4" LOC IV, it doesn't have to be perfect i just want to get dual deploy down a few flights before i build my L2. Still debating on setting it up for dual deploy or just using a jolly logic chute release. I used a chute release for the L1 flight and i dont think i got the strap tight enough and the parachute opened at apogee. Luckily i was able to find it unharmed. If im going to be strapping expensive electronics to my $200 rocket i want it all back in once piece haha

There are many possibilities. Find one you like. I have used PVC, Copper Pipe, Brass cartridges, machined aluminum, glove tips, straws, shotgun shells, and 3d printed charge holders. They all work. It all comes down to preference.

 

[Handeman]

I think the copper pipe idea better. This will be my first ebay in a 4" LOC IV, it doesn't have to be perfect i just want to get dual deploy down a few flights before i build my L2. Still debating on setting it up for dual deploy or just using a jolly logic chute release. I used a chute release for the L1 flight and i dont think i got the strap tight enough and the parachute opened at apogee. Luckily i was able to find it unharmed. If im going to be strapping expensive electronics to my $200 rocket i want it all back in once piece haha

Don't get too intimidated with altimeters and DD. It's really pretty simple. Most of the altimeters, even if they are very customizable, are designed to be flown right out of the box. There are lots of ways to do DD and almost all of them work. Some maybe better than others, but most are dependable.
My first av-bay was a scratch built coupler, end caps, etc. for my L1 cert rocket. I would never build another av-bay the way I built that one since you learn with each one you build and make the next one better. It did work fine because DD really is pretty easy.

 

[manixFan]

There are many possibilities. Find one you like. I have used PVC, Copper Pipe, Brass cartridges, machined aluminum, glove tips, straws, shotgun shells, and 3d printed charge holders. They all work. It all comes down to preference.

This is a great point, but you do need to ground test before you fly no matter what method you choose, especially if you are new to DD. For the small cost of the e-matches you can save yourself a lot of money and grief by making sure you’ve got things setup correctly.


Tony

 

[cwbullet]

This is a great point, but you do need to ground test before you fly no matter what method you choose, especially if you are new to DD. For the small cost of the e-matches you can save yourself a lot of money and grief by making sure you’ve got things setup correctly.


Tony

Good point. It is especially important on first flights or when you change "stuff" from flight to flight.

 

[c0c0m0ke]

Spent shell casings work great! Knock out the primer with a nail and hammer, and replace that with a e-match wrapped in a bit of kleenix, add a drop of white glue and hang out to dry, to seal up that gap. Drying time depends on how much glue you use, ambient temp and humidity. 24 hours is overkill -definitely less time then that is needed to dry completely. Depending on volume of tube to pressurize for ejection -ground test to find the optimum amount. 4/4 gram will do for 38mm tube about 24" long. If the tube is shorter, use less; if it is longer use more. Do ground testing for different size tubes. I understand there are formulas for figuring this out.