Anyone Use Tinder Rocketry Ejection Charge Wells?

[Rob Campbell]

Has anyone used these ejection charge wells from Tinder Rocketry. I just found them on Apogee's website and they look really nice.

https://www.apogeerockets.com/Eject...rs/FireBird-3G-Recessed-Ejection-Charge-Wells

 

[fyrwrxz]

Nope, but they are on the list for my next larger bird. I love the idea of a burst diaphragm that is fairly consistent without worrying if your tape is degraded from heat or dust, common on our western test ranges. The poster putty is available at most dollar stores and the water bottle caps, well, duh. O rings may be redundant.

 

[MidOH]

Flush mounting the charge, and no external connection seems interesting.

But I'll build my own.

 

[Hobie1dog]

Great design, thanks for posting this up for us.

 

[mtnmanak]

Haven't tried these yet, but they look very cool. I will probably order some from the manufacturer, though. Cheaper, lower shipping cost and all versions are in stock. Also, Tinder carries the right size diamond hole saw for composites:

https://www.tinderrocketry.com/charge-cups

 

[ONAWHIM]

O rings may be redundant.

Having reviewed the instructions I'm curious if the intent of the o-ring is to provide a mechanical stop rather than a seal?
Certainly it binds two matches together.

 

[NateB]

Thinking about it and without seeing it in hand, the O rings could be serving double duty to bind the ematches together and increase friction to prevent them from moving in the hole. think the o rings and putty might be a "belt and suspenders" approach to protecting the electronics. The instructions say to spread the wires of a single match or spread the wires of 2 matches apart to create a mechanical strain relief.

 

[Siya]

Here you go!

 

[darrenf]

I'm curious why they don't recommend just one e-match. Are they afraid that it will be too loose in the channel it passes through?

 

[chrocket]

I'm curious why they don't recommend just one e-match. Are they afraid that it will be too lose in the channel it passes through?

I guess they giving the instructions for "Double FireBird Charge Well" where you can connect the e-match for the main and the backup altimeter.
If you use only one e-match, the hole where the e-match cable passes through is not tightend and you would need to install an additional O-ring to prevent the ejection chrarge being blown partially into your e-bay.

 

[Cameron Tinder]

I'm curious why they don't recommend just one e-match. Are they afraid that it will be too lose in the channel it passes through?

Hey DarrenF, I always recommend for two e-matches to be used in all Tinder Rocketry devices used in flight, for redundancy only. All Tinder Rocketry devices work with a single e-match. If you are comfortable using a single e-match for flight, then go for it!

 

[darrenf]

Hey DarrenF, I always recommend for two e-matches to be used in all Tinder Rocketry devices used in flight, for redundancy only. All Tinder Rocketry devices work with a single e-match. If you are comfortable using a single e-match for flight, then go for it!

Thank you for that answer.

 

[Cameron Tinder]

I guess they giving the instructions for "Double FireBird Charge Well" where you can connect the e-match for the main and the backup altimeter.
If you use only one e-match, the hole where the e-match cable passes through is not tightend and you would need to install an additional O-ring to prevent the ejection chrarge being blown partially into your e-bay.

Hi Chrocket, You got the first part right on! One e-match to each of the redundant altimeters. If you use only one e-match however, you will still load these things as directed and that is with putty and only one o-ring. I have tested this method to VERY high pressure and this method works well even when using only one e-match!

 

[darrenf]

Hey DarrenF, I always recommend for two e-matches to be used in all Tinder Rocketry devices used in flight, for redundancy only. All Tinder Rocketry devices work with a single e-match. If you are comfortable using a single e-match for flight, then go for it!

Just placed an order. Can't wait to try them!

 

[Cameron Tinder]

Just placed an order. Can't wait to try them!

Received your order, thank you, it will ship today. And yes, you are going to like these!

 

[bclark989]

These look great, but I wouldn't want to litter the range with spent bottle caps. I might try them at some point but 3D print a cap that the BP charge would blow through instead of blowing it off, so I could remove them afterwards and throw them in the recycling.

 

[darrenf]

These look great, but I wouldn't want to litter the range with spent bottle caps. I might try them at some point but 3D print a cap that the BP charge would blow through instead of blowing it off, so I could remove them afterwards and throw them in the recycling.

I was thinking of tethering them with some thin kevlar string so as not to lose them.

 

[watheyak]

Oh yeah! I meant to order these when they first came out.

Thanks for the reminder.

 

[Cameron Tinder]

Oh yeah! I meant to order these when they first came out.

Thanks for the reminder.

Order received, thank you! Your package went out today!

 

[watheyak]

Order received, thank you! Your package went out today!

Your 30 minute turnaround time is impressive!

 

[mtnmanak]

These look great, but I wouldn't want to litter the range with spent bottle caps. I might try them at some point but 3D print a cap that the BP charge would blow through instead of blowing it off, so I could remove them afterwards and throw them in the recycling.

If you make a small slit in the middle of the bottle cap with an xacto knife, it will still function just fine (assuming you packed the cannister with dog barf on top of the charge...) and the charge will blow through the cap without blowing it off. I have been doing this for the past year or more and it works well.

 

[ONAWHIM]

If you make a small slit in the middle of the bottle cap with an xacto knife, it will still function just fine (assuming you packed the cannister with dog barf on top of the charge...) and the charge will blow through the cap without blowing it off. I have been doing this for the past year or more and it works well.

Interesting, so once fired is that cap usable again or is it one and done?
Thanks

 

[Dave S.]

With these you just connect the leads from the match directly to the terminal block of the altimeter - right?

 

[Cameron Tinder]

With these you just connect the leads from the match directly to the terminal block of the altimeter - right?

Hey Dave, That is the design intent. Connect directly to the altimeter and eliminate other connections/terminal blocks and at the same time, clean up the top side of the bulkhead!

 

[mtnmanak]

Interesting, so once fired is that cap usable again or is it one and done?
Thanks

One use only - the cap gets blown to hell, but it stays on the threads, so, post-launch, you can just unscrew it, dispose of it properly and put on a new cap.

https://www.rocketryforum.com/threa...se-with-water-bottle-caps.164081/post-2109219