what size centrifuge tubes for 2 gms FFFFG black powder?

[Dave S.]

I was planning out my 1st dual deploy rocket and wasn't sure what size centrifuge tubes to get. Those seem popular for pre-filling w/ weighed out BP charges. I am thinking this rocket may need up to 2 grams per charge well.

What size centrifuge tubes do you recommend?

The ones that have the flip top lid are for sale cheap on Amazon. The 1.5 ml and 2 ml type seem popular there. Those look like the ones that come with Aerotech DMS motors, but I don't have one here or I'd check myself.


Thanks!

 

[Rob Campbell]

If you fly Aerotech reloads, you can save the capsules they ship the black powder in. They hold about 2 grams. You can filling unused space with dog barf.

 

[rfjustin]

I was planning out my 1st dual deploy rocket and wasn't sure what size centrifuge tubes to get. Those seem popular for pre-filling w/ weighed out BP charges. I am thinking this rocket may need up to 2 grams per charge well.

What size centrifuge tubes do you recommend?

The ones that have the flip top lid are for sale cheap on Amazon. The 1.5 ml and 2 ml type seem popular there. Those look like the ones that come with Aerotech DMS motors, but I don't have one here or I'd check myself.


Thanks!

2ml should be a good starting point. I'll check a reload or two here in a bit and see what's included.

 

[Dave S.]

If you fly Aerotech reloads, you can save the capsules they ship the black powder in. They hold about 2 grams. You can filling unused space with dog barf.

Thanks, but I will be needing to use several of these tubes before the next time I use another Aerotech motor. So I was just going to get a box of them on Amazon - question is what size tubes (ml) will hold 2 grams of BP?


EDIT - I see that rfjustin has replied too. Thanks for answering the question. The 2 ml tubes seem most common on Amazon. Any additional assistance you can provide would be perfect!

 

[3stoogesrocketry]

I was planning out my 1st dual deploy rocket and wasn't sure what size centrifuge tubes to get. Those seem popular for pre-filling w/ weighed out BP charges. I am thinking this rocket may need up to 2 grams per charge well.

What size centrifuge tubes do you recommend?

The ones that have the flip top lid are for sale cheap on Amazon. The 1.5 ml and 2 ml type seem popular there. Those look like the ones that come with Aerotech DMS motors, but I don't have one here or I'd check myself.


Thanks!

If you take a standard sharpie marker and wrap a layer of 2 inch wide masking tape sticky side out, then another couple layers sticky side in, it turns into a very nice disposable charge holder that just happens to hold 2.5 grams very nicely. Just install your ematch in one end so the heads in the middle of the tube, then pinch the end with the wires going in into a cone and tape it securely. Load your charge , fill the rest with dog barf and more tape. Disposable and cheap.

 

[cwbullet]

I use 2ml. If I have extra space, I add a ball of dog barf. You can get 200 of the 2 ml tubes on Amazon for about $10. I usually can get expired tubes from the lab at work occasionally. If you have a family member who works in a hospital or lab, check there.

 

[Banzai88]

2ml and 5ml vials are readily available in bulk from Amazon.

Drill a hole in the bottom V part of the vial, run the wire through until the ematch head is seated at the bottom, seal the hole with a dab of hot glue, and fill the powder and snap the cap closed.

If you need to take up a little extra space, a pinch of dog barf works perfectly.

Works like a charm, and fits cap down in cpvc pipe caps as blast holders on the av bay lid.

 

[Buckeye]

1 gram per ml is a good approximation for BP. Note that the ematch head, wire, and hot glue will consume some of the volume of the vial.

 

[Handeman]

I use the 2ml tubes that Aerotech ships their ejection charges in. I only use them to measure the charges since they are graduated in 0.1 ml, or about 0.1g. I don't use them to hold the charges, that's what the copper pipe caps attached to the end of the av-bay are for. The caps for 1/2" pipe will hold about 2g of BP, depending on how big and type of screw you use to attach them to the av-bay cap with. Caps for 3/4" pipe will hold up to 6g of BP. You can get caps that fit 1" copper pipe, but I don't know how much they hold since 6g is the largest charge I use. The 1/2 and 3/4 caps are less then $2 a piece and last forever and don't bend and distort when the payload section lands on them like ammunition brass will.

Even if you do use the tubes to contain the charges, I would use a separate tube to accurately measure the BP so you are always consistent.

 

[David Schwantz]

l use both 2 and 4 gram ones. I have found that putting 2 grams of BP into a 2 gram vial and then putting the e match down inside is a little tight. Some BP always spills out. I would use 4 gram vials for that much BP and then stuff dog barf on top. I also like to put 2 layers of tape across the top at 90 to each other, and one around the whole thing. that last one also holds the wires to the vial.

 

[Titan II]

Another option you may want to consider.

 

[Viper3]

I agree with David. 4ml tubes are perfect for 2 grams of black powder, the electric match, and some dog barf. One ml equals one gram of black powder is a good estimate.

 

[PSLimo]

Wildman took the work out of it. Just pour the black powder in, fold the cardboard tube over and tape.

https://wildmanrocketry.com/collect...ejection-lighter-w-cb#judgeme_product_reviews

 

[Dave S.]

Thanks to everyone for your quick replies to my question.

 

[terryg]

For glove tip ejection charges, I use electrical tape rather than the rubber bands used in the video. It gives you a nice tight ball of black powder for the ejection charge. Use a black sharpie to label the size of the charge.