A10-0T vs B6-0, which is the preferred booster?

[Dotini]

I'm building my first multi-stage rocket since the 80's, and I want to use a cluster of two in the booster. I'm trying to decide between the A10-0T and the B6-0. Reliability of ignition and dependable performance is what I'm most looking for. Any advice or things to consider? Any input would be gratefully appreciated.

 

[neil_w]

Well, the B6 has a slightly larger thrust spike to get the rocket moving, and anecdotally there seem to have been a lot of A10 CATOs lately. So I would vote for the B6.

(Thrustcurve.org reports 100 A10 CATOs vs. 20 for B6 in the MESS database)

Addendum: I'll further note that the A8-0 (is that still available?) has a similar start up spike to the A10. By going with an 18mm mount you leave yourself considerably more flexibility.

 

[samb]

Two motors in the booster section igniting one in the second stage adds to the degree of difficulty but is definitely doable and certainly cool. Whether to use 13mm or 18mm motors in the booster is a design choice. I think the reliability issue is what you use to ignite the two booster motors and what your controller can deliver in the way of amps. Estes "clear" tip starters definitely need aftermarket enhancement; you will find many threads on different techniques here. I don't know if the newer "grey" tips are any better for cluster ignition but I suspect that they are. MJG Technologies has some alternatives that I haven't personally tried yet but I have seen used successfully.

 

[Dotini]

Well, the B6 has a slightly larger thrust spike to get the rocket moving, and anecdotally there seem to have been a lot of A10 CATOs lately. So I would vote for the B6.

(Thrustcurve.org reports 100 A10 CATOs vs. 20 for B6 in the MESS database)

Addendum: I'll further note that the A8-0 (is that still available?) has a similar start up spike to the A10. By going with an 18mm mount you leave yourself considerably more flexibility.

Yeah, I'm now convinced the 18mm motor is the more reliable and flexible. The cost is having to use a BT-60 tube instead of the BT-55 tube I could use with the 13mm boosters. If I used a BT-60 booster tube and a BT-55 sustainer tube, how could I best deal with the launch rod riding on the booster? Do nothing? Use stand offs on the sustainer? Cut a groove in the booster?

Two motors in the booster section igniting one in the second stage adds to the degree of difficulty but is definitely doable and certainly cool. Whether to use 13mm or 18mm motors in the booster is a design choice. I think the reliability issue is what you use two ignite the two booster motors and what your controller can deliver in the way of amps. Estes "clear" tip starters definitely need aftermarket enhancement; you will find many threads on different techniques here. I don't know if the newer "grey" tips are any better for cluster ignition but I suspect that they are. MJG Technologies has some alternatives that I haven't personally tried yet but I have seen used successfully.

My controller is the latest Estes unit that uses 6 C cells. I'll check my inventory for grey tip igniters.

In igniting one motor above from two below, I'm thinking there is a preferred separation distance that would allow the burning particles to mix and fill the center of the space well enough to ensure reliable ignition of the sustainer. Would a difference in nozzle opening size be a factor for the upper stage motor?

 

[neil_w]

If I used a BT-60 booster tube and a BT-55 sustainer tube, how could I best deal with the launch rod riding on the booster? Do nothing? Use stand offs on the sustainer? Cut a groove in the booster?

Your choice. Standoffs on the sustainer is probably a bit more traditional and sounds easier to me.

 

[BEC]

Startechs (the grey ones) are fine for clusters of two off the PSII controller. Just don't mix them with either the yellowish-tipped ones folks love to hate or the older black-tipped ones.

I've seen enough A10s blow in my own models, that I'd go B6-0s, too, even though I love the little Checkmate 13mm two-stager.

As far as I know A8-0s are still available. AC Supply shows them in stock.

I agree with @neil_w on the launch lug arrangement.

 

[jmasterj]

Yeah, I'm now convinced the 18mm motor is the more reliable and flexible. The cost is having to use a BT-60 tube instead of the BT-55 tube I could use with the 13mm boosters. If I used a BT-60 booster tube and a BT-55 sustainer tube, how could I best deal with the launch rod riding on the booster? Do nothing? Use stand offs on the sustainer? Cut a groove in the booster?

A standoff in the sustainer is probably the easiest way to assuage any concerns about it getting cocked on the booster during launch.

My controller is the latest Estes unit that uses 6 C cells. I'll check my inventory for grey tip igniters.

In igniting one motor above from two below, I'm thinking there is a preferred separation distance that would allow the burning particles to mix and fill the center of the space well enough to ensure reliable ignition of the sustainer. Would a difference in nozzle opening size be a factor for the upper stage motor?

Estes multi-stage kits are mostly direct-staged, where the booster motor is taped to the sustainer motor. The alternative is gap staging, where the key is vent holes between the booster motor(s) and sustainer motor. The Boosted Bertha is gap staged and works well, in my experience. The gap there is a couple of inches. I believe @BABAR has gap staged with much longer boosters.

 

[BABAR]

Yeah, I'm now convinced the 18mm motor is the more reliable and flexible. The cost is having to use a BT-60 tube instead of the BT-55 tube I could use with the 13mm boosters. If I used a BT-60 booster tube and a BT-55 sustainer tube, how could I best deal with the launch rod riding on the booster? Do nothing? Use stand offs on the sustainer? Cut a groove in the booster?


My controller is the latest Estes unit that uses 6 C cells. I'll check my inventory for grey tip igniters.

In igniting one motor above from two below, I'm thinking there is a preferred separation distance that would allow the burning particles to mix and fill the center of the space well enough to ensure reliable ignition of the sustainer. Would a difference in nozzle opening size be a factor for the upper stage motor?

Emma Kristal (quite the competitor at NARAM events as a kid and I believe still going strong as an adult) did a great experimental evaluation of black powder staging, effectively proving it is hot gas that ignites the sustainer, not particles.



probably better expressed as infrared photons from hot gas. Makes sense, as the nozzle no matter what size is a blinde ending pocket, not a tube, so no matter how hard you ”blow” a cloud of particles at it, all They will do is compress rather than display the gas in the pocket. Photons however will “shine” right through it.

I haven’t had any problems with lighting B or C sustainers, even with their smaller bores. That said, is still prefer A motors with the larger bores. I go with Ds for 24 mm, simply because I just never buy the 24mm Cs, although I think the bore is the same.

around 53 inches is my max successful in flight gap stage, I’ve succeeded with 72 inches on a test stand but it failed in flight. When you go to long gap staging, the IGNITION really is the easy part, the more challenging part for black powder staging is coming up with a system to safely keep the booster from coming in ballistic. My go to has been a cluster with a small second motor with a short delay that releases a chute about three seconds after staging, but @Dotini ‘s HSR is a natural. I have done HSR with a ring fin similar to (but not as purty as) @lakeroadster ‘s design.

 

[Arnie]

I'm not sure if this is helpful or not but two A-10-s will fit in a Bt-52. It'll give you a bit less drag

 

[Arnie]

And 2 B-6-0s will fit in a BT-58