[FFT] Plugging Estes or Quest BP motors

Bit,

I fly lots of Midgets. I think you'll find, with the original K-40, that trying to using rings instead of a full-length 1.75" sleeve (of spent casing) is more trouble than it's worth. Just put the T booster in a spent casing without cutting it into rings. We're talking maybe 5 grams of difference. Not enough to be worth the effort.

Also, you'll find the motor cases aren't perfectly round and centered, or exactly the right size. You'll be more likely to get a mis-aligned (canted) motor using two rings than using a full length sleeve.

For the sustainer, the pickin's are pretty slim. Either a 1/2A3-4T (sleeved) or a sawed-off A8-5.

Here's a couple of my latest incarnations. This one is nearly an exact clone, but I lengthened the booster a tad to accomodate more sustainer motor overhang, to ensure straighter coupling.

Here's a slight upscale using Quest T-30. Uses full sized, standard

18mm motors. No sleeves or saws required :)

BTW, I got some pyrogen. This weekend, I plan to put to use the research you did on staging with pyrogen.

Doug

Very nice Midgets and great paint as well.

OK, so the 18mm rings are not the right way to go, huh? Oh, well.

I just figured it was going to be kind of a pain to friction fit both the Ts into the 18mm adapters and then the 18mm adapters into the BTs, meanwhile trying to keep the 2 T's properly connected for staging. Of course, I guess I could just glue the adapters to the Ts, turning them into 18mm motors, and stage them as such. Just means I have to cut new adapters for each launch.

I know A10-0Ts are OOP - but it looks like they're no longer certed. Stupid... (I think once certed, they should stay certed - at least for sport launching - unless there's a "recall").

Hey! didn't think anyone was listening to my machinations about pyrogen-coated nozzles. :^) I'll certainly be interested to hear about your experiences. What pyrogen did you get? I used Magnelite.

Recently ordered a bunch of powdered metals and other such goodies so that I can get some experience with pyrogen and igniters.

Thanks. I spend too much time sanding and painting.

I've tried using motor cases to cut engine blocks from, but the rings are usually too small, and need to be built up (few wraps of tape) before they fit well. It was easier to just use real centering rings. (Of course, if it's two in the morning, and you're out, then the spent cases are a God-send :)

In trying to use these sawn rings as adaptors, I'm afraid you will find yourself building up the motors to fit snugly in them, then building the rings up on the outside to fit in the motor tubes, then getting frustrated with all the effort required. Sawing off the case at 1.75" and sliding the T motor is a lot easier (IMHO).

Buzz McDermott gave me some original ~1972 adaptors which look like unused motor cases, but include engine hooks, on the inside IIRC. The hooks are flush with the ends. Basically, they turn T motors into S motors, but are reusable. Of course, the adaptors still need to be friction fit into the motor tubes. I haven't gotten around to playing with them yet...

FWIW, these variants just use the T motors as is, without adaptors:

That's the easiest way :)

That's the tradeoff. Either make the extra effort to cut new ones each time or make the effort to friction fit the T's into the adaptors.

It helps to just cut a bunch at once and put them in your range box so you always have one. Also, if the motor slides in and seems to stick well without tape or glue, then you can maybe reuse that one. In fact, using these adaptors, I just made up a bunch of syntho-S motors and put them in my range box, right next to my few genuine S motors.

Don't get me started.

I got some from a friend. I'm not sure he's licensed to sell pyrogen, so I won't mention his name, JIC.

I'm already spread too thin with the hobby, without adding yet another aspect of it. But I'd like to play with it someday.

My latest idea is to see if I can put an Aerotech delay into an Estes booster motor and see if the delay will light when the BP burns thru. We could make our own oddball motors that way. C6-1 D12-14 B6-9

And it's no more involved (read: dangerous) than assembling a 24mm reload.

Doug

Pickens are even slimmer for the booster now that the A10-0T is history :-(

Bob Kaplow NAR # 18L TRA # "Impeach the TRA BoD" >>> To reply, remove the TRABoD!

Me too, but at least you get a decent results! I just get the same ol' same ol'...

Flush with the end? Allowing one to be used in the sustainer and still permit non-gapped staging?

This is just getting out of hand!!! :^)

sounds like you feel the same way - and a lot of others on rmr

I still haven't heard any good justification for the way things are - just "that's the way its always been"

Well, he obviously didn't "sell" it to you, did he? that's why he's your friend.

Do you know what his 'gen is based on? (or is that a trade secret?)

Its spreading all that paint that spreads you too thin. Fly naked!

I got one out. Pic and scans here:

Looks like it's best for single stage, but could be used for staging. The hook is flush, but on the outside contrary to what I said earlier. The user must cut a shallow slot for it to fit in.

Basically, the challenge will be dealing with the ends of the hooks where the two adaptors (booster and sustainer) come together. Might want to grind a bit of relief in the end of each adaptor case so the hook ends are flush into the end of the mating cases.

Did you see this?

(There are 5 newer ones not shown. And the 6-inch is in lawn dart heaven.)

Basically, I look at it like this: They could have just said "no motors over 3 years old" period. But they allow us to fly older ones because they don't check the date if they're on the approved (still in production) list. Still, I have over 100 A10-0T's in my stash. Gonna take a while to whittle that down at non-sanctioned launches.

I didn't ask. I'm an electrical engineer - I'm supposed to know a little chemistry - but my pyro chemistry knowledge is embarassingly lame. Basically, it's some gray stuff with acetone :)

That'd put a serious imbalance in my mojo :)

Doug

You should use a tubing cutter for that, not the bandsaw!

:>

-dave w

No. Only praxctical and safe.

Jerry

"Wrong. You don't get to decide the cert/decert rules. That's for the certifying authority to decide."

- Ray Dunakin

Ah, looks interesting. Gives me some ideas for something similar, but with the hook embedded on the inside of an 18mm casing.

I just ordered 10 packs (40).

I'm a EE too, though only

I just received an order of 40 A10-0Ts, which brings my stock up to 50+. Of course, since they aren't certed, they must be dangerous so I can't fly them. :(

Correct.

If you forget this obvious fact, be sure to repeat the NAR/TRA mantra continuously until your "bad attitude" changes.

"Just fly rockets." - Bruce Kelly

Except uncertified motors.

:)