AeroTech Open Thread

[4regt4]

easier to grab and tighten, without shredding my hand? 24/40s are sharp. AT used to sell a wrench, at least for 18/20 closures, never got one of those.

I just use a thick paper towel.

Hans.

 

[SolarYellow]

Makes it more obvious which one is which so someone doesn't mismatch them and cross thread them. The threads are different diameter and pitch, but not different enough that a determined idiot couldn't make a mess of things before it became impossible to turn it any further.

 

[dpower]

What is the largest diameter and length of a 24mm thrust ring that will fit in an Estes and/or Aero Pack motor retainer?
View attachment 670051

The Estes 24mm retainer has a 2mm pitch, and the 24/40 case (3mm thrust ring height) is tight with a bit over 1.5 turns. So I’d say 4mm. The 24/60 gets maybe 1/4 turn on the example I have. Here’s the ID:

 

[kjhambrick]

Hmmm ...

Lots of interesting discussion about 24/40 -vs- 24/60 aft retainers here ...

But Gary's pic looks like a single use motor ... llke maybe a re-released 24 x 177 mm G55 but with a thrust ring, maybe, I hope ?

-- kjh

EDIT: This, maybe ?

 

[AeroTech]

easier to grab and tighten, without shredding my hand? 24/40s are sharp. AT used to sell a wrench, at least for 18/20 closures, never got one of those.

Wrench is available. Fits 18, 24 & 29mm model rocket RMS motors.

 

[AeroTech]

Hmmm ...

Lots of interesting discussion about 24/40 -vs- 24/60 aft retainers here ...

But Gary's pic looks like a single use motor ... llke maybe a re-released 24 x 177 mm G55 but with a thrust ring, maybe, I hope ?

-- kjh

EDIT: This, maybe ?
View attachment 670232

I think I mentioned a while back I was looking at 24mm DMS. G55W would be the logical choice for a first offering.

 

[AeroTech]

So 1.063" (27mm) O.D. X 0.197" (5mm) long would work as a 24mm thrust ring?

 

[RocketTree]

My measurements of the Estes plastic 24 mm retainer are 1.060” x 0.175” @ 1.5 turns of the cap.

 

[SolarYellow]

I would really like to see it no larger than 1” OD so it fairs inline with HD 24mm tubing like that sold by LOC, BMS, and Semroc (ST-9).

I don’t see the point of a thrust ring being larger than the OD of the thing it’s thrusting against.

 

[bad_idea]

So 1.063" (27mm) O.D. X 0.197" (5mm) long would work as a 24mm thrust ring?

Would this be a glued-on thrust ring that could be sanded or removed as an allowed modification, or would it be part of the case itself?

 

[kjhambrick]

And another Q for @AeroTech.

The old 24mm G55W C-slot SU motors came with a Copperhead which fit very nicely up the slot to the top of the grain.

I actually LIKED Copperhead ignitors after Steve Cello or Scott Bartel showed me how to treat the end with a BIC lighter (*) to melt the mylar insulator so I could separate the opposing copper foils.

Copperheads worked as well as any other ignitor for me after I learned to separate the two copper foils.

What are you thinking for ignitors for the narrow C-slot ?

Thanks Gary !

-- kjh

(*) now that I think about it, it was probably Steve because he and I were smokers and Scott was not

 

[bad_idea]

So 1.063" (27mm) O.D. X 0.197" (5mm) long would work as a 24mm thrust ring?

I just checked a Rocketarium retainer, and it looks like it can accommodate a thrust ring up to 1.075" / 27.3mm. Sadly it's too short for the 24/60 rear closure; it only gets 1/3 of a turn or so of thread engagement.

Didn't test it on CTI cases, but given their spec is also for 0.25" thrust ring thickness, I suppose it won't work with those either. Pity, for the retainer is well-made and inexpensive.

Sounds like it would work for this DMS motor though.

 

[AeroTech]

I would really like to see it no larger than 1” OD so it fairs inline with HD 24mm tubing like that sold by LOC, BMS, and Semroc (ST-9).

I don’t see the point of a thrust ring being larger than the OD of the thing it’s thrusting against.

Since we are using 3D printed plastic for the thrust rings, making them too thin makes me concerned about them fracturing during operation.

 

[AeroTech]

And another Q for @AeroTech.

The old 24mm G55W C-slot SU motors came with a Copperhead which fit very nicely up the slot to the top of the grain.

I actually LIKED Copperhead ignitors after Steve Cello or Scott Bartel showed me how to treat the end with a BIC lighter (*) to melt the mylar insulator so I could separate the opposing copper foils.

Copperheads worked as well as any other ignitor for me after I learned to separate the two copper foils.

What are you thinking for ignitors for the narrow C-slot ?

Thanks Gary !

-- kjh

(*) now that I think about it, it was probably Steve because he and I were smokers and Scott was not

I agree with you about the Copperheads
Since the G55W slot is 3/16” (0.19”) wide, a FF Mini or even a Jr. should fit just fine.

 

[AeroTech]

Revised. This ring has the same exterior dimensions as the 24mm molded cases.

 

[AeroTech]

Would this be a glued-on thrust ring that could be sanded or removed as an allowed modification, or would it be part of the case itself?

Glued-on like the 29-75mm DMS.

 

[SolarYellow]

Revised. This ring has the same exterior dimensions as the 24mm molded cases.

Perfect!

 

[Tractionengines]

@AeroTech I just want to say it again. YOUR OPENNESS WITH BUSINESS OPERATIONAL DECISIONS AND COMMUNITY INVOLVEMENT IS AMAZING. THANK YOU.

 

[2-0turbo]

Can’t wait to get my hands on some G55’s!

 

[4regt4]

Can’t wait to get my hands on some G55’s!

24mm G55? Holy crap, I hope there is room for a tracker.

Hans.

 

[bad_idea]

24mm G55? Holy crap, I hope there is room for a tracker.

24mm is plenty for @cerving 's Eggfinder mini, @Brainstormz123 's beacons, or @Adrian A 's Featherweight.

 

[rharshberger]

I think I mentioned a while back I was looking at 24mm DMS. G55W would be the logical choice for a first offering.

Followed by a G110T.....oh yeah. Still have one of each, love those little speed demons.

 

[Theory]

YES, G55 and G110 FTW!!!

Though if we’re talking “new” motors, would like to see the L2775 be released

 

[bad_idea]

Well, if we're talking about new motors, how 'bout a 29/720 case with J motors?

 

[4regt4]

24mm is plenty for @cerving 's Eggfinder mini, @Brainstormz123 's beacons, or @Adrian A 's Featherweight.

Uh, yeah, I know. I have a Featherweight. Just saying that I hope whoever uses that G55 leaves room for said tracker because they are going to need it.

Hans.

 

[bad_idea]

Uh, yeah, I know. I have a Featherweight. Just saying that I hope whoever uses that G55 leaves room for said tracker because they are going to need it.

Hans.

Aha, got it. Sorry.

 

[rharshberger]

Uh, yeah, I know. I have a Featherweight. Just saying that I hope whoever uses that G55 leaves room for said tracker because they are going to need it.

Hans.

Nah...really long mylar streamers, its all I have ever used on my Vanishing Act rocket, flights to 2400 feet using a Quark for deployment. Vanishing Act is a modified 29mm SBR Fusion with a 24mm motor mount so not minimum diameter but close.

 

[dpower]

Revised. This ring has the same exterior dimensions as the 24mm molded cases.
View attachment 670323

Nice!

FWIW, the F32 style molded case also fits well in the Estes 24/29 adapter.

• 24/40 - 3.2mm
• F32T - 4.5mm (0.18")
• E35W - 5mm

These are too high for the Estes adapter or the Estes 24mm retainers

• CTI 24mm - 6.3mm
• 24/60 - 6.5mm

1/4" Masking tape does work in the Estes retainer, since it soft enough to be compressed for a full turn.

 

[AeroTech]

YES, G55 and G110 FTW!!!

Though if we’re talking “new” motors, would like to see the L2775 be released

Patience…

 

[boatgeek]

These are too high for the Estes adapter or the Estes 24mm retainers

• CTI 24mm - 6.3mm
• 24/60 - 6.5mm

The TARC team I mentor has used CTI 24mm cases with the Estes retainer for years. It works fine, you do need to tighten firmly.