Add delay to delay-less motor?

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nickrulercreator

nickrulercreator

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I am getting my L-1 cert, and I do not want to use a reloadable motor, just for reasons, and I'd like to use the Aerotech H45W-P, as it is an HPR 38mm motor, and it has a low average impulse. The only problem, it has no delay (hence the "P"). Is there any way I could add a delay to this motor, or would I need to get a different one (or is this motor still OK to use)?
 
Plugged delays are because the burn is too long to guarantee an accurate delay. The best choice if you want to use this motor is to have electronic ejection (doesn't need to be DD). What is the weight of your rocket (plus motor)?

If the thrust curve here is correct, you should have a really long rail/rod, because it doesn't come up to speed very quickly.
 
I would say you can't add a delay and even if you did, you couldn't cert with it.
 
rstaff3 said:
I would say you can't add a delay and even if you did, you couldn't cert with it.
Click to expand...

Correct. Tampering with a motor moves you into EX territory, and cert flights must used a commercial motor. The only caveat to this is that drilling of a delay grain is allowed (and expected).

My personal feeling is that if you are not ready for a reloadable motor and/or electronic ejection, you are not ready for level 1.
 
Do you need a 38mm? I'd just use the 29mm H135 with an adapter. H45 is a long burn designed to put a light rocket pretty high.
 
nickrulercreator said:
I am getting my L-1 cert, and I do not want to use a reloadable motor, just for reasons, and I'd like to use the Aerotech H45W-P, as it is an HPR 38mm motor, and it has a low average impulse. The only problem, it has no delay (hence the "P").
Click to expand...

What rocket are you flying for your L1 (model, weight)?
I can't think of any 38mm MMT rocket that would require the gentleness of a 6.0 second burn motor!

Keep it simple, and fly H100, or any of the other DMS motors.
For the full list of 38mm L1 DMS choices, look here:
https://www.siriusrocketry.biz/isho...evel-1-single-use-111/38mm-hp-single-use-165/


nickrulercreator said:
Is there any way I could add a delay to this motor, or would I need to get a different one (or is this motor still OK to use)?
Click to expand...

Need a different motor, or single-deploy electronic ejection with black powder charges and separate igniters.
If you've never flown such an arrangement before, don't go there for L1. Try it later. You will get there sooner or later, no need to rush and over-complicate things.
KISS !


Bat-mite said:
My personal feeling is that if you are not ready for a reloadable motor and/or electronic ejection, you are not ready for level 1.
Click to expand...

I will disagree here.
Assembling an RMS motor is not, nor meant to be, part of L1 certification validation. Building quality rockets that can withstand HP motor acceleration is. Getting them back in one piece definitely is.
RMS is yet another thing that can, and occasionally does, fail due to any number of variables, including user assembly error.
If anything, I would vote for the complication of a GPS tracker over RMS motor for L1/2/3 flight!

Everyone will migrate to RMS motors for cost/flight and motor availability reasons, sooner or later.
If getting an L1 cert is what keeps a person's interest in the hobby burning, then there is nothing wrong with flying a single-use motor for the cert flight, and exploring RMS motors / electronic ejection / DD /GPS trackers / staging / clustering later down the line.

YMMV,
a


P.S.: Speaking of RMS failures during cert flights, I had just that happen during my L1 flight! The time delay element expired after ~1 second of flight, and the ejection charge deployed at ~300 feet while the rocket was on the upward trajectory. That, in turn, transformed my L1 bird into a flying flame-thrower. Cool and painful to watch at the same time. I fixed the rocket and flew it again on RMS motors many times since then, but when the time came to retry L1 cert, I flew on H100 DMS motor just so that I would not have to worry about it.
 
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afadeev said:
If anything, I would vote for the complication of a GPS tracker over RMS motor for L1/2/3 flight!
Click to expand...

All other arguments aside, because I'm just too tired.... but how does a GPS tracker complicate anything? Or add to anything such that it should be required? The entire statement makes zero sense.
 
nickrulercreator said:
I am getting my L-1 cert, and I do not want to use a reloadable motor, just for reasons, and I'd like to use the Aerotech H45W-P, as it is an HPR 38mm motor, and it has a low average impulse. The only problem, it has no delay (hence the "P"). Is there any way I could add a delay to this motor, or would I need to get a different one (or is this motor still OK to use)?
Click to expand...

As other have said, you can't add a delay to a motor that was certified without one.
My question is, what kind of rocket are you flying on a H45W that you want to cert L1 on? If it is light enough for a safe flight on a H45W, it is going to get a lot of altitude. Why would you want to fly that high and use motor ejection at apogee? (east coast flyer talking here).

Why not fly a RMS? cost of case? or no experience with RMS? If it is because you don't have experience with RMS, I would highly recommend 5 to 10 flights on a 29/40-120 Hobbyline motor with E, F, G motors before you move up to L1, especially if you can safely fly it on a 45Ns average thrust motor. If it's because of the case cost, you could go with CTI case and reload which is very simple, or a 38mm AT and consider the case an investment in future flights. Assuming you will make more L1 flights after you get the cert, you might as well open your wallet now.
 
nickrulercreator said:
I am getting my L-1 cert, and I do not want to use a reloadable motor, just for reasons, and I'd like to use the Aerotech H45W-P, as it is an HPR 38mm motor, and it has a low average impulse. The only problem, it has no delay (hence the "P"). Is there any way I could add a delay to this motor, or would I need to get a different one (or is this motor still OK to use)?
Click to expand...

As others have said, you will not be able to add a delay to this motor. The H45 is designed for use with electronic deployment.

We don't know much about your rocket, but based on some of your other posts in the forum, I'm guessing you scratch-built something with a 38mm motor mount, plywood fins and a section of PML 54mm "Quantum-Tube" air frame. You have had some issues with motor retention and paint... -But that's just a wild guess...

It will be much easier for us to suggest a motor if you can explain the size and shape of the rocket. Also helpful it you can tell us where you will be flying. The UP part is only half the problem. You need to return your undamaged rocket to the cert team for inspection - so RECOVERY is very important. If you can tell us where you might try to cert, we can assist with suggestions that better suit the field :cool:.
 
DavidMcCann said:
All other arguments aside, because I'm just too tired.... but how does a GPS tracker complicate anything? Or add to anything such that it should be required? The entire statement makes zero sense.
Click to expand...

Ditto that for an L1 flight. Listen to David. Pick the rocket and the motor for the venue so you can watch the whole thing and recover without a tracker. That's stupid complexity with the L1 for something that should be straight forward and easily mastered if
the basics of stability and flight are understood. Use a sim, get the all up flight weight and drill the delay if needed. MUCH more important on a cardboard rocket. Don't ask me how I know. Kurt
 
ksaves2 said:
Ditto that for an L1 flight. Listen to David. Pick the rocket and the motor for the venue so you can watch the whole thing and recover without a tracker. That's stupid complexity with the L1 for something that should be straight forward and easily mastered if
the basics of stability and flight are understood. Use a sim, get the all up flight weight and drill the delay if needed. MUCH more important on a cardboard rocket. Don't ask me how I know. Kurt
Click to expand...

I agree with that, somewhat. You could do like I did, scratch build a near minimum diameter 38mm DD rocket with shipping tube BTs, self turned nose cone and homemade av-bay tube and cert on a moonburner to get maximum altitude. I did all that to learn about building HPR rockets and learned more building and flying that rocket then I ever did on my L2 or L3 rockets. Of course I would never build a L1 rocket like that again, I know better now.
 
I've finally had enough to drink to be dumb enough to comment.


It sounds like you just don't want to hit the rocket hard.


The H45 is the wrong motor to be flying. it's soft, sure, but that opens a TON of problems you're likely not ready for.


Get a CTI 3 grain case and an H133BS, or an AT 29/180 and a H123W and be done with it. Both can fly in an Estes rocket built with freaking elmers glue.

or any of the random DMS motors if you're serious into single use.
 
DavidMcCann said:
I've finally had enough to drink to be dumb enough to comment.


It sounds like you just don't want to hit the rocket hard.


The H45 is the wrong motor to be flying. it's soft, sure, but that opens a TON of problems you're likely not ready for.


Get a CTI 3 grain case and an H133BS, or an AT 29/180 and a H123W and be done with it. Both can fly in an Estes rocket built with freaking elmers glue.

or any of the random DMS motors if you're serious into single use.
Click to expand...

Now you're sounding like me!

Prost :cheers:
 
I wish the OP would come back and tell us what kind of rocket he wants to cert with. Now I'm curious.
 
DavidMcCann said:
[/COLOR said:
afadeev]
Click to expand...
[/COLOR said:
If anything, I would vote for the complication of a GPS tracker over RMS motor for L1/2/3 flight!
Click to expand...


All other arguments aside, because I'm just too tired.... but how does a GPS tracker complicate anything? Or add to anything such that it should be required? The entire statement makes zero sense.
Click to expand...


[h=1]Complication
noun[/h]
1.the act of complicating.

2.a complicated or involved state or condition.

3.a complex combination of elements or things.

4.something[FONT=Verdana, Arial, sans-serif] [/FONT]that[FONT=Verdana, Arial, sans-serif] [/FONT]introduces,[FONT=Verdana, Arial, sans-serif] [/FONT]usually[FONT=Verdana, Arial, sans-serif] [/FONT]unexpectedly,[FONT=Verdana, Arial, sans-serif] [/FONT]some[FONT=Verdana, Arial, sans-serif] [/FONT]difficulty, problem,[FONT=Verdana, Arial, sans-serif] [/FONT]change,[FONT=Verdana, Arial, sans-serif] [/FONT][FONT=Verdana, Arial, sans-serif]etc.:
[/FONT]
[FONT=Verdana, Arial, sans-serif]

[/FONT]GPS is a thing that adds unnecessary complexity for the purpose of flying an L1 certification attempt.
One can fly and pass L1 cert without it, and have fewer things to worry about.
It is not required.
Neither is an RMS motor.
Sorry if my statement caused any confusion on the subject. I thought I was pretty clear.

Is GPS nice to have - yes, I would argue so. If you want to be sure to get your rocket back. But it's neither a precondition for a successful flight, nor much of a prerequisite assuming your rocket is reasonably large and will stay under 2-3K feet and be visible.

OP was planning to fly a 38mm MMT rocket.
Recommending 29mm motors is probably not ideal....
:confused2:

Cheers,
a
 
GPS is a ride along. My confusion is that it adds zero complexity to a flight. I'm not suggesting it's needed, but it adds no problems.

OP is planning a 38mm H motor. I see no issues suggesting 29mm motors that are much, much more ideal (in just about any rocket) than the motor he's asking about.
 
DavidMcCann said:
GPS is a ride along. My confusion is that it adds zero complexity to a flight. I'm not suggesting it's needed, but it adds no problems.

OP is planning a 38mm H motor. I see no issues suggesting 29mm motors that are much, much more ideal (in just about any rocket) than the motor he's asking about.
Click to expand...

No matter what, I suggest a pre-flight checklist. The more stuff you need to set up, the more chance of forgetting something. The chance go down once you have done things a few times, whether it's altimeter setup, building motors or connecting quicklinks.
 
Handeman said:
I agree with that, somewhat. You could do like I did, scratch build a near minimum diameter 38mm DD rocket with shipping tube BTs, self turned nose cone and homemade av-bay tube and cert on a moonburner to get maximum altitude. I did all that to learn about building HPR rockets and learned more building and flying that rocket then I ever did on my L2 or L3 rockets. Of course I would never build a L1 rocket like that again, I know better now.
Click to expand...

Which flight after the successful L1 did you lose it?:wink::facepalm::surprised: Kurt (jocularly intended)~!
 
This has been an interesting thread. Along with others, I think the H100W is a great choice for the Original Poster based upon his criteria! Despite the following, I would agree that the H45 isn't the best option for a L1 attempt.

Separate from that conversation, I have to spill my guts on the H45W's forward end. Observations and thoughts, for what they're worth, and in no particular order:

-The H45 contains a smoke grain. Smoke grain = delay grain. Delay grain = motor ejection is conceivably possible. One doesn't then have to "add delay to delay-less motor".
-Several -P or plugged Aerotech (and other mfg) motors have been flown using motor ejection. Not condoning it, nor implying whether this makes it a "research" motor or otherwise, but it's been done successfully in the past. Sometimes, a -P designation is used for simplification of the certification of the particular motor, despite the fact that the motor is ejection capable.
-A recent batch of H45's are marked H45-10 on the packaging. It is likely then, that motor ejection with this particular specimen is then possible.

So, what's with my babble? Well, I was in a similar position as the original poster. I like low thrusting long burn motors. I love nostalgia motors (the H45, I65 moonies certainly fit in this category)! BUT, for me, a H45 isn't worth the effort of electronic deployment; kinda defeats the original intent IMO...just me, I know:eyeroll:. So I skipped over the H45 in the "Trailer of Doom" for several launches. Only after the "Enabler" informed me of the -10 delay on the packaging, did this motor warrant purchase for me personally.

I did purchase said motor, but haven't had the opportunity to burn it yet. I will likely use the motor with both motor ejection and electronic ejection to test the waters. I've burned several of the bigger brother I65W motors in both the motor eject and plugged versions, both vintage and new production. If one has the ability to build light, moonies are great fun! EZI's on I-65's, Hi-Tech's on H45's, Vulcanites on H76's...Yummy!!!
 
I know you said "no reloads", but if you had a 29-38 adapter, you could use the Cesaroni H54 WLB. CTI motors are really simple to put together, and it has an adjustable delay. There's also an H42 and H53 mellow, although those have more total Ns. Plus you could also play with other fun motors like the G54 Red Medium Burn, or the infamous G33 "jd2cylman hunter" mellow
 
 
Last edited:
DavidMcCann said:
https://www.aerotech-rocketry.com/uploads/5255c286-b5e0-424e-96ac-09c25ae8ab03_AT H45W SU jun 19.pdf

cert doc lists 2014.

The only reference I can find to an H45-P is at Apogee and Sirius. Can't find cert docs.... Combined list only shows the H45-14A Weird.

https://www.apogeerockets.com/Rocket_Motors/AeroTech_Motors/38mm_Motors_Single_Use/Aerotech_38mm_Motor_H45W-P_HP_SU

https://www.siriusrocketry.biz/ishop/aerotech-high-power-h45w-p-38mm-dms-hazmat-1511.html


EDIT- this list from 2015 lists the delay as plugged w/smoke- https://www.aerotech-rocketry.com/u...58_DMS[emoji769] Data Sheet 6-11-15 Small.pdf
Click to expand...

You’re right; that is confusing. If you read the certification announcement it lists the manufacturer designation as H45-14A. The manufacturer creates that designation, not the certification organization. The A after the 14 shows that the manufacturer intended the motor to have an adjustable delay.
Then TMT tests the motor. Using the instructions from the manufacturer the delays are tested. If they vary too much from what the manufacturer’s instructions say the delays should be, TMT contacts the manufacturer and offers one of three choices:
1. Redesign the delays and submit more samples for testing
2. Accept the TMT results for the delays, or
3. Sell the motor as plugged.
At that point it’s up to the manufacturer.

I believe that because it’s listed and sold as a P motor the delay should not be adjusted. I don’t know why the certification announcement doesn’t address that. We intend to improve our certification documents over the next year. I’ll put this type of thing on the list.


Steve Shannon
 
ksaves2 said:
Which flight after the successful L1 did you lose it?:wink::facepalm::surprised: Kurt (jocularly intended)~!
Click to expand...

It was the 12th flight after cert. I did get a couple of Warp 9 I1299 flights on it and a J350W after my L2 cert before I flew it on a altimeter/battery that had landed on drogue only. The battery tested good, the altimeter beeped everything correctly on boot up at the pad. It was beeping continuity as I walked back to the flight line, but it never fired either ematch. Both matches fired with a single AAA battery later and I'm still flying the altimeter, so I believe it was the battery that was compromised.
 
jnelson said:
How recent?
Click to expand...

Purchased August or September 2017. I did some quick inspecting of the motor; here are my findings:

Packaging 1: Notes an H45-10

p4_zpsoj3dwagf.jpg


Packaging 2: Denotes H45-P. So...which is it?:cyclops:

P2_zpshr2w47fp.jpg


Open up the package: Standard DMS forward closure, pre-capped with the rubber cap. Note, with DMS motors intended for motor ejection, this cap comes packaged separately, along with a vial of black powder.

pl3_zpslslfjus5.jpg


Let's pull that plug. With the cap removed, you can see that Aerotech plugged the gas-passage hole with epoxy.

P1_zpsepcj7ncf.jpg


So what is it that I just purchased? An Aerotech H45W-Plugged. While it contains a delay (I'm assuming), it is plugged by the epoxy in the powder cavity.

Could one take the Aerotech drilling device and carefully drill through the epoxy in order to use motor ejection: possibly. But you'd have to static test for delay length (and as DJS mentioned moonies tend to produce delays that vary a bit), you'd be modifying the motor, it would void the commercial certification, and you'd have to be extra careful drilling through the epoxy and into the delay grain.

I'll be using electronic ejection with my H45W.
 
djs said:
Plugged delays are because the burn is too long to guarantee an accurate delay.
Click to expand...

Or the burn is too short such as I1299N-P with Warp9, that sh*t shreds rockets, because its a K class thrust curve in a third of a second burn time. For when you absolutely must get a FAA cleared launch with a control tower, out of a L-1 impulse MD multistage, in a salt flat nowhere kind of area for competitions... Predicted 22,500ft+ with a design staging to an H, structurally failed. With plugged delays you run an electronic timer such as Minitimer4, program it to the delay time you want, or another brand and set it off with an MJG FIREWIRE to ignite a BP charge you pack yourself. It'll need a 9V or a small lipo too. Try not to blow your hand off. I'd say grab a magnetic switch... Had a charge go off near my hand not running a magnetic switch, so be careful. Then you can cert with plugged motor, but is more crap for Murphy to break.
 
Handeman said:
Both matches fired with a single AAA battery later and I'm still flying the altimeter, so I believe it was the battery that was compromised.
Click to expand...

There's free batteries out on Bonneville Salt flat, courtesy of UTC SEDS... We found our electronics post 1299N-P minus the chutes, but there's no telling where the acceleration and force loadings threw those batteries. We had zip tied and plugged them in, didn't matter. Disconnected in flight. Hahahaa.
 

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