Frustrated by Aerotech missing o-ring - couldn't do my L1 cert flight today.

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kramer714 said:
Just following all this, is the spacer kit really worth all the extra weight / issues. They are $60 dollars vs buying a 24-240 case for $80 or so plus the 360 complete motor you need anyway. Gets you all of the 360 - 240 reloads. Would you likely take the 360 and adapt it down to a 180? 100?
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The 29/360 is too long for many of my rockets. So the 29/240 was a necessity for me. And given the cost of the RAS kit, I just bought a 29/180 instead.

And then... Stuff shows up on Ebay. So I also ended up with both blue and red 29/180s and 29/240s. And I couldn't resist the price on a 29/120 and 29/100 that showed up. The end result is that I have enough 29mm tubing to plumb a house.

As for 38mm, I did get the 38/480 with RAS. It's worked well so far.

Hans.
 
kramer714 said:
Just following all this, is the spacer kit really worth all the extra weight / issues. They are $60 dollars vs buying a 24-240 case for $80 or so plus the 360 complete motor you need anyway. Gets you all of the 360 - 240 reloads. Would you likely take the 360 and adapt it down to a 180? 100?
Click to expand...
The RAS includes the closures, so that $ comparison isn't quite right. It should be RAS vs 240 complete motor, which can be better argued for the RAS side. New HPR flyers (including me a couple years ago) often concentrate on the cost side of the equation vs convenience or other factors.
 
You could just get the RMS29-240 size motor for $149 (or less, discounted), and if you wanted to use larger motors than 240 allows, say an I motor, you could get a single use for about 5 bucks more than the reload. A lot less hassle, too. Getting the 360 and the RAS allows you access to two -motors (H268R and I200W). So you pay $169 for the 360 motor and $53 for the RAS. So about 73 bucks extra to give you access to the 240 size and those two 360 size motors. There's probably a 30 or 40g difference in mass between 240 and 360 plus RAS.

As far as going down to 180, there are folks her telling me that you can't do that. On the other hand, you do have three spacers, and if you used all three you might be able do 180 motors. Apogee's matrix chart shows that you can. I kind of tend to trust the experts here, though. So I won't be buying any 180 motors for this setup. There's only four 180 motors in the 29mm reload arena anyway as far as I can tell:
G75J-10
H128W-14
H165R-14
H238T-14A

It would be sweet if one could use those, though: You'd be able to fly G75 to I200 reloads. That said, for the number of times flying a G75 with a 360 casing, I'd be better off using single use. Also, if you want to do multiple launches during a day you don't have to clean out the casing each time.

I'm thinking single use would have been better for me. If one was launching a lot of rockets using motors in the F62 to G138, then I think the 90 bucks for RMS-29/40-120 would be worth it. There's 22 different reloads availble for that motor size.
 
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jmasterj said:
The RAS includes the closures, so that $ comparison isn't quite right. It should be RAS vs 240 complete motor, which can be better argued for the RAS side. New HPR flyers (including me a couple years ago) often concentrate on the cost side of the equation vs convenience or other factors.
Click to expand...
The RAS kits that I've seen or bought only had the forward closure. On the 38mm system, I had to buy an extra rear closure to give me 2 sets of closures for use with an extra tube.

Hans.
 
I applaud you coming to the forum to ask the right questions and get the answers, but this thread is a good example of why I consistently recommend fliers use DMS motors for Level 1 certs. There is a lot of time, once you have your cert, to work out the intricacies of RMS motors and all the permutations of them, but using a DMS motor takes away almost all the motor issues for a cert flight.

Good luck on your attempt!
 
kramer714 said:
Just following all this, is the spacer kit really worth all the extra weight / issues. They are $60 dollars vs buying a 24-240 case for $80 or so plus the 360 complete motor you need anyway. Gets you all of the 360 - 240 reloads. Would you likely take the 360 and adapt it down to a 180? 100?
Click to expand...

It’s more useful when there are single-grain steps to the next case size.

I lost a 29/180 motor. I still had a 29/240 case. For the price of the RAS, I got the new front closure, saved the cost of a 180 case plus the benefits of a 120 case.

Likewise, I had 38/720 and 480 motors. The price of the RAS allowed me to add 38/600,360 snd 240 loads to my mix.

Yep, worth it. Especially for new HPR flyers who haven’t yet succumbed to the dark side. (“Good! Your home equity has made you powerful. Now fulfill your destiny and buy that 98mm hardware!”)
 
mtnmanak said:
I applaud you coming to the forum to ask the right questions and get the answers, but this thread is a good example of why I consistently recommend fliers use DMS motors for Level 1 certs.
Click to expand...
Agree 100%! When I did my L1 back in 2009, DMS was not yet an option and the older single-use AT motors were long OOP, so there was no choice but to understand RMS. But those days are gone, at least if you have an on-site vendor or are willing to pay hazmat.

I also acknowledge that the RAS documentation is confusing, and the evolution of the RMS design (seal disc, no seal disc, etc, etc.) is far from obvious to someone who didn't live through those changes. In some respects the older AT instructions were less confusing than the current ones.

Of course, CTI is much less confusing, too bad their motors are not readily available/reliable at the moment. There was a time when I would advise new people to just fly CTI.
 
A simple rule of thumb I follow:

Paper liner - no forward seal disk
Phenolic liner - forward seal disk (& seal disk o-ring)

However, ever rule has an exception. For example, the G-25 (29/120) has a phenolic liner but no forward seal disk.

The instructions also alert you to whether a forward seal disk is required but be on the lookout for the wrong instructions included with your motor. I recently had the wrong instructions inserted in a G-25 motor. I knew something didn't seem right when the parts list didn't match the contents. I opened another G-25 I had on hand and retrieved the correct instructions.



1719881139632.png
 
4regt4 said:
Hmmm..... Every one of the 29mm and 38mm motors that I've used over the last few years has included a large diameter forward plastic cap that goes over the ejection charge. Including 5 that I shot this last weekend. And there is a notation to not use it if using a baffle or anything else blocking the ejection gas path.

Hans.
Click to expand...
My bad…confused with the larger motors!
 
This is all coming back to me - why I chose a reloadable motor and why I chose Aerotech.

The key issue was that for a single-use motor in the H category, needed for L1, I would have to have paid a hazmat fee of about 50 bucks. I hate gratuitous fees and wanted to avoid that. According to what I saw on the interweb, all the Cesaroni motors and all the Aerotech single use had that hazmat charge. If I was ordering bulk with (for example) nine other BARs each ordering 10 motors, then the extra cost for my motor would be 50 cents. But because I was ordering the motor myself, and they wouldn't trust me and sell me multiple h motors, my $50 H182R single use would have been $100.
I figured that I'd order an Aerotech reloadable H motor, many of which do not incur the dread HAZMAT fee. So I pay $194 for the 360 motor and the RAS. Its more money, but deduct the HAZMAT fee of 51 that I saved, and about a $15 difference in motor costs, and so for the difference of $128 I get the motor casing and RAS flexibility. Would have been a better idea to just get the RMS-29/240 if I really wanted a reload.
If I'd paid $45 for the SU motor and bit the bullet and paid the HAZMAt I would be dollars ahead, and probably could have launched last weekend, even feeling crummy.
But I would have missed out on learning stuff from you guys!
The stuff you are telling me is making sense. Thanks!
 
WizardOfBoz said:
This is all coming back to me - why I chose a reloadable motor and why I chose Aerotech.
Click to expand...
Although I ended up flying L1 on a hazmat motor, Aerotech's lineup of no-Hazmat motors is what pulled me into the RMS ecosystem too. Incidentally, for after your cert or if the first cert attempt goes awry (mine did), the I200 is a beautiful hazmat-free motor for that 29/360 case, no RAS needed.
 
WizardOfBoz said:
This is all coming back to me - why I chose a reloadable motor and why I chose Aerotech.

The key issue was that for a single-use motor in the H category, needed for L1, I would have to have paid a hazmat fee of about 50 bucks. I hate gratuitous fees and wanted to avoid that. According to what I saw on the interweb, all the Cesaroni motors and all the Aerotech single use had that hazmat charge. If I was ordering bulk with (for example) nine other BARs each ordering 10 motors, then the extra cost for my motor would be 50 cents. But because I was ordering the motor myself, and they wouldn't trust me and sell me multiple h motors, my $50 H182R single use would have been $100.
I figured that I'd order an Aerotech reloadable H motor, many of which do not incur the dread HAZMAT fee. So I pay $194 for the 360 motor and the RAS. Its more money, but deduct the HAZMAT fee of 51 that I saved, and about a $15 difference in motor costs, and so for the difference of $128 I get the motor casing and RAS flexibility. Would have been a better idea to just get the RMS-29/240 if I really wanted a reload.
If I'd paid $45 for the SU motor and bit the bullet and paid the HAZMAt I would be dollars ahead, and probably could have launched last weekend, even feeling crummy.
But I would have missed out on learning stuff from you guys!
The stuff you are telling me is making sense. Thanks!
Click to expand...

You're analysis and reasoning are perfectly understandable and we have all gone through the same dilemma, at some point.

If you happen to try your cert at a big launch or one where you know a vendor is going to be there, it is great to get the DMS motors on the field and avoid the HAZMAT fee. When I was first trying accumulate HPR motors, I would often save up for the chance to stock up on the field when a vendor was available.

Again, good luck on the attempt, and, if you decide to use the RMS, don't hesitate to get some help with the assembly.
 
bad_idea said:
Although I ended up flying L1 on a hazmat motor, Aerotech's lineup of no-Hazmat motors is what pulled me into the RMS ecosystem too. Incidentally, for after your cert or if the first cert attempt goes awry (mine did), the I200 is a beautiful hazmat-free motor for that 29/360 case, no RAS needed.
Click to expand...
Actually, I like the H268R better. For some reason, it goes higher in the rockets that I have tried it in, plus there is the bonus of that nice red flame!

Hans.
 
WizardOfBoz said:
The key issue was that for a single-use motor in the H category, needed for L1, I would have to have paid a hazmat fee of about 50 bucks. I hate gratuitous fees and wanted to avoid that. According to what I saw on the interweb, all the Cesaroni motors and all the Aerotech single use had that hazmat charge. If I was ordering bulk with (for example) nine other BARs each ordering 10 motors, then the extra cost for my motor would be 50 cents. But because I was ordering the motor myself, and they wouldn't trust me and sell me multiple h motors, my $50 H182R single use would have been $100.
I figured that I'd order an Aerotech reloadable H motor, many of which do not incur the dread HAZMAT fee. So I pay $194 for the 360 motor and the RAS. Its more money, but deduct the HAZMAT fee of 51 that I saved, and about a $15 difference in motor costs, and so for the difference of $128 I get the motor casing and RAS flexibility. Would have been a better idea to just get the RMS-29/240 if I really wanted a reload.
Click to expand...

This is the big selling point for AT 29mm, IMO. No HAZ charge is a big deal when you can only buy one motor and can't/don't want to rely on a field vendor. I started with the 29/180 complete motor and an H128W for my L1, and don't regret that in the slightest.
 
jmasterj said:
This is the big selling point for AT 29mm, IMO. No HAZ charge is a big deal when you can only buy one motor and can't/don't want to rely on a field vendor. I started with the 29/180 complete motor and an H128W for my L1, and don't regret that in the slightest.
Click to expand...
Bingo!

Did L1 on 29/180 H128. My signer/cert guy (L2) said he had no interest in seeing me assemble the motor as we had launched many dozens of MPR RMS together, and he commented that he'd never seen a failure on my part. He said build it and send it.

It didn't even shake him up when I asked about how many o-rings should be left over.

And went very well.

Hans.
 
bad_idea said:
Although I ended up flying L1 on a hazmat motor, Aerotech's lineup of no-Hazmat motors is what pulled me into the RMS ecosystem too. Incidentally, for after your cert or if the first cert attempt goes awry (mine did), the I200 is a beautiful hazmat-free motor for that 29/360 case, no RAS needed.
Click to expand...

I didn't know where my 29/360 case ever went and still have not found it, but still have an H reload for it*. I did find my Dr. Red 29/240 but it needs some cleaning inside**.

I just bought the DMS I205 at motor vendor on site, BMS. Flew it in my Estes Partizon twice.
It and the I200 are a nice motor.

*Edit: It might be I lost it in a rocket and I had bought two of the max 29 H motors.
** But that does not explain why I have a brand new 29/240 in AT black and gold sticker
 
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WizardOfBoz said:
You could just get the RMS29-240 size motor for $149 (or less, discounted), and if you wanted to use larger motors than 240 allows, say an I motor, you could get a single use for about 5 bucks more than the reload. A lot less hassle, too. Getting the 360 and the RAS allows you access to two -motors (H268R and I200W). So you pay $169 for the 360 motor and $53 for the RAS. So about 73 bucks extra to give you access to the 240 size and those two 360 size motors. There's probably a 30 or 40g difference in mass between 240 and 360 plus RAS.

As far as going down to 180, there are folks her telling me that you can't do that. On the other hand, you do have three spacers, and if you used all three you might be able do 180 motors. Apogee's matrix chart shows that you can. I kind of tend to trust the experts here, though. So I won't be buying any 180 motors for this setup. There's only four 180 motors in the 29mm reload arena anyway as far as I can tell:
G75J-10
H128W-14
H165R-14
H238T-14A

It would be sweet if one could use those, though: You'd be able to fly G75 to I200 reloads. That said, for the number of times flying a G75 with a 360 casing, I'd be better off using single use. Also, if you want to do multiple launches during a day you don't have to clean out the casing each time.

I'm thinking single use would have been better for me. If one was launching a lot of rockets using motors in the F62 to G138, then I think the 90 bucks for RMS-29/40-120 would be worth it. There's 22 different reloads availble for that motor size.
Click to expand...
Basically, look to see how many spacers you can use and determine what all cases you need to get in order to cover the full line. You can use those same spacers in a 240 case to get the 180 loads, or in a 180 case to get the 120 loads. So, with 2 cases and the RAS, you should be able to fly any 29mm load you want (for the HPR style cases, not the 29/40-120 loads.
 
4regt4 said:
Bingo!

Did L1 on 29/180 H128. My signer/cert guy (L2) said he had no interest in seeing me assemble the motor as we had launched many dozens of MPR RMS together, and he commented that he'd never seen a failure on my part. He said build it and send it.

It didn't even shake him up when I asked about how many o-rings should be left over.

And went very well.

Hans.
Click to expand...

Back in 1989, for my "confirmation" flight, I just got a 29mm H70 single use and put it in my NCR Big Brute. I saw that rocket in the back of my storage shed [not my work shed]. I remembered it had an LMS* motor road flare up the forward closure and burn it out inside like around 2005.

* don't build an LMS motor on the field below freezing...
 
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bad_idea said:
For evil fun, buy packs of spare o-rings and sprinkle them liberally on folks' tables around large launches.
Click to expand...
Those of us old enough remember Heathkit. A friend was assembling an oscilloscope. When he wasn't looking, I added a couple extra resistors to the parts pile.

Hans.
 

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