54mm motor or 38mm with Adapter?

[JSW]

Hello.

Fairly new to HP rocketry. Just certified L1 with a one-time-use 38mm motor. L2 rocket will use a 54mm motor.

Looking to buy a reloadable motor setup for upcoming launches.

The question is:

Does it make sense to buy a 38mm reloadable and 38-to-54mm adapter? So I can use the 38mm motor in either rocket?​

​

Or would it make more sense to buy a 38mm reloadable and also a 54mm reloadable?​

Seems like the cost is about the same for either setup. Any insights would be appreciated.

Thanks!

 

[Antares JS]

Hello.

Fairly new to HP rocketry. Just certified L1 with a one-time-use 38mm motor. L2 rocket will use a 54mm motor.

Looking to buy a reloadable motor setup for upcoming launches.

The question is:

Does it make sense to buy a 38mm reloadable and 38-to-54mm adapter? So I can use the 38mm motor in either rocket?​

​

Or would it make more sense to buy a 38mm reloadable and also a 54mm reloadable?​

Seems like the cost is about the same for either setup. Any insights would be appreciated.

Thanks!

I'm kind of lost here. What products are you looking at such that a 38mm case with a 54-to-38mm adapter costs the same as a 38mm and a 54mm case? The former should be far cheaper...

 

[JSW]

Here is how I calculate it.

Option 1: 38mm motors with 54mm adapter.

$45 Aeropack 38mm-to-54mm adapter​

$36 Aeropack 54mm retainer (required for the adapter).​

$105 AeroTech RMS-38/720 CASING​

$40 Aerotech 38mm Forward Closure​

$40 Aerotech 38mm Aft Closure​

$27 Aerotech 38mm Delay drilling tool​

$293 sub-total.​

To be fair with the comparison below, I'd need to account for being able to use two different ranges of motors. So I'd need to either buy an adapter or another casing:​

​

$63 Aerotech 38MM RELOAD ADAPTER​

$68 AeroTech RMS-38/240 CASING​

​

$356 new total.​

Option 2: 38mm motor and 54mm motor.

$68 AeroTech RMS-38/240 CASING​

$112 AeroTech RMS-54/852 Casing​

$40 Aerotech 38mm Forward Closure​

$40 Aerotech 38mm Aft Closure​

$40 Aerotech 54mm Forward Closure​

$40 Aerotech 54mm Aft Closure​

$27 Aerotech 38mm Delay drilling tool​

$27 Aerotech 54mm Delay drilling tool​

$394 total.​

The cost of Option 1 is about 15% cheaper than Option 2. (Still expensive! Maybe just stick with one-time-use motors until I can cost justify?)

Option 1 also seems more flexible - about to fly a greater range of motors with both rockets. But I worry about the complexity.

Any other insights other than cost? Or other recommendations?

 

[jmasterj]

Option 1 allows you to fly motors that fit in the 38/120, 38/240, 38/480, 38/600, and 38/720 casings. Option 2 only covers the 38/240 and 54/852 casings. Have you looked at those motors and found what you're interested in? I'd also recommend looking at a vendor besides Apogee if you're really price-conscious.

 

[Arsenal78]

For your L2, get something easy like the LOC 5.5 Goblin. It's comes stock with a 54mm so do option 1 as it'll give you a better variety of motors. Better to have the 38mm stuff to play with across other rockets and occasionally fly a 54mm. I did my L2 on the Goblin with a J425 to 1700ft or so. Stupid easy.

 

[JSW]

Thanks for the feedback. Helps a lot.

 

[DabCat]

There are 38-54 motor adapters that are way cheaper than what you quoted above. You could use a cardboard/plywood version from LOC Precision. 38-54 adaptor.

Another option to consider when thinking about the 38mm motors route; Wildman rocketry sells a 38 special or something along the lines of that. It comes with a 38/720 case, a 38/360 case, 1 set of closures, and the spacer system. This ends up cheaper than buying all the components separately, and it still allows you to fly every 38mm motor (except the longer 1080 and 1320 reloads). (38 Combo).

I would suggest the 38mm motors and an adaptor route as it allows you to fly a bigger variety of motors while still being able to fly bigger rockets. It also helps to get experience with smaller reloadable motors before moving into larger motors.

When considering cost of high power motors and hardware, I usually avoid apogee as they tend to have the highest price. I like the pre-order option at Balsamachining for motors and hardware. If you want to spend an extra $30, wildman rocketry has a club member discount that gives you discounts on a larger variety of items such as kits, motors, casings, parachutes, retainers, and more.

Hope this helps and good luck in your high power adventure!

 

[Antares JS]

Made a lot more sense when you spelled it out... I was thinking of just the adapters and cases themselves.

I pretty much agree with DabCat's advice. It was actually not until a couple of years after I got my level 2 that I started flying 54mm motors, and even then I did so only occasionally as the reloads were pretty darn expensive even 12 years ago, and that's only getting worse.

Also agree that while Apogee is great for some things (I LOVE their branded parachutes and kits), I generally avoid buying consumables like motors from them as they have the highest price. Motor hardware can also indeed be had much cheaper from Wildman or buyrocketmotors.

 

[ThirstyBarbarian]

For Option 2, don’t you still need the 38/54 adapter and 54mm retainer included in Option 1? You need the retainer either way to retain either size motor. And you need the adapter to use the 38mm hardware. So add another $81 for Option 2.

I think my approach would be to figure out what motor you want to start with, and just get hardware for that. Then add hardware as you go to support the new motors you want to fly. Start by picking the loads, not the hardware.

 

[dr wogz]

it also depends on what your goals are, and what you plan to do in the hobby. (And how long you want to spend in it!)

You will soon be buying these parts.. depends on when "soon" is..

Buy a 38mm case now & the RAS system soon after. That covers a fair amount of L1 motors. (and it'll soon pay for itself, rather than continually buying DMS motors) Eventually you will buy another [longer] 38mm case. This new / 2nd case can be used for your L2, in a bird that has a 38mm hole. (Why buy a 54mm bird now?)

Your next rocket may come with a 54mm hole. Now get the adapter. You can then use a variety of higher end 38mm reloads with the 2 cases (and likely 3 cases now!)

Now you can buy rockets with either a 38mm or 54mm hole. Soon you will buy a 54mm case.. And so on. This is what I did, over about a 3 or 4 year period.. Buy a piece of hardware each year. Budget to take advantage of the yearly sales (Wildman Black Friday for instance - if budgeted right, you can have a year's worth of HPR motors for 20-40% less than buying them individually)

If you fly L1 regularly, you will get into RMS motors. You will also have the budget for $100 a day for motors. Miss one week-end, and buy hardware instead. L1 motors are typically 29mm & 38mm. Once you get your L2, you will soon fly 54mm motors.. L2 rockets can be flown on 38mm & 54mm motors..

It's not a race.. Remember, that guy down the street with the sweet '68 Chevelle started with a basic junker, and has slowly added to it over the years.. (One / 2 years was just the paint!!)


Watch the yard sale forum. Cases come up all the time (but go fast!) Also, take part in the annual TRF Secret Santa.. I received the whole 38mm CTI case set one year, and some 29 & 38mm cases other years..

 

[boatgeek]

Another thing to think about is what your ceiling is with your L1 rocket. Can you reasonably fly it on the bigger 38mm motors at your home HPR field? If not, then that takes away some of the utility of having the long cases. Likewise your L2 rocket. If you would have trouble flying it on a K at your local field, you might want to consider a different design, either a larger airframe (more drag, less altitude) or a smaller MMT.

Things to consider when thinking about how high you can actually fly at your field:
The waiver (the only hard limit)
Field size (I have an MPR field where I can nominally fly to 2000'+ but flights over 1500' are sketchy due to trees, river, etc.)
Club rules (I doubt most clubs would have a J maximum, but you never know. Also, some say that all flights over X' need to be dual deploy)
Other factors (how good is your eyesight, do you want to invest in a tracker, do you have mobility limitations preventing long walks, etc. etc.)

 

[crossfire]

Here is how I calculate it.

Option 1: 38mm motors with 54mm adapter.

$45 Aeropack 38mm-to-54mm adapter​

$36 Aeropack 54mm retainer (required for the adapter).​

$105 AeroTech RMS-38/720 CASING​

$40 Aerotech 38mm Forward Closure​

$40 Aerotech 38mm Aft Closure​

$27 Aerotech 38mm Delay drilling tool​

$293 sub-total.​

To be fair with the comparison below, I'd need to account for being able to use two different ranges of motors. So I'd need to either buy an adapter or another casing:​

​

$63 Aerotech 38MM RELOAD ADAPTER​

$68 AeroTech RMS-38/240 CASING​

​

$356 new total.​

Option 2: 38mm motor and 54mm motor.

$68 AeroTech RMS-38/240 CASING​

$112 AeroTech RMS-54/852 Casing​

$40 Aerotech 38mm Forward Closure​

$40 Aerotech 38mm Aft Closure​

$40 Aerotech 54mm Forward Closure​

$40 Aerotech 54mm Aft Closure​

$27 Aerotech 38mm Delay drilling tool​

$27 Aerotech 54mm Delay drilling tool​

$394 total.​

The cost of Option 1 is about 15% cheaper than Option 2. (Still expensive! Maybe just stick with one-time-use motors until I can cost justify?)

Option 1 also seems more flexible - about to fly a greater range of motors with both rockets. But I worry about the complexity.

Any other insights other than cost? Or other recommendations?

How often do you fly? You can fly a good number of AT DMS motors until you just pay off hardwear.

 

[bobbyg23]

Here is how I calculate it.

Option 1: 38mm motors with 54mm adapter.

$45 Aeropack 38mm-to-54mm adapter​

$36 Aeropack 54mm retainer (required for the adapter).​

$105 AeroTech RMS-38/720 CASING​

$40 Aerotech 38mm Forward Closure​

$40 Aerotech 38mm Aft Closure​

$27 Aerotech 38mm Delay drilling tool​

$293 sub-total.​

To be fair with the comparison below, I'd need to account for being able to use two different ranges of motors. So I'd need to either buy an adapter or another casing:​

​

$63 Aerotech 38MM RELOAD ADAPTER​

$68 AeroTech RMS-38/240 CASING​

​

$356 new total.​

Option 2: 38mm motor and 54mm motor.

$68 AeroTech RMS-38/240 CASING​

$112 AeroTech RMS-54/852 Casing​

$40 Aerotech 38mm Forward Closure​

$40 Aerotech 38mm Aft Closure​

$40 Aerotech 54mm Forward Closure​

$40 Aerotech 54mm Aft Closure​

$27 Aerotech 38mm Delay drilling tool​

$27 Aerotech 54mm Delay drilling tool​

$394 total.​

The cost of Option 1 is about 15% cheaper than Option 2. (Still expensive! Maybe just stick with one-time-use motors until I can cost justify?)

Option 1 also seems more flexible - about to fly a greater range of motors with both rockets. But I worry about the complexity.

Any other insights other than cost? Or other recommendations?

Huge peice of advice. You can get all that stuff a ton cheaper if you go somewhere other than apogee

 

[rcktnut]

I'm positive you would be very happy starting with this: 3836SC - 38/360-38/720 combo – wildmanrocketry.com and go from there. You can L2 with the 38/720 casing. Loads are a little cheaper than the 54/852's too. When I became a BAR had to buy all the motors separately no RAS at the time. If I was starting out now it's what I would do.

 

[Arsenal78]

Don’t use the LOC adapters unless you want a lot of weight in the back and if you don’t care about looks

 

[cerving]

If you fly enough, you'll end up with rockets that have 38mm motor mounts, and others with 54mm motor mounts. There WILL be times when you reach into your motor box and don't have that 54mm I or J, but you do have something similar in 38mm, and you'll end up using the 38mm motor with an adaptor, even though it's going to be somewhat longer. Having both sizes of hardware is a good thing.

That being said, if you don't have any motor hardware yet but your L2 rocket has a 54mm mount and you want to maximize your L2 options for the buck, you'd probably be best off getting a CTI 54mm/4G with a couple of spacers, or an AT 54/1706 with the Reload Adapter System. Either one of those options lets you use 2G through 4G motors (or in AT lingo, 852, 1280, and 1706 motors), so you have a wide variety of motors to choose from using the same hardware.

 

[emckee]

OK, I haven't thoroughly read the whole thread (TLDR), but one point I haven't seen yet - you don't have to buy cases and closures separately. You can usually get a better deal if you buy the "motor" (which includes the case, both closures, and seal disk, if needed) rather than "casing" and "Closures"...

 

[GlueckAuf]

For the same propellant and pretty much the same total impulse, I find the Aerotech motors for the 38/360 and 38/480 cases tend to jump off the pad quicker and fly straighter than their 54/426 equivalents. Like the 38mm I245G Mojave Green vs the sedate 54mm I170G. Or the 38mm I1299N Warp Nine (yowsah!) vs the 54mm I599N. And, the 38s are usually a few bucks cheaper.

 

[Arsenal78]

If you fly enough, you'll end up with rockets that have 38mm motor mounts, and others with 54mm motor mounts. There WILL be times when you reach into your motor box and don't have that 54mm I or J, but you do have something similar in 38mm, and you'll end up using the 38mm motor with an adaptor, even though it's going to be somewhat longer. Having both sizes of hardware is a good thing.

That being said, if you don't have any motor hardware yet but your L2 rocket has a 54mm mount and you want to maximize your L2 options for the buck, you'd probably be best off getting a CTI 54mm/4G with a couple of spacers, or an AT 54/1706 with the Reload Adapter System. Either one of those options lets you use 2G through 4G motors (or in AT lingo, 852, 1280, and 1706 motors), so you have a wide variety of motors to choose from using the same hardware.

Between those two, the Aerotech is better. CTI has a lot of catos in the 54mm line.

 

[cerving]

Between those two, the Aerotech is better. CTI has a lot of catos in the 54mm line.

Maybe I'm just lucky, but I've never had ANY 54mm motor cato... including ST/VMax and longburns.

 

[Titan II]

Don’t use the LOC adapters unless you want a lot of weight in the back and if you don’t care about looks

The LOC one you would use is not much weight and looks just fine. It works well and is a whopping $7.88. I do not understand the problem about looks.

 

[StreuB1]

Go 54mm with RAS. Buy K1100T. Go full send.

In all seriousness though. It really depends on what you want to long term. 38mm is extremely versatile with the ability to go all the way down to a G motor (G69 / G339) and all the way up to a J. Though, a 54mm set will go down to an I and all the way up to an L. So really it depends less on your current situation and more on what you want to grow into.

The latter question really comes into play with 54mm as with an RAS, you can cover wide ranges of motors but you need to decide on what your largest case(s) you want to use will be.

Personally.....I have both. I started with 38mm, then bought 54mm, then expanded on both to what I currently have. I couldn't have said that the hardware I have now, is what I would have bought initially or started with. In the beginning, buy something that is flexible (AT RAS) and buy something that gives you options now but something that you can grow into. The fields you fly on and the rockets you have also play a big role. If there is cloud cover one day, do you have options to fly lower than you normally would or are you cornered into cases with available reloads that only fly above usual cloud decks.

Here in Illinois, the latter question I just posed plays a significant role in decision making. We can have a planned launch where it should be blue skies and we can go full send. Then the weather might shift and we have a 4k cloud deck and need to go with hot fast burn motors to get it off the pad but not through the clouds. The 54/852 and 54/1280 are perfect examples. I can fly high on a J800 in the big case or fly low on a J275 in the smaller case. The 54/426 loads are also really nice as there are loads for slow and loads and then the I599N to punch bigger rockets off the pad but fly really low.

This set from Wildmans is one of the most versatile. You can fly I through K with one setup. If you want to then go bigger, you buy the 54/2800 big boy case and then you can go from L down to J's. Essentially hitting the entire 54mm lineup with 2 cases.

5417SC

54/1706 case, 54FSD, 54AC, 54RAS

wildmanrocketry.com

 

[Antares JS]

Couple of small corrections...

38mm is extremely versatile with the ability to go all the way down to a G motor (G69 / G339) and all the way up to a J.

Loki makes two 38mm K reloads.

This set from Wildmans is one of the most versatile. You can fly I through K with one setup.

You cannot fly 426 I reloads with this setup. With the two-spacer limit for certified motors, the 1706 4-grain case cannot be loaded with a 1-grain I reload. Plus, you need the small-opening aft closure for the 426 reloads.

 

[terryg]

One other thing needs to be mentioned is hazmat shipping. It costs $44 plus the actual shipping costs to get 54 mm reloads. Do you have an on site vendor? If so, what brands do they carry. You can get hazmat free shipping on Loki motors all the way thru J reloads. Aerotech has one hazmat free J reload. Most 29mm aerotech reloads ship without a hazmat fee. Most of the time, I end up flying 38 mm reloads and adapting down to 29mm reloads when I need to. The great thing about aeropack retainers is that they can stack. For my upcoming club launch I am flying an H268 redline reload in a rocket with a 54 mm motor mount.

 

[StreuB1]

Couple of small corrections...



Loki makes two 38mm K reloads.



You cannot fly 426 I reloads with this setup. With the two-spacer limit for certified motors, the 1706 4-grain case cannot be loaded with a 1-grain I reload. Plus, you need the small-opening aft closure for the 426 reloads.

Loki does and I have their 38mm hardware but as time goes on, Scotts stuff seems to be more and more obscure. AT is bog standard and the supply is not going anywhere so I feel its a comfortable supplier. So I guess I should preface this by saying that I am referring to AT and not Cesaroni or Loki.

Yes, forgot about the 426 being the outlier. Especially since I have that case and the small nozzle closure. I am reminded daily that I and human and get things wrong.

 

[John Kemker]

Yes.

Buy a 38mm to 54mm adapter. Also buy 54mm motor casings. You can (and should) do BOTH!

 

[Arsenal78]

Loki does and I have their 38mm hardware but as time goes on, Scotts stuff seems to be more and more obscure. AT is bog standard and the supply is not going anywhere so I feel its a comfortable supplier. So I guess I should preface this by saying that I am referring to AT and not Cesaroni or Loki.

Yes, forgot about the 426 being the outlier. Especially since I have that case and the small nozzle closure. I am reminded daily that I and human and get things wrong.

I feel like Loki is trying to get out of the model side and aim more toward experimental and university stuff. After canning Chris as a vendor and not stocking FlightSketch up, it seems like there’s something going on.

 

[GlueckAuf]

I feel like Loki is trying to get out of the model side and aim more toward experimental and university stuff. After canning Chris as a vendor and not stocking FlightSketch up, it seems like there’s something going on.

I have no inside knowledge, but I interpret the guidance below from Loki's recently revised Dealers page to indicate that it has modified its business plan, not its target market or product line. Apparently, Loki now intends to fill all online retail orders itself, retiring the dealer network to whom it formerly provided reloads and hardware at wholesale. Loki will, however, retain a carve-out for selected launch site and in-person sales vendors, as I interpret this.

Loki is a great small company that produces a great, uncompromisingly high-quality product for our sport. If a tough business decision like this was necessary in these extremely difficult times to keep its enterprise from folding altogether, then in the great scheme of things, Loki's decision was the right decision for us, too, the consumer.

Adapt, or die. And I for one do NOT want Loki Research to die.