AeroTech Reload Adapter System questions

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woferry

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I've posted a similar question around the CTI spacer system, which makes a lot more sense to me. I find AeroTech's case naming system rather confusing (at first I thought it had to do with the length, I understand now that it's a rough max impulse indication, but looking at total impulse for various AT reloads it doesn't appear to be a rigid rule, there being a 1814N motor in the 54/1706 case for instance). Honestly I'm more likely to go with CTI for reloads due to the larger number of options in each case size / diameter, but I'd still like to understand the AT RAS in case I do consider it later (and I figure this may help others as well). So the pitch of the RAS is that it lets you fly more reloads with fewer cases, but nobody seems to say which cases you need to cover the largest number of sizes, so that's what I'm trying to clarify here, especially since I believe there are invalid combinations in the AT cases, which I do not believe is the case for CTI and their spacer system (noting the cases where an XL spacer is required instead of [or in addition to] the standard spacer).

So I'm hoping somebody 'in the know' can confirm or correct these statements (feel free to comment on as much or as little as you know for certain, i.e. first-hand experience):

29mm: There are 6 'standard' cases, plus one special one which doesn't support the RAS (the 29/40-120): 29/60, 29/100, 29/120, 29/180, 29/240 and 29/360. The 29/100 appears to be an odd size, and the 29/360 is more than one "unit" longer than the 29/240. But going by the case lengths listed in AT's 2009-2010 catalog (the latest I can find), the length difference between the 29/60 and 29/120 is also different (2") than 29/120 to 29/180 (1.75") or 29/180 to 29/240 (1.76").

It appears the 29mm RAS kit comes with 3 spacers, two 'standard' and one 'extended'. I'm pretty sure the 29/240 can adapt down to 29/180 with one standard spacer, and 29/120 with two spacers, and similarly a 29/180 could adapt down to 29/120 with one spacer, though I believe it cannot adapt down to 29/60 using two spacers(?). The 29/360 requires one standard and one extended to adapt down to 29/240 reloads, but you can't add the second standard spacer to get down to 29/180 due to the "no more than 2 spacers" rule. So even with the 29mm RAS kit, it seems to me you would still need the 29/60, 29/100, one of 29/180 or 29/240, and the 29/360 case to cover every reload in this diameter. Effectively, the 29mm RAS kit lets you eliminate 2 cases at best? Still saves money, but only reduces 6 cases to 4.

Right now (just FYI in case anybody else cares), my tally of reloads available for each 29mm case size (using BAR's current store list) is as follows: 29/60: Fx2; 29/100: Gx2, 29/120: Gx3, 29/180: Gx1, Hx3; 29/240: Hx5, 29/360: Hx1, Ix1 (18 reloads total: Fx2, Gx6, Hx9, Ix1).

38mm: There are 8 cases: 38/120, 38/240, 38/360, 38/480, 38/600, 38/720, 38/1080 and 38/1320. The first 6 have 1.875" between them, and 38/1080 is 5.625" longer than the 38/720, and the 2009-2010 catalog doesn't mention the 38/1320 so I don't know its length (the number is 240 more, which suggests it *may* be 3.75" longer and work with two spacers). 5.625 happens to be 3x 1.875 (just as the number is 3x 120 more), but since only 2 spacers are provided/allowed that wouldn't seem to let the 38/1080 get down to the 38/720 size.

The 38mm RAS kit seems to come with two equal length spacers. Based on the length deltas, this would seem to work with any case from the 38/720 down to 38/240. So you could buy the 38/360 and 38/720 and the RAS to cover everything from 38/120 up to 38/720, for 38/1320 you need that case, and I'm guessing the same is true for 38/1080 (or can two spacers adapt the 38/1320 to a 38/1080)? So it seems to me you could fly the entire 38mm reload line with 4 cases instead of 8 using the 38mm RAS, or perhaps 3 instead of 8 if the 38/1320 can be adapted.

Right now, my tally of reloads available for each 38mm case size is as follows: 38/120: Gx4; 38/240: Hx5, 38/360: Hx4, Ix5; 38/480: Ix7; 38/600: Ix5; 38/720: Ix3, Jx4; 38/1080: Jx3; 38/1320: Jx1 (41 reloads total: Gx4, Hx9, Ix20, Jx8).

54mm: There are 6 cases: 54/426, 54/852, 54/1280, 54/1706, 54/2560 and 54/2800. The first 4 have ~3.33" between them, the 54/2560 is 6.65" longer than the 54/1706 and the 54/2800 is 1.82" longer than the 54/2560. The extra length of the 54/2650 is basically 2x that of the smaller case deltas, so it's not clear to me whether a 54/2560 with two spacers can take the place of a 54/1706 or not (but it seems like it should). The 54/2800 certainly does not appear to work with the RAS.

The 54mm RAS kit seems to come with two equal length spacers. Based on the length deltas, this would seem to work with any case from the 54/852 to the 54/1706, and the 54/2560 can possibly be adapted down to handle 54/1706 reloads(?). If the 54/2560->1706 works then it seems like you could fly all 54mm reloads using the RAS and the 54/1280, 54/2560 and 54/2800 cases (3 cases instead of 6).

Right now, my tally of reloads available for each 54mm case size is as follows: 54/426: Ix6; 54/852: Jx7; 54/1280: Jx6; 54/1706: Kx9; 54/2560: Kx6; 54/2800: Kx1 (35 reloads total: Ix6, Jx13, Kx16).

75mm & beyond: There is no RAS for these larger motors, you need the appropriate case for the reload you buy. I didn't count the reload options above 54mm as I'm not expecting to go beyond a 54mm mount just yet.

I think I've also read that some AeroTech case sizes are compatible with CTI reloads (I think this includes 54mm and perhaps larger)? Is there a mapping of what AeroTech case matches which CTI case? Is it an unwise idea to consider the use of spacers even if mixing cases and reloads is an option here? If it's not an issue, presumably you'd want to use the CTI spacers with a CTI reload in an oversized AeroTech case? If it is an issue, this certainly might influence which cases you'd want to buy if there were "interesting" CTI reloads that would be compatible with that AT case.

Now of course I realize not everyone wants every case. For example, the 38/1320 and 54/2800 seem to have very little value since each one only has a single reload option (the 38/1320 is a bit better sell if it can be RAS-adapted to support 38/1080 reloads). I'm just trying to understand the 'worst case' for each motor diameter for AeroTech and CTI to avoid any 'surprises' later.

As my first posts here, I'm not sure whether I can edit it after the fact or not. If I can I can apply any corrections to the text above, so perhaps the top of this thread can serve as a reference.

Thank you in advance!


Will Ferry
NAR #96512, L1
TRA #15328, L1
L1: 9/2013 @ XPRS, GLR T-Bolt "Thunderbolt" (R.I.P.), H148R
Impulse flown: 2013: 767N, 2014: 4298N
Launches & Videos
 
I think I've also read that some AeroTech case sizes are compatible with CTI reloads (I think this includes 54mm and perhaps larger)?
75mm and 98mm, not smaller. https://www.pro38.com/faqs.php#compatibility

See instructions at https://www.aerotech-rocketry.com/resources.aspx?id=4
In general AT motors have a variable number of fixed-length propellant grains, and a standard spacer can take the place of one grain. So for example you can fly an H128 in a case for the H180 with one spacer. Some cases like the 29/360 use larger grains so you need an extended spacer. Below 29/120 things get a bit odd. I agree that CTI's nomenclature is simpler than AT's.
 
https://www.aerotech-rocketry.com/resources.aspx?id=6 has the internal drawings of the reloadable AT motors. The grain dimensions are listed in the parts index on the RHS if the drawings.

It does not make sense to simply go out an buy all the casings, even if you are using spacer to reduce the numbers, from any one manufacturer until you are ready to use them. Most folks would purchase a 38 mm L1 Certification starter for their L1 certification flight. Both AT and CTI sell a complete 3G 38 mm motor casing with closures and (2) 1G grain spacers so you can use 1G, 2G and 3 G reloads in the 3G casing. If you purchase a 6 G casing later on, you can use all the 1G thru 6G reloads which represents a majority of the 38 mm offerings. For L2 certifications, both manufacturers have a 54 mm certification special which is a complete 3G 54 mm motor casing with closures and (2) 1 G spacers. If you then purchase a 54 mm 6G casing, then you can use all the 1G to 6G 54 mm reloads which represents the majority of the 54 mm offerings. This method excludes the 6XL and larger reloads, but the options in these cases are limited due to the long length to diameter ratios.

You can certainly do the same for the 75 mm and 98 mm series when you need them, and will probably do the same for the 29 mm and 24 mm series since they are inexpensive.

Bob
 
Bob has a very valid point. While being able to launch anything sounds like a good plan, It's really going to wind up being a waste. Take a look at what motors you want/plan to launch. Personally, I find the 29/60 and 29/100's have sat unused in my box since I got them. I'm much more likely to use the 29/40-120 for motors in that range.

The 38/1320 may only have one load....but it's one hell of a load. And again, unless you've got specific plans to fly it, no real reason to pickup the case. In 54mm, the idea of just buying the case you need makes even more sense. You're looking at motors that cost in the range of 80-150 a flight. Unless you've got a hell of a budget, no need to be able to fly anything in a 54mm case. Just get the one or two that you'll actually be flying. (personally my sweet spot of the 54/1706, love that case and It's going to take a long time to get sick of those loads)

I've got spacers for my AT and CTI 29 and 38mm gear. I've never used one of them. I find myself flying 3 or 6 grain loads, or picking up a single grain cases because the longer ones would add too much weight or are too long.

I personally think getting 1-3-6 for CTI, or 120/360/720 (at) is a good way to go...and then fill in with whatever longer cases you find yourself in need of.
 
Keep in mind also that AT is in the process of updating their product line to use the new delay modules, which will change the forward closure hardware and make hardware cheaper. Several of the 38mm reloads have already been switched over, though I don't know the timetable for the rest or the 29mm and 54mm lines.

Also note that AT has been pretty aggressive about pricing on DMS motors, so it may not make sense to get AT hardware at all depending on your flight rates.
 
To Space or not to Space .. that is the question !

I think an investment in AT hardware is warranted, sometimes the vendor does not have a skidmark (or desired CTI load) and you can find the AT equivalent. Also you can find more discounts on AT year round from a variety of online vendors, the AT 24, 29, and 38mm reloads are cheaper and ALOT will ship with no HAZMAT fee required to ship .

I see AT hardware come up used fairly often and with AT taking over the casing mfg again there are a handful of skus significantly discounted to get the hardware out there-literally like buying the closures and getting the case for free. Always try to buy the longest delay and drill them down, and you will have the bases covered. If choosing between an equivalent DMS or Single Use load the DMS all ship with the longest delay.

24/40 Hobbyline , all the loads are NON HAZMAT required and most are around $15 (after discount) for a 3 pk making them cheaper than an ESTES Black Powder- which require HAZMAT. I like the 24/60 case also but there is only one reload for it right now the F35W but the load is NON HAZMAT .

29 40/120 Hobbyline, also a must have all BUT the Fs and a single G138T are NON HAZMAT required to ship. The G reloads can be found around $10 on discount . Now there is a G125T DMS equivalent to the G138T reload ..both require HAZMAT and both have a long delay and are drillable but use different tools . I only mention because if given a choice, but the DMS ..it will leave your case free to prep another load and if the rocket is lost you still have the unused motor case .

29/180 RMS buy the 29/180 motor case on discount (or two) and buy the 29/240 RMS case .. almost EVERY load is NON HAZMAT required, even with no discount landed cost is the best value in reloads . Having an extra set of closures in this size will not be wasted as you can prep two at a time. The DMS equivalent motors are all HAZMAT required . Spacer kit I have only used once and recommend buying a second set of closures to have two complete motors before grabbing the spacer system. Balsa Machining Service is selling the 29/180 motor case for $44 and the 29/240 Case only at the same price ..you will need a seal disk for most 29/240 reloads and they are under $10 on pre-order . Most loads in these sizes are $15-$18 on pre-order . 29/360 case there are only a couple of loads and there is a DMS I205W equivalent motor also, so the case is the last thing I would acquire in this size or buy a 6XL CTI -- CTI and the DMS would require HAZMAT freight but the 29/360 loads do not. Use the 29 40/120 Hobbyline in lieu of ALL the 29/60 29/100 29/120 RMS cases and loads .. really bypass completely the whole lot - only the G25W is unique.

38MM my recommendation is the same: buy the extra discounted hardware and buy the other good case size and then round things out with a 2nd set of closures before buying the spacer system. All are HAZMAT in this size , but discounts can be had on the loads and there is a good selection with the exception of long burns and super fast / high thrust motors . The Spacer system is useless with adapting down to use the long burn and high thrust motors because a special/different forward closure is required for the WARP 9 loads and the price is higher for those type of AT reloads also .. a CTI 5g motor with a couple of spacers has a true advantage in this class but for motors other than the long burn or high thrust ..AT are cheaper . CTI also maintains a cert special, so if certing you can score a free motor case.. 3grain 38mm, 5grain 38mm or 3grain 54mm and a spacer and closure are the best sizes if the vendor will let you pay the difference . AT has come out with some fast burning and long burns DMS motors which are cheaper than the reloads and dont require the special closures.. Again Balsa Machining Service has the AT 38/720 RMS motor case including the seal disk for $59 on pre-order and 38-360 case only at $32 . Most loads are $27-$44 on pre-order. DMS wise there is a H45W for long burn and the new H550ST and I500T for high thrust . Also new in this size are the EZ RMS with are std RMS hardware but using the forward closure ring from the spacer kit (available separately or sometimes free if you ask, like the DMS drill tool) and the delay, and charge well are preassembled and disposable like the DMS so I like them. 2nd set of closures is more useful in this size than the spacer kit.

54mm I only fly the 54/1706 case, it is the only size that AT has all their types of reloads represented like WARP 9 Propellant X Dark Matter Metalstorm White Lightning Redline Mojave Green and Blue Thunder . The case size is nice too, I had a CTI starter kit and the 6grain case with spacers were too tall to fit in my stock, squat type 5 inch Jart rocket and CaveDucks 5.5" V2 ..but the 54/1706 case fits well. Most loads in this size are $85 on pre-order from Balsa Machining Service. The 54/1280 motor case runs $72 and the 54/1706 case runs $96 and the seal disk runs $12 on pre-order from them also. I dont see the point in buying the spacer system in this size and DMS has a nice long burn with the I65W and the DMS K535W is cheaper than the equivalent sized reload for some reason.

Any time seal disk is used, be careful when tossing the spent motor guts, or you will throw it away . If RMS EZ is used clean up is a snap. If you are going to do Min Diameter or electronics AT you can NOT add the charge to the well , or you can buy the sealed/plugged closure with no well or buy the tapped version for use with min diameter motor retainers. There is also a 54mm and 75mm tapered rear closure available. Neither CTI or AT have a tapered rear closure in 38mm and CTI has one in 29mm .

I have not mentioned AT in 75mm because there is no price or shipping advantage in this size motor. Seems like the hardware is now a $100 more for a motor case and there is no spacer system available. The loads are limited too but 75/5120 has the most choice .

This is just my opinion in what to buy first ..and some thoughts behind it.

Kenny
 
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You can over think all this spacer crap and still not get it right. My first case was a CTI 3 grain 29mm with 2 spacer but I ended up buying a 2 grain case after the first flight. The 2 grain case simply fit the only rocket I had at the time so much better and gave me more room for recovery. I kinda felt a little bad for having the 3 grain when I just didn't use it that much, the 2 was my goto case because I was flying a lot of G80 skids in my Onyx. I think the 3 grain case has only been used less than 4 times all together. Buy what you see yourself using the most.
 
I think you really need to pick the motors you want to fly first, then go from there. Trying to cover everything is way too broad, and still won't work for all rockets.
 
Don't mean to necro this thread, but it is the perfect place for my question, I think- is there a simple guide for AT hardware? My head simply spins- some need FSD, some don't, the numbers don't mean anything to me in terms of impulse and which load can fit (H180 needs a 29/240 case, for example, not the 29/180). Then you add in the spacer stuff and it gets impossible real quick. This is the exact reason I went with CTI when I got started in HPR; now, however, I want to branch out and have more options, plus I like the added challenge of building AT reloads (I fly the 29/40-120 often). However, despite being older and wiser than when I started, I still get a headache when it comes to AT nomenclature!
 
It seems to me once you get to a certain size the FSD is required in most if not all loads, smaller ones don't need it. For 38mm I think it starts at the 600 case size, perhaps 480? For 54mm it seems to start with the 1706 case(?). Could probably judge by which motor HW sets include the FSD and which ones don't. I got a full motor for the 54/852 and case-only for 54/1280 and 54/1706 and wound up missing the FSD, so that suggests to me that there's no 54/852 load that required the FSD, I'm just not sure if ALL 54/1706 loads require it or if there are some that don't.

I definitely prefer CTI's naming scheme which includes the total impulse and not just the average number, though AT's case names are just a guideline I think, when you look at total impulse I don't think it changes case sizes exactly when you would expect it to. But the case name was definitely meant to represent total impulse, not average. Personally I suggest looking up the load on thrustcurve.org, it tells you the case it goes with. I'm hoping that the future version of the site will let you indicate which cases / spacers you own and indicate the valid loads for what you have. AT's price guide (which you can download from their site) also groups their reloads by case size, I forget whether it also indicates when the FSD is/isn't required, I'm pretty sure it indicates when special forward/aft closures are required, which is yet another Aerotech complication (the 38mm for example has two different aft closures, one for smaller nozzles and one for larger ones, and there's a special forward closure for endburners in some case sizes as well).
 
Don't mean to necro this thread, but it is the perfect place for my question, I think- is there a simple guide for AT hardware? My head simply spins- some need FSD, some don't, the numbers don't mean anything to me in terms of impulse and which load can fit (H180 needs a 29/240 case, for example, not the 29/180). Then you add in the spacer stuff and it gets impossible real quick. This is the exact reason I went with CTI when I got started in HPR; now, however, I want to branch out and have more options, plus I like the added challenge of building AT reloads (I fly the 29/40-120 often). However, despite being older and wiser than when I started, I still get a headache when it comes to AT nomenclature!

I recently struggled with this myself. What I found was this:
https://www.aerotech-rocketry.com/c...Flyers_Data_Sheets/09-10_aerotech_catalog.pdf

If you look on page 8, you will find the foot notes for the 29mm reloads (quoted here)
*29mm H210R, H220T, I200W, H250G and H268R reload kits must be used in conjunction with the 29mm
forward seal disc.

I hope this helps.
 
Regarding the seal discs, their order form might be a bit more convenient for reference here https://www.aerotech-rocketry.com/u...b80-ad86d3a51462_Model_and_hp_of_01_04_16.pdf

Specifically the 29, 38, 54, 75, and 98mm hardware sections and you'll note, for example, that the 29/240 and 29/360 indicates "Includes Forward Seal Disc." So any corresponding reload will use it. Same for the other motor calibers. 38's start at the 480 case, 54's start at the 1706, 75's with the 5120, and all 98's require it.
 
Regarding the seal discs, their order form might be a bit more convenient for reference here https://www.aerotech-rocketry.com/u...b80-ad86d3a51462_Model_and_hp_of_01_04_16.pdf

Specifically the 29, 38, 54, 75, and 98mm hardware sections and you'll note, for example, that the 29/240 and 29/360 indicates "Includes Forward Seal Disc." So any corresponding reload will use it. Same for the other motor calibers. 38's start at the 480 case, 54's start at the 1706, 75's with the 5120, and all 98's require it.

Thanks to all for the help, but this link from Pyrobob is pretty straightforward, but opens another complaint I have with AT- too many acronyms! Maybe I'll stick with CTI after all!:blush:
 
Read the directions???

What about when you're first purchasing hardware or deciding what reload to buy?

AT has a problem with educating the new customer and AT fanboys like yourself always blame the newb for not knowing.

Their solution: copy CTI, take a photo with wind chimes, and put a new photo on the cover of the old catalog.

It's sad when I can find more helpful information on a vendor website than I can in either the AT catalog or website.
 
At has the directions for all of their motors on their website.

Yes, but they're three whole clicks in from the main page. Surely you can't expect someone to look that far for information.
 
The issue isn't an ability to read, it's deciding which hardware to invest in, so I can fly. If I mistakenly buy a casing, fore and aft closure, and not something like the FSD, or, the wrong aft closure, I might not fly that day. Not all of us have the assets to purchase every piece of hardware imaginable, so no matter what reload I buy I'm covered. My question was really quite simple and no snark was required in response.
 
For Aerotech I would recommend the getting the starter motor sizes that are the lower price loss leaders (since they are used for certification). From Balsa Machining you can get the following motors at a preorder discount as follows:

29/180 Motor (no seal disk) $43.99
38/720 Motor with fwd seal disk $58.39
54/1280 Motor NO FSD $71.99
$6.00 shipping

https://www.balsamachining.com/

Get other case lengths and seal disks to use with these forward and rear closures a little at a time. You are welcome to borrow cases and seal disks from my collection at a SARA launch to see what best suits your needs. All of 29mm reloads (except for the Black Jack reloads) ship without Hazmat fees, as do the new 38mm H130W (240 case) and I180W (360 case) reloads.
 
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The issue isn't an ability to read, it's deciding which hardware to invest in, so I can fly. If I mistakenly buy a casing, fore and aft closure, and not something like the FSD, or, the wrong aft closure, I might not fly that day. Not all of us have the assets to purchase every piece of hardware imaginable, so no matter what reload I buy I'm covered. My question was really quite simple and no snark was required in response.

I think the point is that an ability to read would let you avoid buying the wrong case...as would talking to your vendor. You don't need to buy everything to cover yourself....and there is more than enough info on the AT website to determine what you need.

Why are you claiming there isn't?
 
Please, gentlemen, let's just calm down and leave it be. This thread is supposed to be helpful and informative, there's really no need for snark, name-calling and questioning people's intelligence (speaking to both sides here). I've personally been bit by the confusion of AT's 'extra parts', having bought a load only to find out that I didn't have the right aft closure and needed to drop more $$ to fix that before I could fly (I didn't even know there was more than one aft closure at the time, so I had no idea which one I had, so it's not like the vendor could have helped either unless I had brought my hardware along). And when ordering online (at least at the places I've looked) most vendors don't provide those extra details, so you'd have to know where to look to even have a chance of getting it right. Having to also dig through AT's website to figure that out is far from convenient, and something you simply don't have to deal with when flying CTI loads (or AT DMS).

I find buying AT RMS stuff a lot like buying from Ikea, it can be complicated, lots of assembly required, and sometimes you find you don't have all the parts you need and you need to go back for more, it helps to do a ton of research before you buy anything. I say that having spent over $20k on an Ikea kitchen that I assembled/installed all by myself, so I certainly don't mind doing this, but I can also understand why some people just don't want to deal with it. The great thing is that we have a choice. Anything that helps reduce the confusion of AT's lineup is a Good Thing™, and just might earn them some more customers. [Aside: If it wasn't for the outstanding ikeafans.com forum I'd have been totally lost on designing my kitchen, and likely would have given up on taking that route. Looks like Ikea has since sued that website into oblivion, a really stupid move] And then there's missing instructions, my Dad assembled his first AT load at LDRS 35 (H242T), and the instructions said to see the enclosed CRDK instructions to assemble the delay assembly, yet there were NO instructions provided (the only papers included were the main instructions and the blue warranty slip). I've put together enough delays now that I could do it blind-folded so I worked my Dad through it, but it sure left a poor taste in his mouth.

While I didn't have any cases when I started this thread, I now have 6 cases for AT (38/360, 38/600, 38/720, 54/854, 54/1280 & 54/1706) and 5 cases for CTI (Pro29-6GXL, Pro38-4G, Pro38-6GXL, Pro54-3G and Pro54-4G) and a full set of 38/54mm RAS/spacers for both vendors. Even though I have fewer CTI cases and 2 of those have never carried a load (the Pro29 which I got for free with a 38mm rocket and the Pro54-4G which I bought on Black Friday but just recently received) I've flown many more CTI loads due to the wider variety they have for each case size. But given the recent difficulty getting CTI loads from my local vendor I'm glad I have the AT cases and will probably be flying them more in the near-term (the vendor carries both, thankfully).

I would be interested in trying to gather all of the FSD/closure information and put it in the first post, but it obviously takes time to do that. I could use to re-read my first post anyway and see if anything else needs updating based on my own experience since I made this post. I looked at the pricing guide that I mentioned above that pyrobob was kind enough to provide the link for (sorry, I didn't have it handy when I posted, and actually it turns out that's an older link, the latest one is here, probably best to always go to Aerotech's Product page to get the latest) as well as the catalog chuck5395 linked to (on the same product page that I just linked to), neither one says anything about the aft closures which sucks, though both seem to provide the details on when FSDs and 'unusual' forward closures are required (just nothing about aft closures). And that catalog is ~6 years old now and is definitely missing some loads, the price list is at least kept up-to-date. I haven't found the 3 clicks it takes to get to the information mentioned above, but I'll keep looking and provide the link once I find it.
 
I downloaded all the directions to the motors I was interested in. There are also great websites such as balsa machine that list the loads per case size. Just figure out what case you want the look at the motors for that case. It's not difficult, just different. My fist AT case was a 29/120. There are only three loads for it even though most places list two. I was a CTI fanboy and never thought I'd fly AT but I lost my 29mm 2 grain case and didn't want to buy another because I had a 3 grain case and spacer to fly when I needed. The 120 case is roughly the same length as the CTI 2 grainer so I figured I'd pick one up just to play with and the loads were cheap enough to make it worth wild. When I flew it for the first time, I enjoyed it many times more that what I was flying. So I looked into picking more cases up. Over time this lead to owning a lot of cases which is expensive if you try to buy all at once but not a big deal if you pick up a case every so often over long stretch. The upshot is I can load several at the same time. On the day I lost my 2 grain case, the aft closure went with it and I had to go home. I still fly CTI 29mm stuff and enjoy them but the AT stuff is just more fun if you like to tinker. Not better, not worse, just different.

So for the people confused about AT. Just buy a case that is the same length as what you are flying with now and the rest will work it's self out. No big deal and nothing to fret about, it's just a hobby.
 
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