Loki vs CTI

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muddymooose

Hoopy Frood
Joined
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Location
Palmyra, MI, USA
Since I got back into rocketry last summer and quickly moved into HPR, I've been using Loki motors exclusively. This was a result of my club vendor having and recommending Loki hardware and reloads. I currently have a 38mm/240Ns (H) and 38mm/480Ns (I) case and they've been great in my PML Ariel and Endeavor.

I'm currently looking for motors for my LOC Precision Warlock with a 54mm mount and no adapter. My default motor choice was going to be a Loki 54mm/1200Ns case and J reload for an L2 attempt. I am however a fan of doing a modest "shakedown" flight on new rockets using the lowest-power motor that will safely achieve a successful flight. A large I would do the job, but Loki doesn't offer a 54mm I option. To be honest I've been kind of frustrated with the limited number of reloads for a given Loki case.

So I was looking around and found the CTI Pro54 Starter Kit. It includes a 3G case, a 6G case, forward enclosures, and spacers that allow for the use of anything from 1G to 6G. This gives an incredible range of reload selections for the given hardware (at least 30 reloads in the I through K range). So that got me intrigued.

The next thing I noticed was the price. A CTI Pro54 Starter Kit is about $220. Seems steep, but let's look at the cost of Loki cases:

38mm/240Ns (H): $80
38mm/480Ns (I): $90
54mm/1200Ns (J): $150
54mm/2000Ns (K): $170
Total Loki cost for H through K cases: $490

Total CTI Pro54 Starter Kit cost for I through K cases: $220

Loki 54mm J reload: $85
CTI 54mm J reload: $90

At this point jumping over from Loki to CTI seems like a no-brainer. More flexible hardware at much lower cost, much larger range of reloads, similarly-priced reloads. Only difference I see is CTI reloads require HAZMAT fees for shipping, which is negated if I buy in quantity or pick up from a local vendor.

So is CTI really that much more cost-effective, or am I missing something?

Are CTI loads more prone to failure than Loki? Is there anything else that makes them less desirable?
 
Some other CTI advantages IMHO are: 1. for 38 & 54 mm motors, no snap rings needed and simpler to add reloads to casings. 2. If you buy from Wildman (after joining the club) an approximate 20% discount to most CTI reloads applies (he doesn't carry Loki). 3. If you-let's say have a 5 grain 54mm CTI casing-you can use this same casing for all 5 grain, 4 grain and 3 grain CTI reloads if you utilize respectively no spacers, 1 spacer or two 54mm CTI spacers. The use of spacers, as far as I know, is not currently available for Loki casings. Shipment of the larger Loki reloads does require hazmat charges. Finally, if one day you want to make Ex reloads, then the Loki casings and hardware are more applicable (check the Loki website).
I hope this helps plus others will offer other points of view.

Fred, L2
member of ICBM
Camden, S.C.
KG4YGP
 
I bought the CTI 54mm starter set, I've never had a failure with a CTI motor and you can't beat CTI for ease of assembly, they are substantially easier and quicker to assemble than Aerotech reloads. Never tried Loki, have heard very good things, although some say the snap rings can be hard to deal with. The 54mm Loki reloads require hazmat shipping, although several 38mm do not.

This article describes some of the pros and cons of Loki, AT, and CTI: https://lokiresearch.com/images/Documents/Loki Article.doc
 
The Loki snap rings are a non-issue for me. As a machine builder I've been using snap ring pliers for years, and they're as intuitive as using a hammer. I can't complain about the Loki motor assembly, they've been great. But the range of reloads and lower cost of CTI is pretty appealing.
 
Look at what you want your motors to do for you. Fly whichever will do that for you.
 
Most of us flyers who have been around for a while fly more than one brand of motors. For me its what my local vendor sells. I just hate to pay the Haz-mat fees.
Both loki and CTI have great products.
 
First off good luck on your cert and shake down flight, I am a big fan of shakedown flights on new hardware for cert flights. Secondly I like having more than one vendor to fly, so if you are willing to spend the money then having options is always a good thing.

As far as your setup, I see that you specified "no adapter". Does this mean that you do not have a retainer or that you do not wish to use an adapter and adapt down from the 54mm MMT to 38 using one of Loc's adapters? Assuming that your setup allows an adapter then for $7.50 you have a solution to use your existing 38-480 hardware and fly one of 6 Loki reloads for your shakedown flight.
 
As far as your setup, I see that you specified "no adapter". Does this mean that you do not have a retainer or that you do not wish to use an adapter and adapt down from the 54mm MMT to 38 using one of Loc's adapters? Assuming that your setup allows an adapter then for $7.50 you have a solution to use your existing 38-480 hardware and fly one of 6 Loki reloads for your shakedown flight.

I hadn't even thought of using a LOC motor adapter, but that looks like a good way to go. What holds it in place? If I have a PML 54mm motor retainer will that interfere?
 
or am I missing something?

Cost per newton

Loki G80 = 122.5 NS / $17.50 = 7 NS per dollar
CTI G46 = 112.5 NS / $22.50 = 5 NS per dollar

Loki I405 = 493.2 NS / $42.95 = 11.5 NS per dollar
CTI I285 = 285 NS / $47.65 = 6 NS per dollar

Loki prices came from the Loki web site and the CTI prices are from the Wildman site (without the WM club discount). This is a quick comparison and I just grabbed some motors at random that were sort of close to each other but I think you'll find similar results if you want to compare Loki and CTI motors with more closely related performance. Other things to consider is that Loki reloads do not come with ignitors but for the amount you're saving I would think you're still coming out ahead. Plus, should you ever make the journey down the research road the Loki casing are very well suited for that.

IMHO there is nothing wrong with either manufacturer. Just depends on where your priorities are.

-Dave
 
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One very important thing I didn't see mentioned is motor ejection vs. electronic ignition.

Does your Warlock have electronics in it for deployment purposes? If not, then Loki 54's aren't an option....they are all plugged motors. You get smoke, but no ejection options. CTI 54's come setup for motor ejection in all but the biggest loads.

Both Loki and CTI are good options, but didn't want you to be surprised that your new motor hardware doesn't support motor ejections.:)
 
I wouldn't rule out AT either. After a few years or so, you will most likely have a case from each manufacturer just because. The AT whites are awesome. Putting together AT motors are no harder than than Lokis.


Sent from my iPad using Rocketry Forum
 
There is no one-size-fits-all motor solution, IMO. Like Mr. McCann said, pick the motor to meet the desired flight profile. BTW, one nice thing about Loki HW is that they are a great segue into EX.
 
I would go with what your vendor sells, if possible, especially for the L-2 stuff. Hazmat fees suck. Plus, vendors can't be there if no one is buying.

As noted, Loki 54mm stuff is plugged. Adapters are a great option.

Reliability is probably in Loki's favor. CTI had a massive runs off recalls and such a while back. I was avoiding them for that reason for a bit. Loki claims the best reliability, but I've never seen numbers to back that up.

I fly AT and Loki. AT because they were the only game in town when I started. I've never had issues with them. Loki got my business because I wanted to make the EX jump, and I always thought the snap ring cases were a slick design. I started getting them when I came back to the hobby after a few years away and AT wasn't for sale onsite.
 
I’ve launched a ton of CTI and I love them. As you say, tons of variety and I like the ease of building the motor. It allows me to quickly turn around a casing and launch again. I’ve never used Loki so I can’t compare, but Loki has a loyal following so they’ve obviously got a good product too.

Since you mention cost as one of your decision drivers, check the prices for the same impulse classes in both 54mm and 38mm. 38mm is lower cost than a 54mm. For example, comparing CTI because that’s what I know, and using prices from AMW PROX:

38mm I impulse (3&4 grain): $40-50. 54mm I impulse (1 grain): $50-$55.
38mm J impulse (5 grain): $55-$59. 54mm J impulse (2 grain) $70-$73.
38mm higher J impulse (6 and 6xl grain): $63-$70. 54mm higher J impulse (3 grain): ~$90.

In addition to the cost difference, the grain geometry of the 38mm vs the 54mm generally makes the 38mm punchier. If you have a heavy rocket, a 38mm will get it off the pad faster than a 54mm of the same impulse class. Plus the weight of the 38mm motor is spread out farther. A 1 grain 54mm I is like a slug of weight at the very bottom of the rocket, not the best for keeping the CG forward.

For these reasons I use 54mm for K and larger. For J and smaller I use 38mm with a 54-38 Aeropack adapter to save motor money and nose weight. I have a 54mm 3 grain case and I only use it for 54mm J longburns (those are awesome).
 
Trying to compare prices and choosing something in this hobby based solely on price will make your head spin. I pretty much settled on Aerotech because I have been able to grab a lot of used hardware cheap. I did just grab a used Pro54 5g case though. That will be my second CTI case, if it ever gets here. I have Loki 38/120 and 240 cases.

If you are after variety go with CTI. They should be up to near full production, I think 85% was last I read. Loki has good loads for sure but 54mm seems to be where they are slacking a bit. No blues or cocktails in 54mm. And Loki has no greens, or smokies at all. You have to clean the nozzle and source starters for them, but you already know that. That being said, pretty hard to beat a Loki White.

Before I get crucified...I am not knocking Loki. I like Loki. I have never flown CTI, though I do have one case, the Pro38 1G. Haven't used it because the loads are so expensive for that particular case.

If your on site vendor sells CTI, may as well go that route. Doesn't hurt to have a variety of hardware from different manufacturers.
 
It's also worth checking prices for all of the grain sizes for CTI. For some reason, they seem to have a floor price for a motor diameter, but adding a grain only costs a few bucks more. That makes it so the 1G in any given size is really expensive for the impulse, but more grains is much cheaper.

I like CTI for the variety and ease of assembly, but I hear many people who fly Loki one and won't go back.
 
Yeah like I said I've really enjoyed my Loki 38mm H and I cases and reloads, but as I move up I feel like Loki is surrounding me with slamming doors. Meanwhile the CTI Pro54 starter kit is like a giant veranda that just opened up in front of me.

I ended up ordering a Pro54 starter kit and a few reloads. I'm looking forward to exploring the wide variety of options available as I continue through L1 and move into L2.

Thanks for the input, everyone.
 
One thing to note is that Loki motors are not certified for use in California. So for those who fly in California it is not a good option. I fly both Aerotech and CTI and they are both good. Right now I would say that Aerotech has the edge simply because CTI is still catching up on inventory since their fire especially in the faster reloads and the larger ones. So again the most important thing is what is available at your launch site.
 
I ended up ordering a Pro54 starter kit and a few reloads. I'm looking forward to exploring the wide variety of options available as I continue through L1 and move into L2.
For maximum variety (I through L motors), after buying the Pro54 starter set I sold the 6g case and bought the 6XL and 6XL spacer. You need a 6XL to fly L motors. They say the 6XL is not certified for use with 4g reloads (XL spacer plus 2 regular spacers) but I've seen people do this with no problems.
 
I fly both Loki and CTI. I got into Loki because I also wanted to get into EX, and I love it. That said, it works best if you prep your motors the night before a launch. Last weekend, I changed my mind on the load that I wanted to fly due to the weather conditions, so it took a while to prep the motor while sitting in the field. My daughter's CTI reload, however, went together in about 2 min (including drilling the delay).
 
Longer... Over 40 inches

+1 on that one. (I may have looked that up to see if it'd fit in my L2 airframe.....)


To the original point of the question, I think you've received a good overview of the pros and con of both Cesaroni and Loki (as well as a couple AT fans chiming in lol)
With that knowledge, I suggest you pick one that makes fire and go from there!
 
Longer... Over 40 inches

Holy cow.

Just an after thought.
I have seen very few failures but:
One CTI (Pro38 forward closure let go)
Two AT (mine was a 29/40-120, the other was the notorious I59 of which there were two failures but I only saw one)
Zero Loki failures
Granted AT is the most commonly flown brand where we fly and Loki probably coming in second.

I agree with the man on the dinosaur. Pick one that spits fire and go fly.
 
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