Loki Research Motor Retention

[jcampb81]

I am planning on using the Loki Research 38/240 Motor Casing and h125 for my level one cert. My question is, what can I use for motor retention?

 

[Antares JS]

Ordinary Z-clips will work just fine. Slimline retainers from Giant Leap Rocketry also work.

Pro tip: Make sure your motor case doesn't fit too tightly before going to the field. One disadvantage I have found with Loki cases compared to Aerotech ones is that there is less area to grip the motor case to remove it, and that area doesn't have a grip knurl like Aerotech aft closures do. It's harder to remove the case if it's tight.

 

[tim cubbedge]

If you have not installed motor retainer, friction fit will work. Wrap masking tape around motor at aft end. It should be very snug. Do a search and you should find some images.

 

[David_Stack]

Loki motors have an external snap ring, so it should work fine with something like an Aeropack or similar threaded retainer (the retainer cap bears against the external ring)

If you are using mirror clips/'z' clips which are held in place by screws threaded into the aft centering ring, that will work as well (the 'z' clips rest against the end of the Loki case).

Lastly, there is always friction fit inside the MMT.

 

[StreuB1]

H125, friction fit all day if you haven't already installed a mechanical means of retention.

 

[jcampb81]

My body tube is 54mm so using the z-clip will probably not be an option since the centering rings will be pretty thin. My main concern was with the external thrust ring. I was concerned that the threaded style retainers might not work either as the thrust ring would cause you to not be able to purchase the threads on the retainer.

But you're saying that the thrust ring will fit inside the retainer and will shoulder against it? And then I will be able to screw the cap on?

 

[jcampb81]

Loki motors have an external snap ring, so it should work fine with something like an Aeropack or similar threaded retainer (the retainer cap bears against the external ring)

If you are using mirror clips/'z' clips which are held in place by screws threaded into the aft centering ring, that will work as well (the 'z' clips rest against the end of the Loki case).

Lastly, there is always friction fit inside the MMT.

My body tube is 54mm so using the z-clip will probably not be an option since the centering rings will be pretty thin. My main concern was with the external thrust ring. I was concerned that the threaded style retainers might not work either as the thrust ring would cause you to not be able to purchase the threads on the retainer.

But you're saying that the thrust ring will fit inside the retainer and will shoulder against it? And then I will be able to screw the cap on?

 

[gtg738w]

My body tube is 54mm so using the z-clip will probably not be an option since the centering rings will be pretty thin. My main concern was with the external thrust ring. I was concerned that the threaded style retainers might not work either as the thrust ring would cause you to not be able to purchase the threads on the retainer.

But you're saying that the thrust ring will fit inside the retainer and will shoulder against it? And then I will be able to screw the cap on?

Yes, the external thrust ring will fit inside the retainer body and then the cap seats against the aft end of the case. Works great.

Also, there have been some reports of Z-clips damaging Loki cases but I have not personally seen this. Just an FYI...

 

[David_Stack]

My body tube is 54mm so using the z-clip will probably not be an option since the centering rings will be pretty thin. My main concern was with the external thrust ring. I was concerned that the threaded style retainers might not work either as the thrust ring would cause you to not be able to purchase the threads on the retainer.

But you're saying that the thrust ring will fit inside the retainer and will shoulder against it? And then I will be able to screw the cap on?

Good Morning;

A Loki 38mm casing I have on hand measures 41.63mm for the outside diameter of the external snap ring/thrust ring. Measuring my Aeropack retainer, the screw-on cap has an external diameter of 49.52mm. Not sure what the ID of your 54mm body tube is, it may be close as to whether an Aeropack threaded retainer will fit. As Antares posted, a slimline retainer may be your only option.

Attached photo shows the pieces of the Aeropack retainer, and a Loki case. Obviously the threaded body to the left is not affixed to the 38mm MMT. That body has a step machined inside the end against which the thrust ring bears, with the end of the motor case protruding ever so slightly beyond the end of the threaded body. The retainer cap presses against the end of the motor case, and forces the thrust ring against that recess.

 

[Bat-mite]

I've never met a commercial retainer that didn't work with Loki motors.

 

[heada]

With the modern Loki cases, they work just the same in threaded retainers like Aeropack

I've never met a commercial retainer that didn't work with Loki motors.

Loki Gen1 case had integrated thrust rings built into the case.
Loki Gen2 cases went to an external spiral thrust ring but the ring was a few thousandth's too wide for Aeropack and Slimline retainers and adapters. You could grind down the spiral ring and then they would fit just fine.
Loki Gen 2.1 (current for over 10 years, since before Scott took over) use a spiral thrust ring that fits in Aeropack and Slimline retainers and adapters without needing to be modified.

If you got your case new, then you can use it just like you would an Aerotech or CTI case in the same size. If you got your case used, its a very good chance you can still use the case in standard retainers without worry. If for some reason the spiral ring is ever so slightly too wide, you can grind it down with something like a dremel or purchase a replacement from Loki for $6

 

[Theory]

I've never met a commercial retainer that didn't work with Loki motors.

this

 

[Brent]

Never had an issue using Aeropak retainers on Loki motors 38 through 75

 

[bobbyg23]

My body tube is 54mm so using the z-clip will probably not be an option since the centering rings will be pretty thin. My main concern was with the external thrust ring. I was concerned that the threaded style retainers might not work either as the thrust ring would cause you to not be able to purchase the threads on the retainer.

But you're saying that the thrust ring will fit inside the retainer and will shoulder against it? And then I will be able to screw the cap on?

Yes, aeropack retainers work great.

 

[bobbyg23]

Also for future reference, be very careful with Loki and z clips.

 

[StreuB1]

I have the Loki 38/600 and up cases and they all fit in my rockets with Aeropack retainers. No issues at all.