Best 38mm case size

[Bsswainston]

Trying to find out what best case size (38mm)to get and what's recommend.

 

[MarsLander]

Seems a bit backward.
What is the size of the field you are going to fly?
What rockets can be flown on that field, and stay within the field? Including expected altitude...
What motors do you need for that rocket that meet stability and speed off the rod you need, while keeping it within the field?
What case fits that motor(s), or as many motors as possible...

Can you give us a bit more?

 

[bad_idea]

Loki 38-1200.

In all seriousness, @MarsLander is right. More info needed. What impulse class, what's your cert level now, do you intend to cert to a higher level using a 38mm case, do you intend to fly it minimum diameter, do you need motor ejection, or will you fly with electronics, what size and mass of rockets do you want to fly, and to what altitude, etc.?

You might also ask a moderator to move this thread to Propulsion, where it will get a lot more views.

 

[tsmith1315]

Trying to find out what best case size (38mm)to get and what's recommend.

Speaking AeroTech:
In general, the upper and lower extremes of available case lengths for a given diameter will have fewer reload kit offerings.
Also keep in mind that the Reload Adapter System, used in place of the standard forward closure, will allow you to fly loads
designed for the two case lengths below the case you have.

So, in AeroTech 38mm, if you want to fly 240, 360, and 480 RMS reload kits, buy the 38/480 case with rear closure and RAS.

To fly 360, 480 and 600 reload kits, buy the 600 case with rear closure and RAS.

My suggestion:
-Look at AeroTech's Master Motor Matrix to see what RMS reload kits are available for each case size here.
https://cdn.shopify.com/s/files/1/0...h_Master_Motor_Matrix_4-2-23.pdf?v=1680530833

-Pick a case that will give you the greatest variety of RMS options.

-If you already have 29mm hardware up to 240 or 360Ns, skip up to the 38mm case size that will take over where your 29mm hardware leaves off.
For example if you have 29/240, then consider the case and RAS that would allow you to fly 38/360,480 and 600 loads. That way, you're minimizing overlap. That would be the 38/600 in this example.

 

[Bsswainston]

Seems a bit backward.
What is the size of the field you are going to fly?
What rockets can be flown on that field, and stay within the field? Including expected altitude...
What motors do you need for that rocket that meet stability and speed off the rod you need, while keeping it within the field?
What case fits that motor(s), or as many motors as possible...

Can you give us a

Seems a bit backward.
What is the size of the field you are going to fly?
What rockets can be flown on that field, and stay within the field? Including expected altitude...
What motors do you need for that rocket that meet stability and speed off the rod you need, while keeping it within the field?
What case fits that motor(s), or as many motors as possible...

Can you give us a bit more?

Miles to work with. Just I didn't know if they had a 38 mm like the 29 40-120

Speaking AeroTech:
In general, the upper and lower extremes of available case lengths for a given diameter will have fewer reload kit offerings.
Also keep in mind that the Reload Adapter System, used in place of the standard forward closure, will allow you to fly loads
designed for the two case lengths below the case you have.

So, in AeroTech 38mm, if you want to fly 240, 360, and 480 RMS reload kits, buy the 38/480 case with rear closure and RAS.

To fly 360, 480 and 600 reload kits, buy the 600 case with rear closure and RAS.

My suggestion:
-Look at AeroTech's Master Motor Matrix to see what RMS reload kits are available for each case size here.
https://cdn.shopify.com/s/files/1/0...h_Master_Motor_Matrix_4-2-23.pdf?v=1680530833

-Pick a case that will give you the greatest variety of RMS options.

-If you already have 29mm hardware up to 240 or 360Ns, skip up to the 38mm case size that will take over where your 29mm hardware leaves off.
For example if you have 29/240, then consider the case and RAS that would allow you to fly 38/360,480 and 600 loads. That way, you're minimizing overlap. That would be the 38/600 in this example.

Awesome thank you. I only have the 29/40-120. And getting my level 1 in a few weeks. Most of my rockets are 38mm and I just used a 29mm insert. I didn't know if the larger 29mm are cheaper than the 38mm or what the best bang for your buck is. I have tons of land around my house . I didn't know if they had certain casings with a wide variety of reloads

 

[MarsLander]

https://www.rocketryforum.com/threads/rms-38mm-cases-which-to-start-with.180891

 

[Bsswainston]

Awesome perfect. Thank you!!

 

[tsmith1315]

I didn't know if the larger 29mm are cheaper than the 38mm or what the best bang for your buck is

For a given total impulse, the larger diameter reloads will be more expensive. 38/240 is more expensive than 29/240.

I have tons of land around my house .

That’s awesome! Be careful that you’re legal. Class 2 rocket flights require a FAA COA.

Class 1 Rocket limits are listed here:
https://www.nar.org/high-power-rocketry-info/understanding-faa-regulations/


edited to add:
Re: Class 1, propellant weights are listed in the Master Motor Matrix.

Another consideration if you're looking to fly at home is Hazmat shipping. Most of the 29mm motors, up to the 360Ns are USPS mailable, meaning there's no Hazmat fees involved to ship. That's about $50 on top of regular shipping charges for the order.



If you're not buying in person from a vendor, or buying in bulk to amortize the shipping across all items, this can be significant.

 

[John Kemker]

Another consideration if you're looking to fly at home is Hazmat shipping. Most of the 29mm motors, up to the 360Ns are USPS mailable, meaning there's no Hazmat fees involved to ship. That's about $50 on top of regular shipping charges for the order.

If you're not buying in person from a vendor, or buying in bulk to amortize the shipping across all items, this can be significant.

If you're going with Loki Research 38mm motors, a lot of them are non-Hazmat shippable, up through a J.

​
J-474 - The delay time is adjustable from 8 to 18 seconds. Motor Data **Requires a #28 nozzle. No Haz-Mat Shipping.	J-474-CT	Cocktail	1.5 sec	709.1 N-s	38-740	$108.00	​
J-326 - The delay time is adjustable from 5 to 15 seconds. Motor Data No Haz-Mat Shipping.	J-326-LR	Loki Red	2.3 sec	732.9 N-s	38-740	$108.00	​
							​
I-110 Moon burner - Delay adustable from 5 to 12 seconds. **Requires #16 Nozzle. MotorData	I-110-LW	Loki White	4.0 sec	487.8 N-s	38-480	$85.00	​
I-316 - The delay time is adjustable from 5 to 17 seconds. Motor Data No Haz-Mat Shipping.	I-316-SF	Spitfire	1.5 sec	408.6 N-s	38-480	$84.00	​
I-377 - The delay time is adjustable from 8 to 18 seconds. Motor Data No Haz-Mat shipping.	I-377-CT	Cocktail (blue/red)	1.4 sec	522 N-s	38-480	$79.00	​
							​
							​
							​
I-210 - The delay time is adjustable from 5 to 14 seconds. Motor Data No Haz-Mat Shipping. .	I-210-LR	Loki Red	2.4 sec	489.8 N-s	38-480	$79.00	​
H-100 - The delay time is adjustable from 5 to 17 seconds. Motor Data No Haz-Mat shipping.	H-100-SF	Spitfire	2.0 sec	200 N-s	38-240	$56.00	​
H-125 - The delay time is adjustable from 8 to 18 seconds. Motor Data No Haz-Mat Shipping	H-125-CT	Cocktail (blue/red)	1.9 sec	240	38-240	$52.00	​
H-160 - The delay time is adjustable from 7 to 15 seconds. MotorData No Haz-Mat Shipping.	H-160-LB	Loki Blue	1.6 sec	260.1 N-s	38-240	$52.00	​
H-144 - The delay time is adjustable from 5 to 17 seconds. Motor Data No Haz-Mat Shipping.	H-144-LW	Loki White	1.7 sec	239.3 N-s	38-240	$52.00	​
H-90 - The delay time is adjustable from 5 to 14 seconds. MotorData No Haz-Mat Shipping. .	H-90-LR	Loki Red	2.7 sec	234.4 N-s	38-240	$52.00	​
HP-G-69 (2-pack) - The delay time is adjustable from 5 to 17 seconds. Two reloads per package. Motor Data No Haz-Mat Shipping.	HP-G-69-SF	SpitFire	1.6 sec	110 N-s	38-120	$70.00	​
G-70 (2-pack) - The delay time is adjustable from 8 to 18 seconds. Two reloads per package. Motor Data No Haz-Mat shipping.	G-70-CT	Cocktail (blue/red)	1.7 sec	119 N-s	38-120	$68.00	​
HP-G-94 (2-pack) - The delay time is adjustable from 5 to 18 seconds. Two reloads per package. Motor Data No Haz-Mat shipping.	HP-G94-IB	Ice Blue (blue/white)	1.3 sec	121 N-s	38-120	$67.00	​
G-80 (2-pack) - The delay time is adjustable from 5 to 17 seconds. Two reloads per package. MotorData No Haz-Mat Shipping.	G-80-LW	Loki White	1.5 sec	122.5 N-s	38-120	$67.00	​
G-66 (2-pack) - The delay time is adjustable from 5 to 15 seconds. Two reloads per package. Motor Data. No Haz-Mat shipping.	G-66-LR	Loki Red	2.0 sec	134.5 N-s	38-120	$68.00	​

 

[tsmith1315]

If you're going with Loki Research 38mm motors, a lot of them are non-Hazmat shippable, up through a J.

A good point to bring up! More non-hazmat 38mm options than AeroTech.