Aeropac 75 mm min dia question

[Bobrogg]

All,

I'm building a Wildman Mach 3 and want to use the aeropac 75 mm min dia motor retention system for my build. I've never used one before and I'm looking for advice and do's/don'ts with this item. I plan on using a CTI 75mm 1540 6xl for the motor, concerns involve not placing the aeorpac short/long in the tube, how do get the mount point correct without building the motor?

thanks

bob

 

[rfjustin]

All,

I'm building a Wildman Mach 3 and want to use the aeropac 75 mm min dia motor retention system for my build. I've never used one before and I'm looking for advice and do's/don'ts with this item. I plan on using a CTI 75mm 1540 6xl for the motor, concerns involve not placing the aeorpac short/long in the tube, how do get the mount point correct without building the motor?

thanks

bob

I would suggest a different solution. I'll grab some pics later tonight, but I would suggest a bulkhead or two that get's bolted directly to the motor. This plate also serves as recovery cord attachment point. I like (2) points of contact on the tube for minimum diameter builds if I can afford the room.

Best,
https://www.rocketryforum.com/threads/wildman-mach-3.158888/

 

[Titan II]

.

 

[Titan II]

how do get the mount point correct without building the motor?

http://www.pro38.com/pdfs/Pro75_dimensions.pdf

 

[Bobrogg]

I would suggest a different solution. I'll grab some pics later tonight, but I would suggest a bulkhead or two that get's bolted directly to the motor. This plate also serves as recovery cord attachment point. I like (2) points of contact on the tube for minimum diameter builds if I can afford the room.

Best,
https://www.rocketryforum.com/threads/wildman-mach-3.158888/

Justin,

I have your Mach 3 build bookmarked. I saw your build and was inspired to give a go myself. I'm using the CTI 6XL because I happen to have that on hand for my Composite Warehouse ARCAS rocket, I found a boattail for the motor and will be using that as well.

One issue using the CTI is that the motor is a 7-grain motor which means that it is taller than an Aerotech 7680 case and room for drogue recovery is very limited, what did you use for your recovery shock cord/chutes?

thanks

bob

 

[jqavins]

I would suggest a different solution. I'll grab some pics later tonight, but I would suggest a bulkhead or two that get's bolted directly to the motor. This plate also serves as recovery cord attachment point. I like (2) points of contact on the tube for minimum diameter builds if I can afford the room.

Best,
https://www.rocketryforum.com/threads/wildman-mach-3.158888/

Bolted directly how? Part of the Aeropack minimum diameter retaining system for CTI motors is a plug that goes in the front of the case, because CTI cases don't have a bolt hole without it. So it seems to me (I could be all wet) that that adapter piece is needed whether one uses the CTI block ahead of it or not.

And then one is still faced with the question of how to place the bulkhead of the block just the same.

 

[cwbullet]

Aeropack Minimum diameter retainers are great. The key is the adaptors. I made my own with threaded rods.

 

[mikec]

Bolted directly how? Part of the Aeropack minimum diameter retaining system for CTI motors is a plug that goes in the front of the case, because CTI cases don't have a bolt hole without it.

CTI 75mm and 98mm forward closures do have a tapped hole compatible with Aerotech.

 

[rfjustin]

Bolted directly how? Part of the Aeropack minimum diameter retaining system for CTI motors is a plug that goes in the front of the case, because CTI cases don't have a bolt hole without it. So it seems to me (I could be all wet) that that adapter piece is needed whether one uses the CTI block ahead of it or not.

And then one is still faced with the question of how to place the bulkhead of the block just the same.

Dont get me wrong, I think Aeropack makes great products. Its my opinion that a minimum diameter retainer such as their offering requires more of a precision fit and precision alignment. My suggested solution makes use of the CTI 3/8-16 threaded forward closure. Their hardware diagram tells me their forward closure is threaded, so I suggest this in concept:

 

[rfjustin]

Specs from 75mm CTI showing threaded closure:

 

[jqavins]

I stand corrected.