Aerotech RMS reload - Grease requirements

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bhargav.shukla

bhargav.shukla

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Hello Everyone,

New member here so not sure to post here or in HPR forum.

I've launched my first L1 rocket last month, though the recovery failed so I didn't get my L1. I flew it on Cesaroni H123. After the L1 launch, I bought AT H238T-14A RMS reload with RMS29/180 casing from vendor onsite. I'd have purchased Cesaroni if available but it wasn't an option due to stock availability.

Anyhow, I'm getting ready for upcoming launch on March 2. Reading assembly instructions, it recommends using super lube. My question is, does any grease work or does it have to be a specific type? Would something like Lucas Oil's Lithium grease work? Curious because I have some left from my other household project. I wanted to ask before I rush to buy the recommended brand/type.

Thank you for all the help and looking forward to more interactions on the forum as I build and launch more.
 
One more question... I will need to adjust delay. For Cesaroni, I drilled the delay on site. Looking at assembly instructions, it seems it may not be easy to drill the delay at launch site if I assemble the reload in advance. I also don't like that the instructions suggest inserting the igniter during assembly! I would never insert an igniter until the rocket is on the launch pad.
 
I drill delays and assemble all reloads at home before a launch. Inserting the igniter before being on the pad is a no-no. I never noticed before, just looked, that the Aerotech instructions do say to put the igniter in the motor before inserting the reload into the rocket. It's stated that way for all HPR motors 29mm-98mm.
 
Last edited:
Awkward Fran Healy GIF by Travis
 
Correct, never install igniter until rocket is on the pad.

The AT RMS instructions show the old 'copper head' igniters which were hard to get through a nozzle. The newer igniters should fit but best to check before installing the nozzle.

The delay needs to be adjusted before assembling the motor.

Is it the MDRA launch this weekend you are going to? I may be down there Saturday (2Mar).
 
waltr said:
Correct, never install igniter until rocket is on the pad.

The AT RMS instructions show the old 'copper head' igniters which were hard to get through a nozzle. The newer igniters should fit but best to check before installing the nozzle.

The delay needs to be adjusted before assembling the motor.

Is it the MDRA launch this weekend you are going to? I may be down there Saturday (2Mar).
Click to expand...
Actually some of the smaller motors REQUIRE installation of the igniter during assembly as the head of the igniter is too small to fit through the nozzle. Its best to communicate with the clubs safety organization when the instructions include this step so they are aware of whats going on and any special precautions they may want you to take.
 
you didn't ask but....

Don't use much grease. Just 'shine the o'rings' and little on the outside of the liner. what you want is the shine, if you see grease you probably have too much. Grease on the delay can cause problems.

Another thing you didn't ask about was which way does the delay grain go after drilling it, the answer is the drilled side points aft (goes to the grainside), the NON-drilled side goes fwd in the end fitting.

As long as im putting out un-solicited advice, dont put catsup on hotdogs, it just isnt right, mustard yes, catsup no.

Mike K
 
rcktnut said:
I drill delays and assemble all reloads at home before a launch. Inserting the igniter before being on the pad is a no-no. I never noticed before, just looked, that the Aerotech instructions do say to put the igniter in the motor before inserting the reload into the rocket. It's stated that way for all HPR motors 29mm-98mm.
Click to expand...
Wow I had never realized that; just looked up the instructions for one of their cases (RMS-29 60-180) and it does indeed say that. As others have pointed out, don't do that.

The reason I'm chiming in: they've got at least one one-grain midpower motor in a two-grain case that simply has to have the igniter inserted during assembly -- but that's not high power, and the *model* rocket safety code allows putting the igniter in early.
 
Only lightly grease the o-rings. Don't get grease on the delay washer. Don't want grease to contaminate the delay or ejection charge. And as someone that has been using RMS since they came out in the 90's, I have learned... best not to grease the liner... You just make a bigger mess to clean up and you usually just end up gluing the liner to the case. Clean the motor is much MUCH easier when its warm, so do it asap! I personally use gun cleaner. I found out the hard way dont grab something that has bleach in it. Vinager is good at removing harden crud but will wear leach the finish.
 
n3tjm said:
Only lightly grease the o-rings. Don't get grease on the delay washer. Don't want grease to contaminate the delay or ejection charge. And as someone that has been using RMS since they came out in the 90's, I have learned... best not to grease the liner... You just make a bigger mess to clean up and you usually just end up gluing the liner to the case. Clean the motor is much MUCH easier when its warm, so do it asap! I personally use gun cleaner. I found out the hard way dont grab something that has bleach in it. Vinager is good at removing harden crud but will wear leach the finish.
Click to expand...
I use CLP brake free https://www.amazon.com/Break-Free-Cleaner-Lubricant-Preservative-Squeeze/dp/B0050GW7KU for cleaning and as a dry-ish lube. Works very well and dosent discolor the cases. It will leave a thin film - and that is agood thing. They have a spray can version too,

As far as greasing the liner, here is my advice, if you start with a dirty case getting he liner out will be harder.
  • lube it if it is dirty and you are going to use it anyway
If you pull the liner out right after flight (the best way!), you dont need any lube on the liner.
  • If you remove the liner soon after launching no lube is best, slides out and nothing to wipe off
If you dont pull the liner out for a few days (or weeks... months... it happens) a lubed liner is easier to get out.
  • if you dont getaround to it, lube is better
Couple of other other things, have a good liner pusher. If everything is good the aft closure or nozzle works, but some times the push in, plan B is to have a wood or plastic disk that is pretty close to the liner diameter to push against with a broom handle or pvc pipe.
  • Have a liner pusher
Greased threads are another issue.....

Mike (really afraid of what the auto-suggestions are going to be on my computer after typing about pulling a lubed liner) K
 
rharshberger said:
Actually some of the smaller motors REQUIRE installation of the igniter during assembly as the head of the igniter is too small to fit through the nozzle. Its best to communicate with the clubs safety organization when the instructions include this step so they are aware of whats going on and any special precautions they may want you to take.
Click to expand...
partially correct.

The motors that require installation of the igniter during assembly are MID power, not subject to HP rules. Every club (should) know this. the standard of practice is to keep the legs of the igniters shorted together until you reach the pad. This is common in the AT 40-120 case.

The only odd exception is AT HP C-slot motors that have the "medusa" style nozzle, then you're condemned to unscrew the aft closure and pull the nozzle out to install the igniter at the pad..... but this is only a few motors, and i think they have pretty much migrated away from medusa nozzles.

yes lucas will work, been there, done that. just don't go crazy with any of them. A little bit goes a long way, and a lot is just super glue when heated.
 
cbrarick said:
partially correct.

The motors that require installation of the igniter during assembly are MID power, not subject to HP rules. Every club (should) know this. the standard of practice is to keep the legs of the igniters shorted together until you reach the pad. This is common in the AT 40-120 case.

The only odd exception is AT HP C-slot motors that have the "medusa" style nozzle, then you're condemned to unscrew the aft closure and pull the nozzle out to install the igniter at the pad..... but this is only a few motors, and i think they have pretty much migrated away from medusa nozzles.

yes lucas will work, been there, done that. just don't go crazy with any of them. A little bit goes a long way, and a lot is just super glue when heated.
Click to expand...
That and the new aerospike nozzle on the J615ST... Makes me want to bond the grains on that one so at least the grains don't come spilling out of the liner when trying to disassemble and reassembly vertically at the pad just trying to get the igniter in.
 
TheTank said:
That and the new aerospike nozzle on the J615ST... Makes me want to bond the grains on that one so at least the grains don't come spilling out of the liner when trying to disassemble and reassembly vertically at the pad just trying to get the igniter in.
Click to expand...
The HPR safety code does not require the rocket be vertical when the igniter is inserted, just pointed in a safe direction (it does have to be vertical before the leads are connected).
 
JoePfeiffer said:
The HPR safety code does not require the rocket be vertical when the igniter is inserted, just pointed in a safe direction (it does have to be vertical before the leads are connected).
Click to expand...
Correct, but often times there are folks down range completing recoveries in the direction the rocket is pointed once a rail is laid down. Sometimes you see them, sometimes you dont. Not worth the risk in my opinion especially since if an event were to happen, the rocket is likely to bounce off the ground once it leaves the rail and then all bets are off.
 
Even though this is not about grease, at this point in the thread this needs to be stated. 2 years ago I had a J800T go off in my face, launch controller failed. I was under the rocket when it ignited. It was vertical on the rail and electronics were armed. As soon as I touched the second lead with the clip, it ignited. I was able to get out of the way, due to my cat like reflexes. No matter what any rules may or may not or allow, always have rocket vertical on rail and electronics ARMED before attaching leads. It ended up being a normal flight, with no one hurt, other than me laying on the ground.
 
David Schwantz said:
Even though this is not about grease, at this point in the thread this needs to be stated. 2 years ago I had a J800T go off in my face, launch controller failed. I was under the rocket when it ignited. It was vertical on the rail and electronics were armed. As soon as I touched the second lead with the clip, it ignited. I was able to get out of the way, due to my cat like reflexes. No matter what any rules may or may not or allow, always have rocket vertical on rail and electronics ARMED before attaching leads. It ended up being a normal flight, with no one hurt, other than me laying on the ground.
Click to expand...
That must have been an interesting perspective to see a launch from.
Rather loud too!
 

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