CTI 54 mm Help

I'm reading the 'Pro54 High-Power Reloadable Rocket Motor System' instructions. I hope to fly my first 54mm motor in a couple weeks. I have flown CTI In both 29 and 38mm. In the 'Motor Assembly' section it reads:

'The o-rings are pre-lubricated at the factory, but we recommend that you apply a light film of silicone o-ring lubricant to the inside edge of the motor casing where the reload kit will be inserted. This will make installation and removal of the reload kit much easier!'

I would love to hear about this from those who have flown the CTI Pro54 reloads. First, do you follow this recommendation, or have you flown these reloads without additional lubrication? If you do follow this recommendation, what specific lubricant do you use? How much of the inside edge of the case do you lubricate...... just inside the aft edge of the case, a couple inches, the entire length of the case? Is there any danger of failure or CATO with too much lubricant?

Thanks.

Me personally, I spray Liquid Wrench silicon in my 54's after I clean them and wipe excess by pushing paper towel thru the motor case. That's all I do. When ready to fly, I just shove a motor in. Nothing else. I'm sure opinions will vary.

I just launched two I445 Vmax reloads on the weekend, which were also my first 54mm CTI reloads. I also read that part about applying silicone to the o-rings and I can tell you it was a good idea that I did. The reload slid out fairly easy but had some resistance. I am pretty sure that without the lube it would of been much more difficult, and the I445 is just a 1 grain reload. Likely the more grains the more effort it is going to take to remove, but that is just a guess. I don't see a down side so long as you use the right lubricant.

mpitfield, what lubricant did you use?

I use plain old white lithium grease.

On most 54s I just use a little super lube on the threads before sliding reload in. Got to love those CTI54 single grain motors.

I typically don't use any lube on the CTI pro54s. But if I did I would use a tiny amount of superlube on the threads and about a half inch of the inside of the rear of the case.

Why would you put any grease on the threads of a CTI 54 load?? The threads are just for a cap. There is zero seal function of the cap.

I have used a tiny bit of Aquaphor (similar to Vaseline) on the threads of my 29 and 38 cases just to keep the threads from seizing and turning smoothly.

Yes your right Griffin I was thinking of the 38mm. Just a little grease on inside of aft end. Sounds better now.

I shoot the inside of the case with a light film of Silicone spray. I use the silicone because penetrating oils --PB Blaster, WD-40, etc.-- can cause O-rings to swell. Once, I put a smidge of dielectric grease on the nozzle end, but I saw no benefit to doing this...


Later!

--Coop

kjkcolorado said:

mpitfield, what lubricant did you use?

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I had one of the tubes left over from an AeroTech reload. Here is a pic.

View attachment 264144

However I also have a can of spray silicon lube in my filed box, that can be used for this as well as rails, etc.

View attachment 264145

OK. Thanks for the 54 mm feedback. Let me open up the question a little bit. I have no idea what the instructions for the larger diameter CTI motors say, but does anyone use their same lubrication technique on the smaller CTIs (29 and 38mm), even though the instructions do not mention lubricating the case? If so, why?

The first Pro54 I flew was a 6GXL L935. I had to put lube in the far end of the case to get the load to slide all the way in. I used a paper towel on a dowel with some vaseline. Without it, I couldn't get the last 5" - 6" if the load into the case, with it, it slide right home.

Wish I had my can of silicone spray on hand. That sounds like it would have been easier and faster.

BTW, I don't think lubing the case as anything to do with sealing the pressure in the case. I think it is all about lubing the assembly so the rubber o-rings slide easily over the metal case walls.

Yes, I agree. The CTI Pro54 instructions do say that the lubrication they recommend is specifically to help the o-rings slide. Wondering if lubrication helps with anything else other than ease of sliding the motor into the case. Any thoughts if it helps keep the case cleaner, or makes it easier to clean afterwards? If so, that might be a reason I would use it in my 29 and 38mm CTI reloads.

kjkcolorado said:

Wondering if lubrication helps with anything else other than ease of sliding the motor into the case. Any thoughts if it helps keep the case cleaner, or makes it easier to clean afterwards? If so, that might be a reason I would use it in my 29 and 38mm CTI reloads.

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Easier to get the spent reload back out. You don't need grease with the 24-38mm motors as the o-rings are internal to the liner. Unless the liner melts through, the case remains clean. 75 and 98 mm motors assemble very much like Aerotech.

timbucktoo said:

Me personally, I spray Liquid Wrench silicon in my 54's after I clean them and wipe excess by pushing paper towel thru the motor case. That's all I do. When ready to fly, I just shove a motor in. Nothing else. I'm sure opinions will vary.

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+1 - Exactly what I do, and have never had a problem installing in the cases (I've flown 2, 4 and 6grain) or removing after flight.