Help with Aerotech rockets

I have an Aerotech Initiator and an Aerotech IQSY Tomahawk which I built several years ago and want to know if anyone has any ideas of how to successfully convert them to use Cesaroni reloadable hardware. I built both rockets per Aerotech's instructions and thus have both the engine block and retaining clip already installed. I have also acquired a Cesaroni Pro29 2 grain case after trading in my old Aerotech 29/40-120 case. I had too many misfires with Aerotech's reloads and decided to switch to Cesaroni after attending some club launches in which they always worked. I didn't have either Aerotech rocket with me when I got the new casing from a vendor and found out after returning home that the 2-grain case, despite being the same basic length as the AT case, wouldn't fit due to the different shape of the forward end of the case. Does anyone have any ideas on how to address this issue. I know removal of the engine block and retainer clip would be ideal, but feel that may be easier said than done as I assembled the rockets with epoxy, rather than relying on cyanoacrylate as per Aerotech's instructions.

One way to remove the engine block is to glue some sandpaper to a length of dowel and chuck it up in a drill. You can carefully sand away the engine block (or sand it enough to get the case to fit)

It may be a moot point now, since you no longer have your Aerotech hardware, but a lot of misfires I've seen come down to two things - copperheads and old propellant. The first can be fixed by using something like a first-fire, the latter by giving the inside of the propellant grain a slight sanding with some 120 sand paper - just enough to knock the oxide layer off.

The Cesaroni hardware and reload system is brilliant, I've just bought the 38mm set (3 grain / 6 grain / spacers & delay tool) and I'm sure that it can only make your rocketry experience all the greater!

Krusty

That motor clip is going to be a tough one since it's under the plastic finlock rings and sticks into the motor tube... The hook at the bottom is easy enough to remove with a cutoff wheel in a dremel, but the interior portion is going to be a PITA... And sandpaper ain't gonna work on that! It'll work fine on the cardboard thrust ring though... I'm interested to see how others would approach the clip...

Long half-round file and elbow grease.

krusty said:

One way to remove the engine block is to glue some sandpaper to a length of dowel and chuck it up in a drill. You can carefully sand away the engine block (or sand it enough to get the case to fit).

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mdoering said:

That motor clip is going to be a tough one since it's under the plastic finlock rings and sticks into the motor tube... The hook at the bottom is easy enough to remove with a cutoff wheel in a dremel, but the interior portion is going to be a PITA... And sandpaper ain't gonna work on that! It'll work fine on the cardboard thrust ring though... I'm interested to see how others would approach the clip...

Click to expand...

Tarasdad said:

Long half-round file and elbow grease.

Click to expand...

Thanks for the ideas. Once I finally have a day off, I'll start working with these ideas and have a follow-up post about how things go.

As far as switching to Cesaroni gear, I began using their Pro24 1-grain case for my larger Estes 24mm rockets, moving away from BP E-impulse motors (I've seen too many E9s and, especially, E12s cato on the pad and wanted to find a more reliable solution). My Cosmic Interceptor has incredible flights on CTI's E22 smoky sam and want to experience the same reliability with my 29mm rockets. In addition, the vendor which shows up for most of the club launches I attend has "fresher" reloads than my local hobby shop. The Aerotech F40 reload I bought last month at my lhs was dated 2005 and it was hesitant to light.

One option for the hook/thrust ring deep in the mmt would be to use a Dremel with the Flex Shaft accessory. You could tape the Flex Shaft handle to some sort of extension handle, install a grinder bit of your choosing, and go to town.

Of course, if you don't have either of those tools, it might be cheaper to buy replacement kits and re-build the rockets without the offending bits in the way.....

G.D.

Another option if you need to get closer to the MMT from the forward end is to get a coupler (A2Z Hobbies sells them) and you could cut the airframe a couple inches forward of the MMT and use the coupler to put it back together when you're done.

If you have 1/4 to 1/2" of the MM exposed take a set of pliers and twist it to unroll the paper MM. The hook and MM with come out like a paper towel roll, use a small drum sander on the CR's then replace the MM.

You can even take a second CR, glue it onto the new MM then slide it in gluing the new CR on top of the old.

I was able to get rid of the upper motor hook using mechanical persuasion (hammer and a long flat tip screw driver). By all means wear safety glasses while using this method. Now the one I was working with was in a QModeling kit to fit the 24/60 casing, but it's similar. I was able to bend it flat against the MMT. The motor is a little snug, but I can get it in there... YMMV