Using Reloads in Estes type rockets..

I use reloadable hardware in Estes rockets all the time, without any modification. You can use the D13W reload in the 18/20 hardware in place of a B or C motor (it is the same size). You can use the D9 or E18 or any number of other reloads in the 24/40 hardware in place of an Estes D motor. I've launched my Big Daddy a number of times on an E11J and F12J with the

24/40 casing, with the motor clip in place. The only time I know of that you need to modify or remove the motor clip is if you are going to use an Estes 24mm E motor in a rocket designed for a 24mm D, because the E is longer. You also have to leave out the motor clip in Aerotech rockets if you want to use hardware longer than the 29/40-120.

Of course you need to ensure that your rocket will be stable and safe and hold together and all that good stuff, with the extra power.

Thanks for the info David. I thought the casings were a little different. And I know I need to build a little stronger, I have a bunch of rockets (some new, some 15 years old that weren't built) that I want to build a little stronger and put a little more lift in the rear!

The problem is usually the ejection end of the motor clip that sticks too far into the body tube, catching on the red ejection cap. While it's easier to file them down when building, I've done it afterwards, even on the field with a rat-tail file. The files sold to sharpen chain saw blades are particularly good for this purpose. A peeled out used motor casing, or even one of the yellow motor mount installation tubes can be used to protect the lip of the body tube while filing.

The only other real concerns are stability and strength. The RMS casing is usually heavier than the motor it replaces, so some rockets may need nose weight, especially those that are marginally stable to begin with. Easilly solved by soe nose weight: balance the rocket with the largest recommended motor, note the CG, then get it back to that point with the reload installed.

And replacing a C6 with a D24 or a D12 with an F39 may have a tendency to rekit some rockets not built for the higher thrust. But most stuff needs little or no changes.

Bob Kaplow NAR # 18L TRA # "Impeach the TRA BoD" >>> To reply, remove the TRABoD!

I think that the weight is more related to the impulse than anything else. An Estes D12-5 is 43 grams, an Aerotech RMS D15-4 is 44 grams; an Estes C6-5 is 26 grams, and Aerotech RMS D24-7 is 31 grams. These differences are real, but are probably not huge in relation to other factors (especially in the 18mm range). However, for the 24mm RMS engines, the larger impulse can get substantially heavier -- the F24-7 is 62 grams (50% higher than the D).

David Erbas-White

I know I have read to cut off the tip of the engine clip so the hardware will fit. Can anyone give me specifics like how much to cut, whether to leave just a little or what.

I've just started using the RMS stuff. I had a problem trying to fit a

24mm RMS casing in a 'D' mount that had an engine hook (I'm sure it was just the ejection cap casing, but didn't want to force things), so I'll have to file down the engine hook a bit to allow it to fit.

These days, I tend to build my 'D' capable kits for an Estes 'E'. Three reasons: 1) most 'D' kits will fly on an 'E' (except for the Saturn V and one or two others), 2) for those that won't fly on an Estes 'E', I can use the 1" spacer and pop in the Aerotech RMS, and the spacer covers the RMS ejection cap nicely, and 3) I'm harboring the hope that one of these days (since the Estes 'E' introduces a new form factor) that one of the composite dealers will come out with a longer 24mm RMS package (for a baby 'G'?).

David Erbas-White