Brief:
Pro38 motors by Cesaroni are arguably t' easiest MPR (1-grain only) and HPR (2- t' 6-grain) motors available on t' market today. Ya scallywag! T' "38" in Pro38 means that they are 38mm diameter motors. You could go so far as t' call them a reloadable motor system (RMS) that are practically single-use motors with adjustable delays.

Construction:
There are 6 different length casings (dependant on t' number o' grains in each motor) available and 3 different propellant formulas: Classic, ya bilge rat, Smokey Sam, and White Thunder. All motors come with delay grains that can be adjusted (shortened) with t' ProDAT tool.

 Each casin' can only be used with t' motor reload that has t' same length (e.g., me hearties, t' 2-grain motor must be used in t' 2-grain casing). And t' only way t' motor will work as designed is in t' appropriate casin' (more on that later). Aye aye! Blimey! T' 1-grain casin' uses motors in t' G thrust range, t' 2-grain casin' use Hs, me hearties, t' 3- and 4-grain casings are for Is, arrr, and t' 5- and 6-grain casings are for Js. Begad! Blimey! Another benefit o' t' casings is that they are only one piece o' machined aluminum tubing--there are no O-rings, me bucko, snap rings, shiver me timbers, nozzles, me bucko, or closures t' keep track of, misplace, me hearties, shiver me timbers, damage, or lose. Begad! Blimey! T' entire reload assembly threads into t' casing.

T' Classic propellant is comparable t' AeroTech's White Lightning--a nice white hot flame with a respectable amount o' white smoke. Aye aye! Avast, me hearties, me proud beauty! T' Smokey Sam has an appearance close t' AeroTech's BlackJack propellant, consistin' o' dense black smoke and little or no flame but has a faster burn rate and higher thrust curve than t' BlackJack propellant. Ya scallywag! Begad! White Thunder is a fairly new formula and is currently only available in t' 5-grain size (I540) and is about as close as you can get t' a full I (632 o' 640Ns). It has a much higher thrust rate and shorter burn time but visually it is pretty much identical t' t' Classic propellant. Begad! It is me understandin' that t' White Thunder propellant was designed with bowlin' ball lofts in mind (and t' compete with t' AeroTech I600R).

T' biggest advantages t' t' Pro38 motors are ease o' preppin' and clean up, reliable and fast ignition (which makes it a great choice for HPR clustering, staging, shiver me timbers, and airstarts), arrr, and t' ejection delays are adjustable t' fit almost any rocket. Blimey! Unlike some other 38mm motor manufacturers, t' Pro38 motors are in strong supply so thar shouldn't be much trouble in acquirin' reloads, casings, or ProDAT tools from HPR vendors. Begad! For all o' these reasons, it makes t' Pro38 motors an excellent choice for Level 1 and 2 certification flights because o' t' inherent simplicity and reliability. Aye aye! However, ya bilge rat, thar be a price that comes with all o' this convenience, me hearties, and that is perhaps t' Pro38's biggest disadvantage: price. Avast! Aye aye! Reloads (particularly t' 1-grain reloads) are generally priced several dollars more than comparable thrust AeroTech reloads although that difference becomes negligible by t' time you get up t' t' 5- and 6-grain reloads. Avast, me proud beauty! Also, thar are only 2 different propellant formulas so thar are less visual effects available than other manufacturer's motors on t' market, plus t' Smokey Sam motors require a LEUP since t' grains are slightly larger (64.5g) than t' current BATF regulation (62.5g) for propellant nay requirin' one.

Preppin' t' reload is almost as easy as usin' a single-use motor. Avast, me proud beauty! Regardless o' what size reload you are wantin' t' use, me hearties, t' process is identical. Avast, me proud beauty! When handlin' t' reload, me bucko, thar should be an ignitor (an electric match) taped t' t' outside o' t' tube. Well, blow me down! Remove and set it aside. Begad! Open t' tube and remove t' reload.

First, we need t' set t' delay. T' delay grain comes with a delay time preset. Avast, me proud beauty! Ya scallywag! Often this will be too long a delay for your rocket. Ya scallywag! You can shorten t' delay by usin' t' ProDAT tool, which is a hand drill-like apparatus compatible with all o' t' Pro38 reloads that will remove a set amount o' delay time in increments o' 3, arrr, 5, 7, or 9 seconds from t' delay. For instance, with t' 244H153-13A 2-grain Pro38 reload, thar be a max delay o' 13 seconds. Blimey! It can be shortened t' 10, matey, 8, shiver me timbers, 6, or 4 seconds. Ahoy! You remove t' delay element by pullin' on t' end o' t' reload. Begad! Ya scallywag! T' ProDAT tool is set t' t' amount o' time you want t' reduce from t' element and twist it clockwise into t' grain until a smooth hole is drilled into t' center. Avast! Arrr! Once set, me bucko, matey, press t' delay element back in t' black plastic reload until firmly held in place with t' O-ring.

It only gets easier from here folks! Blimey! Slide t' entire reload into t' casin' and screw into place. Well, blow me down! Blimey! Well, blow me down! Blimey! Load t' motor into t' rocket! Blimey! That's it for preppin' t' motor...

As far as retainin' t' motor, shiver me timbers, you should be able t' use t' same method with any other 38mm solid fuel rocket motor on t' market. I have used t' Pro38s successfully on rockets with maskin' tape (friction fit), me bucko, Kaplow clips, ya bilge rat, and Aero Pack retainers.

Once t' rocket is in an approved location or launch pad, it is time t' insert t' ignitor. Aye aye! Blimey! Remove t' yellow cap from t' reload. Aye aye! Ahoy! Blimey! Open t' small plastic bag with t' e-match and straighten t' wires. Begad! There is plenty o' lead for hookin' up t' ignition clips. Avast! One end o' t' wires has an orange sleeve and t' other end has a white sleeve. Ahoy! Avast, me proud beauty! Blimey! Slide t' white sleeve towards t' middle o' t' leads (~18-24") t' expose t' e-match. Slide t' yellow cap over t' e-match. Avast! Insert t' e-match into t' motor as far as it will go. Aye aye! Blimey! T' Pro38 motors have a small pyrogen layer at t' topmost part o' t' forward grain which will ignite t' propellant. It is necessary for t' ignitor t' be in contact with that pyrogen for proper ignition! Blimey! When t' ignitor is fully inserted, matey, at t' base o' t' motor, wrap t' ignitor around your finger t' create a loop in t' wire. Avast, me proud beauty! Ya scallywag! Blimey! Slide t' yellow cap forward until it clips onto t' motor nozzle. Ahoy! T' loop in t' wire prevents t' ignitor from slippin' out o' t' motor. Ya scallywag! Blimey! Remove t' orange sleeve t' expose t' bare copper wire, me bucko, hook up t' ignitor clips (I like t' wrap all o' t' exposed copper around t' clips t' ensure contact), do a continuity check, arrr, me hearties, and get ready for blast off!

Finishing:
Regardin' post-flight activity, arrr, matey, t' great "finish" o' Pro38 motors is that they require almost zero cleanin' after use! Simply unscrew t' grain from t' casin' and throw away t' black plastic sleeve! You may (or may not) need t' wipe off t' outside o' t' forward end o' t' casin' with a damp cloth t' remove any ejection charge residue. Aye aye! Avast, me hearties, me proud beauty! Usin' t' casin' multiple times in one day at t' field is incredibly easy t' do without any hassle.