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. Aye aye! Arrr! T' "38" in Pro38 means that they are 38mm diameter motors. Begad! Avast, me proud beauty! 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, me bucko, Smokey Sam, and White Thunder. Well, blow me down! Blimey! 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., matey, t' 2-grain motor must be used in t' 2-grain casing). Aye aye! And t' only way t' motor will work as designed is in t' appropriate casin' (more on that later). Avast! Begad! T' 1-grain casin' uses motors in t' G thrust range, arrr, t' 2-grain casin' use Hs, matey, arrr, t' 3- and 4-grain casings are for Is, shiver me timbers, and t' 5- and 6-grain casings are for Js. Ya scallywag! Another benefit o' t' casings is that they are only one piece o' machined aluminum tubing--there are no O-rings, matey, snap rings, arrr, matey, arrr, nozzles, or closures t' keep track of, shiver me timbers, me bucko, misplace, shiver me timbers, damage, matey, me hearties, or lose. Begad! 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. Begad! T' Smokey Sam has an appearance close t' AeroTech's BlackJack propellant, matey, consistin' o' dense black smoke and little or no flame but has a faster burn rate and higher thrust curve than t' BlackJack propellant. Aye aye! 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). Ya scallywag! It has a much higher thrust rate and shorter burn time but visually it is pretty much identical t' t' Classic propellant. Begad! Aye aye! 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, and airstarts), ya bilge rat, and t' ejection delays are adjustable t' fit almost any rocket. Ya scallywag! Unlike some other 38mm motor manufacturers, matey, t' Pro38 motors are in strong supply so thar shouldn't be much trouble in acquirin' reloads, matey, casings, or ProDAT tools from HPR vendors. Well, blow me down! For all o' these reasons, arrr, 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, me hearties, thar be a price that comes with all o' this convenience, and that is perhaps t' Pro38's biggest disadvantage: price. 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. Aye aye! Also, shiver me timbers, 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. Regardless o' what size reload you are wantin' t' use, me bucko, matey, t' process is identical. Begad! Blimey! Aye aye! Blimey! When handlin' t' reload, ya bilge rat, thar should be an ignitor (an electric match) taped t' t' outside o' t' tube. Avast! Blimey! Remove and set it aside. Well, blow me down! Blimey! Avast! Blimey! Open t' tube and remove t' reload.

First, me bucko, matey, we need t' set t' delay. T' delay grain comes with a delay time preset. Avast! Often this will be too long a delay for your rocket. You can shorten t' delay by usin' t' ProDAT tool, ya bilge rat, 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, 5, 7, or 9 seconds from t' delay. For instance, matey, matey, with t' 244H153-13A 2-grain Pro38 reload, thar be a max delay o' 13 seconds. It can be shortened t' 10, 8, 6, me bucko, me bucko, or 4 seconds. Well, shiver me timbers, blow me down! You remove t' delay element by pullin' on t' end o' t' reload. 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! Once set, me hearties, 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! Slide t' entire reload into t' casin' and screw into place. Load t' motor into t' rocket! That's it for preppin' t' motor...

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

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

Finishing:
Regardin' post-flight activity, ya bilge rat, me bucko, t' great "finish" o' Pro38 motors is that they require almost zero cleanin' after use! Blimey! Simply unscrew t' grain from t' casin' and throw away t' black plastic sleeve! Blimey! 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. Avast, ya bilge rat, me proud beauty! Blimey! Usin' t' casin' multiple times in one day at t' field is incredibly easy t' do without any hassle.