Estes Big E and F Engines Getting Hard to Find.

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Just went to the local Hobby Lobby (Roseville, CA). They had everything in stock. 2 F15-6's still on shelf, 2 E16-6's Couple of packs of the E9-6 CATO specials.
 
disclaimer: I am not an estes employee, have never been to the estes plant, but I have studied bp motor manufacturing (at least the big pictures) and have been told by people who know, that my previous speculations have been fairly accurate.

Estes makes a boat-load of motors. They generally have their facilities running three shifts. probably seven days. They have seven machines, all based on the original Mabel that Vern Estes designed, running as long as possible. These machines are large round index tables, taking an empty casing at one station, rotating it step by step to each manufacturing process, which usually involves a powder dispenser followed by a pneumatic or hydraulic press. The dispenser dispenses either clay powder, fine black powder of propellant strength, fine black powder of delay strength, or coarser black powder for the ejection charge. After the powder is dispensed, the press applies pressure which solidifies the powder into a hard mass, bonding it with the casing and whatever was already there. After the last step, the finished motor is kicked out into a bin, where the motors are sent to a label printer. Because the powders are dispensed slightly damp, the motors then spend time in a warehouse to dry out a bit before packaging and testing.

Like I said, there are only seven total machines (you can see this in a Google Earth image of the plant). There have only been seven machines for probably forty years. AFAIK, at one time each machine was dedicated to a physical size. Two machines made 13mm motors, four made 18mm motors, and one made 24mm motors. All motors at the time were 70mm long.

If you want to make a particular type of motor, you have to set the machine to use a particular pintle (the form that determines the size and shape of the nozzle), you have to set the machine to deposit the correct amount of propellant the correct number of times (a C motor may take four separate deposits and presses of propellant), you have to set the machine to deposit the correct amount of delay material (2, 4, or 6 seconds worth for B; 3, 5, or 7 seconds for C, etc). Once you have the machine set, you make as many motors of that type as you think you can sell in a particular period in the future. So, for a popular motor like C6-5, that machine may be totally dedicated to making C6-5 for weeks. To switch to B6-4 may take some time to reset and recalibrate. So if you have a run on your current supply of B6-4, you may be out for awhile.

This gets exacerbated on the 24mm side. now that you have not just different amounts of powder, but different lengths of casing. And I have to think that they modified that particular machine to accomodate the 29mm motors as well. If I'm right, that one machine makes all 24 and 29 mm motors at Estes.
If it goes down for any reason, you have big delays in supply. And the regular resets may take much longer as well.

It's possible, but unlikely, that one of the other machines can be temporarily converted to a larger size, but they *have* to keep the retail channel supplied with the big three 18mm sizes (A8-3, B6-4, C6-5). They sell probably 1000-2000 or more C motors for every F15 they sell.

So, the shortage of F15 and E16 may just be that they've got to keep us supplied with C11, D12, E9, and E12.

For whoever speculated that they manually make the 29 mm motors --- Flight Systems could get away with that, but not Estes. 'Course, I could be wrong.
 
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