Casting Rack for 38mm and 54mm EX rocket motors

thingiverse

A device to hold propellant casting tubes of various diameters is required. You need one RACKtop and one RACKbottom, then make three spacers for casting 38mm grains using the 38/54 pattern. After that, you'll require three bottom pieces and three top centering pieces for a complete set. These can be obtained in sizes such as 38mm x 3/8” mandrel, 38mm x 1/2” mandrel or 38mm x 5/8” mandrel, or even 54mm x 5/8” mandrel. The bottom caps secure the mandrel, and I use hollow aluminum rod from Lowe's for this purpose. The top caps center the upper part of the mandrel. There is also a file designed specifically for a 38mm tamping head that can be attached to standard 1/2” PVC pipe via epoxy and functions perfectly with 38mm x 1/2” mandrel setups. I will add a head for all other sizes as needed. If you require caps for various size mandrels and tubes, simply let me know and I'll take care of it. I'm also working on a 54/75mm rack. Another note: there are two bottom caps available for 38mm x 1/2”. One accommodates solid (or hollow) rods, while the other is designed specifically for hollow rods, which I prefer to use. UPDATE 1/29/2019: A tamper has been added for casting tubes of 54mm and 5/8" mandrels that can be mounted onto standard 3/4" PVC. The 54mm x 5/8" caps have also been updated, and I can confirm that they work as intended. It's worth noting that initially, I used hollow 1/2" aluminum rods for my first 38mm run but encountered issues with propellant falling into them. Since then, I've switched to solid rods for all sizes, which are readily available at affordable prices (I obtained mine from Grainger) and can be cut to 12" pieces.