CEDAR CITY, Utah USA — RCS is making four different "EMK" motor kits available to the experimental rocket community.

Over the past few years, a number of customers have been requesting that RCS produce experimental motor designs in kit form. After considering several options, it was decided to release an initial line of products based on a variety of popular single-use motor configurations.

These include 60 newton-second (part no. EMK2960SC) and 80 newton-second (part no. EMK2980SC) 'F'-class motors and two different 'G' designs (part nos. EMK29120C and EMK29120S).

RCS is making four different "EMK" motor kits available to the experimental rocket community.

The 'G' kits are different only in the thickness of the paper liner that is packaged with each kit. The 'C' version uses a thin liner for core-burning designs while the 'S' kit includes a thicker liner which is best suited for longer-burning slotted grains. The two 'F' class kits use the thicker liner that may be used with either cored or slotted grains.

The new RCS EMKs use a one-piece phenolic case that includes an integral molded nozzle. The case has been tested to over 1,000 PSI but is recommended for motors running in the 500-600 PSI range. The nozzle throat and exit cone may be easily drilled to accommodate a wide array of grain designs and propellant formulations. The bulkhead end of the case is threaded to accept an included matching molded forward closure which can be bonded to the case with 5-minute epoxy.

The kits contain universal delay charge components such as an o-ring, delay insulator and an ejection charge cap. Users can separately purchase RCS propellant and delay casting tubes that are specified in the EMK "assembly guides" which are packaged with each motor kit. Alternatively, the guides suggest that the customer purchase AeroTech "RDK" pre-manufactured delay elements for use with the kits. The assembly guides have a detailed assembly drawing on the reverse side which portrays a typical motor configuration. A bondable aft thrust ring is also provided for the user's convenience.

EMK prices range from $8.00 each for the 60 N-sec kit to $10.00 each for the 'G' motor kits. Customers should note that RCS EMKs contain no hazardous materials since the propellant, igniter, delay, delay spacer and ejection charge are not included.

Please visit the "Products" page on the RCS website at http://www.rocketmotorparts.com/ to download the current RCS order form which details prices, shipping costs and other information. In addition, all four EMK assembly guides may be downloaded in PDF format from the RCS "Resources" page.

RCS Rocket Motor Components, Inc., Cedar City, UT.

12-07-2006 11:10 PM  #1
Just Jerry Freeform rockets advocate   Joined: Aug 2006 Posts: 1108	This is a positive product release. Good job Gary. This certainly does one thing. It encourages home-brew propellants. Ramifications? Certainly outside of the NAR or TRA or NFPA model rocket or HPR safety codes. Just Jerry

12-07-2006 11:37 PM  #2
Steve_Shannon When in doubt, ask Keenan   Joined: Aug 2006 Posts: 1978	Quote: This is a positive product release. Good job Gary. This certainly does one thing. It encourages home-brew propellants. Ramifications? Certainly outside of the NAR or TRA or NFPA model rocket or HPR safety codes. Just Jerry Well, it falls well within the Tripoli Research Safety Code and at the same time makes it possible to do Research Activities without worrying about ruining an expensive metal case. Perfect for the person starting out. I agree, Jerry, that this is a positive product release. Steve Shannon

12-08-2006 08:03 PM  #3
PeterEkstrom New Member   Joined: Oct 2006 Posts: 8	I'm assuming that this is intended to be a single use product. My question is how many times will someone try to reuse it? Peter

12-08-2006 10:47 PM  #4
Just Jerry Freeform rockets advocate   Joined: Aug 2006 Posts: 1108	Quote: I'm assuming that this is intended to be a single use product. My question is how many times will someone try to reuse it? Peter If you can overcomme the closure rebonding issue and replace the liner each time, the throat should be good for 3-4 firings with low aluminum propellants. USR reloadables can be refired up to 12 times but the plastic used is tougher than AT's single use intended nozzle parts. I do believe Gary has not disclosed the particular material these cases or nozzles use, but perhaps he has lifespan comparisons to, say, a typical RMS 29mm nozzle blank. The AT-LUR product has a replaceable bulkhead. Where did that go? Just Jerry

07-10-2007 01:03 PM  #5
R2K Certified Level Three   Joined: Jul 2007 Posts: 209	I think failure rates simply increase with each (even careful) reuse. Simple hot-cold soak cycles will reduce the reliability of the case and parts. That, before I even think of nozzle erosion. They are pretty cheap, but not so cheap as to replace PVC and other options. Also not so cheap that I would want to try them on any unproven designs. It is interesting to note the size of the product - they probably dont want to be involved in motors that are large enough to be dangerous, or more dangerous than this.