Home 1px View Cart
Can Be Used On Rockets That Are Already Assembled!

Madcow Rocketry's Engine Retainers

The Madcow Rocketry engine retainers offer you a low cost alternative to secure your prized reloadable casings in your rockets. That way, when the ejection charge goes off, the engines stay in place.

The concept is simple; use a metal plate behind the edge of the casing that is held in place by two machine screws. It is a tried-and-true old-school method of engine retention, but it still works. To remove the motor, you unscrew the two screws and remove the base plate.

If you're on a budget, this retention method is something you might consider for your next high-power rocket project.

 Madcow engine retainer

Retainer Order Chart
Engine
Size		 P/N Tube Size Mass Min. Rocket Diameter Madcow
Part No.		 Price Place Order
24mm 24081 Holds 24mm motors. Can also be used for 24mm motors that are in a 24/29 motor mount adapter. 12.5 g 2.0 in.
(5.08 cm)		 P-190 $8.95
29mm 24082 Secures 29mm motors 11.1 g 2.0 in.
(5.08 cm)		 P-189 $8.95
29/38mm 24083 Secures 29mm motors that are in a 29/28mm engine mount adapter 19.3 g 2.9 in.
(7.36 cm)		 P-179 $9.95
38mm 24084 Secures 38mm motors 16.6 g 2.9 in.
(7.36 cm)		 P-188 $9.95

Minimum Rocket Diameter is smallest "INSIDE" diameter of the rocket that the retainer can be used with. The retainer requires space between the motor mount tube and the inside wall of the tube to allow for the threaded inserts to be inserted into the rear centering ring.

The "mass" includes the threaded inserts.

Retainers for Flat-Bottom Rockets

What do you do when you've just completed the construction of your rocket, and notice that the engine mount tube does protrude far enough out the back end to install an Aero Pack engine retainer?

Or, what if you want the cool look of a flat-bottom rocket that can stand up on your trophy shelf? In that case what do you do in order to hold the motor in the engine mount? Are you really going to rely on friction fitting?

These are good questions. The answer is to use a Madcow Rocketry engine retainer.

Engine Retainer
The Madcow Rocketry Engine Retainer system works perfect in any of these situations. If your rocket is already built, you can easily add this all-metal engine retention system. And if you remove the base plate and toss it in your range box, the rocket itself can stand up on its own flat bottom. How cool is that?
How do you install it? Installation is very simple. Take the base plate and lay it on the bottom of the rocket. Mark where holes need to be drilled in the aft centering ring. Then drill the holes and screw in the self-tapping threaded inserts (a simple allen wrench tool is all that is needed). If you want, you can put a drop of thin CyA glue around the edges of the threaded inserts to permanently in place (this is optional in plywood centering rings).

That's it! You'll be done in less than five minutes.

When you're ready to launch the rocket, slide in the motor, position the base plate over the top of it (the nozzle protrudes through the hole), and screw in the two thumb screws into the treaded inserts you put in previously.

 Motor Retainer

Features Include:

  • Light-weight! The base plates are actually laser-cut from thin (0.029 inch thick) steel. Because it is so thin, the weight is kept low.

  • Can be used with any type of reloadable and single use motors

  • Can Be Added to Existing Rockets with Extended Motor Mount Tubes

If you're in a jam and you don't have a motor retention system already on your built rocket, then the Madcow Rocketry Engine Retainer system is just what you may need.

Frequently Asked Questions about the Madcow Engine Retainers:

Q. Do they work with single use motors too?

A. Yes they do!

Video: Other Methods To Restrain Rocket Motors
Laminate your fins How To Restrain Rocket Engines

In this free YouTube video, we'll answer the most common questions that people ask us about restraining the motor in the rocket.

Related Items and Optional Accessories That Go Great With These:
Aero Pack Tailcone Engine Retainers

Want to hold in your rocket engines securely and reduce drag at the same time? Then the Aero Pack Tailcone retention system is you're looking for. They currently come in sizes for 38mm and 54mm engines fitting body tubes with approximately 3" and 3.9" I.D.

 Tailcone Engine Retainers
Aero Pack Engine Retainers

Want to hold in your rocket engines securely without using tape or other unsightly methods? Then they Aero Pack retention system may be what you're looking for. There is a retainer available for all the common high power tube sizes that we carry (LOC, Blue Tube, and Fiberglass), as well as for the mid and high-power rocket kits on this web site.

 Engine Retainers
Spring steel engine retainer clips

Used on small rockets, these engine hooks to allow you to swap out engines between flights in just milliseconds. It is really that fast!

 Modern High Power Rocketry

Motor Mount Adapters

These adapters allow you to put a smaller diameter motor into a rocket that has a motor mount tube up to two sizes larger. This is a great way to save money by putting a smaller motor in a big rocket.

 Motor Adapter

Motor Mount Adapters

These adapters allow you to put a smaller diameter motor into a rocket that has a motor mount tube up to two sizes larger. This is a great way to save money by putting a smaller motor in a big rocket.

 Motor Adapter
Rail Buttons

Rail Buttons are used in place of launch lugs on larger rockets. The reason is that big rockets need a stiffer launcher so they don't sway around in breezy conditions. A launch rail is much stiffer than a circular rod, and therefore are used on big rockets so they launch safely and higher into the sky.

 Rail Buttons
Modern High Power Rocketry 2

The most extensive book ever written about "how to build LARGE high power rockets." Recommended for all modelers getting ready to take a jump to those bigger and more powerful rocket engines. It takes you step-by-step in the process of how to prepare for Level 1, Level 2, or Level 3 high power certification.

 Modern High Power Rocketry

Actual Customer Comment:
"Thank you very much for your time and patience to help resolve MY problem. Keep up the excellent work on your Very Well designed website. It is my pleasure to do business with you fine folks." -- Dale E. Miller

This page last updated on: 7/22/11 1px Site Map 1px Contact Us 1px Website Issues?