WRL Rocketry

Motor Retainers and HAMR Adapters

The HAMR (Highly Adaptive Motor Retainers) system has been designed specifically for use with our rocket kits or any scratch-built rocket using PML motor tubes. These lightweight, tool-free, threaded retainers are precision CNC turned from 6061 aluminum and anodized. The photo on the right shows the basic retainers for 29mm, 38mm, and 54mm motors. These retainers fit virtually all popular motor brands and types including Aerotech RMS (TM), CTI Pro XX (TM), Animal Motor Works (TM), Hypertech (TM), Kosdon (TM), Sky Ripper (TM), Loki (TM), and others.

The HAMR system can be adapted to existing rockets if the motor tube extends at least 3/8” beyond the aft centering ring. The HAMR can also be used with boattail and tailcone rockets.

HAMR-29-SET (in stock)

Designed for rockets with a standalone 29mm MMT (see the HAMR-KS for KwikSwitch 29mm). Includes threaded sleeve and retainer cap for 29mm MMT. 0.65 ounces total.

HAMR-38-SET ( in stock)

Designed for rockets with a standalone 38mm MMT (see the HAMR-KS for KwikSwitch 38mm). Includes threaded sleeve and retainer cap for 38mm MMT. 0.80 ounces total.

HAMR-54-SET

Designed for rockets with a standalone 54mm MMT (see the HAMR-KS for KwikSwitch 54mm). Includes threaded sleeve and retainer cap for 54mm MMT. 1.30 ounces total.

HAMR-KS29-ADPTR (instock)

Adapter disk only for HAMR-KS system. For use with 29mm motors installed in Kwik-Switch 29mm adapter. 0.40 ounces

The HAMR-KS (Highly Adaptable Motor Retainers, Kwik-Switch version) system has been designed specifically for use with our rocket kits or any scratch-built rocket using PML Kwik-Switch motor tubes.

HAMR-KS38-ADPTR (instock)

Adapter disk only for HAMR-KS system. For use with 38mm motors installed in Kwik-Switch 38mm adapter. 0.30 ounces

The HAMR-KS (Highly Adaptable Motor Retainers, Kwik-Switch version) system has been designed specifically for use with our rocket kits or any scratch-built rocket using PML Kwik-Switch motor tubes.

HAMR-KS-SET (instock)

Designed to incorporate into the popular PML "Kwik-Switch" motor mount system. Complete set with all you need for the 54mm main/mother tube, 38mm KS adapter and 29mm KS adapter. 2.0 ounces total.

The HAMR-KS (Highly Adaptable Motor Retainers, Kwik-Switch version) system has been designed specifically for use with our rocket kits or any scratch-built rocket using PML Kwik-Switch motor tubes.

The basic HAMR-54 retainer is mounted to the Mother Tube for use with 54mm motors. Two adapter plates are supplied for flying with 38mm or 29mm motors. Changing from one motor size to another takes just seconds with no tools required!

Adapter for 54/38mm motors in HAMR-retainer-equipped rockets: (instock)

54mm to 38mm
Motor mount adapter to fly 38mm motors in kits with a 54mm MMT and 54mm HAMR motor retainer installed. Urethane part: 1.10 oz; 54/38 offset ring: 0.30 oz; 54/38 stepped ring: 0.30 oz.

Adapters for HAMR Retainers! If you`re using a HAMR retainer on your rocket and want to fly a smaller diameter motor, here`s your solution! The HAMR Adapters are specifically designed to work with our HAMR system, and are available in 54/38, 54/29 and 38/29 versions

Adapter for 54/29mm motors in HAMR-retainer-equipped rockets: (instock)

54mm to 29mm
Motor mount adapter to fly 29mm motors in kits with a 54mm MMT and 54mm HAMR motor retainer installed. Urethane part: 1.10 oz; 54/29 offset ring: 0.35 oz; 54/29 stepped ring: 0.40 oz.

Adapter for 38/29mm motors in HAMR-retainer-equipped rockets:(instock)

38mm to 29mm
Motor mount adapter to fly 29mm motors in kits with a 38mm MMT and 38mm HAMR motor retainer installed. Urethane part: 0.35 oz; 38/29 offset washer: 0.10 oz.; 38/29 stepped ring: 0.10 oz.