Ye Olde Rocket Forum - View Single Post

Sometime back in the 70's Howard Kuhn of CMR had what was called a Thrust Augmenter.

It was a pretty simple device.

a 1/2" piece of bt-20 was cut and a 1/4" eb-20 engine block was glued into the top leaving 1/4" on the bottom.

The engine was taped with masking tape on it's top 1/4" and fitted into the bt-20 so it couldn't eject itself.

this bt-20 assembly was glued inside a bt-20+ body tube such that the aft end of the engine was in line with the rear of the outer bt-20+ body tube.

the thrust augmentation tube was then made from a length of Bt-20 tube that would slip-fit between the 2.5" length of engine and the outer bt-20+.

This augmentation tube was then sealed at the bottom with a nose block which had a hole that was drilled thru its center to allow the ignition wires to come thru. This hole was plugged so no gases could escape.

The idea behind this contraption was to increase the lift off thrust ..sorta like a miniature breech launcher.

I've sketched a rough diagram showing what it looked like.

my questions are:

did anybody ever have one of these or have one of these?
Ninfingers only has the 72 and 87 CMR catalogs..... in the late 70's from what I can tell CMR came out with their piston tube launchers.

This Kuhn augmenter came out I believe sometime in the early to mid-70's.

anybody have any information, pics, instruction sheets or catalogs showing those device?

I spent all day yesterday re-reading ALL of the model rocketry magazines from 68-72 hoping to find some mention and no deal. SO the next few days I will be doing the same for ALL the Model Rocketeers from 72 thru 78....

EDIT NEW INFORMATION

In a CMR Ad in the Oct 73 Model Rocketeer, there is mention of new Thrust Augmenter coming for 1974

Geoff Landis mentions the Kuhn Thrust Augmenter for the 1st time in the 4/74 issue of Model Rocketeer.

CMR introduced their ZVPL piston launchers in March 1974 at the old Pittsburgh Spring Convention

So, this tells me the Kuhn Thrust Augmenter was real sometime previous to Oct 73.

Magazines articles back then were usually on at least a 3-month lag from publication so

perhaps it was intended as a product as early as the June-July 1973 time frame.

Geoff Landis could easily have been one of a number of beta testers for it, hence his knowledge of it.

Howard Kuhn easily would have realized that a true ZVPL was superior to a simple thrust augmented and just changed his mind, and the KTA was never released as a real product.

Howard would have known about the ZVPL piston launcher as early as March 1973 because Geoff Landis gave his 1st public report on ZVPL at the MITCON-6 which he, Howard attended.