Old BP Motors

Hello again everyone. I know, lots of questions. Sorry for so many.

But, they must have answers and I'm hoping you can help with mny of them. I'm researching very old Estes plans extensively. I've found that Estes had other motors back in the day. Series III specifically keeps popping up. I was wondering if anyone might know where I can locate the info no the older designs of motors. Looking for full specs. Size, thrust, the whole nine yards. I want to ensure that the modern motors will reproduce the flights the rockets were designed for. Yes, I realize the simple answer may very well be yes or no, but I'm detail oriented. Any help would be appreciated.

Lots of details in the old Estes catalogs. One good source is here: https://www.ninfinger.org/rockets/rockets.html

BEC's Ninfinger link will give you most of the tech information.

The Series III 'shorty' motors were 18mm motors one inch shorter than standard Series I and II motors (1.75" vs. 2.75"). I think Estes discontinued them in 1970 (the Ninfinger links will tell you exactly).

Some of the old Series III models can be redesigned to use 13mm motors with use of adapter rings, etc etc.

The ninfinger site is a treasure. Don't come back cryin' when you lose a day or two in there. Time well spent !

JStarStar said:

BEC's Ninfinger link will give you most of the tech information.

The Series III 'shorty' motors were 18mm motors one inch shorter than standard Series I and II motors (1.75" vs. 2.75"). I think Estes discontinued them in 1970 (the Ninfinger links will tell you exactly).

Some of the old Series III models can be redesigned to use 13mm motors with use of adapter rings, etc etc.

Click to expand...

Ditto!
I've scratch built many of the early 70's Estes models designed for the Series III motors, retrofitting the design for 13mm motors which were what Estes Replaced the Series III with. They are the same 1.75" length. but with different thrust ratings. For instance the Old A2- motors are now A3-T's I think I still have a couple 18mm Series III motors in my Range box.

On Ninfinger website look up the old pre-1970 Estes Catalogs motor data pages they will contain all the info you are looking for.

Micro's photo archive is a treasure as well !