Thanks, guys! I understand the idea. One other thought came to mind, and that is how to get the anchor peg into the model with the bobbin attached. Answer must be to hold the bobbin inside while pushing the anchor through it from outside.

The bobbin at the rear peg lets the rubber move side to side and rotate a bit around the peg as it unwinds.  This helps prevent the rubber bunching up at the rear peg, allowing you to use longer motors giving more turns and longer motor run times.

There are several articles on this in the NFFS technical library - here's one:

https://freeflight.org/Library/TechLibrary/RubberMotorsVeryLong.pdf

Mike

The bobbin is fixed in the end of the motor with a small rubber band that tightens the end loop of the motor to the bobbin.  I'll look for a picture.
In these two pics you can see how smaller rubber bands are used to keep the loop in a braded motor and keep the bobbin in the loop.

Bobbins can be made from plastic straws where you hold the end of the straw near a candle flame or a lighter and allow the ends to curl back.  Below is a pic of the straw bobbins.
Sky9pilot

There you go, and not a bad price too!!! Thanks for the link!
Amazing what they're making with these
3D printers!

This is an easy to make tool to assist loading motors (even braided) into models.  If you make a long one of 1/4 dowel with 1/32" or 1/16" ply ends to hold a bobbin it can be used for loading even the smaller models.  Here's a picture to help in making your own motor loading stick!
I made this up before following my own advice and researching to see if someone else has already posted this info.  Thanks to cdwebb for his great pictures.  I will add this drawing to assist and hopefully not to take away from cdwebb's post!
Sky9pilot

Not that elegant, but long overdue. I remember when this was all new, that my minute brain couldn't imagine how a rubber loading stick would be constructed. I thought that this might possibly give someone else an idea that I didn't have.

I took a break from the Aeolus to make this up last night. Made from a 3/8" hardwood dowel and 1/8" basswood. I sanded flat surfaces on the dowel opposite each other and the basswood forks (sanded to shape - edges rounded) were epoxied, then bound.

Pretty easy, but lots of sanding. It took a little less than 2 hours and was made from stuff leftover from past projects. It seems to be fine for anything down to around 24" models. For those, something a little smaller will have to be put together.