See https://amzn.to/4aMcnHS (affiliate link)

The putty holds the rings just fine. Just make sure you don’t have any sticking out into the space where it would catch the moving wheel.

i was also wondering about the putty. i agree the pin holes were often not pretty but i wonder how well the putty will hold the rings, etc. i am on house arrest through the summer (COVID19 and leave from work) so i am looking forward to creating wonders of the world.
Just your Average 55 year old man here haha

So I did make videos on using both racks to make patterns. They’re here: https://www.youtube.com/watch?v=ga06ft-HWro&list=PLAkN3L7a4VuMzBX-T0fWLEQlPUB1JyADS

Advantages of putty over pins:
(1) You don’t need to use a special backer board. In my family, when I was a kid, we soon had so many holes in the corrugated cardboard backer board that it didn’t work so well anymore. We cut more out of ordinary cardboard boxes but they weren’t usually thick enough, and they left a ridged pattern on the paper. Later I discovered that a cork bulletin board worked better (see https://spirographicart.com/2011/12/20/a-better-working-surface/). But then the new version came out with putty, and I didn’t look back. With putty, you can even draw spirographs on the wall, or directly on your fridge (if your mommy lets you, ha ha).
(2) You don’t get pin-holes in your paper. That’s nicer if you’re making cards, for example, or artworks you want to frame. See (https://spirographicart.com/2017/11/11/making-cards-spirograph-wild-gears/).
(3) Some people have trouble picking up the little pins, and they’re less safe if there are little kids around.
(4) Pins can break or get lost easily. You can find poster putty anywhere, but if you want to replace your pins, you need to find “map pins”.

It’s on my list of things to do. I haven’t tried it since I was a kid. When I do, I’ll make a video.

Yes. You’ll find it here: https://spirographicart.com/2016/06/05/intro-bar-wheel/