I don't know the plans you mention but how many holes are needed depends on the materials the bin is made of, your climate where the bin will be kept, and how much moisture you are likely to add to the bin.

There are people around who keep worms in plastic storage bins with no holes at all and do just fine but they usually have lots of experience with keeping worms and controlling moisture. I have wood bins that I did drill holes in the bottom but I've now come to the opinion that I probably didn't need to do that since the wood breaths pretty well and the cracks around the edge of the bottom will let water out. However, in a humid climate and with a wet food source for worms will require a better aerated bin. Then again, if the bin is too well aerated and the conditions are very dry, the bin may tend to dry out too much.

You can probably try it with fewer holes since you can probably add more later if you find you need them?

In the last six months I have made several OSCR Jr's and given them to friends (complete with worms) to get them started with vermicomposting. I did not have experience myself with the OSCR Jr., so I finally decided I had better start using one myself to make sure it was a good design before I made too many more of them.
So I did that back in November or December.
So far, the results are good. I don't really know how many worms I put in there to start out with. I just put in a couple of good trowel-fulls of worm-filled mucky stuff from one of my other bins with a good amount of torn-up cardboard, some old cow manure, and random vegetables. I pretty much filled the lower level with that stuff at the get-go. By now, only a few months later, the lower level has a LOT of worms, and they are starting to move up to the upper level, which I already filled with cardboard and a lot of leaves which I raked up last summer and saved for the worm bins.

I haven't read the posts you refer to (about putting fewer holes) but I do not think there are too many holes in the plans as published. The holes are not just for aeration but also for the worms to go through. Compare the openings in the bottom of the trays of a WF or COW. Their grids are far leakier than the bottom of an OSCR Jr.
I wouldn't want to have fewer holes than the plans call for.

And BTW, all of the friends I gave bins to are doing fine with their worms so far.
I do have one modification to suggest, and that is to put a drain hole in the bottom of the bin underneath the working bins. I read about a nifty idea on one of these forums, which was to cut off the top of a plastic bottle (water or soda pop), put the neck of the bottle through the hole in the bin, with adhesive caulk to hold it, and then screw the top back on the outside. Before I did this, I found it to be very tedious to take the bins apart and tip the leachate out of the catch-bin. Not to mention messy. (I always seem to have leachate.)

Oh and one more thing: Instead of holding the screen in place with strips of wood, I have been gluing the screen in place with my trusty hot glue gun. Much easier, and it works just fine.

mbetts

Thanks to you both! I like the bottle cap idea and will try that! I decided to build the design as is until I am familiar with it's conditions.

Chris