On Wed, 6 Aug 2014 13:48:26 -0700 (PDT), trader_4
wrote:

see page 30 of http://www.hicksturf.com.au/pdf/productcatalogue.pdf

He said he wants one with "tubes", by which I think he means one that
cuts plugs out, not one with spikes. That one uses spikes.

I wonder if he's ever used such a thing? Even the contraption in the
catalog, I would think would be next to impossible to use. A 20 gal roller
would weigh 160 lbs+ and you could pull it around by hand on a concrete floor.
But a roller with spikes that sink into the turf? Or even worse, tubes that
go 3" into the soil? I sure wouldn't want to be the guy using it. I've
wrestled with the power ones that you can rent, and even they aren't much
fun.

I agree; plus, the OP is dealing with clay soil. It would be cheaper
and less effort to have a landscaper come and core the area.