I just made an egg tumbler and it seems to be doing the job based on all the tutorials and plans I've looked through.
I never really thought I'd get into the tumbling but my favorite vics keep breeding within 3 weeks of releasing the previous batch and I don't want to wear her out! I even put her in her own tank with a bunch of juvies after the last release to fatten her up and sure enough, three weeks later she drops her tube to lay more eggs without the male around. I put her back in the breeding tank and they spawned within a day or so.
That was a week ago and today I built the tumbler and stripped her so she can go back to eating.