What kind of swing set do you want to anchor? If it's a standard swing with a swing frame, you need to drill holes in the ground like described in this tutorial.
If your swing set is just a simple one (like a toddler swing), check this how to … Read more
You need to know the weight of a liter sand. This will vary of the type of sand and its humidity so there isn't universal formula. If you have the sand around you, get a 10 litters water pail and fill it with sand. Measure the weight and you'll have the weight of 1 litter … Read more
Sorry forgot to log in and couldn't post the link. For a wooden frame you need two triangle frames in the form of letter "A" and a horizontal beam. This article has more detailed explanation: How to build a swing … Read more
For maximum safety you can dig about 50 cm (20") in the ground, but even the half of that would do. The concrete-filled holes can be about 10"-15" (30 cm) in diameter. You can calculate the volume easy - (2 * 30 * 3.14) * 50 = 35357 cubic cm. That's not much.