In reply to MischaHY:
1. If you've got a mobile device there's beastmaker app with different workouts for different ability levels.
2. You could reduce tension using a resistance band, old inner tube or a pulley/weight system
3. Simply add a strip of wood with a rounded edge to your existing setup. A 35mm edge with about 5mm radius edge (sand or plane it down) would be appropriate for most things. If you can't find the right size you can always add thickness to the wood using strips of hardboard or thin plywood sheet.