I've learned the hard way over the past 25 years of enjoying 2 13' Scamps. I used to jack the trailer up under the axle until I read that this is NEVER to be done or one could bend the axle. I used to lower the tongue screw jack all the way down, then extended the STABILIZER jacks down, and just screwed the tongue jack all the way until the tires
came off the ground, until I learned that this could bend the frame. ALL THESE ARE NO NO'S. I now have purchased 2 lightweight scissor jacks from Harbor Freight and have mounted them to the frame just behind the tires
. I use my cordless electric drill to lower and raise them to not only change flats, but to level the trailer, then utilize the welded on STABILIZER jacks off the back bumper and small jack stands to stabilize the front frame between the door and the front of the trailer to help keep some of the weight
off the tongue jack. I can remove the Harbor Freight jacks by just unscrewing one bolt that goes through the frame, when I need more ground clearance while off-roading (along with adjusting my Flexi-ride axle to a high ground clearance stance). Hope these ideas help.
Dave & Paula