July 1, 2020

[@blurglide]

Seems like a good design. What I'd like to see though is for the cage to be under tension, like a bicycle wheel...either with metal spokes or kevlar line. It'd make for a very strong cage.

[@airforceparamotors3104]

Thank you. I entertained many different types of hoop systems and found this to be the best overall. 6 hoop supports and a little thicker .065 tubing turned out to be extremely rigid. The hoop supports are also structural and take some of the load during a hit so the hoop itself does not bear all of the load. Sometimes there is a balance between strength and repairability. The cage has hit the ground pretty hard on numerous occasions with no damage or deformation that would have happened on some other units and caused a prop strike. If damage does occur within minutes you can replace a cage section. Although a spoke system could make a cage even stronger would still be prone to damage and then it would be overly complicated and costly to repair. Added complexity could be more of a negative. I tried to strike the perfect balance between strength and repairability. This cage will hold up with the average face-plant or frame drag on take off without damaging it.

[@philc9305]

Any issues with frame plates cutting the webbing? Seems like some edges can be sharp.

[@airforceparamotors3104]

No issues. The frame plates are laser cut by an aviation machine shop with one of the best cutters available. The same facility also waterjets my active arms and they require very little finishing. Have a reference on my Facebook page showing the equipment used. It's pretty impressive when you see the tech involved in producing this frame.

[@airforceparamotors3104]

I forgot to mention. We polish and round the edge where the harness attaches.

[@riograndeparamotor7360]

how is the torque compensation engineered into the design?

[@airforceparamotors3104]

I spent a lot of time working on the geometry. Everything comes into play including thrust line and even prop selection. The Mantis requires very little offset. The hang point straps hang on the center of the active arm so it doesn't induce a twist. But the backup harness strap is on opposite sides and acts like a spacer on the carabiner. The left side back up strap is on the inside of the gooseneck bar and on the outside on the right side. The Carabiner connects to the hangpoint straps (2per side) at opposite corners due to backup strap spacing so it's more like are carabiners are offset above the gooseneck bars instead of attaching on a bracket on the bar itself inducing a twist. I used to be an aircraft structures specialist. I noticed some items on Paramotors needed to be addressed to make a safe and good flying unit as possible.