martinpa Posted September 4, 2012 Share Posted September 4, 2012 HI, I've noticed that my prop on my top 80 is nearer the bottom of the cage than the top. It looks like the anti vibration mounts have sagged and have ordered new ones. But with the new ones should the prop be in the centre of the cage, as it still looks like there will still be a bigger clearance at the top than the bottom. I only noticed when I landed a little hard and the prop just touched the frame, (no serious damage to the prop, but I don't want it to happen again) Is this normal? Quote Link to comment Share on other sites More sharing options...
stevec Posted September 4, 2012 Share Posted September 4, 2012 Hi Paul. It's more to do with the classic PAP sag than the motor mounts. Every time you ding the frame on the ground (or even over time with the weight of the motor) the lever action of the motor on the mounts bends the main upright bars. They bend very easily but can also be straightened very easily. With mine, I just need to secure the bottom rear of the frame and pull on the uprights until straight. If you have your motor with you at work I'll show you what happens - I know from experience and chipped props! BTW, I only started landing on my a##e after I sold you my wing and bought that damned Nucleon! Steve Quote Link to comment Share on other sites More sharing options...
martinpa Posted September 5, 2012 Author Share Posted September 5, 2012 Steve, I have got new mounts, as they look as if they are sagging. I've just looked at the frame and it is a little off straight. I'll see if I can straighten it tonight. I had a quick go lunch time but it didn't want to move, so I'll have a proper go tonight. Thanks. Quote Link to comment Share on other sites More sharing options...
tony_walsh Posted September 5, 2012 Share Posted September 5, 2012 Martinpa I have a H&E motor that is a lot like a Pap. Same here, with all my rough landings when I was a new pilot the engine droops down in the frame. I changed the rubber mounts and even this didn't make a difference so I cut out some fat rubber washers and put them on the bottom mounting bolts to tilt the engine up. I also took the engine off completely and bent the mounting lugs on the frame forward a bit. Finally a good flying buddy took pity on me. He worked on the frame on its own. He bolted a wooden form to the floor and with pulleys and some long levers bent it back into shape over it. He did it without putting a kink in the steel tubing. It all looked a bit drastic as I watched him but the result is a frame that is as good as new with same prop / frame clearance all the way round. Quote Link to comment Share on other sites More sharing options...
gordon_dunn Posted September 5, 2012 Share Posted September 5, 2012 When I had my H&E's I removed the top engine mount brackets and got a proper cross-member welded in. The crossmember was of arc shape to clear the starter assembly- worked a treat, H&E even said they would consider implementing it on their future machines as there were a lot of similar problems with machines in Ireland. My original mounts were upto 10 degrees out later, with the new crossmember there was no shift. I have 4 of these crossmembers going free if any one wants- collection, or postage at cost. They are 5mm stainless steel. Or if anyone wants a DXF file for lasercutting their own I can forward it- PM me. They will fit R80 and R120 engine frames. GD Quote Link to comment Share on other sites More sharing options...
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