Hi, I am building a model 125cc 9 cylinder Wright Whirlwind J5 radial. I need to source or make a sight glass to check oil level in the planetary gearbox. The wall thickness is 4mm Aluminium, with no space on the internal side for a nut. The hole diameter should ideally be about 8mm. I haven’t been able to find anything so far on the Net ‘off the shelf‘ and my idea so far is to make a threaded plug probably 5/16 40tpi in brass and bore through to accept an acrylic plug which would be fixed in place with epoxy. The acrylic plug in this case will be small in diameter, and not sure how visible the oil level will be, and also not sure about the epoxy fixing. I did think to make the complete plug from Acrylic, but think to cut the fine thread needed might be tricky.
Anyone have better solutions.
Thanks in advance
Paul
Anyone have better solutions.
Thanks in advance
Paul