Updating old Schluters.....
Posted: 18 Nov 2018, 17:19
Some of you may know that nearly two years ago, I inherited a Schluter Cobra that had belonged to my old mentor John Haytree. It was in pretty poor condition, but I set about renovating it. The first job was to sort out the mechanics. The engine was in a very poor state, and beyond my ability to fix, so I decided to convert it to electric.
The first job was to get it flying and see what further work needed to be done. The initial hops were promising:
but the gearbox was noisy and leaked like a sieve! I had to increase the pitch on the (fixed-pitch) blades considerably over the factory settings. The original recommendation was 4 degrees, though it wasn't clear if this was measured from the flat bottom, or through the chord (about 1.5 degrees difference). I ended up at about 7 degrees!
Nonetheless, it flew well enough to give it an airing at Charmouth at the end of last year - along with my newly built Schluter HeliBoy (late 70s).
Even managed to get it flying in formation with Martin Briggs' machine!
My intention was to completely strip it this year and renovate the fuselage. I've already rebuilt the gearbox into some new casings I managed to obtain, and fitted new bearings - and yes, it still leaks, but not as badly!
However, life got in the way, and I'm only just getting round to stripping the fuselage! Whilst I've got the mechanics out, I've fitted a motor with a higher KV rating (580, up from the original 500). Hopefully this will more closely match the output of an "Old School" 61 2-stroke!
The motor I'm using is from Overlander. The shaft needs "reversing" so as to stick out of the revolving end of the motor, which can then be rear mounted on a couple of pieces of L-section aluminium. I've used existing mounting holes, so that in future, the mechanics could be swapped back to IC quite easily.
Next job is to try and remove the many layers of paint on the fuselage, fill in the holes where the tank and exhaust poked through, and then repaint it all! Not a task that I'm looking forward to, but hopefully, the end result will merit the effort!
You never know, it may even be ready for Ponty next year!
--
Pete
The first job was to get it flying and see what further work needed to be done. The initial hops were promising:
but the gearbox was noisy and leaked like a sieve! I had to increase the pitch on the (fixed-pitch) blades considerably over the factory settings. The original recommendation was 4 degrees, though it wasn't clear if this was measured from the flat bottom, or through the chord (about 1.5 degrees difference). I ended up at about 7 degrees!
Nonetheless, it flew well enough to give it an airing at Charmouth at the end of last year - along with my newly built Schluter HeliBoy (late 70s).
Even managed to get it flying in formation with Martin Briggs' machine!
My intention was to completely strip it this year and renovate the fuselage. I've already rebuilt the gearbox into some new casings I managed to obtain, and fitted new bearings - and yes, it still leaks, but not as badly!
However, life got in the way, and I'm only just getting round to stripping the fuselage! Whilst I've got the mechanics out, I've fitted a motor with a higher KV rating (580, up from the original 500). Hopefully this will more closely match the output of an "Old School" 61 2-stroke!
The motor I'm using is from Overlander. The shaft needs "reversing" so as to stick out of the revolving end of the motor, which can then be rear mounted on a couple of pieces of L-section aluminium. I've used existing mounting holes, so that in future, the mechanics could be swapped back to IC quite easily.
Next job is to try and remove the many layers of paint on the fuselage, fill in the holes where the tank and exhaust poked through, and then repaint it all! Not a task that I'm looking forward to, but hopefully, the end result will merit the effort!
You never know, it may even be ready for Ponty next year!
--
Pete