Guest Posted October 14, 2007 Share Posted October 14, 2007 Please use this thread to continue the conversation about Props. I would like to start by saying, I know 100% that the compact Parajet (the one that I fly) has a prop that is 100% designed and built for Parajet. The same can be said for the Micro. Although I know that Giles had something to do with the design of the prop on the Macro (Normans motor) It does not stop the maker for selling them to someone else. SW Quote Link to comment Share on other sites More sharing options...
paulb Posted October 16, 2007 Share Posted October 16, 2007 Hi guys I'm a newbie and thought I would jump in with a post and say Hi. My other aircraft is a gyroplane with a ground adjustable prop. I have spent a lot of time and money playing with these things. I replaced my original GSC three blade with an adjustable Arplast three blade. The main benefit being the reduction in weight and therefore load on the engine and a slight increase in thrust. There is no manufactuer recommended or designed prop/engine set up for my aircraft. I am no expert but would suggest that it will be almost impossible to improve on or match the orininal manufactuers set up. I am assuming here that we are talking about a well designed and thought out motor package from a leading vendor. An adjustable prop will at least be heavier, more complex, and if wooden need checking reguarly for adjustment changes due to to environment effects on the wood. It is also one more thing to go wrong, and in aviation you really want to keep it simple. In my case with the gyroplane I couldn't afford to loose any thrust as my engine performance was marginal. PaulB Quote Link to comment Share on other sites More sharing options...
admin (Simon W) Posted October 16, 2007 Share Posted October 16, 2007 Dont forget to start your Training Blog mate Welcome. SW Quote Link to comment Share on other sites More sharing options...
Guest Posted October 16, 2007 Share Posted October 16, 2007 (edited) ...My other aircraft is a gyroplane with a ground adjustable prop. I have spent a lot of time and money playing with these things. I replaced my original GSC three blade with an adjustable Arplast three blade. The main benefit being the reduction in weight and therefore load on the engine and a slight increase in thrust. There is no manufactuer recommended or designed prop/engine set up for my aircraft.I am no expert but would suggest that it will be almost impossible to improve on or match the orininal manufactuers set up. I am assuming here that we are talking about a well designed and thought out motor package from a leading vendor. An adjustable prop will at least be heavier, more complex, and if wooden need checking reguarly for adjustment changes due to to environment effects on the wood. It is also one more thing to go wrong, and in aviation you really want to keep it simple. In my case with the gyroplane I couldn't afford to loose any thrust as my engine performance was marginal... I spent several years buying up unairworthy PFA aircraft, restoring them to flyable condition and then selling them on to fund my commercial training. One thing I did find out in that time was that most of the propellers in use were very much a compomise and could easily be improved on depending on your requirements. Out of interest, the small increase in weight of the machined aluminium hub on the GSC prop provides better starting due to increased rotational inertia (particularly noticeable on the manual start version where you need to achieve 60rpm for the engine to catch)! Also perhaps I can quote some stats for my own PAP system. If you look in the PAP manual it states that a Black Devil with an original PAP propeller for my 1250mm cage size will produce 59kg of static thrust at sea level. I have 2 friends in Colorado flying with the same diameter GSC adjustable from an elevation of 6000' who at that altitude are reporting a measured static thrust of nearly 65kg. That's a 10% improvement on manufacturer before you even consider the >1 mile height difference!!! They also can tailor each prop to precisely match the powerband of each individual motor if you know how to set them up. Edited October 16, 2007 by Guest Quote Link to comment Share on other sites More sharing options...
Guest Posted October 16, 2007 Share Posted October 16, 2007 Here's a direct quote from another forum with an interesting point... ...In all the testing that we have done with our thrust tester we have never found a machine that was more powerful with a composite propellor... Quote Link to comment Share on other sites More sharing options...
norman Posted October 25, 2007 Share Posted October 25, 2007 New prop arrives on Friday. Pulse 125 from Pendle Paramotors. I had to do it to save the £75. The price includes vat and postage. (Yes, I know it says 123cm but actually they are 125.) Quote Link to comment Share on other sites More sharing options...
admin (Simon W) Posted October 25, 2007 Share Posted October 25, 2007 Norman, FYI and others. Parajet will soon be replacing the current MACRO prop with a larger version of the parajet signiture prop. Thrust tests suggest a good lump more thrust from the 'Parajet' Prop, numbers will be posted here soon. SW Quote Link to comment Share on other sites More sharing options...
Guest Posted October 26, 2007 Share Posted October 26, 2007 Norman, did you order a 2 blade prop? Also, I'm curious about the way it is said to be foldable. Does it fold in flight for reduced drag engine off like the Razzeebus? Quote Link to comment Share on other sites More sharing options...
norman Posted October 27, 2007 Share Posted October 27, 2007 Ian, Foldable? Naaa - a standard Pulse 125 two piece prop. Clip it together and bolt it on and away you go Sir! Quote Link to comment Share on other sites More sharing options...
admin (Simon W) Posted October 27, 2007 Share Posted October 27, 2007 All of your props seemed quite foldable to me mate! SW Quote Link to comment Share on other sites More sharing options...
norman Posted October 27, 2007 Share Posted October 27, 2007 I resemble that remark! Quote Link to comment Share on other sites More sharing options...
Guest Posted October 27, 2007 Share Posted October 27, 2007 The webpage in the link says it is foldable. Even if that was just when not in-flight that would still probably allow replacement of a single blade in the event of minor damage. Helps keep those costs down. Quote Link to comment Share on other sites More sharing options...
Guest Posted November 8, 2007 Share Posted November 8, 2007 Photo of the GSC prop and adjustable hub on my album page. Quote Link to comment Share on other sites More sharing options...
norman Posted November 8, 2007 Share Posted November 8, 2007 Hey Ian, Replacement blades. I am a SMIFTT member, when I smash a prop I do both blades good and proper. No nancy notches out of a single blade. ...But I do take your point - it is a good one and would save a few shillings. Quote Link to comment Share on other sites More sharing options...
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