Trevor Grace 1 Posted September 17, 2019 Share Posted September 17, 2019 i intend to build a 48-50 inch w/s flying wing type model using a irvine 53 and wondering if anyone could give me an idea on the size of 3 bladed pusher prop. looking at about 3lb -3 1/2lb flying weight many thanks. Quote Link to comment Share on other sites More sharing options...
Nigel R Posted September 17, 2019 Share Posted September 17, 2019 you sure you're going to need a .53 in something weighing 3-1/2lb? anyway, I thought the rule of thumb was, standard prop size, minus one inch diameter. Quote Link to comment Share on other sites More sharing options...
Trevor Grace 1 Posted September 17, 2019 Author Share Posted September 17, 2019 hi Nigel R. thanks for your reply, i went electric a few yrs ago so lost touch with the i.c. world, the engine (brand new) has been sitting in my shed all of this time. Not making exactly a flying wing but a star wars type twin fin long nose job. Will be making it up as i go along but loosly based on the KR84 TORTUGA Robodrone. Quote Link to comment Share on other sites More sharing options...
Martin Harris - Moderator Posted September 17, 2019 Share Posted September 17, 2019 If "push" in the thread title refers to the engine, be very cautious with an Irvine. The needle valve is extremely close to the propeller arc - Irvine users regularly get a slap on the knuckles while making adjustments to engines fitted with conventional props. If you try this with a pusher prop it will almost certainly inflict serious injury due to the blade coming at you at a chopping angle which pulls the blade into whatever it contacts. I was bitten (twice in one day) back in the 70s by a pusher driven by a little Veco .19 - I still have the scars to remind me. I shudder to think what an Irvine 53 would be capable of. Edit: Just spotted your last post after posting this and it seems to confirm it's a pusher. I would seriously advise against the Irvine unless you can arrange a remote needle adjustment. Edited By Martin Harris on 17/09/2019 14:17:05 Quote Link to comment Share on other sites More sharing options...
Don Fry Posted September 17, 2019 Share Posted September 17, 2019 I too have the scars of adjusting, in my case a pre Scnurl (spelling?) ported plain bearing 40. So a tidier to the power of the Irvine. When I had a 53 Irvine it was as big as ever I flew alone. I had eternal debates with myself as to wheather I could get to casualty if it bit me. And working behind the engine was tight. I ended up with a simple expedient, slow needle, stop engine, and adjust. Main needle, Ok with caution, On a pusher, I would not touch those needles if it's running. Have you thought of the launch, a chuck, excepting one of those underhand discus affairs also brings digits to the slicer. Quote Link to comment Share on other sites More sharing options...
Denis Watkins Posted September 17, 2019 Share Posted September 17, 2019 With the Irvine Trevor You could fly a 6lb model with a 10 x 6 3 blade prop These models are usually driven by .36 - .39 motors Quote Link to comment Share on other sites More sharing options...
Trevor Grace 1 Posted September 17, 2019 Author Share Posted September 17, 2019 hi guys the remote adjusting needle valve will be no prop, what has got me foxed at the moment is the exhaust to prop clearance. Quote Link to comment Share on other sites More sharing options...
Don Fry Posted September 17, 2019 Share Posted September 17, 2019 True, but I bet it's a dose of fun on a 53. Quote Link to comment Share on other sites More sharing options...
Trevor Grace 1 Posted September 17, 2019 Author Share Posted September 17, 2019 hope so as for the props, had a fight with a 20x8 a few years back-guess who won. Quote Link to comment Share on other sites More sharing options...
Nigel R Posted September 17, 2019 Share Posted September 17, 2019 "what has got me foxed at the moment is the exhaust to prop clearance." Just point it forward. It'll look a bit funny but will work fine. Or a) find a dustbin, or a pitts type, or some other compact silencer type b) fit a pusher pipe (weston do them) re, Tortuga drone, try: **LINK** note, prop in correct (!) place a bit smaller than you are looking for but could easily be scaled up a bit Quote Link to comment Share on other sites More sharing options...
Trevor Grace 1 Posted September 17, 2019 Author Share Posted September 17, 2019 thanks Nigel R. I will check the Weston link. ps you have got the wrong plane the TORTUGA -KR84 is on the microbirds.com and type in TORTUGA Quote Link to comment Share on other sites More sharing options...
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