Neil Ok lets design it. I reckon we have both been thinking along much the same lines.
You thinking rotary wing, something the size of a R22 or smaller? I reckon vertical mount rotary engine, planetary then differential gearset to give counter rotating rotor drive. Can all fit in a very compact package directly above the hopper. Planetary should have no fixed gears but connected to pancake style axial flux motor/generators that form the gearbox housing, control the output ratio and replace alternaror and starter on the motor. no clutch is required & engine can be set to run at constant rpm. Have also considered hybrid drive of engine/generator driving counter rotating motors, easier to build but ends up heavy. We have already helped development of agopengps, which we use on our machines for application control, mapping & autosteer. Its not autonomous just yet, but is open source, farmers helping farmers is the motto. would just rewrite it into a specific operating system for this application with 3d maps.
I like the idea of keeping it all open source. That way if anyone uses or copies then they take responsibility. Plus ideas flow between the crazies for superfast development.
Andrew Andrew, Yeah, that is the current legislation, but with demand that will change – I think. Here in Oz, regardless farmers will disregard the directives as CASA has not got the resources to police. Even if reported, we are simply spraying water!@!! That damage sounds bad, have been called on to fix the fibreglass on the local ag sprayer to keep him in the air,--- No I must be dreaming, paint covers a lot of repairs!!! Currently here any unmanned aircraft must be fully certified if over 25 KG!!! That will kill all and sundry but under experimental??? --- will be interesting as CASA fights to keep authority. So far great season here and late with wet cold conditions. Fear we will lose much to a wet harvest which happens every 20 years or so. Still, farming is a terminal disease, so we keep on. Neil. He Neil Way to go with the ag drones. Just a pity cant do commercial ops with Exp. Btw. 2 Ag Thrush's and a C180 damaged on our farm when the hangar collapsed during a cyclone in April. Bit annoying. Good to see you still developing. I still got my original 20b that will be looking for an airframe when time allows. Marc,
I am the only one making redrives at all recently. Currently teaming up with a partner who has access to all maching gear to make another version. Why another version? Well it appears that the ford planetries and g/box parts in the US are now superseded and difficult to source so the cost goes up. In my search to find an alternative I am now to get a planetry from the GM automatics as there are thousands of them in OZ and naturally reasonably priced. The ratio is approx. 3:1 which is ideal.
Planetry sourced, the rest of the redrive is also undergoing a rethink as to cut cost. Currently just the prop shaft cost $1000 if I take 10 at a time! Singularly the cost is $1500! Looking at getting one cast instead of CNC. The housing cost me nearly $1200 for a very "pretty" CNC job, so again casting is much cheaper. A standard planetry is mandatory, as to change the ratio again the cost is horrendous. Whatever is closest to 3:1 will have to do.
Input shaft will have to be made as I prefer a sold unit over a "pinned" unit. Again cost, but necessary.
Cushion drive is mainly cast and CNC to finish -- not difficult to set up for CNC and 10 of will not break the bank.
The mounting plate will be cast from Magnesium alloy rather than the 1/2 inch 6061 alloy plate. Again cost, lightness and strength.
The end result? Cannot tell at this stage but without this progression, there will be no redrives available. The experimental market is no reason the go into the cost of producing redrives, but the real demand looming is the Agricultural drone crop spraying market. Here the need is for high power / weight engines (mazda) and therefore a redrive (affordable). Much legislation involved, but under the experimental banner that all alters. This market is huge if a drone that can lift up to 500 KG can be made. Even 200 KG is marketable which is a single rotor mazda. The "electric" charge cannot compete I feel with the power to weight of the Mazda.
Looking at a twin rotor helicopter mazda powered. Now that will get the natives talking! Here in Oz a self propelled crop sprayer is way over $500,000. Then it cannot spray on boggy ground. Spot spraying is costly, and timing is critical, so drones will come as lifting capacity arrives. CASA (aust) and the FAA have many regs regarding spraying chemical by air, but as demand increases the rules will be forced to change, I think. Regardless the market is there which will benefit the experimental aviation sector. Built on farm, used on farm, even if only to spray plant deficiencies and fungicide , the market is there.
Hopefully it will all happen, but first a redrive.
Neil.
-----Original Message-----
From: Rotary motors in aircraft <flyrotary@lancaironline.net>
Sent: Friday, October 15, 2021 8:22 AM
To: Rotary motors in aircraft <flyrotary@lancaironline.net>
Subject: [FlyRotary] Planetary re-drive?
Who is making a 13b fit 3:1 planetary now-a-days? That is since I can’t get a Mistral unit! Need for a 20b.
M
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Regards
Andrew Martin
Martin Ag
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