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About Maxsimal

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    Lead Cat Wrangler

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  1. That's correct. ISPs are slightly higher than the kickback for these two, but still lower than LF engines.
  2. You know Jeb's a pro - he's gonna go back home on EVA pack fuel alone. Was always the plan.
  3. 1700kn and 3300kn in vacuum. They'll rattle some windows.
  4. Don't have a long time to get into the details today, but the answer you're looking for is no, there's no effect the front propellers pass to the rear propellers. Something else is different about the two propellers, but without looking at the craft file, I can't say what that might be - it'd have to be a difference of blade angle or a difference of rotor RPM.
  5. Hahah sorry all, fixed the issue. You knew what I meant
  6. We’ve raced to fix bugs and add a whole bunch of new parts and functionality in this update – it’s almost a new version unto itself. I just want to take this time to highlight some of the additions and changes. Propellers: Our new propellers take a different route than jet engines in the game. Jet engines, while historically more difficult to construct, are simpler for a pilot to manage. Propellers are not meant to compete with them. However, propellers do offer one unique benefit – you can build rotor craft to fly on planets without oxygen in its atmosphere with the electric rotors. I'll cover the basics here - but if you want a more in depth look behind the physics of propellers, this video goes into a lot of the actual real world mechanics - many of which are simulated by KSP. Managing Propellers: So, what makes propellers so difficult to manage for a pilot? It’s because you have to manage the angle of attack of the propeller – which is basically just a spinning wing. First, consider the case with a normal fixed wing aircraft, illustrated below: The above is easy to manage. When you want to increase angle of attack, and get lift - at the cost of more drag – you point the nose – and your wings - above prograde. In level flight, that just means pointing them above the horizon. Now, consider a spinning propeller on plane that is not flying – just sitting still with its brakes on and the propeller spinning. In this case, all the airspeed is coming from the fact that the propeller is moving through otherwise still air – pictured below for what one section of the propeller would see. The angle of attack is still large and the propeller can generate a lot of lift, though it also causes a lot of both drag and the lift in a direction not fully parallel with forward – both of which the torque of the rotor has to counteract. Now, picture what happens when the plane starts moving. Now the airspeed across the propeller comes from both the rotation of the propeller and the movement of the aircraft. Consequently, the angle of attack has gone down dramatically, and you get less lift. This is why propeller planes either have to change the angle of propeller blades – called their pitch – or remain limited to a low airspeed. You could increase RPM, but RPM is limited in both KSP and the real world because propellers lose effectiveness if the propeller tips go faster than mach 1. In KSP, you can adjust the angle of our propellers by setting their ‘Deploy’ field to ‘Extended’ in the PAW, and adjusting the authority limiter, as pictured below. KAL-1000 can assist you with coordinating the settings on multiple sets of propellers if you build a multi-engine plane. Using aero-debugging visualization – F12 by default – can assist you by letting you visualize the lift off of the propeller – your aim should be to adjust the pitch so that the yellow arrows are as long and as far forward as possible. Rotor Changes Rotors have seen a significant set of changes and improvements, as well as the addition of the liquid-fuel consuming rotors, which model a turboshaft engine for a propeller plane and for a helicopter. Now all rotors are set to max out at 460 RPM – near the limit that our physics engine allows. Further, now you can reach that RPM limit regardless of how little torque is applied. Before the rotor RPM and torque were unrealistically interrelated. However, just as a rocket can reach any velocity in space regardless of how much thrust you use - lower thrust just means it takes more time - now a rotor can do the same, barring things like atmospheric drag that would oppose it. Finally, rotor RPM is more stable, you won’t see the RPM numbers vibrating as much. This all required retuning. Further, our initial pass for rotor power gave too much torque. Rather than reducing the available torque, we’ve increased the resource usage and weight/cost requirements for a given motor power. Be aware that you absolutely don’t need to always keep the motor size at 100% - for many applications, a lot less torque will be more than enough. Robotics Resource Usage Changes While we endeavor to simulate physical systems in as realistic way as possible, that has to be balanced against fun and development feasibility. With 1.7.3, we’ve now improved our resource usage simulation for robotics parts, though it is still by not 100% accurate to the real world. What this means is that in 1.7.3 the traversal or rotation rate you request from a part will now impact how much EC/LF is used by the part, where before it was not a factor in the resource usage calculations.
  7. Some improvements may be made in how the LF rotors work, calculate their consumption and communicate it to the player in the future. However, the overall fuel usage is unlikely to change. This craft that I threw together can just about circumnavigate Kerbin - fewer passenger compartments and more fuel would easily allow it to do so. That's more than enough efficiency for Kerbal - we understand that a real long-haul turbo prop would be able to go Keep in mind that propellers are harder to use the jet engines - that's just part of how we implemented, and also mirrors reality.
  8. This actually goes beyond just the numbers. We changed how the PhysX joint is configured, the rotor behavior is more stable now - if you watch the RPM figures they will hold a lot steadier than before.
  9. Btw, this is what a helicopter blade looks like without the perspective issue.
  10. No. The only core difference between the LF rotors and the electric ones are which resource is consumed. There are of course other tuning differences. In fact, the propeller blades should also work if you attach them to anything that spins fast enough - one reason we selected this approach is its a little more Kerbal (for better or worse!) than what you see in many mods. You'll have to learn about propeller dynamics to build a craft that works well. One of our testers suggests this video as a great resource, many of the dynamics of real world propellers apply to the these.
  11. So to address a couple of issues that have come up in this thread. 1. The helicopter blades in those images were tilted back in a fashion to get them to fit within the image frame. Like someone took a picture from near the root-end, which is making them look leaf-shaped. The in-game ones are much closer to what you'd see in a real helicopter. 2. The propellers, and to a lesser extent the helicopter blades, calculate their velocity/AOA from an artificially offset position. This allows them to act like they're at a higher RPM than they actually are, to get around the PhysX RPM limit, with the consequent effect on AOA, drag, and lift. They also use their own aerodynamic values with a lift peak closer to a realistic AOA value than standard KSP aerodynamics. Pitching your blades is still 100% necessary, but the pitch amounts are more reasonable and realistic. 3. The blades have been set up so you can deploy and use the authority limiter to adjust the pitch of the blade - which you can easily do with KAL. So you don't have to set up a servo system to do variable pitch, and therefore you can set up a propeller with just a rotor, two blades, and a nosecone and have a workable system. These were on the drawing board for a while, but our time frame from BG meant we had lots of ideas that didn't get in. We saw how many people were really interested in rotor craft though so the team pushed hard to get these into the 1.7.3 patch. There are definitely a few things that we'd still like to do with them, but I think this will give a better & more aesthetic result than the elevon-based craft that the locale Kraken-mechanics have been rigging up up to this point.
  12. They were considered for both uses, as you'll see when you get to read the part descriptions.