Working(mostly) turboshaft Synchropter with synchronizing gears. Possibly the first one in KSP?

[Jakalth]

Yep, that's right. I was actually able to make a working Synchropter with synchronizing gears. This Helicopter has twin rotors that inter mesh above the body of the heli. And the synch gears keep the rotors timed together so they do not hit. It even works, for a while. It uses jet engine powered turbo shafts that work in conjunction with the sas system on the rotors to produce lift. Nothing fancy, just makes the rotors compact.

This design is highly experimental at the moment and is prone to malfunction. The rotor bearings are not sufficient to keep the rotors and synch gears in line at high speeds, but, it is a working design and I though you all might like to have a look at it and see how I did it anyways. Hope to see improved designs released by you all soon.

[download --->] Jak-19x Kerbakon

Here is a close up picture of the synch gears under each of the turboshaft engines. They are made from a small fl-a10 adapter with 2 sets of 8 small pylons attached to it. The two sets of pylons are then angled towards each other so that their tops meet, making a gear tooth. This gear setup allows the two turbo shafts to be synched at an angle. The results look like the following.

The gears work decent enough, but I keep having issues with the shaft getting deflected enough that the gears can slip a tooth. Also, under high enough load, the adapter fails completely due to over stressing. But this only happens with the throttle is set to over 75% and the power limiter on the jet engines is turned up to 100%.

Simple preflight checklist:

1: turn on SAS

2: hit spacebar to active the small seperators shown above

3: make sure your controling from the cockpit

4: hit spacebar again to activate the engines

5: fly

[Azimech]

Good work! At last, some new original designs based on my turboshaft are spawning. Anyway, you've encountered the KSP limitation of not having different materials with different properties. Building gears in KSP is very irritating process. The colliders aren't respected properly or the drag is too high. The more people understand these awkward limitations, the more people can push Squad to implement a better materials system. Have some rep!

[Jakalth]

Yeah, they just do not mesh cleanly and there is a bit of play in them. But if the turbo shaft is kept below 90 RPM, then the suspension on the landing gear(used to make the bearing) can react fast enough to push the gears back into place before they can slip. Sadly, the rotors used in this test model prefer to run over 90 RPM, so issues arise. I've tried making much larger, conventional rotors, but they get too big. And once again, the rotor bearing sets show that they are not strong enough to handle the added mass of the much larger conventional rotors, and they fall apart even quicker.

I might just have to try making a second version using the sturdier rotor bearings I have. But the problem there is that the sturdier bearing sets have about 20% more parts, and this heli is already pushing 520 parts total... Not ideal either.

[Jon144]

Awesome! I feel like I literally have no purpose in KSP making helicopters anymore. You have all surpassed my abilities. I'm happy to have helped inspire this movement towards better spinning contraptions!

Edited February 21, 2015 by Jon144

[PSOliver]

Awesome helicopter. I want to build a helicopter but I don't know how to make propeller so i haven't made one yet. Really good job with the gears:).

[Starwhip]

There are no words to describe the sheer awesomeness of this design...

[burnoutforzai]

Holy... crud... That thing is amazing. GG WP

[Redshift OTF]

This thing is incredible. It looks like a giant fly or something. I was surprised how easily it took off as well. Impressive work on the gearing system too.

[Guest]

The mechanism is neat and works perfectly fine, impressive.

It doesn't look like the rotors are mirrored, did you build each one separately? or duplicated it with ctrl+z? They looks similar except for the hardpoint placement.. interesting

[Jakalth]

The left and right turbo shafts are about 5 degrees off rotation from each other so yeah, the two shafts do not line up exactly. This was intentional, so I could get the gears to line up. I had forgotten to do a thing or two when I mirrored them as well, so there might be a few other small differences. That and with that many parts, the game is not happy about mirroring the engines. As for the rotors, yeah, made them separately. They are balanced well enough weight wise, but there are little differences in positioning. Had to do it this way, otherwise they would not line up like they do and might end up knocking into each other, even when the gears are working.

Currently working on a coaxial rotor design. Have it functional using electrics, but trying to rebuild it using jet engines and the turbo shaft design idea. Would not be the first one using coaxial rotors, but I've been enjoying the difficulty of figuring out how to get it working. Might even try making one that uses gears to reverse the spin of the inner rotor and only use 1 turbo shaft engine to run it. That is if it is even possible considering the power loss through the gear system.

I can admit to one thing, I don't really like the look of the cockpit I used. At least not from the outside... But I don't have a good design made up using creatively placed structural parts, and, I do like how it looks from the interior view.

@ Jon144 I still say your KH-7 Electrocopter looks better then mine. I wish I was better at making free form bodies like that. I keep ending up having to use existing parts instead... Can't seem to get the custom looking craft to turn out myself.

Edited February 20, 2015 by Jakalth

[Azimech]

If you look at my coaxial rotor systems, the big one has more than 500 parts. The small, parts reduced version ... 400. Introducing gears ... then you would additional 150 - 250 parts pure for driving that mess (separate turboshaft with it's own bearing, three separate gears, extra bearing supports, lots of them)... and then you have a 30% power loss due to friction in the abysmal unity colliders - you need a more powerful turboshaft than the left & right rotating in my design, combined. Thus more mass, which means a heavier bearing system - even more parts.

Edited February 21, 2015 by Azimech

[problemecium]

In the immortal words of Rovemax's late CEO: WHYYYYYYYYY *dies*

[Jakalth]

In the immortal words of Rovemax's late CEO: WHYYYYYYYYY *dies*

For Science!...

@Azimech And a realization that going with a shared bearing setup would save on both part count and headaches.

[Jon144]

Should try using the technology to make some sort of chinook

[Redshift OTF]

Should try using the technology to make some sort of chinook

The technology is already there. I will try and knock something up.

[Azimech]

I have a chinook on my harddrive ... needs some tuning.