Automotive Differential Pumpkin

[AcidTonic]

Lately I've been using the infernal robotics joint parts to create usable U-Joints. Wanting to build a 4x4 off roader I took the engine model from the ICE engine mod (purely for looks, not using their wheels) and then bolted an IR rotatron at the end of the motor. Then of course I attached the U-joint and then the driveshaft, and another U-joint and finally that goes into a non-powered rotating bearing. Looks exactly like a real setup and by spinning the shaft when moving it looks real. It even articulates properly if the angles are kept reasonable. 

 

EDIT: Uploaded some Photos: http://imgur.com/a/Sqybh

EDIT: Uploaded some videos below too inline. Here's the direct links.
Kerbal Space - 4x4 Off-Roader with Simulated Differential and Driveshaft.
Kerbal Space - 2-Engined-Driveshaft-Driven-2-wheel-drive Drag Racer

Problem is there is no actual differential available to get this power to the wheels. So I had to "cheat" and add rotatrons again for each wheel coming out of the simulated differential. By driving all at once it "looks" like a driveshaft is powering the differential. Pretty cool!

Looks very realistic to see a driveshaft working as the wheels articulate. It even properly "snaps" as it rotates by not using a linear speed as the joints bend. Using the bearings from IR I can even make multi-piece drive shafts. Worked way better than expected and got me excited.

So then I decided to simulate the idea of driving using these shafts and just ran parallel driveshafts to overcome the diff limitation. I used multiple 45-degree Ujoints to basically bend the shaft 90-degrees so each shaft was dedicated to the left and right wheels. By then using two motors I got a rear-drive tractor built that drives without using any actual wheel parts. I attached the large heat shield scaled up for the wheels and it gets the *perfect* amount of traction. I even get wheel hop when making an independent suspension and less when making it a solid design just like in real life.


So with all this said I have a quick request for help making a mod. I want a quick and basic hack to existing models to make a real differential that works on rotation. Should be easy to tack 3 IR rotatrons onto the Ground Pylon and simply transfer rotation torque from any rotatrons to the others . So if the input shaft rotates 90* then the two output shafts also forcefully rotate 90*. Basically the same if either side receives a torque load it would transfer into the other two rotatrons. Eventually more logic could be added for limited slip functions of a rear-end multiplier. (Shiftable  2-speed rear like a semi would be even cooler)

I just registered here and this is my first post so I'll wait to upload photos until after this gets approved. I'm also a rather crazy software engineer well versed in C++ but not at all in C# but I'd be happy to code this if someone could point me towards what to do. Appreciate the help.
 

Edited January 1, 2017 by AcidTonic
Fixed typo

[hypervelocity]

i would really love to see a video of this!!!

[Dman979]

Hello, @AcidTonic, and welcome aboard!

That sounds pretty cool! I'm not the person to help you, but I really would like to see pictures. The best way to do that here is to upload them to an image sharing site, such as Imgur, and link them here.

Good luck!

[Mecripp]

7 minutes ago, Dman979 said:

Hello, @AcidTonic, and welcome aboard!

That sounds pretty cool! I'm not the person to help you, but I really would like to see pictures. The best way to do that here is to upload them to an image sharing site, such as Imgur, and link them here.

Good luck!

You can click on the link he has posted and see really nice job at putting it all together

Here is his link if you missed it http://imgur.com/a/Sqybh

Spoiler

 

Here are some

EDIT whoops that didn't work right lol

Edited December 31, 2016 by Mecripp2
EDIT

[Azimech]

I haven't read everything, I'll read all of it later.

You might be interested in this:

 

[AcidTonic]

Working on the requested videos....   This is driven purely by the two rotatrons coming out of the back of the twin-engines. I gave it a decent top speed but slow acceleration to show the joints working. Added wheelie bars to keep it planted. I used cheat mode purely to keep the heat-shield wheels together otherwise it's not required if I hack just the wheels to be stronger. The joints sometimes bind if I get them under serious load which causes the mounting of the white bearings to move rather than the joint. At extreme angles they spin but stop transferring power so I try to limit them to 45-degrees max from any plane. Just like real vehicles the driveshaft U-Joint works best if slightly bent and not exactly a straight line. 

I'll work on videos of the rock crawler you seen in the other screenshots next.
 

Here is the other one.... edited with landing struts a tad to help it flip back over. I'm using a single inverted group for the hub articulation which is still subpar for self-righting but easier to control. The hubs let me articulate it even on solid ground so I can show off the driveshaft and climb obstacles at slow speed.

 

Edited January 1, 2017 by AcidTonic
Added video link of other craft.

[AcidTonic]

Spent some time tonight creating a working differential scaled up from parts out of frustration of not having one.... Decided to scale up my next vehicle to make use of three of these for four wheel drive from a single motor.

You guys should hopefully enjoy this one.... Feeling like I'm on a roll here.

 

[Azimech]

38 minutes ago, AcidTonic said:

Spent some time tonight creating a working differential scaled up from parts out of frustration of not having one.... Decided to scale up my next vehicle to make use of three of these for four wheel drive from a single motor.

You guys should hopefully enjoy this one.... Feeling like I'm on a roll here.

 

 

That's probably the first in KSP, congrats!

[erasmusguy]

It works far better than mine. I never bothered to improve my diff.

[AcidTonic]

14 hours ago, erasmusguy said:

It works far better than mine. I never bothered to improve my diff.

This one? Or a different design? I looked through your album and was the closest looking thing. Pretty cool

 

Next on my agenda is to try to scale down and optimize my design to get it as small as possible without ruining the functional aspects.

 

Any ideas on this? I'm using the latest 1.2.2 and thus don't have many options as mods are still out of date. I'm going to work on making this smaller tonight and keep posting progress... Thanks for all the kind words.

Edited January 2, 2017 by AcidTonic

[erasmusguy]

http://imgur.com/TJKSmev it still needs a ton of work on it but I have new gear designs to try out. It only works at low speeds and sometime not at all :,(

I use editor extensions redux mod so I can move the parts further a part then is normally possible. 

Edited January 2, 2017 by erasmusguy

[AcidTonic]

It just occurred to me that an easy way to stabilize the design I showed is to simply connect the four spinning sides by placing a free-rotating bearing on each spinning gear hub and a small drive shaft in the middle connected to a four-way hub like a not-rockomax.

I may build this and get a better video. I think that would vastly stabilize the movement so it binds up less and more importantly has less parasitic losses.

I foresee a contest to drive the farthest with a working differential using a contest-set amount of fuel. Fuel-efficiency contest essentially.

Edited January 3, 2017 by AcidTonic

[AcidTonic]

Much improved design and annotated video... turn on the closed caption (CC) icon for a lot of help following...

Getting closer to something small that will be easy to incorporate into a driving craft...

This one is jammed full of features!

Selectable drive modes.....
* Left wheel drive with low torque (slips easily, may be good for traction on slick surfaces)
* Right wheel drive with low torque (Right drive engaged but not locked)
* Right wheel drive locked (Right drive engaged all the way into lock)
* Left and Right Wheel Torque Biasing Drive
* Left and Right Wheel Locked
* 3-Way custom gear ratios  
---> Since each piston is independently movable so you can underdrive the left or right wheels by retracting a few on only one side. This would produce a yaw effect for turning or allow you to essentially have more than one rear end speed if you do it for both sides. Start with 4 out for slow crawling speeds and shift 4 more out for high ratios.

Should be all we need for some serious fun!

 

Edited January 4, 2017 by AcidTonic
Description of modes....