tank with tracks

[klond]

link to where the work began

Edit: no mods!

 Well it's more a tracked rover than a tank.  And it's technically one big track, not two.  Ten thermometers per bearing really pushed up the part count.  I think it's 19 separate craft + all the unexploded separators.

 Focus the motor in the back and set full trim, then focus main machine to twist slowly left or right via SAS (controls might be backwards).  Unit can also reverse.  Tracks will probably start falling apart after a few minutes.  I hope Jeb's ok with that.

 

 Giving each track part a separate job and only 1 job helped me troubleshoot issues and improve reliability at the expense of machine complication and part count.  Each track pair is in 3 sections

-The ouside parts are the frame of each piece and its foot.

-Mid sections are bearings.

-Inside parts are the guide balls that slide in the frame guides, gear notches, and idler.  Check out these MS paint skills.

Spoiler

 

 Here's some other important things I had to figure out.

 

How do we keep the bearing balls from popping out of their holders?

 Use way too many thermometers and pray to the kraken.  Keep motor torque low and try to figure out why/where sticking points are.  Keep total vehicle weight low.  It helps if drive gear allows some slippage so parts aren't under high pressure when there's a hangup.

 

How do we get the tracks to turn around the gear without stretching and binding?

 My answer - put each bearing perpendicular to direction of travel AND exactly on the centerline of the guide ball making that the horizontal axis.  This way we can have a small diameter gear and not have to worry about a tight radius turn.

 The gears originally had 4 thermometer cups to catch the guide balls and pull them around, then release.  I could not get the cups shaped right for good release, plus there was no slippage to allow for slack and hiccups.

 

How do we prevent track explosions?

 Choose high tolerance parts like the RCS port and the Vernor engine, keep speed low.

 

How do we prevent the track from slipping out of it's groove.

 Put railings on the gears and idlers to prevent lateral motion.  Remember, it's one big track, not 2 separate ones, so both sides help with alignment.  Slow rotation speed helps.

Spoiler

 

If each track piece can rotate, how do we keep the feet facing the right way?

 Each track piece's bearing shell contains a ball from the one before it, all the way around in a big loop, each side.  Each piece drags the one after it and is pulled around by the one in front of it, and force each other's orientation.  Since both the left and right side are connected it's more like a bike chain than a rubber band - you can't flip it inside out.

 

What she looks like with guides missing.

Spoiler

 

Credit to Majorjim! and RedshiftOTF

Spoiler

Majorjim!

RedshiftOTF

 

 

KerbalX

Edited January 2, 2017 by klond

[Castille7]

A Kerbal work of art man, love it! All stock? very impressive!

[Majorjim!]

I knew it could be done!

 I have not worked on my old original design since the ant engines where broken.. I am certain now that the RCS port/thermo hinge is superior to the antenna/thermo hinge design. I just hope they don't change the geometry of it in the next patch..

 Epic work dude, truly. A work of art.

[cubinator]

7 hours ago, Majorjim! said:

I just hope they don't change the geometry of it in the next patch..

I can just see it: We finally get that part overhaul everybody's been pleading for, and then they find out all their propeller planes and tanks don't work anymore and there's a wave of complaints even though those things are as unintended in the stock game as Kraken drives.

Anyway, this tank is really spectacular. There is so much in this game that is possible if you use parts in unconventional ways!

[klond]

8 hours ago, Majorjim! said:

I knew it could be done!

 Thanks for the inspiration!  There are so many things that have to go right and the kraken doesn't like that.  Just barely squeezed it into 2016.

1 hour ago, cubinator said:

I can just see it: We finally get that part overhaul everybody's been pleading for, and then they find out all their propeller planes and tanks don't work anymore

 I have come to terms with that now.  Positive side- maybe new shapes of parts will allow new stuff to be made.

[Vanamonde]

This is the best kind of ridiculous.  

[Azimech]

Again, fantastic work! Hopefully we can use it one day for stuff like a timing belt on a 4-stroke engine.