pic: Precision Guessworks 1646 - 2009 Drive Teaser

[Kyle Love]

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[Kyle Love]

Obviously the electronics are not totally ready to be put in quite yet, but this is the basic design of the drive.

[colin340]

wow that's crazy any chain slip ???

[Vikesrock]

How rough were you guys on the chain when you were testing? We have a very similar setup and were just contemplating moving our Toughboxes further back yesterday to get more chain wrap on the drive sprocket. We wanted to avoid doing so because that would involve replacing the angled braces with another method of holding up the transmissions due to wheel interference.

[Taylor]

Would you consider using a floating tensioner on that long front loop?
I wonder what that open front is for....
Be careful with that, you don't want your frame to twist inward there at the front. That will give you horrendous chain trouble.

[Booksy]

Sorry to say but your end cap is 5 inches long. It needs to be 6 for a bumper. I hope you have some c channel left over.

[Vikesrock]

Originally Posted by Booksy

Sorry to say but your end cap is 5 inches long. It needs to be 6 for a bumper. I hope you have some c channel left over.

The endcap itself is only 5 inches but depending on how they choose to mount the bumpers some structure above or below the endcap (still in the Bumper Zone) that stretches the full 6 inches could be used to meet the bumper mounting requirements as the "module" is over 6" wide.

[Kyle Love]

Originally Posted by colin340

wow that's crazy any chain slip ???

Nope, it's still really tight, after an hour or so of driving.

Originally Posted by Booksy

Sorry to say but your end cap is 5 inches long. It needs to be 6 for a bumper. I hope you have some c channel left over.

It's been measured, there will be a 6 in bumper segment on the front of the sides, it will be entirely legal.

Our testing used forward/backward quickly, long stretches of driving, and vigorous motions to try to throw the chains. So far, this chain set up has really impressed me, previously I have been told you need 120 degrees of wrap around a sprocket for it to stay on, but this has proven that wrong, so far. Chain tensioners will not be necessary due to the extremely tight chains that are on it currently. The frame is very sturdy, although it appears weak due to the hole in the front, that is conveniently about 24 inches wide, I don't know why it would be that wide? hmm...

[blhenze]

How will you be able to tighten the chain?

We set up our prototype this way to give our drivers a feel for tank drive. The chain will stretch with usage, so you will need some way to re-tention or you'll be throwing the chain.

The team has decided on 4WD/4 motors with gear boxes and tention the chain with the mounting angle (Gearbox Bracket - PN: am-0204) that have the long holes to allow the adjustment.

[waialua359]

He could probably use the new AndyMark Chain tensioner. Simple and inexpensive.

[MrForbes]

One way to tighten the chain is to shim the transmission and bracket up, by putting washers between the frame channel and the brackets.

[Kyle Love]

It shouldn't need tension for a good long while, we will more then likely replace the entire chain with new chain when it eventually fails, it is extremely tight and does not require and sort of tensioning device.

[JVN]

Did you test at full weight?
120 lbs + Battery + Bumpers = ~150 lbs

[Rizner]

Also, did you test stopping quickly (like what will happen when two robots collide)?

[Justin Stiltner]

If weight wont be a problem (at least a big one) I like 2 chains for redundancy. Maybe the chain doesn't fail, but say your wheel sprocket mounting does, etc etc.