Chain Drive

One of my schools team had a chain drive using high strength chain, did any other team make a base using a similar design. I want to see some variety of the chain drive. I will post pictures after, because you can’t attach pictures on iPhone. Please and thank you

https://vexforum.com/showpost.php?p=183868&postcount=142
is the relavent diagram from the Team 1103 robot thread.
It shows a HS chain driving 3 wheels from 2 motors.

There were several chain drive robots from Cleansweep that used a cluster of motors near the back, to drive a HS chain for wheels, and for buckets. Looking around in the “reveal” threads from back then might find you some pictures.

One common chain drive you’ll see is a motor stack geared together, geared to the rear wheels, then a chain driving the front wheels from the rear wheels.

Here’s one example:

https://vexforum.com/gallery/files/2/0/9/1/dsc_0252_smaller.jpg

Interesting. So the motors, which are running the base with the chain are under the base? Thats pretty interesting. in addition to that, you are using 6 motors… Hmm. Ill post a picture of one of my brother team’s robot. Sorry if you cant see it that clearly.
orea.PNG

Look more carefully.
The wheel chain drive motors are not under the base.
The 6 motors that you can see ARE the wheel drive motors.
Thats the “cluster of motors near the back,” that I mentioned.
Rick’s picture is of the back of the robot, not the bottom.

There is another motor on each side, (behind the C channel near the UltraSound) that operate the arm.
That makes 8 motors you can see.
There are probably two more motors on the intake roller in the front, that you cant see from this angle.

254A opted for the use of LS chain instead of HS chain, because LS chain can be pulled tighter so there is typically less slop in the drive. Another advantage to LS chain is that if we abruptly changed motor directions, the chain would skip just a wee bit, taking a lot of stress off of the motors.

We doubled up on LS chain, because the chain tended to break when we only had one chain running down the drive.

Our robot had 1 HS motor and 1 LS motor, geared up 15:40 on the 2.85" VEXplorer wheels. We had small omni wheels in the front and back, which are slightly smaller (2.75") than the VEXplorer wheels, so our robot rocked a little bit over the center VEXplorer wheels, meaning that we turned extremely quickly around the center of the robot, which was one of the keys to our robot being as successful as it was at Orlando.

Aren’t VEXplorer products against the rules?

 Edit: nevermind - only VEXplorer electronics are illegal

Only the electrical parts. (Microcontroller, Motors, etc.)

~Jordan

[EDIT]I see I was too quick to respond, and you’ve noticed this already.[/EDIT]

Hello,
The current project i’m working on for my GATEWAY drive train has a pretty interesting chain drive. And the collaboration project I did wish Aperture also used something similar to my GATEWAY design. Feel free to ask any questions!

VEX Nonatread chain:

Gateway teaser chain:

-Dave

you can do that with HS too (with weird configurations)
and i thought that feature was the whole point of clutches…

@davepowers, that is a very interesting design. Are you using regular wheels or are you using tank treads?
@Kendalls, What do you mean by ls chain? is that low strength chain? Do you have any pics of your chain drive from the bellermine competition, before you switch to the little arm grabber.


I got some better pictures of my chain drive, i will post it.
gear.jpg
gear2.jpg

Last year we used chain drive shown in this thread https://vexforum.com/t/lynfield-drive/19114/1&highlight=lynfield+drive

This year for gateway, we have opted for a slightly different drive - although it is still chain shown in these photos -

[http://img542.imageshack.us/img542/3700/img3356.jpg

we decided to do it like this because we found it has less friction and slipping gears than if it is one big loop (for 4wd)](http://img542.imageshack.us/img542/3700/img3356.jpg)

This year for gateway, we have opted for a slightly different drive - although it is still chain shown in these photos -

[http://img542.imageshack.us/img542/3700/img3356.jpg

we decided to do it like this because we found it has less friction and slipping gears than if it is one big loop (for 4wd)](http://img542.imageshack.us/img542/3700/img3356.jpg)

That is an interesting design. Does that concept work. Not where the two wheels are side to side and 2 in back, but i mean the initial chain drive. With the wheeels aall facing same direction. You have any other pictures. Close up perhaps

sorry, im not sure which one you are talking about… the new gateway chassis?

EDIT: after reading it again, i think you do mean this - we dont have any more photos, but we are going into robotics tomorow and can take some if you wish. It works well, we did it for 2 main reasons 1) to have 4wd without slipping chain and less friction and 2) to move the motors forwards (we originally had it chained from the tower) meaning that our center of mass is more forward as we had backwards tipping issues… and if you cant see from the original pictures, there is a second chain going to the back wheel.

Interesting. So it was kinda like mine before? so is this one better, than having it on the towers? and yes please, can you post som pictures towmarrow

Its very much like yours, thats why i posted it. Its really up to the team to decide which is better, they are both very similar. One disadvantage of having a separate “tower” for the motors is that there is then 2 towers, possibly creating more weight. I thought i would just post the pictures just to open up the possibility of having two separate chains next to each other for the front and back wheels, i will get more photos tomorow to make it clearer

I don’t know if you saw our robot at Orlando, but it didn’t have any room for “weird configurations”, as in our design limitations forced us to use specific holes for the motors and wheels, so we decided to just use ls chain, instead of attempting to use hs chain and finding out that it didn’t get taught enough.

Another advantage to ls chain is that it is lighter, which made the whole robot lighter and gave us quicker acceleration. The ls chain also allowed us to chain our robot 15:40, which we had determined was the optimum ratio because a 1:3 ratio was not only too fast to control well but tended to draw too much current.

We don’t use clutches. There is no point to them if you are careful with how much power you attempt to draw from the motors. Clutches can also make autonomous modes and code unreliable if the clutches become loose enough that they skip when the robot first starts moving or turning.

Also our robot didn’t have any room to put clutches on it, even if we wanted to (plus clutches add unnecessary weight).

Yes, “ls chain” is the same thing as “low strength chain”, just easier to write. :slight_smile:

We should have pictures of it, but I’m not sure where they are… I’ll ask around on my team and see if I can find them. But I’m pretty sure that it was 1:3 on HS chain with 1 LS motor and 1 HS motor on each side. The motors may have been geared together with 36t HS gears and then chained, but I am not sure… We built maybe 10 drive bases for the same type of robot design, so my memories of them kinda all fade together…

Edit:
I found a couple pictures that show the drive base:
https://vexforum.com/gallery/files/1/5/9/3/6/bellarminerobot_002.jpg
https://vexforum.com/gallery/files/1/5/9/3/6/bellarminerobot_001.jpg

And bigger versions are at:
https://vexforum.com/gallery/showimage.php?i=5269&c=8
https://vexforum.com/gallery/showimage.php?i=5266&c=8

How many motors are you using on the base? it seems as though 6?

There are six, i really think that going any less is a bad idea this year, at least for an interaction robot

we usually have all 4 HS on our drive (internal gearing 1.6:1)
that provides us with speed as well as power
and that would also simplify the drive chain (6:6) because the motors are all the same kind