We are team participatin for first time
We built our chassis as you see
We attatched gear(size 36) direct to the front and the back wheels
Then we connected them with 4 gears (( size 12)
We think this will balance the torque and speed as we are planning to use 4 motors and speed up our motors instead of using gears
What do you think?
Another thing is the back 35" bar important?
Appreciate your comments
Ww are team participatin for first time
We built our chassis as you see
We attatched gear(size 36) direct to the front and the back wheels
Then we connected them with 4 gears (( size 12)
We think this will balance the torque and speed as we are planning to use 4 motors and speed up our motorsby 60%
also we are planning to use 1:3 or 1:5 for speed
What do you think?
Another thing: in the back we will take out the 35" bar and leave the one in the middle, to lightning the waight ; any idea?
Appreciate your comments
First, you will have almost 0 torque when you use the low strength chain. consider getting some High Strength Chain. 2 or 4 kits should be plenty. If you cannot buy these for monetary reasons, I understand, but you would be better off using low strength gears that the low strength chain.
Second, I would take the back 35 HOLE (I doubt you actually got a 35’’ one 
)c bar off, and put one like shown in the second pic and take the c bar at the back and rotate it so that it is oriented like the other one.
Yeah, that chain will definitely snap, I recommend getting high strength chain as well. Now, with the way you have 3 bars going accross. The one farthest to the left is only supporting the outer two bars of your drivetrain. The one inbetween the other two is also only supporting the inside two bars of the drivetrain. The one farthes to the right is done well because it supports all 4 bars of the drivetrain. So I recommend taking out on of the bars that is only supporting two sides of the drivetrain, and making the other bar that is supporting the outer 2 sides of the drivetrain support all 4 like the bar farthest to the right. Hope that’s not worded to confusing.
Is this for competition? If so, gearing down is not going to help you. Direct Drive 1.6:1 is the bare minimum you would want to use, which is the internal high speed setting on 393 motors. What you’re suggesting is (I think) .053:1. That’s (likely) going to be a problem.
If this is for a classroom activity, ignore me.
Inspector Gadget and team 7793r
We really apreciate your comments as its really showed us new points.
We got the idea of supporting the back ( will modify it and post pictures)
( last week we avoided it ciz we thought this will add extra whight over the back wheels which might flip the robot when we rise the 6 bars, so we decided to put 35" as far as we couk)
)
** 4 Omni wheels is faster but its not stable. Do you suggest going with ours as its Or using 4 omni alone Or 4 omni with normal wheel in the middle (torque)?
*** can we use 1:5 gear or 1:3 ratio in the back if we speed up our motors ( I just read that we cant use y cable to connect the motors if we speed up 2-wire motor) OR its better to use one method to go faster ( speeding motor -using gears)?.
We are building our 6 bars; any suggetion to avoid mistakes before we cut it ( less than a week left to our comptition)
Thank you all and appreciate your replys.
Ephemeral_Being
Thank you for your comment
Yes its a competition and we just knew today that we can open the motor and change its inner gears
We did that and we were planning to use gear ratio but we are not sure now if it is a safe and good idea to do it. ( as we speeded the motor today)
Okay. There’s basically three gear ratios used for competition in VEX.
1:1 involves directly affixing the 393 Motors straight out of the package to the wheel, or chaining it with a 1:1 gear ratio. This is typically used when your robot is unusually heavy (> 18 lbs.) and/or you feel like you need torque.
1.6:1 is when you take the 393 Motors from the package, take the fronts off, swap out the gears, and then attach them either directly to the wheels or using chain with a 1:1 ratio. This is the most common, because it provides a nice balance of speed and torque. If you don’t have the time to test anything, just do 1.6:1.
2:1 is uncommon, but still fairly stable. You take a stock 393 Motor from the package, hook it up to a 12 tooth Sprocket, and then chain it to a 6 tooth sprocket on the wheel. Unless you went super light (< 12 lbs.) don’t bother. It’s going to stall.
With all of those, just use 4 Omni Wheels. The High Traction ones are worthless. And you can use Y-Cables with 393 motors. I’m not sure where you got the idea that you couldn’t. Just go Motor → Extension Cables → Motor Controller 29 → Y-Cables → Cortex.
You’re playing Toss Up, yes? Put the wheels below your chassis using Pillow Blocks like this to be able to cross the bump easily. Turn your motors vertically to mount them. You can see one in the background of that photo. It’s really easy, and you’ll never get stuck.
That should be enough to get you started.
Ephemeral_Being thank you for helping us taking decision
We are going for inner gear change and 4 omni
we did as ur picture and its perfect but we are going to change itthe omni now.
Thank you again for fast reply
Anyone have close picture for connecting 6 bars to the robot.+ connecting the magic intaker to the six bar?
There are a couple of ways to mount a Six-Bar. What gears have you got? The High Strength ones? Or the thinner ones? And if so, specifically how many of the 84 tooth thin gears?
just saying I think ever bodies magic intake is a little different. I based my flap configuration off of 323z’s and 21’s and my flap size off of hydras. My intake is set at a twenty degree angle but I know another team who’s intake is at fifteen degrees. so I recommend trying as many designs as you can because every bodies is different.
if your looking for mounting a six bar look here
http://www.team323z.com/lift-cad.html
we have bought all the gears
We have 4 gears 84 thin and thick if not more. We had a small competition before this one and our six bar worked perfectly in the first match but it didnt work after that (stopped in the middle of the 2nd match for seconds then worked again twice)
The picture in the website( as I understood) is using one motor and we are planning to use 2 but we didnt find enough space in our 11.5"-highet-bot unless we go further than 11.5"
Just mount another motor on the same axle. Or reposition the motors so they fit.
You could add another 12tooth gear on the other side of your large gear and attatch your other motor there.
Updating our train, 6 bars and intaker
Any suggestions?
*The collars still drops , any way to make them stay in place?
** we are trying to connect the bars on the middle bar, any idea on how to connect them?
Thank you
This is drivetrain without motors
Jarred do you mean using speeding motors plus speeding gears?
One more question:)
Do we have to use rubber in our six bar?
I agree with most of what you say. However I think that the 4 inch high traction wheels do have some use, because this year the battle in the goal zone is the key, and I have seen countless good robots get pushed away at the moment they are going to dump because they have all omni wheel drive. It’s a tradeoff. Using high traction wheels and omni wheels gives your driver less pressure in the push battles but all omni wheel drive gives you more freedom. For beginners I always tell them, just use omni wheels and don’t ask why.
Except for this, the other speed and torque balance is enough experience that can get you started. I wish I knew all this before I started…
Also, between 160 rpm and 100 rpm, you can also try 140 rpm, 84 tooth gear driving 60 tooth gear. That is also a quite common drive design and it gives you a nice balance of torque and speed, and most importantly, safety. Last season robots are generally heavy with sacks and teams reported their drive stalling with 160 rpm, and team 359A used 140 and they never reported this issue.
If you want a speed demon, rather than using 4 motor 1:2, try six motor 1:3. In our last tournament we are killed by sucha speed demon. Althoughit requires your robot to be approximately 10 lbs.
Thank you
We used omni wheel
But we got confused for the gear ratio
Yesterday we speed up our motor by 60% but we couldn’t attach all the four motors in the back(as we need space for the 6bars).
we have to attach 6 same size gears (3 in each side) while we only have 4 from each size. So today we changed it to 1:3 using this as shown
Please advice us on this issue,
How are you driving the front wheels?
For toss up, the front almost must be driven.
Otherwise, if the ratio still lets you drive for ~5 min straight, it looks good. If not, get a new ratio. Maybe use two low strength gears doubled with lock plates for strength.
1:3 in the back seems fine now , any way I cant judge it now coz we didnt finish everything yet,
Q: Why we have to change the high strength gears to low and what is lock place ?