So… We have high hanged before, with a 7:1 gear ratio and with ease too but our lift was definitely slow. This was costing us alot so we decided to change our lift to a 5:1 gear ratio which definitely improved our performance but it made high hanging impossible. My question is, can anyone hang with the same gear ratio as ours and how did you manage to do it? We’ve tried rubber bands to lesser the tension, using all aluminium to make sure our bot is lighter, but we haven’t been able to get it just yet. Any help would be appreciated!
Thanks
Are you using speed or torque notors?
Make a mechanism that releases the tension for the rubberbands when you lift. If you still cannot lift after that, recheck your build quality for friction or your robot is simply too heavy.
Torque motors
What type of mechanism are you suggesting? We have tried with and without rubber bands attached to the back of the robot connecting to the lift
So can you lift without any rubberbands assisting?
If you can you would only need a passive release lever on your arm (assuming you use a 2 bar arm with a backwards hang) to release this tension to let you hang.
A picture of your lift would be helpful also.
We can lift without rubber bands. What do you mean by a release lever though? If you have a picture that would help
I do not have a picture, but I can try to explain my process.
When using a 2 bar mechanism to hang, when you prop your arm against the pole and begin to lift, you could use this force to push a lever which pulls up to pull out a pin that is holding your elastics.
So, let’s say you wrap your rubberbands around this standoff which is connected to the lever, so whenever it pushes up the standoff is pulled away and all of the rubberbands slip off allowing your robot to hang without fighting the elastics/rubber bands.
If I had my robot I could post a picture but it may not be until next Thursday that I could, so I hope this helps somewhat.
I’m going to try high hang again tomorrow and I’ll try to make a video to show you guys what I mean
There is also another “small” problem for us which is our anti flip mechanism, that we NEED to stop our bot from flipping during autonomous and for driving as well, as our lift is faster now.
Thanks
it should be noted, we have a 1:5 HS 6 motor lift, and can successfully lift through around 5 rubber bands on each tower in about 4 seconds. Check friction and the weight of the robot. The closer it is to the tower, the less torque it will extrude upon the system.
Though I haven’t made through hook for our yet, in testing my lift, it’s powerful enough to lift our robot with a 1:5 gear ratio using HS motors without elastics. The most important thing to remember is a bad lift gearbox can ruin an otherwise good robot. Also our robot is super light which is helpful.
We can hang with a 1:5 gear ratio on arms. The trick is to try to put all your weight on the tower for your arms so the weight is closer to the fulcrum, thus reducing the load on motors. We have our batts mounted inside our tower. Our tower is all the at the back of our chassis.
WITHOUT RUBBER BANDS
some robots can hang on a 1 : 3.125 gear ratio on 6 motor with out rubber bands.
Here’s an example of a rubber band release system(Not ours):
I would ask for internal gearing but it really doesn’t matter, so I’ll ask: How many motors are you using? The 2 main reasons that most lifts can’t lift as much weight as other lifts is because of build quality and friction. Build quality is important, however it is something that you get after a long period of building (For me it was a year). Now for friction. This is what makes or breaks good gearboxes. We had a decent gearbox, but it maxed out at 4-5 stars. After rebuilding it we just magically happened to max out at 8 stars. Some things you could do to reduce friction is to put nylon washers in between areas where pieces of metal contact, make sure that your gears are meshing properly, and use white lithium grease (I like WD-40) and make sure that no gears are chipped (You don’t want a slip gear). If you reduce friction and improve build quality enough, then your lift should start working more efficiently. Plugin: We are using a 1:3125 gear ratio with a passive rubber band release on our lift and we can hang.
We can hang with 6 motors 1:3 with rubber bands
That’s interesting. Do you have a video of that?
6 motors on a 1:3 ratio is essentially the same as 1:5 on speed motors. 1:5 speed is 1:3125.
That’s interesting
I’ll try to upload a video or pictures of our bot after school today
Yes, build quality is important my robot can hang on 6HS 5:1 so yes it is very possible