Scaling Winch Motor Help

[MoistRobot]

I strongly recommend the JVN Mechanical Design Calculator.

[Boltman]

We use 2 Full CIM + Toughbox...tested it to well over 100lbs

Winches up bot in 6 seconds to necessary height after hooking the bar

[pilleya]

Originally Posted by MoistRobot

I strongly recommend the JVN Mechanical Design Calculator.

Go to the linear motion tab, and put in the variables that you would like such as distance of raising, speed of raising and pulley size. It will help you identify the type of motor(s) that you will require and the gear reduction you will need to ensure adequate torque.

If you need help or you want me to double check your calculations just PM me

[DonRotolo]

See all the above first.

Next, you should consider some kind of winch system. The smaller the 'spool' the greater the mechanical advantage, while larger spools will wind more material per rotation.

With a winch you want to prevent back-driving, the tendency for the weight to let the spool unwind when unpowered. But remember you need to be able to get the robot down, eventually.

The 'rope' you use needs to be more than 2x as strong as necessary. A 300 lb breaking strength is not, in my own opinon, safe enough.

Look up the term 'fairlead' as it applies to winches, and consider using one.

Lastly, remember that if your robot turns sideways (wheels against the tower), your 'hook' will be more than 15" outside your frame perimeter, which is a problem.

Good luck!

[Tmeziere]

We are using a rack and pinion with a 30t gear.
775 pro with versa-planetary 7:1 gearbox then through a 20:1 worm gear.
total ratio is 140:1 and it is very fast. Also the worm gear keeps it from back driving

[OccamzRazor]

3506 is using a Mini-CIM on a vex versa planetary gearbox with a ratio of 63:1 on a 2" diameter spool. We realize most teams forget this but when the power to your robot shuts off you need a brake to keep your robot from back driving so we used a small pneumatic cylinder as a brake. It deploys into a cam attached to the winch spool shaft to stop the decent of our robot when the power shuts off.

We had the fastest and most reliable climber at the event with this setup but we did have a small failure on one of the sun gears that we are not sure about. It might have been overloaded, it might have been a defect but either way we had to take the gearbox apart and put a new stage in right before finals.

[Bruceb]

we are using all 4 of our drive motors with a PTO

[c.shu]

We use a single 775 pro with a versa-planetary geared down to 125:1 (3 stages of 5:1) and it seems to lift the bot without any problems.

If you have concerns about the power or performance of the 775 pro you can easily use the same system with a mini-cim.

[pilleya]

Originally Posted by c.shu

We use a single 775 pro with a versa-planetary geared down to 125:1 (3 stages of 5:1) and it seems to lift the bot without any problems.

If you have concerns about the power or performance of the 775 pro you can easily use the same system with a mini-cim.

What size pulley are you using on that?

However the mini-cim is not a 1:1 replacement for the 775pro, although the 775pro is about 125 watts more powerful than a mini-cim the main difference is output speed the Mini-cim rotates at around 6000rpm vs the 775pro which rotates at around 19300rpm so about 3 times as fast, this means that if you were to use a mini-cim you wouldn't require such a large gear-reduction( but also take into account that the mini-cim outputs less torque vs 775pro geared to the same speed as the mini-cim)