Planetary 100:1 gear box - VEX - w/ CIM motor - Stripped gear

#7

The highest ratio on a versa with a cim is 64 to 1. Use an Andy Mark Sport.

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#8

To expand on this, the Andymark Sport gearboxes have a special “HD” stage for their third stage. It’s designed for higher torque applications, and let’s them have higher reductions than you can get in a VP.

Also, for a standard elevator, 100:1 is probably going to be much slower than you want. My team’s elevator last year ran on a 7:1 with a CIM, using a 1" diameter spool - good speed, plenty of torque. I might go a little higher if it was a 3 stage elevator, but it was fine for our 2 stage!

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#9

I have never tried the AM Sport…but I really need a 100:1 Cim this year. This is the perfect solution! I wish I had see it earlier!!!

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#10

Do you use a redline motor with this sport gearbox or a CIM ?

#11

Stripped a VEX planetary 100:1 gear box last night on our elevator under no real load or stress. Not looking to put the same thing back in.

This is what I have:

Single stage elevator moving about 15 lbs - output to sprocket 1:1

These are parts that I have on hand:

Option 1
toughbox mini - 10.71:1 (Drive box off last year’s drive chassis)
Use this with two 2.5 CIM motors? Or is one CIM enough?

Option 2
Redline motor with sport 57 gear box 64:1 (hex 1/2 out put)

option 3

two motor Redline coupler (sorry can’t remember proper name but it came in 2019 KOP) to 64:1 sport gear box.

scrambling here and need some help.
Thanks

#12

Option 4:

CIM 2.5 motor to 10:1 to 5:1 planetary gear box 1/2 hex output (over all 50:1)

#13

It’s late in the season for this already, but you should use either JVN’s or my design spreadsheet to help you calculate the proper motor-ratio combination for your application.

One CIM is plenty for a 15 lbs elevator. Using the 10.71:1 TB mini should give you a decent speed and not too high current/stall-voltage. The 50:1 VP is too large of a reduction, so your elevator will move very slowly.

Normally I would say you want two Redlines so you can have a lower stall voltage, but if the elevator is truly only 15 lbs then you should be fine with one. Using the 64:1 57 sport should put you in the right speed range. Adding the Two Motor input would increase that to 208:1, which is way too high.

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#14

Stripped a VEX planetary 100:1 gear box last night on our elevator under no real load or stress. Not looking to put the same thing back in.

This is what I have:

Single stage elevator moving about 15 lbs - output to sprocket 1:1

These are parts that I have on hand:

Option 1
toughbox mini - 10.71:1 (Drive box off last year’s drive chassis)
Use this with two 2.5 CIM motors? Or is one CIM enough?

Option 2
Redline motor with sport 57 gear box 64:1 (hex 1/2 out put)

option 3

two motor Redline coupler (sorry can’t remember proper name but it came in 2019 KOP) to 64:1 sport gear box.

scrambling here and need some help.
Thanks

#15

Learn to use one or both of these calculators now. It is better late than never.

You have only several more days until you have to put your robot in the bag. It is quite likely that a thoroughly tested version of your final gearbox design will not go into the bag. If you bag your current gearbox design, it is likely to fail and you will be relegated to playing defense. Not much fun as my team discovered last year :frowning:

Have you built a practice robot or do you intend to do so? If you are, you can test your gearbox solutions on it. If not, can you replicate just some parts of your elevator design so you can test your gearbox solutions?

It is just over a month until your one Regional. If you plan your work well and design the gearbox mounting so it is easy to install, you can go to your Regional and install a proven, robust gearbox design in a short time and still have time for some practice matches and have some fun. You may also want to keep your elevator carriage and intake mechanisms and refine them further along with the gearbox. Quite a few teams do this to effectively extend their build time. We are.

You have one shot at this so learn to use the calculators that AriMB linked and make it a good shot. Best of luck!

#19

Not sure if using TB mini is an option available to you for immediate assembly. We thought of doing the same for our elevator earlier but discovered that KoP chassis TB mini did not come with a front plate that is needed for mounting to the elevator.

#20

This is inaccurate. Redlines can absolutely be used in an elevator application.

I urge you to use the JVN calculator linked above to determine the loads your motors and gearbox would experience and act appropriately. The Sport gearbox you have on hand sounds like a reasonable solution.

#22

Plenty of teams use them. In fact some use exclusively 775pros/RedLines. I understand that your past experience with them may not have been positive, but they are reliable workhorses when put into a mechanism with some thought. The benefit of CIMs is that they will take all sorts of abuse so you can get away with throwing them at pretty much any problem. 775pros/RedLines are a lot lighter and will do the same tasks if you take a moment to use the JVN or AMB calculators.

#23

I’d caution you from spreading mis-information. Plenty of teams have used and continue to use 775pros and Redlines for their elevators, intakes, and almost any other application. If you use them properly, they are very reliable motors. It’s important to understand the tradeoffs of the different motors, and use the proper gear ratio for your motor and application.

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#24

I’m not posting misinformation I’m just sharing my experience with them

#25

Go ahead and use them they work amazing but we just always had ares blowing up

#26

And redlines have a tendency to blow up if they are going fullspeed and then just all of a sudden just stop

Yes your correct they could be used but I don’t see them being reliable

Go ahead and use them they work amazing but we just always had ares blowing up

This is what I was talking about. That’s not just your experience, it’s generally misleading. You might not be doing it on purpose, but you should know that just because it didn’t work when your team tried it doesn’t mean it doesn’t work for any team or won’t work for this team. In fact, I’d reckon that in the vast majority of cases where teams used 775pros/Redlines properly (i.e. with the proper gear ratio, impact dampening, voltage/current limiting) they worked well.

#27

It’s just stressful times trying to finish the robot and I’m not meaning to be misleading

#28

AndyMark has sport gearboxes for either one. The “57” works with either 500 or 700 series motors.



They even have a neverest sport, and a Dynamo sport, and a dual-775 sport.

If you do want the torque from a 100:1 CIM using a VP, you can use gears to get down to 50:1 or so, then do another 2:1 reduction with chains or belt. Sometimes this makes packaging easier as well.

#29

I wish VEX would take this off their product configuration. It is just such a misleading configuration. I bought into it and then read the horror stories after the fact. At least I didn’t implement it and destroy 2 gear sets.

#30

Except it isn’t. If you look at their load ratings guide, the 100:1 ratio is properly rated for some motors - the am-9015, RS-550, RS-775, BAG motor, 775Pro, depending on your choice of output shaft.

There could be improvements to the website, to integrate the load ratings into the gear selection. The way it is right now, it’s a free-for-all, that lets teams hurt themselves if they don’t do their research. It’s important to still have the free-for-all ability - it’s entirely possible I would get on there and order a combination of gear reductions that could look large, along with the CIM adapter, but be intending to combine those with parts I already have in hand to make several gearboxes that would fall within the load ratings guide. So having a “free-for-all” section, along with a section where you can select the motor being used, then the desired gear ratio (from a limited list of gear ratios), would be ideal.

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