NeveRest 60 in FRC

[cadandcookies]

RE: Neverest 60 gearmotors (all the Neverest motors are the same motor with different gearboxes, correct me if I'm wrong, Billfred)

The actual motor is compatible with anything (okay, I've only seen them in VPs and Banebots) that will take a 550 motor. This has become popular in FTC this year-- I know some teams running them through VersaPlanetary gearboxes and one of the FTC Robot In 1 Weekend teams used them on their shooters with Banebots gearboxes.

I think that FRC teams that use them (presuming they're legal), will be very pleasantly surprised compared to the old garbage Tetrix motors. I've seen a Neverest 40 stall for a full two minutes and perform just fine for the rest of a tournament. Compare this with the Tetrix motors that burned out if you looked at them funny, they're a major improvement. I would hesitate to call these guys "magic smoke generators" after watching teams abuse the different flavors of Neverest for the past few years. The only failure mode I've ever seen on them is due to improper/uncareful use of set screws, not due to the motors themselves.

[EricH]

Question for anybody who has some older motor specs lying around:

Can someone do a quick comparison of the Globe motor/gearbox setup (discontinued for FRC purposes about a decade ago) and the NeveRest 60? Seems like somewhere around the same power and form factor, off the top of my head--think the Globe might have had more power, though.

[Billfred]

Originally Posted by bobbysq

I was more going off of that minibots were made of FTC parts in general, although, I guess the definition of "FTC parts" has expanded quite a bit since 2011.

Quite a bit, indeed!

2010-2011 FTC Rules (R5 is the approved materials)

2016-2017 Game Manual Part 1 (RM01 is the start of what's approved.)

In theory, the husk of an FTC robot might not have changed all that much for a DIY team since you could try and do it out of angle and flat aluminum. But if you're low-fabrication type like many FTC teams are, there are now many more options for structure, motors, wheels, gears, and other motion components--AndyMark, Rev, Actobotics, and Matrix are all making parts explicitly for FTC teams, and BaneBots and VEXpro parts are starting to make some inroads where their qualities are helpful.

[Jared Russell]

Originally Posted by EricH

Question for anybody who has some older motor specs lying around:

Can someone do a quick comparison of the Globe motor/gearbox setup (discontinued for FRC purposes about a decade ago) and the NeveRest 60? Seems like somewhere around the same power and form factor, off the top of my head--think the Globe might have had more power, though.

NeveRest 60 is 11.5W max power.

Globe Motor was 47W.

BAG motor is 149W.

[Billfred]

Originally Posted by cadandcookies

RE: Neverest 60 gearmotors (all the Neverest motors are the same motor with different gearboxes, correct me if I'm wrong, Billfred)

The actual motor is compatible with anything (okay, I've only seen them in VPs and Banebots) that will take a 550 motor. This has become popular in FTC this year-- I know some teams running them through VersaPlanetary gearboxes and one of the FTC Robot In 1 Weekend teams used them on their shooters with Banebots gearboxes.

I think that FRC teams that use them (presuming they're legal), will be very pleasantly surprised compared to the old garbage Tetrix motors. I've seen a Neverest 40 stall for a full two minutes and perform just fine for the rest of a tournament. Compare this with the Tetrix motors that burned out if you looked at them funny, they're a major improvement. I would hesitate to call these guys "magic smoke generators" after watching teams abuse the different flavors of Neverest for the past few years. The only failure mode I've ever seen on them is due to improper/uncareful use of set screws, not due to the motors themselves.

The two things I've seen that tend to do in NeveRests are:

1) Set screw hub maladies. We released D-bore Nubs this year to help solve this problem.
2) The NeveRest 20 gearhead is less tolerant of shock loads than the 40 and 60 gearheads. (The number is the reduction from the bare motor: 20:1, 40:1, 60:1.) However, per Kate's blog post, only the NeveRest 60, am-3103, as pictured here has been announced as legal at this time and (as far as I've seen) FIRST hasn't announced whether switching (or removing) the gearhead will be an approved modification for the 2017 FIRST Robotics Competition. So that may be a moot point.

Originally Posted by EricH

Question for anybody who has some older motor specs lying around:

Can someone do a quick comparison of the Globe motor/gearbox setup (discontinued for FRC purposes about a decade ago) and the NeveRest 60? Seems like somewhere around the same power and form factor, off the top of my head--think the Globe might have had more power, though.

This white paper shows the Globe has a free speed of 79.87 RPM and 3195 oz-in of stall torque (at 21.58 amps). The NeveRest 60 has a free speed of 105 RPM and 593 oz-in of stall torque (at 11.5 amps).

[EricDrost]

We've been doing FTC for three years and I think we've seen every possible failure these motors can have. Less common failures I've seen are magic smoke (only once and it was totally our fault), and cold solder joints under the black plastic caps (two times). Billfred is spot on about the two most common failures:

Originally Posted by Billfred

1) Set screw hub maladies. [...]
2) [...] shock loads [...]

We've tried a lot of solutions to the D-shaft/set screw issue, a lot of which had slipping issues we couldn't solve. The most effective solution we found that still used the NeverRest gearheads was mounting these to the D-Shafts, then drilling through hex adaptor and the D-shaft and tapping to 4-40. About 90-95% of the D-shafts were hardened steel and required a carbide drill bit, 5-10% were mild steel. Before we settled on this solution, we lost ~5 motors in one season because a set screw would round out part of the D-shaft.

We didn't try the nubs because the above was more effective at converting D to 0.5" Hex in our opinion.


Shock load causing the individual gears to shear teeth is the most common problem (in my experience) with 20s, 40s, and 60s. The gearheads share the same design as the 2011 tetrix gearheads with spiraling pairs of spur gears held together by hopes and optimism. We lost ~15 motors in one season due to shock load, mostly in drive train applications.

Originally Posted by Billfred

FIRST hasn't announced whether switching (or removing) the gearhead will be an approved modification for the 2017 FIRST Robotics Competition. So that may be a moot point.

I can't imagine it would be illegal as swapping the gearhead isn't an electrical modification. I sincerely hope this is legal because the two most common failures are gearhead failures, not motor failures.


My recommendation to any team using these motors in FRC (or FTC) is to remove the gearhead/buy the version without the gearhead. As others have said, these motors integrate very well into VersaPlanetary gearboxes. We put 2 of our 8 NeverRest motors into VP gearheads last season and experienced zero failures with them. This season we have put every single motor on the robot into a VP and have had zero failures so far.

TL;DR: The motors are pretty good but replace the gearhead for serious use.

[AdamHeard]

Originally Posted by EricDrost

My recommendation to any team using these motors in FRC (or FTC) is to remove the gearhead/buy the version without the gearhead. As others have said, these motors integrate very well into VersaPlanetary gearboxes. We put 2 of our 8 NeverRest motors into VP gearheads last season and experienced zero failures with them. This season we have put every single motor on the robot into a VP and have had zero failures so far.

TL;DR: The motors are pretty good but replace the gearhead for serious use.

For FRC this seems like a pretty unoptimal choice. By going into a VP you're barely saving any weight over a BAG/775 (and no weight over a 550) and giving up a HUGE power advantage.

For FRC applications where you desire a motor w/ low speed, low power (to be more robust) and integrated encoder, the PG71's motor on a versaplanetary fits the bill much better.

[EricDrost]

Originally Posted by AdamHeard

For FRC this seems like a pretty unoptimal choice. By going into a VP you're barely saving any weight over a BAG/775 (and no weight over a 550) and giving up a HUGE power advantage.

I'm in total agreement.

The point of my post was to alleviate some of the headaches for a team that chooses to use them. The biggest advantage I can see (the integrated encoder) also disappears when you put them into a VP because of the new encoder stages available for VPs.

[Andrew Schreiber]

Originally Posted by EricDrost

I can't imagine it would be illegal as swapping the gearhead isn't an electrical modification. I sincerely hope this is legal because the two most common failures are gearhead failures, not motor failures.


My recommendation to any team using these motors in FRC (or FTC) is to remove the gearhead/buy the version without the gearhead. As others have said, these motors integrate very well into VersaPlanetary gearboxes. We put 2 of our 8 NeverRest motors into VP gearheads last season and experienced zero failures with them. This season we have put every single motor on the robot into a VP and have had zero failures so far.

TL;DR: The motors are pretty good but replace the gearhead for serious use.

There's precedent - the Window and Globe motors both had what FIRST deemed "integral" reductions on them and we were not allowed to use the motors w/o the reductions. Could have a similar ruling here. That being said, if the NR60s are allowed I'd hope the 20s and 40s would be too.

[Billfred]

Originally Posted by EricDrost

We've tried a lot of solutions to the D-shaft/set screw issue, a lot of which had slipping issues we couldn't solve. The most effective solution we found that still used the NeverRest gearheads was mounting these to the D-Shafts, then drilling through hex adaptor and the D-shaft and tapping to 4-40. About 90-95% of the D-shafts were hardened steel and required a carbide drill bit, 5-10% were mild steel. Before we settled on this solution, we lost ~5 motors in one season because a set screw would round out part of the D-shaft.

I never knew about these adapters, but I'm impressed! (The true low-buck method is to take churro tubing, hacksaw one end about an inch down, jam it in place, and then use a shaft collar to clamp. Worked well enough to get through Fight Night for a few of us.)

My recommendation to any team using these motors in FRC (or FTC) is to remove the gearhead/buy the version without the gearhead. As others have said, these motors integrate very well into VersaPlanetary gearboxes. We put 2 of our 8 NeverRest motors into VP gearheads last season and experienced zero failures with them. This season we have put every single motor on the robot into a VP and have had zero failures so far.

TL;DR: The motors are pretty good but replace the gearhead for serious use.

To achieve a 63:1 reduction with a VersaPlanetary costs $84.95 ($89.95 if you want 1/2" hex)--base stage, two ring gears, 7:1 and 9:1 stages. That buys you six NeveRest 60 gearheads (and most of the 7th), which also tucks into a smaller space (shorter, and the diameter is basically that of the motor itself). If you have means to protect against shock loads in the design, the packaging and budget advantages of the stock gearhead may be attractive to you.

(And at the risk of being a broken record, FIRST has still not announced whether removing or changing the gearhead is an approved modification.)

Sent from my desk at AndyMark

[Libby K]

Originally Posted by Billfred

To achieve a 63:1 reduction with a VersaPlanetary costs $84.95 ($89.95 if you want 1/2" hex)--base stage, two ring gears, 7:1 and 9:1 stages. That buys you six NeveRest 60 gearheads (and most of the 7th), which also tucks into a smaller space (shorter, and the diameter is basically that of the motor itself). If you have means to protect against shock loads in the design, the packaging and budget advantages of the stock gearhead may be attractive to you.

I think it's a difference worth spending for teams that can afford it - That $85 is the means (for our FTC teams) of protecting against the shock load. Our FTC teams were so thankful when buying them without the gearhead became available. The spiraling spur gears don't hold up well on the small robots, I'd be really worried about FRC team applications. Releasing latches or other servo-like replacements work with the gearhead on, but anything more heavy-duty, in our experience, is less reliable.

Originally Posted by Billfred

(And at the risk of being a broken record, FIRST has still not announced whether removing or changing the gearhead is an approved modification.)

Yep! Definitely something teams will have to pay attention to. Our mods come from the FTC world where it is legal. Hopefully they allow for it in FRC - the modifications our FTC teams have learned to make have made their robots significantly more dependable. If there's a situation where teams need to use them (cue the 2011 flashbacks) I hope teams will be able to customize in a way that lets them play their best.

[FTC5110]

Originally Posted by Libby K

I think it's a difference worth spending for teams that can afford it - That $85 is the means (for our FTC teams) of protecting against the shock load. Our FTC teams were so thankful when buying them without the gearhead became available. The spiraling spur gears don't hold up well on the small robots

It really comes down to how you treat them. We've used NeveRest motors since they arrived on the scene and gearbox failures aren't an issue. Our team has given these motors death in drivetrains and lift systems but always made an effort to minimize shock loads through control systems.

Okay the 20:1 is a bit weak (we broke 2 last season) and some emit funny noises but they're cheap and don't leak smoke.

Never had an issue with the spiraling spur gears. What on earth are you doing to them!

[xjschwen]

We are playing the FTC game this year and have blown out 4 of the Neverest 20 gearboxes. This was because the middle school teams did not set them to float at motor power 0.. W hen the motor power was set to zero the brake would come on and there was enough inertia in the shooter to trash the 20:1 gearboxes.

We took the gearboxes off and put an FTC motor collar directly on the spur gear.

So instead of attempting to gear up from 300 RPM to about 1800, we now start at 6000 RPM and gear down to 2000 RPM. We have a far better shooter than we had. The gear train is far simpler... less friction.. more reliable.

In 3 years of FTC we have burned out only 1 of these motors but have trashed many gear boxes.

[Tom Line]

Originally Posted by bobbysq

Something tells me that minibots aren't as fun as I thought they were.

Edit: For discussion of the motors themselves, I made a thread in the Motors subforum about them:
https://www.chiefdelphi.com/forums/s....php?p=1617079

Imagine designing a game where 20-40% of the game score can hinge on the last 15 seconds of the game. Then require the teams to use parts that none of them have in stock for their minibot in a somewhat misguided attempt to bring middle-school kids into FRC. Then act surprised when teams spend thousands and thousands of dollars developing faster and faster minibots, so the point where the fastest ones were thousandths of a second apart. Then design a system that doesn't always register when a minibot finishes, so that the entire crowd can HEAR the minibot hit the finish plate but the system never registers it. Then, ask the refs to watch and try to enforce a rule that the minibots are not crossing an imaginary starting plane ahead of time.

It was a fiasco - one that I still grumble about. You can go back and watch some of the 'fastest' minibots cross the plane well ahead of the light change using youtube slowmo. Those poor refs.

[Tom Line]

Originally Posted by Andrew Schreiber

There's precedent - the Window and Globe motors both had what FIRST deemed "integral" reductions on them and we were not allowed to use the motors w/o the reductions. Could have a similar ruling here. That being said, if the NR60s are allowed I'd hope the 20s and 40s would be too.

You might be recalling incorrectly - we were allowed to modify the globe motor geartrain. Many times we glued the planetaries to the sun and ground the outside ring teeth off to remove a reduction.