Banebot Gearbox
 

We tried to take the metal plate off like your supposed to but couldnt get them off. Anyone know what size we need. Nothing we had worked and the ones that looked like they fit just would slip. They seem to be in there very tight.

Re: Banebot Gearbox
 

FYI the allen screws are English I don't remember the size but I assembled them not to long ago

Re: Banebot Gearbox
 

I'm not meaning to hi-jack this thread, but has anyone else had problems with their gearbox jamming? One of the boxes is fine, but the other ones keeps jamming up. We have taken it apart and re-assembled it numerous times to no avail.


P.S. the allen wrench size is: 3/32" for the plate.

Re: Banebot Gearbox
 

Much appreciated. If i can figure out where we put our allen wrenches ill let you know if ours jam. Maybe put some grease on em.

Re: Banebot Gearbox
 

Thanks, we've added more grease, but still nothing. I look forward to your response though!

UPDATE: We figured out what the problem was, apparently, the bushing was too long on one of the motors, so we ground it down on the lathe and all is well!

Re: Banebot Gearbox
 

Using 3/32" only works for half of them for us. The others use something large than that but its smaller than the 1/8" wrench. Its so annoying. Im going to have to see if I have a 7/64" wrench or figure out what the heck is wrong with these screws.

Re: Banebot Gearbox
 

Has anyone pulled one apart? Is there only that one bearing I can see from the outside? I'm guessing it wouldn't be wise to slap a wheel smack on there without another bearing eh?

Re: Banebot Gearbox
 

I haven't pulled apart the gearbox yet, but I was wondering the same thing. Dr Joe, care to give an answer to this?

While picking up the KOP at the Manchester Kickoff, I noticed that FIRST had built a couple practice bots. One robot used the new Banebot Trannies, and left the drive shaft fully cantilevered. Below you can find a picture. I was quite surprised to see if used in this configuration.



I don't think I'll be using it in this configuration, but YMMV.

BEN

Re: Banebot Gearbox
 

I too have concerns about shaft loading on the BB trans. If we were to use the 2 cim adapter and use 2 sprockets to duplicate last years 4 motor 4 wheel drive kit bot, can the 56mm trans take that shaft load and input? Has it been tested. Is the bearing support necessary for a 2 sprocket load? Can the 56 mm trans handle 2 cims? Would a safer bet be 4 cims 4 trans? Joe any comments?

Re: Banebot Gearbox
 

I hate cantilevered loads. But I learn to live with them if their is good support for the shaft and if the loads are not too great.

So... ...my first recommendation is that you figure out a way to support the end of the shaft if you can. In fact, I recommended that FIRST put the bearing plate in the kit.

But...

There ARE two bearings supporting the output shaft but the bearings are side by side so things are kind of in a gray area. Yes I think is okay to have some side load on these shafts, but I would not suggest teams cantilevering load if the sprocket or gear is going to be far out on the shaft.

You can probably get away with it is you have a single sprocket and are not using the encoder (which spaces the load out).

Joe J.

Re: Banebot Gearbox
 

Thank you for your reply but can you answer why a 3/32" allen srench only works on half my screws? As of right now my only solution is to cut them out and buy and replace them with new ones from BB.

Re: Banebot Gearbox
 

I don't have an answer. Have you tried a metric hex wrench? It seems unlikely, but I suppose it is possible that a few metric screws got mixed in the bin where ever BB has them assembled?

Anyone else having this issue?

Very odd.

Joe J.

Re: Banebot Gearbox
 

are you using a VEX allen wrench? they're not quite up to spec....and will strip out a screw that is really tight.

Re: Banebot Gearbox 2.5mm metric hex wrench required
 

See this thread:

http://www.chiefdelphi.com/forums/showthread.php?t=51250

Re: Banebot Gearbox
 

All of the Banebots screws are metric (I had fun taking it apart), and if you dont use metric then you will strip the socket heads.

Re: Banebot Gearbox
 

Ah. Thank you.

Re: Banebot Gearbox
 

Whoa! I don't know how I missed seeing that picture earlier but to me, that is about the scariest picture I have seen in a long time.

Perhaps the bearings inside that gearbox are better than I thought, but I would have never never never hung a sprocket that far out on that shaft.

I am thinking that the only way they got away with it was that they weren't really using it in competition and they must not have had the grippiest of tires.

Looking at that picture sends shivers down my spine! Really -- read this post for more on my views of emotion and engineering.

Joe J.

Re: Banebot Gearbox
 

Agreed,
They are definitely metric. Go get your self a good set of ball end metric allen wrenches.

- Bochek

Re: Banebot Gearbox
 

We were experiencing the same problem with the gearbox as well, the bushing was indeed too long. It was trimmed with the lathe and voila!

Re: Banebot Gearbox
 

Anywhere I could get specs on the gearbox? (load capacity, structural integrity, etc.) We're thinking of using these for our bot's chain-driven 4WD, but we aren't sure what they can handle.

Re: Banebot Gearbox
 

The allen screws in the end plate are 2mm metric. (the label reads made in China)

Re: Banebot Gearbox
 

We need them too!!

Re: Banebot Gearbox
 

I'm noticing a great number of posts on the lack of QC on the BB transmission... Should my team be worried about maybe using this, as lack of QC can mean robot failure at the most inapprapriate time?

Re: Banebot Gearbox
 

What exactly does the bushing being too long do to cause it to bind? Does the pinion on the CIM hit the planet carrier?

Re: Banebot Gearbox
 

anyone know how reliable the new BB 2 CIM gearbox adapters are?

Re: Banebot Gearbox
 

If anyone from FIRST is reading this, please include 1/2" shaft collars next year because it was no fun having to retain the sprockets onto the shaft with duct tape. :(

Re: Banebot Gearbox
 

I suppose a trip to a hardware store or web browser was out of the question?

Re: Banebot Gearbox
 

No, what I mean that since the Kit of Parts should include the materials for any team to build a basic robot, they could have included some shaft collars in the crates.

Re: Banebot Gearbox
 

It should? Says who? (remembering the days when all we got in the Kit Of Parts was a surplus computer printer and a Small Parts Incorporated catalog...)

-dave

Re: Banebot Gearbox
 

I actually emailed BaneBots tech support for EXACTLY this question. Here is their response:

The two motor adapter does not change the gear reduction so in a best case [assuming no mechanical loss] the RPM would be the same as with 1 CIM motor and the torque would be twice that of a single CIM motor.

The 56mm gearbox and two motor adapter was specifically designed for FIRST applications and we believe they will support two CIM motors.

BaneBots

I don't know though---It doesn't seem like that little sucker can handle those two big CIMs. I'd hate to find out the wrong way.

Re: Banebot Gearbox
 

Umm. :rolleyes: Does that mean they didnt test them?

Re: Banebot Gearbox
 

Dunno. That's all they wrote to me so I sent a second message for some numbers and things.

All I gotta say is - YOU BETTER HOPE THIS THING WORKS!!!


sorry banebots. I like your company name. I just don't like your indecisiveness.

Here's my reasoning. If FIRST made the switch from those big square single-speeds of the past 2 years to these BB planetaries, they've got to be substantial enough. For them to replace something THAT GOOD, these new ones are probably just as good.

sorry FIRST. I think it's cool that your company name is an acronym. I just don't like your choice of gear reduction devices.

Re: Banebot Gearbox
 

Has anyone tryed to put a big cim in the BB tranny?... and if so what kind of modifications did you have to make?

Re: Banebot Gearbox
 

By the sounds of things team 2200 will be getting 2 of thoes doubble cim adapters. as well as 2 more Cim's

Only time will tell how well the BB trannies hold up.

- Bochek

Re: Banebot Gearbox
 

Our team may go with the 56 BB and 2 cim adapter. We will be supporting the shaft if this is the teams choice.

Re: Banebot Gearbox
 

i was wondering what the 80/20 to 1/2 aluminum square stock was in weight

we may go with a 6 wheel design and need to cut down on weght got any ideas

Re: Banebot Gearbox
 

Our team is also questioning the possibility of these transmissions with the 2 cim adaptor to fail. So instead of hoping and praying were going with 4 individual trannies. Our design will provide redundancy and safe guards to prevent chronic failure.

Re: Banebot Gearbox
 

This is a post by BaneBots

The 56mm gearbox and 2 motor adapter were tested independently by BaneBots and FIRST.

The only issue we are currently aware of is with mounting the CIM motor to the 56mm gearbox. We have seen that in some instances the pinion extends too far into the gearbox and causes the gearbox to bind. We have identified three things that may cause this:

1) There is grease between the stages that temporarily holds the stages too far apart. This can usually be resolved by turning the gearbox a few times by hand or removing the internal gears and reinserting them. DO NOT REMOVE THE GREASE FROM THE GEARS.

2) The pinion spacer is to long. If the pinion extends beyond the shaft the spacer is too long. The easiest fix this issue is to shorten the spacer so that the pinion is flush with the end of the shaft.

3) The motor mounting plate is too thin or shaft is too long. We have recently seen small variances in the thickness of the mounting plate and the length of the CIM motor shaft. If the pinion is flush with the end of the motor shaft and there is still a problem, this is likely the problem. There are two ways to address this problem. You can either shorten the CIM shaft and spacer or you can add a thin spacer between the gearbox and the motor mounting plate.

With proper correction, the mounting problem does not affect the reliability of the gearbox. We do not know of any reliability issues with either the gearbox or the two motor adapter.

Please keep the following two points in mind:
- Either support the gearbox shaft or keep the load as close to the face of the gearbox as possible.
- Do not depend on the gearboxes to support the weight of the motors - support the CIM motors.

If you are having a problem with any of our products, please contact us for assistance - www.banebots.com/contact.

BaneBots

Re: Banebot Gearbox
 

Thanks for the detailed info on the fixes - its good to hear the scoop from the source.

Hopefully this isn't too off-topic..... do you have any efficiency data for the gearbox with the CIMs? Or, short of that, perhaps a measured free-speed value based on testing of a gearbox?

Thanks,
Ken

Re: Banebot Gearbox
 

We just tested a prototype using the Banebot trannies, Kit sprockets, and kit AndyMark wheels. One CIM per gearbox.
<These figures are the best I have. These numbers were exchanged quite a lot tonight and they may very well be off a little>
My figures were as follows:
CIM-5370 rpm->tranny (12:1) ->sprockets (1.625:1)->AndyMark wheel
Gives you ~ 7.3 fps
When we timed it (free wheeling up off the ground) we came up with~6.75, which gives you about 92% efficiency, and from that we figured that the gearbox shaft was turning such that a directly mounted wheel would give you ~ 10.8 fps. That doesn't take into account loss in the chain and sprockets.
This was timed off of our slower motor, so others' figures may not line up. If anyone finds a big discrepancy, please let me know.
Hope this helps! Good luck!

Re: Banebot Gearbox
 

It's a 2.5mm wrench. If you use the 3/32" wrench, when you tighten it, it will strip out.
~Olav
team 2039

Re: Banebot Gearbox
 

Team 2200 had the bot driving around today and encountered a problem with the BB gearbox,

the screws that hold the case together. (4 on each end of the case)

One of them was not lined up properly when drilled. So when the bolt was installed the case was flexing enough to cause the gears to bind.

The simple temporary fix was to remove the screw.

- Bochek

Re: Banebot Gearbox
 

We are having the same problem. How much did you grind down your bushing anyways? Thank you!

Re: Banebot Gearbox
 

Looking at #38 above, I'd say you should grind the spacer until the pinion gear is flush with the end of the CIM shaft. If you still have interference then the shaft is too long -- shorten it or shim between CIM and gearbox.

Re: Banebot Gearbox
 

I'm not aware of exactly how strong the gearbox is, however I would not suggest direct drive without added support.

That being said, BaneBots sells the bearing plates with the same mounting holes as the transmission itself, meaning all you have to do is get one of those and figure out where you're going to mount it.

I do suggest, however, running a chain drive system. Even if it's short. The weight of the chains and added mounting hardware shouldn't be too much (say, 5lbs for a 4-wheel setup and some heavy chain), plus if a motor or gearbox fails and you don't have time to take it out, just disconnect the power, take a link out of the chain, and take the chain off, leaving the corresponding wheel free to move.

Re: Banebot Gearbox
 

OK

For what it's worth I ran our teams 2 BaneBot trannys with single CIM's mounted on the workbench last night in a no load condition.

Note: this was after machining (ok grinding :D ) the bushing down to make sure it doesn't bottom out against then planetary. It was ground down to make the pinion even with the end of the CIM shaft.

The units appear to be lubed up nicely from the factory. However with experience being my guide I did add some light grease to the pinion (read: Vaseline) when I re-assembled the unit.

Initially the CIM's drew over 6 amps measured with a DC clamp-on. After running them for approximately 1/2 hour the current dropped to a steady 3.5 amp draw. There was a noticeable change in sound from the units as well during this break-in period. Not so much in volume as in smoothness.

One of the units did seem to have some issues when you flexed the motor/tranny assembly slightly while running. Note that all screws were tight. Once the current draw had settled to the 3.5 amp area I noticed that the slight flexing now had no effect.

After running each CIM for 1/2 hour the outer casing of the motors were each measured at 105 deg F. I was happy with this temp as 1/2 hour is a long run time for these motors. With last years KOP trannys our CIM's never came in after a match any less than 160 deg F.

This is well within what we consider a "safe" area. When drill motors were the main drive motors a few years ago the temp was usually around the "hot enough to boil spit" range so I'll take under 200 deg F any day.

Conclusions?

I would trim the bushing down and carefully assemble your units, keeping everything clean.

Break-in the transmissions and let them run for a while. This is good practice anyway and lets all the parts get "comfortable" with each other.

When mounting them on your robot I would carefully tighten them down to make sure you don't add any undue stress/flex. I would also recommend a support under the CIM's. A small piece of wood is the simplest.

Then drive the snot out of your robot base and see where any weak points may be.


This was our experience and as always your mileage may vary.

Good luck.