Are those Globe motors on the wings? Looks like it to me. Globe’s can’t take sideloads, I’d expect those to break down.
Are those the 12" stroke x 2" bore cylinders? Those look massive and longer than 16" total length, maybe just my perspective
*Originally posted by Gadget470 *
**Are those Globe motors on the wings? Looks like it to me. Globe’s can’t take sideloads, I’d expect those to break down.
**
I second the notion, he is correct.
great bot though
Side loads are definitely a no-no on Globes. We fried about four of them in 2000 before we realized that. Anyways, I’m not sure how much of a side load would be present on this 'bot. I’d be careful regardless, though.
The major problem will occur when the wings are pushed at the ends. Unless the globes provide enough power without breaking down, the robot will easily spin.
Good looking bot though and I look forward to seeing you at the Buckeye Regional this weekend.
ACK!!
those wheels are terrible!!!
absolutly NO traction on any surface…unless you modified them, cause i cant see a difference.
but nice design though
BAd
I’m guessing that the wheels are used simply to help move and stabalize they’re arms, which need no additional traction.
Some of you guys are going way to hard on this robot and the way it was designed. I think almost everyone that has replied to this has been out right rude.
Think before you speak. Such as the comment about the globe motors breaking off; it should have been worded differently.
Then the wheel comment; well someone needs to improve alot on how they reply…
I like Andy Baker post in one of my teams last forums, teams need to think about what they say, because there can be a lasting hardship.
Overall I think the robot looks good. I can see the wings folding down and the outward wheels providing power. The way it looks to me is that the globe motors are isolated enough that a side load to the wings should not affect them. However a sideload to the motor housing could. You guys, might think about making a metal housing if you have weight at your first competition to protect them. If you don’t happen to have the materials or man power and we are at a competition with you guys, swing by our pits (Team 68) and we will more than gladly make something up for you. Good luck!!!
I don’t feel my comments were out of line. Globe motor’s can’t take sideloads. They have a nice design, in fact, one of my design ideas was to have a wheel coming down on a set of wings to drive against robots on the HDPE. It ended up being shot down though
Using globe motors though was a bad idea, hopefully they can find a way to swap it with something else, chip, drill, fp… The Globe’s would work with a worm gear to stop the sideload but it looks like (from thier other picture) they have gears. Gears will create a massive sideload on the motor. The motor has a lot of torque, but can easily burn out. Being that they can’t buy new one’s and MIGHT not be able to get spares from FIRST (Motor death due to design flaw that isn’t being changed)
Many of the motors supplied in the kit of parts were not originally designed to be used as robot drive motors. The motor shafts on the drill and Globe motors were designed to provide axial torque only. They have very little ability to sustain side loads imposed on their motor shafts. Take care to securely fasten these motors and couple them with flexible couplings to the rest of the drive train when they are used for motive power.
This is from the Robot Construction section of The_Robot.pdf.
Thier globes do not have (again, from my perspective) a Flex. Coupling on them nor are they very securely mounted. I don’t think the globe’s will break off but break down.
I like thier overall design, but I do think there are flaws. I’d be willing to help them out at my regional, but they may not need it. I do hope to see them as a competitive force, but I don’t want to see them fail because nobody pointed out a flaw. Maybe they have securly mounted the Globe beyond what I can see from the pictures provided. Maybe they will be a champ. Maybe they will be a powerhouse. I have no idea as I’ve never seen the robot drive. It’s a nice design, with a flaw. Everyone’s bot has a flaw, it would be naive to say one’s doesn’t. But many flaw’s can be fixed, as I think is the case with their Globe’s driving.
I guess it was just the way you initially come across when I read this thread. It may have not been your comments along, however I thought the comments were going in a very negative direction for this team, which they weren’t able to defend. Just my feelings.
It seems as though many people like the wing idea. I know I did as well as many other T3 members and as a result T3 was born.
I agree with you that the output shalf or motor housing can not take side load. I usually assume that a pivot point would be at where the motor face plate bolts on to the robot. You would have a lever arm for the motor housing as well as the output shaft. By controlling the deflection of the motor housing, meaning very little movement, the output shaft can handle a much larger load as a result of this bracing. This just using some common enigneering, I believe the college course that I learned most of this in was Mechanics of Materials.
I hope that they can either come up with a housing for the globe motor to decrease deflection or have multiple spares on hand. In either case I have talked to a few of our metal makers and they are willing to help, with a design and build if needed. Also I agree with you that FIRST might not have spares on hand, hopefully they can count on other teams to provide this as well. Swing by our pits, I think we might have an extra case or two of globe motors. (Not using them this year).
Hope this clears things up, and please don’t feel as though I was attacking you, I was only attacking the way in which you posted your comments.
Those little globes are tougher then most of you give them credit for
We have a similar setup to that and we broke a axle instead of the globe.
Greg