| Drive motors? | |
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+6Cody rdubard Dan Curhan Frisco tb1h Andy 10 posters |
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Andy
People Skills : 5359 Registration date : 2010-04-16 Location : South Park, PA
| Subject: Drive motors? Fri Apr 16, 2010 11:59 pm | |
| Alright so I was at the SWPA bots iq competition today (15 lb class) and I noticed tha a lot of teams were using castle creations brushless motors with a 26:1 banebots gearbox gear ration. I considered using a monster max brushless for drive myself. However we ran out of time and money for those so we stuck with the stock brushed motors with a 16:1 gearratio. This leads me to my question...I also noticed that a lot of the more experienced or better teams were using the stock brushed 540 drive motors as well instead of highend brushless motors for the drive. Does anyone know why this is so? Is there a perfomancething I don't know or was it just that the brushless were too expensive for those teams? | |
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tb1h
People Skills : 5336 Registration date : 2010-04-10 Age : 30 Location : center township
| Subject: Re: Drive motors? Sat Apr 17, 2010 6:30 am | |
| i would say a mamba max would kinda overkill for a drive motor also the regular mamba we have the 550 motors in our bot and the have tons of power and its a little to quick its hard to control which would lead me to believe that a mamba would be twice as fast and even more hard to control | |
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Frisco super contributor
People Skills : 5917 Registration date : 2009-11-01 Age : 52 Location : Brownsville, Pennsylvania
| Subject: Re: Drive motors? Sat Apr 17, 2010 7:29 am | |
| Banebots for the drives. And either a Brushless that has good torque and over or near 1000kv or the mamba for the weapons.
Stop over and talk to me about it today.
Frisco (advisor for West Mifflin) | |
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Andy
People Skills : 5359 Registration date : 2010-04-16 Location : South Park, PA
| Subject: Re: Drive motors? Sat Apr 17, 2010 5:25 pm | |
| Your right it probably would be overkill and especially not worth the price. Thanks for the advice guys. | |
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Dan Curhan Admin
People Skills : 6570 Registration date : 2009-03-14 Age : 33 Location : Sarasota, FL
| Subject: Re: Drive motors? Sun Apr 18, 2010 10:29 am | |
| I have no experience with brushless drive, but my one comment is this:
DC brushed motors have maximum torque at 0 RPM. Brushless motors have very little startup torque in comparison. | |
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Andy
People Skills : 5359 Registration date : 2010-04-16 Location : South Park, PA
| Subject: Re: Drive motors? Mon Apr 19, 2010 7:23 pm | |
| Ok thanks guys! I'm gonna try and do some r&d and see what works for us. | |
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rdubard mega contributor
People Skills : 6135 Registration date : 2009-06-10 Age : 59 Location : Ransom Everglades, Miami, FL
| Subject: Re: Drive motors? Tue Apr 20, 2010 6:23 am | |
| Dan's got the right idea--too much load on a brushless before it starts and you get cogging (unless it's a sensored brushless, which it seems no one is using), but a simple brushed DC motor has max torque on startup, always.
Brushless systems are generally also expensive, but to compensate they have amazing efficiency, so you might be able to get by with smaller batteries.
Overall, brushless drive doesn't seem like a great idea to me.
However, most of the brushed drive motors that come with the gearboxes are really cheap junk. (We have continued to use them anyway, because my students have been too busy to research alternatives) I know that Team Jag/rjw has found some quite superior aftermarket hobby motors but it seemed dishonest of me to peek to closely at the fruits of their labors, so I cannot make a specific recommendation. | |
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Cody 2000+ club
People Skills : 8015 Registration date : 2009-03-16
| Subject: Re: Drive motors? Tue Apr 20, 2010 9:06 am | |
| i've only ever seen one robot use a brushless drive. It was team from meadville and the bot was a major fail in my oppinion. The kid just kept talking about his batteries when I tried talking to him lol
Brushed drive is the tried and true way to go. | |
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Andy
People Skills : 5359 Registration date : 2010-04-16 Location : South Park, PA
| Subject: Re: Drive motors? Tue Apr 20, 2010 12:44 pm | |
| is everybody using the banebots brushed motors or is anyone gettin high quality rc car brushed motors? | |
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rjw Chief Bottle Washer
People Skills : 7968 Registration date : 2009-03-31 Location : Miami
| Subject: Re: Drive motors? Tue Apr 20, 2010 12:55 pm | |
| - Andy wrote:
- is everybody using the banebots brushed motors or is anyone gettin high quality rc car brushed motors?
mlec uses aftermarket motors on all but 1 bot, which is still using some bb's Don't jumo too quickly tho....the higher end rc stuff is not without it's own set of problems.....I've seen bushes, brush holders, endcaps, etc all go south if steps aren't taken to prevent ...and they can get expensive. do your research and 'AVOID THE PAIN' jmo | |
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Cody 2000+ club
People Skills : 8015 Registration date : 2009-03-16
| Subject: Re: Drive motors? Tue Apr 20, 2010 2:28 pm | |
| At the pa competition you are already a step ahead of most of the teams with p-60s and banebot motors | |
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jtm94 great contributor
People Skills : 5582 Registration date : 2010-04-23 Age : 30 Location : Clairton, PA
| Subject: Re: Drive motors? Fri Apr 23, 2010 7:25 pm | |
| I must say that for our first year our team made THE worst mistake and bought some terrible, and I mean terrible, robotmarketplace drive motors. If it wasn't for that our robot may have actually been competition in the losers bracket. At the competition at Century III I did notice that "most" of the robot failures resulted from awful drive motor gearboxes. | |
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rjw Chief Bottle Washer
People Skills : 7968 Registration date : 2009-03-31 Location : Miami
| Subject: Re: Drive motors? Fri Apr 23, 2010 7:45 pm | |
| If you look around here, elsewhere and ask a LOT of questions, next year will be totally different. All teams go thru a weening period...do you homewoark and 'AVOID THE PAIN' | |
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jeeves_m_d ULTRA contributor
People Skills : 6254 Registration date : 2009-04-21 Age : 31 Location : Sudbury, MA
| Subject: Re: Drive motors? Fri Apr 23, 2010 9:07 pm | |
| RJW is right, my weening period has been the past 3 years hopefully senior year i might know what i am doing | |
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rjw Chief Bottle Washer
People Skills : 7968 Registration date : 2009-03-31 Location : Miami
| Subject: Re: Drive motors? Fri Apr 23, 2010 9:25 pm | |
| - jeeves_m_d wrote:
- RJW is right, my weening period has been the past 3 years hopefully senior year i might know what i am doing
everyone easnt s to vuild the New LATEST AND GREATEST..but except for a few things, most of it has already been done. No shame in steeling....or should I say borrowing stuff from other bots that actually works. It's actually a compliment to whoever built the other bot. Plus, most mistake are made in how it is executed. Many bots have drums or beaters and BIG AXI motors, etc but few matched up to Hummdinger....He had a whole package 1) Good design 2) Good choice of materials and components 3) Good driver 4) Godd execution of the design 5) Goos funding or sponsorship, in that large chunks of S7 and Ti aren't cheap and more Lolcano looked good, but perhaps you should have spent a bit more time getting your weapon tweaked before nat's...I know, I know...so much to do and so little time... the point is, if you skip any steps or take shortcuts.....others will show up and be better prepared and will kick your robutt..... Fluffy 2 was looking like it was going to be a heck of a bot, but I think that Will spread himself too thin with all the other bots he was working on...and to my surprise, Sting WMD got in a good hit, a couple of bolobat type bounces and it was basically all over..... Sometimes the draw at these events will kill you..... fwiw: it will be hard (unless you have a hummdinger) to go to an event with 1 robot and compete against teams with 3 or 4 or more strong bots. Over time, attrition is a VERY big factor. Until they change the rules and force teams to fight their own bots full force, there will always be an advantage to bringin more ...unlees they're all weak bots. | |
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jeeves_m_d ULTRA contributor
People Skills : 6254 Registration date : 2009-04-21 Age : 31 Location : Sudbury, MA
| Subject: Re: Drive motors? Fri Apr 23, 2010 9:37 pm | |
| Thank you for that, its funny you mention humdinger 2. Matt was a big help when we were coming up with the first lolcano 3 years ago he sorta let slip his funding story and it was really amusing how dedicated he was. Apparently most of his bot was self funded, His grandmother left him money to buy a car and he used it to make humdinger 2. I didn't here it from matt himself but my team mate who had been talking with him for a while. | |
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rjw Chief Bottle Washer
People Skills : 7968 Registration date : 2009-03-31 Location : Miami
| Subject: Re: Drive motors? Fri Apr 23, 2010 9:49 pm | |
| I met him at nat's in 2008..he was all alone and I felt bad for him....that was before they fought and he kicked everyone's butts...lol
Anyhow, he told me a bit about how Boeing helped out or whatever.....
In any case, he had plenty of driving expereince and was extremely dedicated.
So if you spend a lot of your time on the couch watching the tube or whatever and you end up losing to someone who lives it, eats it, dreams about it, etc. well that's sometimes how it goes.
Like anything else, the more effort you put into it, the more you'll probably get out of it. | |
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Cody 2000+ club
People Skills : 8015 Registration date : 2009-03-16
| Subject: Re: Drive motors? Sat Apr 24, 2010 12:42 am | |
| he had told me it was between a car or a new humdinger but he never mentioned where the money came from.
There is no doubt in my mind he deserved to not only win that competition but the best driver award also | |
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SenaiERI mega contributor
People Skills : 6160 Registration date : 2009-03-15 Location : Dallas, Tx
| Subject: Re: Drive motors? Sat Apr 24, 2010 11:44 pm | |
| - rjw wrote:
- No shame in steeling....or should I say borrowing stuff from other bots that actually works.
It's actually a compliment to whoever built the other bot. Plus, most mistake are made in how it is executed. Wow wow wow, how can you say that? It's one thing if you ask about advice on drive motors or something like that, but steeling/borrowing doesn't stimulate innovation and progress, and does the exact opposite of what this competition stands for. I've seen many teams copy, and I mean exactly, what other teams have done, but the simple fact is that they didn't design it. They didn't put in the effort or time to come up with something original. It's just disrespectful. | |
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rjw Chief Bottle Washer
People Skills : 7968 Registration date : 2009-03-31 Location : Miami
| Subject: Re: Drive motors? Sun Apr 25, 2010 12:28 am | |
| well...steeling a complete bot design is one thing....borrowing a few ideas is another. In many cases (for example the shock bot clone) they actually missed the boat and didn't do such a good job at replicating. true innovations are few and far between. A few years back, I first saw a picture of Maximum Impact and I thought that it was fabulous.....after doing a lot of looking around, I realized that it was just mostly stuff borrowed from much older bots.... If the event is just about innovation, then they would just have teams submit designs , pictures, etc and hand out the awards. Currently, the bots have to actually compete in combat.....so, while perhaps a spoon as a weapon could be considered innovative, it might not hold up against some of the current 12" diameter x 1" wide solid tool steel spinners. If you look closely and analyze a bot such as Hummdinger......there's more there than what seems obvious and easy to copy. If I had a group of NEW kids that could accurately and effectively replicate that bot, I'd be impressed, in that they would have to have a very good understanding of a lot of physics and engineering concepts to be sucessful. Would it be original...No but it would still have a lot of ecducational value. Try cloning the space shuttle and see how any of us do....but it would be a heck of a learning experience the borrowing thing is part of what this sport is about. We all share ideas and some implement them better than others. look at the evolution of the tank (which is kind of close to a combat bot) they really haven't changed all that much...still on a track with a rotating turret.....lots of subtle innovations, mostly due to changes in technology, but still looks very similar to the oldest ones. If you want a competition that forces or spawns a lot of innovation, then maybe FIRST is a better choice. but then you don't get to DESTROY the opponent....... jmo | |
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Frisco super contributor
People Skills : 5917 Registration date : 2009-11-01 Age : 52 Location : Brownsville, Pennsylvania
| Subject: Re: Drive motors? Sun Apr 25, 2010 10:25 am | |
| I have to say that when designing a robot from scratch ( we have done it 3 times) you always look at what has been a winner and what has been a loser.
Then you pick out the points that are good and bad as far as those robots design. (There might be good designs in a losing bot) (There might be bad designs in a winning bot)
Then you look at the parts and materials that were used in what you have decided was a good design.
Then you match the good parts and materials to the good designs.
Then you look at sizing that might have been a deciding factor...
This is where your design process starts..... You have an idea of a good concept and chassis and you have an idea of what parts need to be used where and you have an idea of what materials can be used where..
Now you design a chassis that works with what materials and parts and how big things should be....
To say you stole an idea is not right but you looked at what works and what doesnt...
We have looked at Robots like Surgical Strike for our Robot Doomsday..... We looked at K2 for our Robot To the Roof.... We looked at Solaris and Jeremys Bots for others...
To say we stole anything is false but we used their research and fights to change ideas and materials and designs for what we built....
They look nothing alike and the materials were far different but we tried our own things...
Some worked and some didnt...
This is designing at it's best!
Although new concepts are always the way you start, somethings just dont make it past the Cadd Drawing.. Some Things make it to a final build...
Frisco | |
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Cody 2000+ club
People Skills : 8015 Registration date : 2009-03-16
| Subject: Re: Drive motors? Sun Apr 25, 2010 11:47 am | |
| taking what has been done and tweaking it is the only way bots are going to get better
Senai how much influence did mini blender have on your bot? and the original blender?
Theres nothing wrong with it, but please just dont make an exact replica.
When we finally fought aftershock clone at the end i laughed, leaned over to alex and said "i'm pretty sure we never had a wheel fall off" lol | |
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SenaiERI mega contributor
People Skills : 6160 Registration date : 2009-03-15 Location : Dallas, Tx
| Subject: Re: Drive motors? Mon Apr 26, 2010 11:17 am | |
| Oh no I agree completely. The way I read it, it sounded like you were advocating taking things from other teams and claiming them as their own. Research and design of different components are absolutely necessary, and it is impossible(unlikely) to start from scratch every year. Perhaps I miss understood you. My mistake. And as far as my TM goes, I always call it a "15 lb shrunken down version of The Blender, which was my high school's robot a few years back." I always make sure give the credit for the concept to the team that started it all and did such a great job with the design. AAAAnd if you look at the two bots, mine should have been called "Blender Mini" cause it most resembles The Blender, but someone had already taken the name. The modifications I made to TM were defiantly necessary but that goes to with what you guys were saying earlier. About looking at what works and what doesn't, and optimizing the design from there. Again, I think I misunderstood what you were saying. | |
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