I just added a second battery wired in series. It's fast, and I'm going to need to practice driving it.Can I see a video please?
Can we get a pic of your AW too?
Really all depends on how many spot are available on the bracket if it is a competition...
You're gonna get some hate if you get a joke bot in and someones legit contender doesn't make the cute because the bracket is filled up.
But if there isn't really a bracket and everything is chill, sounds like a good opportunity for lulz. Play your cards well young jedi.
Or you could try and straddle that thin line of funny/effective like Dr Inferno Jr and Tentomushi did
By the way how's your big robot coming along?
Where does that compare to say RedRums
Where does that compare to say RedRums
Similar size. It looks like Redrum has a 24" drum.
Actually, part of my inspiration for the design in the first place was Redrum (the other part was an Ork Battlewagon from Warhammer 40,000, which with a Death Roller looks a lot like a giant version of Redrum crossed with a military half-track and covered with armour plates).
Welll than that's one huge drum. Could make for some very impressive gyro dances
a 24" drum is like twice the height of your average 220. sewer snake is only 8" high last rites is less 10" high.
The bigger it is the harder it hits right?
The bigger it is the harder it hits right?
Rotational kinetic energy is 0.5*(moment of inertia)*(Angular Velocity^2)
What that means is doubling MOI doubles energy, doubling angular velocity quadruples energy. I'm personally a fan of the compact, dense drum geared for high rpm, but both have their benefits.
The bigger it is the harder it hits right?Yes, and a drum of that size will be pretty killer...but, the drum will be 24 inches in diameter, bigger than most robots in their entirety. Hell, if you cut it in half, it could be a bot on its own!
The bigger it is the harder it hits right?
Rotational kinetic energy is 0.5*(moment of inertia)*(Angular Velocity^2)
What that means is doubling MOI doubles energy, doubling angular velocity quadruples energy. I'm personally a fan of the compact, dense drum geared for high rpm, but both have their benefits.
Exactly.
My reasons for using a large drum rather than a small are three-fold. 1. It looks awesome. 2. As you said, 24" drum spinning at 1000 RPM has twice the power as a 12" drum spinning at 2000 RPM. This way I can take advantage of using a brushless motor designed for 1/5th scale RC car electric conversions (at least until I upgrade to a PERM PMG-132) without worrying about whether it can keep up the massive RPMs needed for an effective drum. 3. Smaller drums don't seem to have that killer uppercut I'm looking for.
That's not quite an accurate reading of what I said.
For the sake of simplicity, let's pretend that the 24" drum has exactly twice the MOI of the 12" drum. We'll call them 1 and 2, since it doesn't really matter as energy is linear for MOI increases.
We'll say the big drum is at 2500rpm, little drum is at 5000rpm
5000rpm gives an angular velocity of 523.6 radians per second
2500rpm gives an angular velocity of 261.8 radians per second
So, for the 24" drum, you have (0.5)(2)(261.8^2), which is 68,539J
So, for the 12" drum, you have (0.5)(1)(523.6^2), which is 137,078J
Those numbers are way, way high, as the MOI would be lower in reality, but for illustrative purposes it works. This is why there's been a trend recently to spin a lighter single toothed disk/bar/etc at a much higher speed for spinning weapons.
Let's see what's left on the to-do list...
Get batteriesAlready done.Get Speed Control for drive motorsAlready done.Preliminary wiring for test purposesAlready done.- Find weapon motor and components
- Install power distribution circuit (Y harnesses, cutoff link, fuses and main power switch)
- Go to scrap yard in search of some still-useful plate metal for armour and some spiky bits for decoration
- Find another HW builder in the area for practice
- Enter first competition
http://www.ebay.com/itm/DC-MOTOR-GENERATOR-10-hp-12-24-48-Volt-Etek-MT-Electric-Car-Permanent-Mag-/300764013728?pt=LH_DefaultDomain_0&hash=item4606eea4a0 (http://www.ebay.com/itm/DC-MOTOR-GENERATOR-10-hp-12-24-48-Volt-Etek-MT-Electric-Car-Permanent-Mag-/300764013728?pt=LH_DefaultDomain_0&hash=item4606eea4a0)
etek for $270 gogogogoogogo
it's AC. DC doesn't have a switching frequency.
1/2 a horse for an almost 30lb motor at 115v is comically weak. a chinadrill (http://www.harborfreight.com/power-tools/cordless-drills/18-volt-cordless-38-drilldriver-with-keyless-chuck-68239.html) at 18v produces nearly 1/2 a horse.
a Inexpensive Chinese Brushless Motor (http://www.leaderhobby.com/product.asp?ID=9394001224160) or ICBM at 37v will produce just under 4 hp, weighs 2 1/2 lbs and it costs $70.
Might I recommend this:
http://www.hobbyking.com/hobbyking/store/__4935__KB45_11XL_1000kv_Brushless_Inrunner.html (http://www.hobbyking.com/hobbyking/store/__4935__KB45_11XL_1000kv_Brushless_Inrunner.html)
At 36 volts it will out put about 3.5 horse power. Use two for extra fun!
but your 1/2 horse motor puts out only 50w more than your standard 550 motor...
Alright... I'm considering an E-Tek Mars PMAC Brushless Motor (http://www.robotmarketplace.com/products/ETK-ETEKBL.html) for my weapon motor. Would you say its a good choice?
Alright... I'm considering an E-Tek Mars PMAC Brushless Motor (http://www.robotmarketplace.com/products/ETK-ETEKBL.html) for my weapon motor. Would you say its a good choice?Very nice motor, but why not get an original (http://www.robotmarketplace.com/products/ETK-ETEK.html) E-tek instead? Then you can just use a meaty solenoid (http://www.robotmarketplace.com/products/0-SL1168.html) and a battle switch (http://www.robotmarketplace.com/products/0-BATTLSW1.html), and you would be in business.
Honestly, if you're going to spend all that money you should really reconsider your entire plan... You've got a wheelchair frame with some angle iron bolted on and you're planning on strapping an etek to it... You could take all that money, order a whole set of parts, build a decent frame, get good wheels, etc.
If that one etek you buy breaks you're screwed. Build something that will be easier to fix when it breaks. It's for combat, it WILL break.
Very nice motor, but why not get an original (http://www.robotmarketplace.com/products/ETK-ETEK.html) E-tek instead? Then you can just use a meaty solenoid (http://www.robotmarketplace.com/products/0-SL1168.html) and a battle switch (http://www.robotmarketplace.com/products/0-BATTLSW1.html), and you would be in business.
what hes saying is that youll get more out of your bot and your money if you tone down the motor and toughen the frameHonestly, if you're going to spend all that money you should really reconsider your entire plan... You've got a wheelchair frame with some angle iron bolted on and you're planning on strapping an etek to it... You could take all that money, order a whole set of parts, build a decent frame, get good wheels, etc.
If that one etek you buy breaks you're screwed. Build something that will be easier to fix when it breaks. It's for combat, it WILL break.
I'll cross that bridge when it comes. Honestly, I don't really care too much if this first one gets trashed. It's a prototype, and I will be mothballing it after a few tournaments to build something better, even if it somehow gets a good win record. That's why I decided on going the cheap route with the frame.
what hes saying is that youll get more out of your bot and your money if you tone down the motor and toughen the frame
Just let him build the robot he wants to ffs. Even if he gets torn apart in the first eight seconds of a match, this sh** isn't about winning, it's about having fun. If his idea of fun is making something homebrew out of an old wheelchair, let him do it.im all for fun and all but eteks cost loadsamoney and if he breaks it hes essentially screwed out of $1000+ and im doubting if a wheelchair can even handle the force of an etek
im all for fun and all but eteks cost loadsamoney and if he breaks it hes essentially screwed out of $1000+ and im doubting if a wheelchair can even handle the force of an etek
im all for fun and all but eteks cost loadsamoney and if he breaks it hes essentially screwed out of $1000+ and im doubting if a wheelchair can even handle the force of an etek
If I break it? I know it will get trashed (at least eventually), but I'm not going to be the one who breaks it. If anything it's probably going to be one of the serious teams, like the Redrum or Tornado Mer guys, or maybe Jim Smentowski himself if he still competes with Nightmare.
Also, $1,000 isn't bad for what some people pay to build these things. Most Heavyweights cost around ten times that much, maybe more.
If Smentowski breaks it with anything it would be with Breaker Box, but I know for a fact that Nightmare is still in existence.
Nightmare had trouble winning 10 years ago, nevermind now.
Dude Nightmare is done. Electric Boogaloo is the new vertical to worry about...
do you have any concept of time. most of the robots you're afraid of haven't fought in 8 years.
You should probably make yourself up to date with modern competition....unless you plan on using a time machine and competing in 2003.
For reference, this (http://combots.net/cup/print/OriginalSin-bot.jpg) is the top ranked bot in the US.Huh? I thought Sewer Snake was in the top these days.
OS overtook SewerSnake at Robogames.For reference, this (http://combots.net/cup/print/OriginalSin-bot.jpg) is the top ranked bot in the US.Huh? I thought Sewer Snake was in the top these days.
uhh
Yeah if you actually plan on building a combat robot you should actually figure out how to get connected with people. it's really not that hard at all.
http://www.facebook.com/groups/RoboCommunity/ (http://www.facebook.com/groups/RoboCommunity/)
For reference, this (http://combots.net/cup/print/OriginalSin-bot.jpg) is the top ranked bot in the US.
Botrank.com has an active list of the robots which have competed in the last year or so.
uhh
Yeah if you actually plan on building a combat robot you should actually figure out how to get connected with people. it's really not that hard at all.
http://www.facebook.com/groups/RoboCommunity/ (http://www.facebook.com/groups/RoboCommunity/)
Something you might want to know about me: I hate facebook, and I hate the fact that you really cant do much online anymore without it even more.For reference, this (http://combots.net/cup/print/OriginalSin-bot.jpg) is the top ranked bot in the US.
Didn't that thing compete in Battlebots 5.0?Botrank.com has an active list of the robots which have competed in the last year or so.
Thanks. That will really help.
Then have fun missing out on a chance to get connected with fellow builders and event organizers.
Gary Gin(The builder of Original Sin) competed with Big B in series four and five. Big B still competes today, and is ranked fith historic on BotRank.For reference, this (http://combots.net/cup/print/OriginalSin-bot.jpg) is the top ranked bot in the US.
Didn't that thing compete in Battlebots 5.0?
Yeah, I hate the fact that the human race has developed the technology that allows people from around the world to stay connected with each other in an organized fashon. We need to go back to the 1800's and use telegrams to communicate, that would make so much more sense.
Forget facebook. ::ot:
Gary Gin(The builder of Original Sin) competed with Big B in series four and five. Big B still competes today, and is ranked fith historic on BotRank.For reference, this (http://combots.net/cup/print/OriginalSin-bot.jpg) is the top ranked bot in the US.
Didn't that thing compete in Battlebots 5.0?
As for Original Sin, its first tournament was RoboGames 2006, and it steamrolled the competition. To give you an idea on how good it is, Original Sin has won a total of eight competitions, five of which it won with out a loss.
http://www.lynxmotion.com/c-110-rc-combo-kit.aspx (http://www.lynxmotion.com/c-110-rc-combo-kit.aspx)
Just curious, but would this be any good for a starting platform for a smaller robot? Of course it wouldn't be an insect class, but maybe a hobbyweight?
And here: http://www.youtube.com/mattmaxsr (http://www.youtube.com/mattmaxsr)
watch some videos there.
MikeNCR also has a bunch of videos of east coast events http://www.youtube.com/user/mikencr/ (http://www.youtube.com/user/mikencr/)http://www.lynxmotion.com/c-110-rc-combo-kit.aspx (http://www.lynxmotion.com/c-110-rc-combo-kit.aspx)
Just curious, but would this be any good for a starting platform for a smaller robot? Of course it wouldn't be an insect class, but maybe a hobbyweight?
Nope, not at all. It's PVC so you'd end up replacing pretty much everything with steel or UHMW anyways. That and it runs a sabertooth and sabertooths tend to randomly die...
The motors it comes with are really slow and underpowered for a combat robot. 250 rpm with 4.75" wheels is going to be slow.
Final drive axle rpm x wheel diameter / 336= MPH
so...
253 X 4.75 /366 = 3.2 mph
That's really really slow. My 30 is geared for about 10 mph and it is a little above average in terms of speed. If I had to guess I'd say average top speed for a 12 or 30 lb robot is 6-8 mph.
with 4" wheels you want to look for a final output around 550-900rpm
The Mechanics
The robot chassis is made from heavy-duty anodized aluminum structural brackets and ultra-tough laser-cut Lexan panels. It includes four 12.0vdc 30:1 gear head motors and our 4.75" tires and wheels.
First one I watched was Sewer Snake vs Raging Scotsman. It looks like people use flamethrowers to get around the active weapon requirement, if it's still enforced.
Or is that a sportsman class rule?
Where I read it was PVC (http://www.lynxmotion.com/p-607-a4wd1-combo-kit-for-rc.aspx). I still wouldn't buy it. It's mystery aluminumTM and lexan of unknown thickness and weighs "n". Most of the parts such as the motors, hubs, and esc would need to be replaced anyways.QuoteThe Mechanics
The robot chassis is made from heavy-duty anodized aluminum structural brackets and ultra-tough laser-cut Lexan panels. It includes four 12.0vdc 30:1 gear head motors and our 4.75" tires and wheels.
Speed's still a little slow (4 MPH), but I could upgrade that. I mainly want to know if it would be better to buy materials separately rather than using a Lynxmotion rover kit.
First one I watched was Sewer Snake vs Raging Scotsman. It looks like people use flamethrowers to get around the active weapon requirement, if it's still enforced.
Or is that a sportsman class rule?
Sportsman class ruleWhere I read it was PVC (http://www.lynxmotion.com/p-607-a4wd1-combo-kit-for-rc.aspx). I still wouldn't buy it. It's mystery aluminumTM and lexan of unknown thickness and weighs "n". Most of the parts such as the motors, hubs, and esc would need to be replaced anyways.QuoteThe Mechanics
The robot chassis is made from heavy-duty anodized aluminum structural brackets and ultra-tough laser-cut Lexan panels. It includes four 12.0vdc 30:1 gear head motors and our 4.75" tires and wheels.
Speed's still a little slow (4 MPH), but I could upgrade that. I mainly want to know if it would be better to buy materials separately rather than using a Lynxmotion rover kit.
I can attest to the killability of a Sabertooth. I've killed a 2x12 in a 3lb robot with serious shock mounting. Stuff just kinda pops off the board.
You would end up spending over 400 dollars what could be done better for 250.First one I watched was Sewer Snake vs Raging Scotsman. It looks like people use flamethrowers to get around the active weapon requirement, if it's still enforced.
Or is that a sportsman class rule?
Sportsman class ruleWhere I read it was PVC (http://www.lynxmotion.com/p-607-a4wd1-combo-kit-for-rc.aspx). I still wouldn't buy it. It's mystery aluminumTM and lexan of unknown thickness and weighs "n". Most of the parts such as the motors, hubs, and esc would need to be replaced anyways.QuoteThe Mechanics
The robot chassis is made from heavy-duty anodized aluminum structural brackets and ultra-tough laser-cut Lexan panels. It includes four 12.0vdc 30:1 gear head motors and our 4.75" tires and wheels.
Speed's still a little slow (4 MPH), but I could upgrade that. I mainly want to know if it would be better to buy materials separately rather than using a Lynxmotion rover kit.
I can attest to the killability of a Sabertooth. I've killed a 2x12 in a 3lb robot with serious shock mounting. Stuff just kinda pops off the board.
Probably a typo. The main product page is the best thing to look at, rather than the smaller ordering page.
Also, I've built Lynxmotion kits before (a BRAT 6DOF Biped, specifically) and at least for a biped the aluminum brackets hold up well. As for the Lexan, it's quarter-inch. The kit weighs 4.6 lbs altogether, so it would probably be a Hobbyweight.
I just want to know if it would cost me more to custom-build rather than just modify the chassis, and whether it would be worth the savings.
You would end up spending over 400 dollars what could be done better for 250.
Still no.You would end up spending over 400 dollars what could be done better for 250.
Would it be worth it if I got the version without electronics?
Still no.You would end up spending over 400 dollars what could be done better for 250.
Would it be worth it if I got the version without electronics?
Those motors are slow, and kinda cost a bit. Even the one with the lowest gearing only produces about 200 rpm, and cost 21.95 US dollars each. For the same price, four Harbor Freight 900 RPM drills (http://www.harborfreight.com/power-tools/cordless-drills/18-volt-cordless-38-drilldriver-with-keyless-chuck-68239.html) will give you a tried and true drive motor, and a decent battery and charger. I'll leave other costs to other members because I went crabbing yesterday and my hands hurt.
Well I for one completely support the idea of getting an Etek. I always think it's better to get the better parts than to buy cheap ones and then later decide that you need to upgrade. Just make sure you mount it securely with a lot of protection as you wouldn't want it getting damaged.
However, those kits do not look suited to robot combat at all. You'd end up needing to build a completely new robot. On the most part, kits are not the best choices, as they tend to be made to be cheap and to introduce new roboteers than to be competitive.
and yet you can afford a friggin etekWell I for one completely support the idea of getting an Etek. I always think it's better to get the better parts than to buy cheap ones and then later decide that you need to upgrade. Just make sure you mount it securely with a lot of protection as you wouldn't want it getting damaged.
However, those kits do not look suited to robot combat at all. You'd end up needing to build a completely new robot. On the most part, kits are not the best choices, as they tend to be made to be cheap and to introduce new roboteers than to be competitive.
Alright, although until I can get the money for that E-Tek Mars and a brushless controller that can handle the current load I'm going to be running Battlewagon as a Wedge/Ram
By the way, I finally got some armour. Aluminum Tread Plate. I know the stuff can't stand up to a spinner (Hypnodisc could slice through it in Series 2), but again I'm not Team Whyachi so I will have to make do with what I can get for the time being.
Hypnodisc started in the third wars, and ran a Lynch motor.
I know the stuff can't stand up to a spinner (Hypnodisc could slice through it in Series 2), but again I'm not Team Whyachi so I will have to make do with what I can get for the time being.
I agree with SKBT, you should probably just put Battlewagon on Hiatus and work on making a 12 pounder or a 30 pounder like I am. It's a lot less complex (and usually cheaper) than building the bigger stuff but its still large enough for the satisfaction of making something...well, big....and "I'm not Team Whyachi" is an attitude that will get you no where.
and yet you can afford a friggin etek
Hypnodisc started in the third wars, and ran a Lynch motor.
and the lynch is a pretty badass motor....I know the stuff can't stand up to a spinner (Hypnodisc could slice through it in Series 2), but again I'm not Team Whyachi so I will have to make do with what I can get for the time being.
Dude that is a terrible build philosophy. A thrown together from scrap robot will preform like a thrown together from scrap robot...
I think it would be better for you to forgo your ego and stop building a 220 until you get more experience. Realistically you've never been to a competition, you don't have any money to build it correctly and assuming you are planing to take it to combots and robogames you have no money to ship it there. (It will cost you about three grand to ship everything: tools, robot, spare parts there and back.)
You seriously need to attend a competition before you go out and build a robot. Youtube videos don't do the destruction and forces involved justice. Its also a chance to talk to builders and see their bots and how they are built. I've never seen a good robot from a rookie whose never been to a competition and I've been competing for a few years now.
Instead of building a 220 maybe you should consider building a 30 and attending an event with it before you invest a crap ton of money in a 220. Also it doesn't hurt that there are more events for 30s on the east coast.
what were trying to get across to you is that you somehow can afford an etek
As for building a smaller robot, you guys have been shooting down every single one of my ideas so far. So let me ask this... Does every single robot that you see have to be the best, most destructive thing you've ever seen? I'm happy that I got the !@#$ thing to move at a decent speed to begin with using the tools I have on hand. This isn't RA2, and I don't have an unlimited budget. If I did I wouldn't be building the thing out of a wheelchair do begin with. :realmad(
Have any of you who are actually commenting here even built a heavyweight before.
As for building a smaller robot, you guys have been shooting down every single one of my ideas so far. So let me ask this... Does every single robot that you see have to be the best, most destructive thing you've ever seen? I'm happy that I got the !@#$ thing to move at a decent speed to begin with using the tools I have on hand. This isn't RA2, and I don't have an unlimited budget. If I did I wouldn't be building the thing out of a wheelchair do begin with. :realmad(
I know it's a lot like Sewer Snake
well, condsidering you havnt bought it yet let me make a suggestion- dont buy an etek, seriously you need $$$ for armor too you knowwhat were trying to get across to you is that you somehow can afford an etek
Except I can't. I'm considering one but I would have to save up. My budget for this project (not my idea to set it this low) is just a bit over $1,500, and the fact that I got the thing moving (and at around 15 MPH at that) for half that cost is a miracle.
I know it's a lot like Sewer Snake
So because it has wedges....it looks like Sewer Snake?
lol seriously who gave you the roboteer title
This is the Great Pumpkin (http://combots.net/cup/print/GreatPumpkin-bot.jpg), built by the same team that made Last Rites. Take it as an example, all it consists of is pretty much what you have, a pair of wheel chair motors, a solid construction, and filled with high quality parts. No active weapon, no exotic materials, I doesn't even have wheel guards. The only thing of note about it is the fact that it runs off of A123 batteries.
Here's my last bit of advise, if you are still going to build a heavy, use whatever is left of your budget to invest in armor and batteries, especially the last one. A good set of NiCads (http://www.battlepack.com/NICAD-Battlepacks.asp), or even better, A123 batteries (http://www.battlepack.com/LiFEPO4.asp), will give your bot the amps it needs. I'm not sure if your running your bot on 24 volts or 36, or even 12, but I strongly urge you to invest on good quality batteries. They will last you several builds if properly maintained, saving you money in the long run. Use a quality charger, like the AstroFlight 112 Deluxe (http://www.astroflight.com/index.php?main_page=product_info&cPath=1&products_id=25)(Or the AstroFlight 123 (http://www.astroflight.com/index.php?main_page=product_info&cPath=1&products_id=130), you'll need a balancer (http://www.astroflight.com/index.php?main_page=product_info&cPath=34&products_id=21) though!) and a good power supply (http://www.astroflight.com/index.php?main_page=product_info&cPath=1&products_id=26) like this one, and again, they will last you a long time if properly cared for.
That's my two bits. You've already gone farther than most members here, and I really hope that you can make it to ComBots this year.