Author Topic: Possible bot? (Read 4473 times)

That Robot is a Spy! · « **on:** August 02, 2011, 09:47:31 AM »

Here's a possible bot I could make:
Size: Square (20 X 20 X 7)cm
Weight: Featherweight
Material: 70% Titanium 20% Aluminium 10% Steel
Motors: Golf Caddy Motors
Wheel Drive: 2
Wheels: Possibly Go Kart Wheels
Receiver: 6 channel ( 2 drives, battery, speed controllers and weapon)
Speed Controllers: GT Electronics H5
Weapon: Drum with horizontal bars. Drum made from titanium and bars from steel.
Weapon Power: ~~Perm~~ Unknown as of yet

Not bad IMO. What else do I need?

SKBT · « **Reply #1 on:** August 02, 2011, 10:06:45 AM »

No golf caddy motors and wheels. Cheapo 18v drill motors and caster wheels are better for FW's

Good luck finding a TI pipe. That could be used as a drum. I'd recommend a 1/8" wall steel pipe with S7 tool steel drum teeth.

20x20 is very very small for a FW to put it in prespetive my FW flipper is 30x50cm but if you can build a smaller bot go for it.

How much machining experience do you have? TI is very hard to work with and hard to weld.

R1885 · « **Reply #2 on:** August 02, 2011, 10:10:23 AM »

Possible, yes.
Are you a first timer in bots? Whats your budget? Whats your country (UK? USA?)
Some tips:
That's an awful lot of titanium, perhaps switch to 7050 aluminum alloy for less cost and around the same strength?
In the feather world, The ampflow A28-150 rules all.
Golf Caddie motors are a false economy, you need to chain them down, and there heavy. This motor should do you nicely: http://www.robotmarketplace.com/products/0-PDX26.html
The go cart wheels also have the same problems, go with Colson performa tires instead.
You haven't specified a battery, nor voltage.
Do they even make the ESC you specified any more? You could go with a Vantec, or an IFI Victor 883 if you need the money.
How is the weapon controlled?
You also have not specified the radio, either.

SKBT · « **Reply #3 on:** August 02, 2011, 10:26:39 AM »

Ampflow doesn't rule anymore. Now it's brushless motors that rule. I dont know enough about them to tell you what's good though.

The PDX gearmotor is not great for drive. It's too slow. You want at least 500 RPM as a final motor output to get any decent speed with reasonably sized wheels. By reasonably sized I mean 4"

R1885 · « **Reply #4 on:** August 02, 2011, 10:38:08 AM »

Ampflow motors, I think, are still better for combat, they have a proven tack record, and compared to a lot of the brush-less motors on the market, I think the're built with better quality, and they don't fry under load.
Also, didn't that PDX motor output 923 RPM at 12 volts?

That Robot is a Spy! · « **Reply #5 on:** August 02, 2011, 10:38:48 AM »

Quote from: SKBT on August 02, 2011, 10:06:45 AM

No golf caddy motors and wheels. Cheapo 18v drill motors and caster wheels are better for FW's
I thought GCM were a bit heavy. I'll give the drill motors a try.

Good luck finding a TI pipe. That could be used as a drum. I'd recommend a 1/8" wall steel pipe with S7 tool steel drum teeth.
I'll use a steel pipe. I'd rather bars than teeth as teeth do get in more, but the tradeoff is that they break easier.

20x20 is very very small for a FW to put it in prespetive my FW flipper is 30x50cm but if you can build a smaller bot go for it.
I'll start big and shrink if I need to. About 40 x 40 x 7 and see if I can shrink it.

How much machining experience do you have? TI is very hard to work with and hard to weld.
I'm not great with the metal fronts of things, but my next neighbour used to make private airplanes. I could ask him. As for electronics, I can manage that. I've used a soldering iron before.

Quote from: R1885 on August 02, 2011, 10:10:23 AM

Possible, yes.
Are you a first timer in bots? Whats your budget? Whats your country (UK? USA?)
Yes, first timer in bots. Budget's about £1000ish. I'm British.
Some tips:
That's an awful lot of titanium, perhaps switch to 7050 aluminum alloy for less cost and around the same strength?
I know, but I want my bots armour to last longer. If it's constantly being replaced (the armour I mean), perhaps I could try 7050.
In the feather world, The ampflow A28-150 rules all.
I might use different motors, but I want to keep my motors fairly cheap.
Golf Caddie motors are a false economy, you need to chain them down, and there heavy. This motor should do you nicely: http://www.robotmarketplace.com/products/0-PDX26.html
The go cart wheels also have the same problems, go with Colson performa tires instead.
Do you have a link?
You haven't specified a battery, nor voltage.
Forgot about that. Need some time to think about it. Probably 24V though.
Do they even make the ESC you specified any more? You could go with a Vantec, or an IFI Victor 883 if you need the money.
I'm not sure, I'll need to look at some more speed controllers, see if there's more choice.
How is the weapon controlled?
Spin motor. Need some advice here.
You also have not specified the radio, either.
6 Channel Spectrum most probably

I was thinking a lot about heavyweights with my drive and wheels.

R1885 · « **Reply #6 on:** August 02, 2011, 10:50:01 AM »

Made a mistake, it's 7075, not 7050. :x
But yah, go for the aluminum. Compare the costs of a two foot by two foot sheet of 7075, 1/8 inches thick:
http://www.onlinemetals.com/merchant.cfm?pid=12663&step=4&showunits=inches&id=916&top_cat=60
Compared to the costs of a titanium sheet of the same size and thickness:
http://www.onlinemetals.com/merchant.cfm?pid=7852&step=4&showunits=inches&id=322&top_cat=1353
Link to Colsons Performa wheels are here:
http://www.robotmarketplace.com/products/colson_wheels.html
Just keep in mind that Colsons have no hub or key way, you need to make your own or get one with a hub built in(Will provide a link if you need it)

Also, if you want to a little cheap on the motors, an 18v Dewalt old style motor can be used as well.

That Robot is a Spy! · « **Reply #7 on:** August 02, 2011, 11:11:45 AM »

Quote from: R1885 on August 02, 2011, 10:50:01 AM

Made a mistake, it's 7075, not 7050. :x
But yah, go for the aluminum. Compare the costs of a two foot by two foot sheet of 7075, 1/8 inches thick:
http://www.onlinemetals.com/merchant.cfm?pid=12663&step=4&showunits=inches&id=916&top_cat=60
Compared to the costs of a titanium sheet of the same size and thickness:
http://www.onlinemetals.com/merchant.cfm?pid=7852&step=4&showunits=inches&id=322&top_cat=1353
Man, that's a huge diffrence :O
Link to Colsons Performa wheels are here:
http://www.robotmarketplace.com/products/colson_wheels.html
Seem decent
Just keep in mind that Colsons have no hub or key way, you need to make your own or get one with a hub built in(Will provide a link if you need it)
Probably will need the link please :)
Also, if you want to a little cheap on the motors, an 18v Dewalt old style motor can be used as well.
Would that work with 24v batteries?

Does 60% 7075, 20% Titanium and 20% Steel sound better?

Also, I might make an antweight first, just so I can get used to it. Should I make an Antweight before my Featherweight?

haz · « **Reply #8 on:** August 02, 2011, 11:25:47 AM »

R1885 · « **Reply #9 on:** August 02, 2011, 11:43:39 AM »

The Dewalt old style drill motor can be over volted to 24 volts, just be careful that it does not stall.
Team Delta can make hubs for Colson wheels, you have to specify the shaft size and the key size.
Link to team Delta's website:
http://www.teamdelta.com/products/prod5b.htm
If the wheels are to pricey for your use, you can use NPC wheels with delrin hubs, but you may have traction issues.

haz · « **Reply #10 on:** August 02, 2011, 12:37:35 PM »

or robot chalange blue wheels

Vertigo · « **Reply #11 on:** August 05, 2011, 10:35:23 AM »

Your budget doesn't make a good robot

Explosion only cost £500, which I know is much less than a lot of others, but is currently ranked 2nd in the UK

It's how you make it, and only then what you use

If you wouldn't mind me asking, how old are you, and how much do you understand about robotics?

infiniteinertia · « **Reply #12 on:** August 05, 2011, 10:51:32 AM »

Low budget? Beetleweight / antweight then move up. Vert is right. $$$ is an issue.

SKBT · « **Reply #13 on:** August 05, 2011, 08:04:55 PM »

Quote from: Vertigo on August 05, 2011, 10:35:23 AM

Your budget doesn't make a good robot

Explosion only cost £500

How did you do that when a burket valve alone costs $165 (£116)?

I've dropped $1400 (£990) to build a very similar bot. What did I do wrong? How did you so cheaply?

Edit: I realized Explosion doesn't have TI armor so thats probably where the cost discrepancy was. :P

Stagfish · « **Reply #14 on:** August 07, 2011, 09:43:19 PM »

My feather cost £110.

GoldenFox93 · « **Reply #15 on:** August 07, 2011, 09:46:20 PM »

Quote from: Vertigo on August 05, 2011, 10:35:23 AM

Your budget doesn't make a good robot

Indeed- look at Mortis, for instance. Sure it's a good robot, but it cost about £30,000 IIRC, and only recorded two more wins than 101, which cost only £1.01.

G.K. · « **Reply #16 on:** August 08, 2011, 02:33:54 AM »

Except it didn't - Mike Franklin had spent upwards of £1,000 on Robodoc and scavenged the parts from that to make 101.

Conraaa · « **Reply #17 on:** August 08, 2011, 02:36:04 AM »

So it didn't really cost a pound and a penny?
This is almost as bad as the time I found out Santa Claus died.

G.K. · « **Reply #18 on:** August 08, 2011, 12:10:53 PM »

The new parts for 101 cost that - so making THAT robot did cost £1.01. The cost for the parts of the bot however wasn't £1.01.

Badnik96 · « **Reply #19 on:** August 08, 2011, 12:37:55 PM »