Society of Robots - Robot Forum

Electronics => Electronics => Topic started by: garriwilson on December 16, 2007, 10:17:54 PM

Title: New RC robot project
Post by: garriwilson on December 16, 2007, 10:17:54 PM
Hello, I'm planning yet another project. (are you getting pissed because I keep changing and just gather information from you without using it?)

It will be (might be if I actually decide to make it) like a tank with a webcam on top.

Here are the things I want to buy:

1. http://www.budgetrobotics.com/shop/?shop=1&cat=51&cart=533785 (base-chassis)
2. http://www.allelectronics.com/cgi-bin/item/JS-6/search/6-CHANNEL_TRANSMITTER_AND_RECEIVER_.html
   This will be the radio system. However, it says in the note that you need to use a microcontroller module to      separate the channels (do I have to do that?)
3. http://servocity.com/html/spt100_pan___tilt_system.html (to hold and move the webcam)
   For the pan and tilt I need two servos. I have two HS-311s at home but they are continuous rotation. Will those work? I believe it will work for the horizontal pan but not the tilt right?
4. A webcam I already have (I have a question about sending the footage to a computer, it is at the below).

OK, question about webcam: how do I make the webcam send the live footage to a computer but wirelessly? Will that cost a lot? Or should I just buy a wireless webcam? I don't want to buy a new one because I already have a $40 one.

If there are any contradictions please notify me. Thank you.
Title: Re: New RC robot project
Post by: garriwilson on December 17, 2007, 11:33:46 AM
By the way, my budget will be about $200.
Title: Re: New RC robot project
Post by: airman00 on December 17, 2007, 02:06:53 PM
OK, wireless cams to the internet cost much $$$. What you might be able to do is to either use Zigbee or maybe have a regular RF camera and then connect the output to a laptop's videocard


Or , maybe just use wireless USB hubs or just bluetooth USB hubs.


All of the above interfaces can be bought online and also they could be made by you as well.
Title: Re: New RC robot project
Post by: JonHylands on December 17, 2007, 03:08:46 PM
You really don't want to use continuous rotation servos for tilt or pan. You really can't pan the camera all the way around, unless the camera has a built-in battery and is wireless, and you put the tilt servo below the pan one. Otherwise, the wires will just get twisted up...

- Jon
Title: Re: New RC robot project
Post by: Admin on December 17, 2007, 04:15:02 PM
Quote
should I just buy a wireless webcam?
definitely the easiest way . . . have you tried ebay?

so to transmit camera data requires a lot of bandwidth . . . probably easier to just use a CMUcam/AVRcam, or put your laptop on your robot . . . you can get a ipaq or some other handheld computer that has a webcam driver, too.
Title: Re: New RC robot project
Post by: garriwilson on December 17, 2007, 09:30:19 PM
I mean I could get this but I think it's a little pricey. Is $90 pricey in the world of these:

http://servocity.com/html/2_4ghz_color_video_system.html

?

Title: Re: New RC robot project
Post by: garriwilson on December 17, 2007, 09:38:57 PM
Thanks to this post by gshoger, (http://www.raidentech.com/miwicocaspyc.html), I found out about this:

http://www.raidentech.com/miwicocaspyc.html

I need to know if:
1. I can apply my pan and tilt system I listed above to this
and
2. How do I plug it into my computer or TV?
Title: Re: New RC robot project
Post by: airman00 on December 18, 2007, 05:37:57 AM
I need to know if:
1. I can apply my pan and tilt system I listed above to this

Why not?


2. How do I plug it into my computer or TV?
I have the same type camera. To connect to a TV you just plug the RCA plugs from the reicever into the TV. TO connect to the TV you need a RCA to USB capture hardware
http://www.brickhousesecurity.com/ad02a.html (http://www.brickhousesecurity.com/ad02a.html)
(http://us.st11.yimg.com/us.st.yimg.com/I/yhst-81126207287951_1977_89923916)
Title: Re: New RC robot project
Post by: ed1380 on December 18, 2007, 07:19:27 AM
I mean I could get this but I think it's a little pricey. Is $90 pricey in the world of these:

http://servocity.com/html/2_4ghz_color_video_system.html

?


youd need to buy teh transmitter/camera and the receiver

look at sparkfun they had a small wireless cam, and someone posted one like sparkfun's but cheaper. sry couldnt fint it
Title: Re: New RC robot project
Post by: garriwilson on December 18, 2007, 11:36:43 AM
Oh sorry, wow I didn't notice there were two separate parts. Crazy prices!

Quote
Why not?

How would I attach it? Isn't it like a circuit board?

And for the HEX Radio system, is the microcontroller channel separator difficult to make? Could I use my $50 dollar robot board? Thanks

So, I have to get the 100$ cable??? No way Jose! LOL
Title: Re: New RC robot project
Post by: garriwilson on December 18, 2007, 02:18:28 PM
Hey, I whipped up a new list:

1. Awesome deal (4channel transmitter, receiver, 2 servos for just $110)
http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXBCP2**&P=0 (http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXBCP2**&P=0)

2. Chassis with third deck (about 75$)
http://www.budgetrobotics.com/shop/?shop=1&cat=51&

3. Futaba pan&tilt system from servocity.com ($20 plus ship+handling)

4. 12 rechargeable batteries from a local store (I'm estimating about 20-40 bucks)

So about $200-250. Considerable.  :D
Title: Re: New RC robot project
Post by: airman00 on December 18, 2007, 06:19:50 PM
What about the camera. have you decided what you'll use?


also, the chassis is a rip off   - make your own out of plexiglass for a 1/4 of the price
Title: Re: New RC robot project
Post by: ed1380 on December 18, 2007, 07:39:50 PM
+1 on price of the body

Title: Re: New RC robot project
Post by: airman00 on December 18, 2007, 07:49:16 PM
+1 on price of the body



What does that mean?
Title: Re: New RC robot project
Post by: garriwilson on December 18, 2007, 09:17:18 PM
Quote
What does that mean?
Yea, I second that.

Quote
What about the camera. have you decided what you'll use?
thanks I forgot to put that
here: http://www.raidentech.com/miwicocaspyc.html

Two problems: what the heck is plexiglass and I don't really have any tools. (It's so pathetic I don't even have a power drill.  :'(

And even with the servos it's a ripoff?

I'll find out what plexiglass is on google.
Title: Re: New RC robot project
Post by: garriwilson on December 18, 2007, 09:55:36 PM
I heard that tracks are hard to tension and get perfect. Should I just use wheels if I decide to make my own chassis?

Also, If I do make it, I'm probably going to use HDPE from McMaster.com

Can HDPE be cut be a utility knife? I mean relatively easy. I know that chassis is kind of a ripoff. If I had the tools, I would so make it.
Title: Re: New RC robot project
Post by: garriwilson on December 18, 2007, 10:34:12 PM
How do I know what kind of batteries or battery pack I need for the transmitter and receiver in this:
http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXBCP2**&P=0 (http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXBCP2**&P=0)

I am pretty sure I need a 4.8v battery pack for the receiver, but for the transmitter how do I know if you put in alkaline batteries or attach a battery pack?
Title: Re: New RC robot project
Post by: garriwilson on December 18, 2007, 10:40:59 PM
I want to get this battery (FUTABA): (http://www.servocity.com/html/4_8v_600mah_nicad_battery.html) the FUTABA one because my receiver is Futaba. But then the only NiCd charger says Hitec!!! Are they compatible.

Here is the charger: http://www.servocity.com/html/cg-25_charger.html
Title: Re: New RC robot project
Post by: airman00 on December 18, 2007, 10:47:45 PM
I heard that tracks are hard to tension and get perfect. Should I just use wheels if I decide to make my own chassis?

Also, If I do make it, I'm probably going to use HDPE from McMaster.com

Can HDPE be cut be a utility knife? I mean relatively easy. I know that chassis is kind of a ripoff. If I had the tools, I would so make it.


I prefer to use plexiglass ( basically plastic glass , think hockey rink walls ) because it looks cool, but HDPE is much easier to work with.
I cut HDPE with a jigsaw
I actually bought this hobby tool - its a jigsaw , chisel, and sander all in one. It works well too ,@ only 50 bucks

http://www.sciplus.com/singleItem.cfm/terms/7948 (http://www.sciplus.com/singleItem.cfm/terms/7948)



Also just use wheels instead of tracks. And put a caster in front or back.
I want to get this battery (FUTABA): (http://www.servocity.com/html/4_8v_600mah_nicad_battery.html) the FUTABA one because my receiver is Futaba. But then the only NiCd charger says Hitec!!! Are they compatible.

Here is the charger: http://www.servocity.com/html/cg-25_charger.html

Looking at the picture of the charger , i cannot tell its ratings. It probably is compatible, but too make sure find a battery that IS MEANT to be compatible with that charger. Then we'll be able to figure it out. ;)
Title: Re: New RC robot project
Post by: garriwilson on December 19, 2007, 11:53:47 AM
I want to get a battery pack over a battery holder because a battery pack has the connector thingy on the end and I don't know how to attach a battery holder to the receiver pins.

I might get that 3in1 tool but I'll ask my dad, he probably has a ton of tools at work maybe he could bring some. ?

I'm kind of a beginner and since HDPE is easy to work with I'll just stick with it. I might use plexiglass for future projects though. (This is my second project after the $50 robot).

So now I need to work on the design of my "robot." Also I heard that it is better to put the caster in the back. Is that true?

And airman00 thanks for telling me the chassis was a ripoff. I could use my already modified HS-311's from the $50 robot. So I'll only need to buy some tools and HDPE.

P.S. I've almost never worked with power tools, only power drill.
Title: Re: New RC robot project
Post by: airman00 on December 19, 2007, 12:46:01 PM
why don't you just get a regular AA holder and buy a rechargeable AA charger and 4 rechargeable AA batteries???

What do you mean by put the caster in back? Back relative to what?

I think you're saying that you should have the motorized wheels in front , since pulling is better than pushing, and then the caster would be in back. Yea, then you should have the caster in front.

I would suggest you download Google Sketchup and make a 3D model of it, to scale. The model should be exactly like you want it , even with the drill holes.

Get the 3in1 tool, and you'll be working with HDPE with ease. What you need to work with HDPE is a drill, some  type of saw (handsaw, jigsaw is good) , sander( optional, but makes it smooth.
Title: Re: New RC robot project
Post by: garriwilson on December 19, 2007, 01:01:24 PM
Because the regular AA holder doesn't have the molex pins that you plug into your receiver. It has a black and a red wire with the metal just sticking out.

Quote
Yea, then you should have the caster in front.
you mean in the back?

I mean in the back like if there are 3 wheels, the ones with the servos are in front when it's going forward.

Yea I decided to get the 3in1 tool because I'm saving money on the chassis.

Thanks for the tool link airman00.
Title: Re: New RC robot project
Post by: airman00 on December 19, 2007, 01:03:08 PM
Because the regular AA holder doesn't have the molex pins that you plug into your receiver. It has a black and a red wire with the metal just sticking out.

you mean in the back?

I mean in the back like if there are 3 wheels, the ones with the servos are in front when it's going forward.


Oops , yeah i meant in the back. With the servos in front , thats the best.

Also, why don't you just get a molex pin connector and crimp it onto the wires of the battery
Title: Re: New RC robot project
Post by: garriwilson on December 19, 2007, 01:20:38 PM
Don't have a crimp tool-  :-[ .

I might get one in the future, but for now it's not necessary.

And there are only two wires
Title: Re: New RC robot project
Post by: airman00 on December 19, 2007, 02:24:52 PM
Well yeah, power and ground. Some batteries have 3 wires, but thats just two wires form power and one from ground( unless its 2 batteries in one ) meaning theres total of lets say 6 batteries. The 3rd battery has a power wire coming from it ( which si 3V lets say) and the 6th battery has a wire which is 6 V. And they obviously share a common ground
Title: Re: New RC robot project
Post by: garriwilson on December 19, 2007, 02:44:26 PM
Ok, I still don't have a crimp tool.

So, it doesn't matter if you only have two wires in a three pin molex connector and you connect it to the battery pins which has 3 pins sticking out?
Title: Re: New RC robot project
Post by: airman00 on December 19, 2007, 02:54:56 PM
So, it doesn't matter if you only have two wires in a three pin molex connector and you connect it to the battery pins which has 3 pins sticking out?

it does matter , what i was saying is to find out what each pin needs

lets say pin 1 and pin 2 are for power and pin 3 is ground. SO from the positive wire from teh battery you would solder on a second wire. All you are doing is giving the components what they need
Title: Re: New RC robot project
Post by: garriwilson on December 19, 2007, 03:02:55 PM
OH Sorry, now I understand it perfectly. My bad.  :-[
I'll try to find some information about the receiver.
Title: Re: New RC robot project
Post by: Admin on December 19, 2007, 04:55:50 PM
Quote
I don't know how to attach a battery holder to the receiver pins.
http://www.societyofrobots.com/electronics_wire_connector.shtml

Quote
Also I heard that it is better to put the caster in the back. Is that true?
It strongly depends on what your robot needs to do. There is a good post about it hidden somewhere in the forum if you do a search on casters.
Title: Re: New RC robot project
Post by: airman00 on December 19, 2007, 05:16:26 PM
Yea, i asked that question awhile back

anyway here is that post http://www.societyofrobots.com/robotforum/index.php?topic=2224.0 (http://www.societyofrobots.com/robotforum/index.php?topic=2224.0)
Title: Re: New RC robot project
Post by: garriwilson on December 19, 2007, 06:46:34 PM
Sorry for this noob question: When using a jigsaw, where do you put the material you are cutting? Is there supposed to be a hole for the blade to go through? Where do I put the HDPE? A table?
Title: Re: New RC robot project
Post by: airman00 on December 19, 2007, 07:01:05 PM
You just clamp it to the table, with the part you want to cut sticking off the table. Make sure the HDPE is clamped tightly. Turn the jigsaw on and then just cut the piece of the HDPE you want cut. You should probably buy work gloves to not cut your finger off


BE CAREFUL WHEN USING POWERTOOLS!

No hole, its just slicing across the plastic in the shape you make

seriously, do not cut off your fingers ., be super careful
Title: Re: New RC robot project
Post by: garriwilson on December 19, 2007, 07:09:43 PM
When I'm designing my robot, how do I know how I should put the caster. I mean so it's at the same level as the drive wheels? I'm getting these wheels: http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXB913&P=0
Dave Brown Lite Wheels 4" in diameter (outside)

Also, I want to use an omniwheel as a caster for this robot. You know those small wheels on wheelchairs? And those metal attachments that connect the wheels to the wheelchair. What are those connections called? I want to get a small version of that, to attach the omniwheel to my robot so it can swivel.

Thanks
Title: Re: New RC robot project
Post by: airman00 on December 19, 2007, 07:18:04 PM
you have to make a 3D model  to scale

get the measurements for everything and then figure it out

an omniwheel is this (http://www.kornylak.com/images/wheel/transwheel/fxa159-s.jpg)

a swivel caster is this  (http://tbn0.google.com/images?q=tbn:JHYOSenXXcefLM:http://www.germes-online.com/direct/dbimage/50185096/Caster.jpg)

a ball caster is this  (http://www.pololu.com/products/tamiya/0066/small.jpg)

What type of surfaces do you expect the robot to go on?


By the way, I used those same wheels before. Get a long servo screw from servocity to mount those wheels.
Title: Re: New RC robot project
Post by: garriwilson on December 19, 2007, 07:27:02 PM
OK, I'm getting a swivel caster then.
I know I added those screws already to my cart.
I expect it to go on everything.  ;) (carpet, concrete, dirt)

By the way I just found this really good tutorial on How to Use a Jigsaw:

http://www.rd.com/content/openContent.do?contentId=18223
Title: Re: New RC robot project
Post by: garriwilson on December 19, 2007, 07:39:32 PM
Is this caster good from McMaster.com

Casters
This product matches all of your selections.
   
Part Number:  9950T51    
 $12.22 Each
Capacity
   225 lbs.
Mounting Type
   Plate
Caster Type
   Swivel
Wheel Material
   Rubber
Floor Material
   Asphalt and Brick and Ceramic Tile and Concrete and Dirt and Hardwood and Linoleum and Ribbed and Steel and Terrazzo
Wheel Diameter
   3-1/2"
Wheel Width
   1-1/4"
Mount Height
   4-3/4"
Rubber Wheel Material
   Rubber on Polypropylene
Plate Length x Width
   3-5/8" x 2-7/8"
Plate Thickness
   1/8"
Center-to-Center
   1-3/4" x 2-15/16"
Slotted to
   Not slotted
Bolt Hole Size
   11/32"
Frame Material Type
   Steel
Frame Construction
   Cold Formed and Heat Treated
Frame Finish/Coating
   Zinc Plated
Application
   General Purpose
Swivel Construction
   Rivet Kingpin
Kingpin Diameter
   1/2"
Wheel Bearing Type
   Ball
Swivel Bearings
   Double Ball
Leg Thickness
   3/32"
Axle Diameter
   3/8"
Axle Construction
   Solid
Specifications Met
   Not Rated
Wheel Bearing Features
   Debris Guards
Wheel Durometer Range
   Hard
Wheel Durometer
   70A
Wheel Color
   Gray
Number of Wheels
   One
McMaster-Carr Name
   Hammin
For Compatible Rigid Caster, Order:
   9950T52
For Field-Installable Face Wheel Brake, Order:
   2877T81
Title: Re: New RC robot project
Post by: airman00 on December 19, 2007, 07:46:26 PM
nice find with the jigsaw info


that caster is huge!, way way to big

you want a smaller one , rated for about  15 pounds



Title: Re: New RC robot project
Post by: garriwilson on December 19, 2007, 07:51:41 PM
I can find that at McMaster right?
Title: Re: New RC robot project
Post by: airman00 on December 19, 2007, 07:55:26 PM
probably , for all terrain you probably need a six wheel robot , an insect robot, steering ( like a car) , or tracked vehicle.

forget all terrain for now, just do it for indoor use

for indoor use,  a ball caster is fine

and for outside you need suspension......
Title: Re: New RC robot project
Post by: garriwilson on December 19, 2007, 08:09:02 PM
I got confused at McMaster, so I went to Towerhobbies.

This is the only ball caster I found and there are no measurement specifications.

http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXWB21&P=7 (http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXWB21&P=7)
Title: Re: New RC robot project
Post by: Admin on December 19, 2007, 08:10:26 PM
Quote
When I'm designing my robot, how do I know how I should put the caster. I mean so it's at the same level as the drive wheels?
CAD it up!

As for caster wheels, go to Homedepot and ask.
Title: Re: New RC robot project
Post by: garriwilson on December 19, 2007, 08:11:27 PM
Just found this but again no specs:

http://www.pololu.com/products/tamiya/0066/ (http://www.pololu.com/products/tamiya/0066/)
Title: Re: New RC robot project
Post by: airman00 on December 19, 2007, 08:26:00 PM
yes, ordered that one for my robot in the tutorial

If you are patient enough to wait until next Tuesday , specs will be posted for that caster , as well as how to mount it , etc.

also, that caster is for smooth surfaces( or mostly smooth)  its basically a (relatively) low friction skid.
Title: Re: New RC robot project
Post by: garriwilson on December 19, 2007, 08:28:27 PM
I mean I want it to go on carpet, because my house is covered in carpet. However, I could live with just concrete and stuff. (outside)

Is there a caster that can go on carpet and asphalt?
Title: Re: New RC robot project
Post by: david_or_johnny on December 19, 2007, 09:58:58 PM
Make your own with two pieces of sheet metal and a Dubro 1.5 in foam tailwheel
Title: Re: New RC robot project
Post by: garriwilson on December 19, 2007, 10:04:35 PM
Omni-wheels work on carpet and asphalt right?

ADMIN, in your Experimental Robot Platform, how did you attach the omniwheel to the chassis? A metal rod axle?

Also, is 4" too big for wheels?
Title: Re: New RC robot project
Post by: Admin on December 19, 2007, 10:17:07 PM
The concept of an caster is to have as low friction as possible.

Quote
ADMIN, in your Experimental Robot Platform, how did you attach the omniwheel to the chassis? A metal rod axle?
check out the last four images on this page:
http://www.societyofrobots.com/robot_mobot_2007.shtml

I reused the same exact parts from this line following robot on the ERP. The rod was plastic and press fit between two plates with holes. You will also find an interactive CAD of it on that page, just rotate the robot to see the bottom.
Title: Re: New RC robot project
Post by: garriwilson on January 02, 2008, 10:19:52 PM
Why can't I attach a CAD of my robot? I think it says it's too big. Are CAD files too big to attach? How should I post it?
Title: Re: New RC robot project
Post by: airman00 on January 03, 2008, 05:40:46 AM
if u used google sketchup export it as an image file. Then upload it
Title: Re: New RC robot project
Post by: garriwilson on January 03, 2008, 08:59:17 PM
Trying that right now in this post.
Title: Re: New RC robot project
Post by: airman00 on January 03, 2008, 09:30:44 PM
Very nice CAD!!!!


Are you sure that it is to scale?
Title: Re: New RC robot project
Post by: garriwilson on January 03, 2008, 09:32:39 PM
Quote
Very nice CAD!!!!
Thanks, in fact it is my first fully done CAD. 


Quote
Are you sure that it is to scale?
You know, I think I need to double check it. But most of it is to scale.

I will post more when I make changes.

Title: Re: New RC robot project
Post by: airman00 on January 03, 2008, 09:34:37 PM
Next step: Buy / make the parts

Though I suggest you make another dedicated thread for the actual building of this new project
Title: Re: New RC robot project
Post by: garriwilson on January 03, 2008, 09:55:33 PM
Well..., actually the next step is make some money. (~350$)  ;D
Title: Re: New RC robot project
Post by: Caduscus on January 04, 2008, 08:58:01 PM
try checking out www.popsci.com they have a DIY project for something exacly like that, with places to buy the stuff and everything, I think it's called RC  tank or something it's really neat  ;D
Title: Re: New RC robot project
Post by: garriwilson on January 05, 2008, 11:32:08 AM
Is this what you mean: http://popsci.typepad.com/how20blog/2007/10/build-it-the-al.html

You know what, you gave me the idea to use a tank for chassis. I mean then I don't have to buy the radio equipment.

Thanks!