Author Topic: Wheels & Tires (Read 4241 times)

Skyfer · « **on:** April 17, 2009, 10:13:16 AM »

I won't be original - this is my first robot ever and I've already looked through that "THE $50 ROBOT", a very popular one tutorial. I want the same result to be going on with.
Now, as I started to collect the required parts I've got a question - how to choose a proper wheel/tyre? I want efficient on different surfaces an durable wheels so I don't think I'll pick those big cardboard things

I know that you'll probably just send me there, so in advance I suggest you to start discussing here general and specific questions about WHEELS&TIRES.

galannthegreat · « **Reply #1 on:** April 17, 2009, 11:10:30 AM »

Well, I assume you're using servos, and if you aren't using hitec you can use something like these:
http://www.solarbotics.com/products/sw/

Skyfer · « **Reply #2 on:** April 17, 2009, 11:22:38 AM »

Yep, I thought about exactly this model before... So, no other specific recommendations?

SmAsH · « **Reply #3 on:** April 17, 2009, 04:49:27 PM »

well, be creative! use your imagination. do you want to make or buy?

galannthegreat · « **Reply #4 on:** April 17, 2009, 07:21:17 PM »

Well to be more specific... when it comes to wheels having them premade for off the shelf servos really comes in handy, and when you think of it, it won't make a price difference if you make them yourself versus just buying them premade.

SmAsH · « **Reply #5 on:** April 17, 2009, 07:34:29 PM »

true, i was just asking because there are some people on this forum who like to make everything and buy nothing

and to ts: you can use pretty much any wheel but one with a tire would help you grip surfaces. with a bigger wheel your can go faster but will need more torque, with a wider wheel you can take more load but once again you need more torque and it will be harder to turn...there are a lot of things you need to take into account when choosing a wheel so we cant do it for you but we can make suggestions about what you should buy.

galannthegreat · « **Reply #6 on:** April 17, 2009, 07:51:21 PM »

Okay, here is my motor/wheel combination that I have myself and recommend for $50 dallor type robots.

Servo:

Pre-modified:http://www.solarbotics.com/cad/products/22140/(better if you don't feel comfortable modififying a servo)
Un-modified:http://www.solarbotics.com/cad/products/servo/ (better of the two due to that it has more torque and it is cheaper)

Wheels:

http://www.solarbotics.com/cad/products/sw/(come in cool colours... and they are decent in size)

Skyfer · « **Reply #7 on:** April 18, 2009, 10:34:38 AM »

Quote from: galannthegreat on April 17, 2009, 07:21:17 PM

it won't make a price difference if you make them yourself versus just buying them premade.

Yeah, it won't.

Quote from: SmAsH on April 17, 2009, 07:34:29 PM

there are some people on this forum who like to make everything and buy nothing

Sounds just like me ^^

Quote from: SmAsH on April 17, 2009, 07:34:29 PM

there are a lot of things you need to take into account when choosing a wheel so we cant do it for you but we can make suggestions about what you should buy.

That's why I am here

Quote from: galannthegreat on April 17, 2009, 07:51:21 PM

Okay, here is my motor/wheel combination that I have myself and recommend for $50 dallor type robots.

Is this combination powerful enough to run pretty quickly and smoothly and on the carpet?) Could you show me a vid starring your creation?)

Quote from: galannthegreat on April 17, 2009, 07:51:21 PM

Wheels:

http://www.solarbotics.com/cad/products/sw/(come in cool colours... and they are decent in size)

That's exactly what I think about them.

You know, I got a reckless idea. What if I'll make the wheels myself? I can make a mould but I'm not sure of which medley to use...Kinda of a glue-based, I suppose. or... carbon?!

mdmedlin · « **Reply #8 on:** April 19, 2009, 09:43:26 AM »

I am also making a $50 dollar robot, so I will show you what I did for the wheels. Now I understand that not everyone has access to a machine shop or a lathe, but I know that you can get a bench top lathe rather inexpensively. Besides, you could always ask someone for help that likes to make baseball bats or something like that. Well I used a piece of lexan because I wanted the wheels to be clear. I used a cog belt and turned it inside out so that the ribs were on the outside. This will give me better traction. I used the circumference of a circle to get the diameter of the wheel. I picked a point on the cog and rolled it along a tape measure to get the length of the cog belt, which you could probably also get from the manufacturer, but this way was more fun. Divide that number by Pi and that is your diameter. After I turned the piced of lexan down on the lathe, I superglued the cog onto the outside of the lexan. I then screwed the horn for the servo to the lexan itself. If I knew how to put pictures in this post, I would do so but like I said a benchtop lathe will run you about 120 dollars for a cheap one. As for the lexan, well any piece of plastic will do. I would see if you can look around and see if anyone has spare pieces laying around. Cog belts you can get from just about any manufacturer like grainger or applied.

Skyfer · « **Reply #9 on:** April 19, 2009, 10:16:27 AM »

wow
I suppose you could host your image somewhere if you succeed in making lexan wheels

Otherwise, send me some photos by mail please.

galannthegreat · « **Reply #10 on:** April 19, 2009, 03:51:44 PM »

It definately will run on carpet perfectly fine, but there's an exception to shag carpets, which most likely you won't be running on them.

mdmedlin · « **Reply #11 on:** April 20, 2009, 04:25:11 AM »

I attached the pictures to this post, I hope it works

SmAsH · « **Reply #12 on:** April 20, 2009, 04:35:17 AM »

why are they only 64x64 pixels, they're too tiny to see anything...

Ro-Bot-X · « **Reply #13 on:** April 20, 2009, 05:26:41 AM »

If you want to make your wheels the easy way, go to Walmart and get a couple of DelMonte plastic canned fruit jars and use the lids. The lids have ribs, they come in a few sizes, easy to screw to the servo horns as they have a indentation on the center of the lid, and if you need more traction you can use a wide rubberband (from the office supplies isle) as a tire.

Here is a picture:

mdmedlin · « **Reply #14 on:** April 20, 2009, 09:29:00 AM »

sorry I took the picture with my camera phone that is why they are so small.

Skyfer · « **Reply #15 on:** April 20, 2009, 09:34:39 AM »

I can hardly make it out $:-\$

mdmedlin · « **Reply #16 on:** April 21, 2009, 03:41:38 AM »

OK I am trying to upload larger pictures sorry if it doesn't work The first picture is of the rough cut of the lexan. I used a band saw to basically cut out the shape. I have a socket head cap screw in the center. This is used to help center the lexan on the mill. The next picture is of the cap screw mounted to the mill and my friend milling it down for me. The third is of the cog belt glued to the lexan. The last picture is the finished product

SmAsH · « **Reply #17 on:** April 21, 2009, 03:51:51 AM »

wow mdmedlin they look excellent! im defiantly going to see if i can use my schools mill!

mdmedlin · « **Reply #18 on:** April 21, 2009, 03:55:15 AM »

Hey thanks smash I appreciate it. I am going for a kinda see-through robot look. I have my battery pack in clear lexan also. I had to make a case for it because the 6v battery pack I got from radio shack doesn't have any connectors to hook up my board to. I had to mill out a little piece so I could put in a spade connector and I am holding that in place with a set screw. So far it works and I am getting 6v out of the spades. I just need to figure out how I am going to design the chasis.

Skyfer · « **Reply #19 on:** April 21, 2009, 09:25:48 AM »

WoW, mdmedlin, you've impressed&inspired me!

If only I knew where to get some lexan...

mdmedlin · « **Reply #20 on:** April 21, 2009, 09:36:16 AM »

http://www.mcmaster.com/#8574k11/=1jjbxb
that link will send you to mcmaster carr and this is a 1/4 by 6 by 6 sheet of polycarbonate. It's 2.52 each, so for 5 bucks you can have the beginnings of your own clear wheels LOL

Skyfer · « **Reply #21 on:** April 21, 2009, 11:00:12 AM »

ok, thx, but where did you get just that famous LEXAN poly?

mdmedlin · « **Reply #22 on:** April 22, 2009, 05:50:26 AM »

I had come scrap at work that we use to make guard doors. They were just laying around in the scrap bin, so I deceided to put it to good use

The Polycarbonate on the McM-C website says it is a viable alternative to lexan. If you are really jonesing for some lexan, check out this link: http://www.estreetplastics.com/category_s/51.htm

Admin · « **Reply #23 on:** May 07, 2009, 05:45:10 PM »

If you look at my past robots you'll see a wide variety of wheels. It really depends on the terrain and robot specifics.

If you want a wheel that "just works" for a small robot, just get a ~4" diameter foam wheel or a basic off the shelf servo wheel and call it a day.

hoosier122 · « **Reply #24 on:** May 16, 2009, 03:41:01 AM »

From experience an old CD/DVD with a rubberband around the diameter does not provide enough traction.

SmAsH · « **Reply #25 on:** May 16, 2009, 08:32:56 PM »

Quote from: hoosier122 on May 16, 2009, 03:41:01 AM

From experience an old CD/DVD with a rubberband around the diameter does not provide enough traction.

probably because its too thin, 2-5 cds would do it..

hoosier122 · « **Reply #26 on:** May 17, 2009, 05:00:40 AM »

Quote from: SmAsH on May 16, 2009, 08:32:56 PM

Quote from: hoosier122 on May 16, 2009, 03:41:01 AM
From experience an old CD/DVD with a rubberband around the diameter does not provide enough traction.
probably because its too thin, 2-5 cds would do it..

Nope. But 2-5 CD's you have to start worrying about weight.

SmAsH · « **Reply #27 on:** May 17, 2009, 05:03:46 AM »

well, some "fatter" things would work better like peanut butter jar lids...
it all comes down to a case by case basis, it isn't just weight, there are a number of factors that come into
choosing wheels for your robot such as speed, terrain and weight of the robot...

michelle83 · « **Reply #28 on:** June 23, 2009, 05:59:04 PM »

Quote from: Admin on May 07, 2009, 05:45:10 PM

If you look at my past robots you'll see a wide variety of wheels. It really depends on the terrain and robot specifics.

If you want a wheel that "just works" for a small robot, just get a ~4" diameter foam wheel or a basic off the shelf servo wheel and call it a day.

What about omni wheels? I saw these wheels on a show called the new inventors on ABC and have been wanting to try them on something... has anyone used them? They are called Rotacasters... Thanks!

jamort · « **Reply #29 on:** June 23, 2009, 10:12:52 PM »

Quote from: michelle83 on June 23, 2009, 05:59:04 PM

Quote from: Admin on May 07, 2009, 05:45:10 PM
If you look at my past robots you'll see a wide variety of wheels. It really depends on the terrain and robot specifics.

If you want a wheel that "just works" for a small robot, just get a ~4" diameter foam wheel or a basic off the shelf servo wheel and call it a day.

What about omni wheels? I saw these wheels on a show called the new inventors on ABC and have been wanting to try them on something... has anyone used them? They are called Rotacasters... Thanks!

yeah ive used them... but couldnt really get an a.t.v. out of them...
i think admin has got a tutorial with them

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Author Topic: Wheels & Tires (Read 4241 times)

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