As announced in our previous post, we are working on wheeled version of our robot. Tires and shaft adapters are arrived today and we mount them to conduct first test drive. Here are some photos:
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| Wheeled version of the "Shark" model |
The first test drive was more or less successful. However, there are still some problems we need to solve:
- Shafts are too long for adapters we are using and as a results wheels are sitting to wide. The simplest way to fix it would be just to cut about 10mm out. The front wheels on the second picture illustrate how it would be.
- While turning with one wheel stopped works reasonably well. However, the on-place turn where wheels are rotating in different directions does not work as it should be. It happens because we are using two-wheel drive version of the chassis. I hope that four-wheel drive chassis will fix the problem.
This is what you need:
ReplyDeletehttp://www.vexrobotics.com/vexpro/wheels-and-hubs/mecanum-wheels.html
Mecanum wheels might indeed be useful for indoor. Not sure how they would behave in outdoor though. Anyway, thanks for suggestion!
DeleteBtw, the link you posted shows 404 error.
This is really cool!
ReplyDeleteI'm going to print one of your bodies for my Rover 5.
With the wheels and those crappy shafts you're going to need to upgrade them.
I'm going to drill out the wheel adaptors, thread them and use a 4mm bolt all the way through.
The metal the existing shafts are made out of is just plain out too soft, you will bend them running with wheels.
Dagu really need to beef up the chassis, I'll bet it was warped like mine was when you got it from being shipped with the gearboxes at their fullest extension.
This is my first VERY rough run with mine
http://www.youtube.com/watch?v=43zqBtQyBF0
and on night patrol
http://www.youtube.com/watch?v=iFQzK0W5_ow
Great work guys!
> This is really cool!
DeleteThanks! :-)
> I'm going to print one of your bodies for my Rover 5.
Cool! Please feel free to post about your experience or ask questions. And please do not forget to post pictures when you are ready.
BTW, before you start printing, please check out that your printer have enough Z space to print middle body part (labeled as S.001.01 here https://github.com/veter-team/veter/wiki/printing-body) . We are using Ultimaker.com printers which have rather large working area. Recently, several makers reported that the part is too high for some other popular printer models. We are currently working on splitting this part to make it printable on all typical printers.
> With the wheels and those crappy shafts you're going to need to upgrade them.
To be honest, I am not sure that Rover 5 chassis are at all good for wheeled version. I feel like the motors are too weak, shafts are not hard enough as you said, etc. That is why I am thinking towards completely self-printed wheeled version. Something similar to this http://www.thingiverse.com/thing:42198 but probably with fixed wheels (no steering) like with Rover 5 chassis and much higher clearance for outdoor usage.
> This is my first VERY rough run with mine
I've found these videos several days ago on the Pololu community projects page. Looks really cool. How long does it take you to build this bot?
I tried to turn with a four wheeled two drive version : find it hard.
ReplyDeleteIf i have only the front left wheel runing it dont turn quickly on the right :
the 3 other wheels are not helping at all !
How did you turn ?
Have you a video of your wheeled bot ?
Cats
We have only two (rear) wheels drive. So the only option to turn is to let the rear wheels rotate in the opposite directions (or just stop one). It works more or less good on the carpet and better on the tile. Unfortunately, I did not made the video and now we mounted tracks back again for the next demonstration.
Delete