Rover 3.0 Design Begins

Now that the Raspberry Pi Zero W is continually running for a few weeks, It’s time to start the process of redesigning the rover and printing it out in PETG. Just wish I had more time to play, work has become, well work. Oh well.  My new plan is to have a working rover for next summer.
I purchased an XYZ da Vinci Pro printer for printing PETG. There are many mixed reviews on the internet talking about the XYZ printer. My experiences have been outstanding. There are a few little quirks, but I think you will get that with any printer on the market. I guess because it’s my second printer, I understand better the methods and limitations of 3D Printing. One part I am glad I upgraded to is the EZ-Stik Professional Hot 3D Printer Build Surface from GeckoTek 200x200mm. This pad is wonderful, PLA and PETG stick to the pad without the need for a glue stick or hairspray, and more importantly, they pop right off when done. It’s great my printer is nice and clean after over 100 hours or printing multiple parts.
Printer after printing over 100 hours and many parts.
I was a little bit worried about switching from PLA to PETG. I thought it would be difficult to get it to work. To my surprise, my first print came out perfect the first try. I kept the settings and was able to print out the differential. The only “trashed” 3D print was the one I did not design correctly.
First part printed with PETG

Modifications for Version 3.0 so far:

I increased the size of the bearing fittings by 1mm. This small increase allowed the bearing to fit without forcing them into the differential housing and causing it to break.
Not enough clearance, and too much hammer.
Redesign of the central differential gear axel. I redesigned the axel to have an integrated endcap, allowing for an adjustable and secure fit of the center gear.   I am also redesigning the Rover Tub to be larger now that I have a larger printer. My old printer can only print 100mm x 150mm x 125mm. My new printer will print 200mm x 200mm x 200mm. Overall the rover will be the width, I am just removing some of the gaps. The extra hight of the tub will be a welcome addition as well. The other change is with the motors, I upgraded to larger motors after breaking off a gear tooth during the first test run. The run you saw in the video on the homepage. Hopefully, these motors will be a bit stronger.  They also have a sensor in the back to measure RPM.  That may come in handy to measuring slipping and slow that wheel down to prevent it from digging in. But that would require having an Electronic Speed Controler for each wheel.  My initial design was to have two ESC one for each side of the rover.
CHIHAI MOTOR 6V 100RPM Encoder Motor DC Gear Motor
Finally, I decided to write the date printed on all the parts. For the failed parts I am writing the reason for failure and date printed. I don’t know why it just seems like a good idea.
Rover

Leave a Reply

Your email address will not be published. Required fields are marked *