It's time to show of the finished Sphero Strandbeest combined with the MobBob.(New video in the videos tab as well
It's alive and walking! Finally after a long build the Sphero Strandbeest has taken its first steps. It consists of 102 parts all 3d printed and about 20-30 washers and spacers that are also printed.
Hackaday wrote about my build: https://hackaday.com/2015/08/26/sphero-riding-strandbeest-is-a-robot-with-an-exoskeleton/
It is still a bit wobbly but a little tightening and some more custom spacers at exact lengths will probably do the trick.
The last part of the build was mostly putting it all together. I swapped a lot of normal nuts for lock nuts to keep it from unwinding and I also made a lot of spacers to keep everything in its place.
A lot of washers, custom 3d printed spacers and nuts.
Tested the sphero on the wheels today and it worked great.
Started todays work with getting arranging all the gears and cutting the threaded rods to the correct lengths, might have been a little hard on the length of the main 8mm rod, so I may have to replace it. I then test fitted everything and used a lot of time on finding the right distances between everything. It's a really tight fit and I had to do it several times before I got it right.
Finally I test built the whole model to find out if the 8mm rod would be able to turn everything. So far it unwinds itself so I might have to but a lock nut on it.
Whats left to do now is finding the right distances between the leg assemblies and cutting all the screws that are too long. I found out that I have to take them of the model since my dremel made the plastic soft while cutting a screw. Luckily i found out early enough and didn't ruin any part. Note to self: Do not cut screws fitted in PLA plastic with a dremel tool.
Today I redesigned the gear flange to fit my setup better. And I think the design turned out pretty well.
I also had to make a few bushings because the skate wheels were 6mm instead of 8mm. It worked out great and made some in different lengths to use as spacers as well, to keep the number of nuts to a minimum.
Next step is figuring out all the gears and placing them correctly.
All the printing is now done and the bearings have arrived. I have completed the assembly of one side as seen in this picture. A test of the walk cycle can also be seen in the video. I will continue tommorrow.
I came across this really cool looking strandbeest that was powered by a Sphero and I just had to try and build it. I will post my progress here.
I found the strandbeest on this site http://www.thingiverse.com/thing:428931 . There was STL-files and images but no build instructions.
The design is based on a walking mechanism by Theo Jansen. This gif showing how the mechanism works is pretty mesmerising.
I therefore decided to try and build it with the STL-files in Inventor first. I found a nice plugin for Inventor that allowed me to convert the STL-files into solids. I then had good references when building the model in Inventor.
After a successful build digitally I decided to start printing.
The first parts I printed were the major and minor frame.
I kept on printing a LOT of parts, in total the print time is probably 30-40 hours. Everything is printed on a Wanhao Duplicator 4s with 0.2mm layer height in PLA.
The gears were the most crucial parts, so I printed them early to be sure that the build was possible with my printer.
There are four leg assemblies in total. Every leg assembly consists of two indentical assemblies connected together
The joints are secured with m4 machine screws and lock nuts.
A test assembly for checking dimensions.
Test fitted the complete leg assembly on one side. Things are starting to look good.
I have about 6 hours worth of printing left before I have all the parts I need. I'm also waiting for some bearings I have ordered and some skate wheels.