RoboDerby Posted June 6, 2020 Author Share Posted June 6, 2020 WOOOOOHOOOOO!!!!! Still learning the design software and as a result the linkage for the leg was a nightmare for me to get rendered. But all of the clearances are good and I am optimistic that once I have the rest of the parts printed for the legs, I’ll have this guy walking and can move on to the arm mechanics. Link to comment Share on other sites More sharing options...
Roboto Posted June 6, 2020 Share Posted June 6, 2020 Great leg motion!! Link to comment Share on other sites More sharing options...
Brian.. Posted June 6, 2020 Share Posted June 6, 2020 You are making excellent progress. I see you have the rear strut linked to an inner box inside the foot. That's neat. I just hinge the whole foot. If you slow down the motor it will make perfecting the walk easier. You can speed it up once you get the balance right. Fast movers can often wobble. Link to comment Share on other sites More sharing options...
RoboDerby Posted June 6, 2020 Author Share Posted June 6, 2020 Thanks Brian! Yes, I plan to use a slower motor. But I currently only have two of them on hand. So I have been using one of the faster motors, of which I have several, for fitting parts and checking tolerances. Here is a photo of the parts in the leg assembly. You can see I have designed the brake to be integrated into the carriage as one solid piece and the wheels just snap into place. I have a new motor mount on the print bed now as the leg makes ever so slight contact with the base and causes the gear to flex on the shaft a bit. But I moved the motor housing forward on the base plate which should give everything proper clearance. Once the mount finishes, I will print the second leg and have what I need for a proper walking test which I can hopefully share tomorrow. I’m still using my original cam gears. But I’ll redesign those to correct the issue of stress on the layer lines that John pointed out. Also, I’m very pleased with the new colors of Paramount USA filament that I received yesterday. Here you see two of the colors, appropriately named Decepticon Purple, the legs, and Autobot Blue, used for the wheels. Additionally , thanks to all so far for the kind comments and encouragement. Link to comment Share on other sites More sharing options...
robothut Posted June 7, 2020 Share Posted June 7, 2020 You might want to beef up the area around the holes on the linkage part as well just to make sure they do no become a breakage problem down the road. Link to comment Share on other sites More sharing options...
RoboDerby Posted June 8, 2020 Author Share Posted June 8, 2020 I did it gang! My robot walks. I’m very pleased with this initial test though there are some adjustments to be made. First, the front of the foot makes contact with the ground when the leg is in its back position. This will be easy to modify with a slight upward rake of the bottom of the foot at the front. The bigger issue is that the weight of the batteries means that the front wheels don’t make proper contact with the ground. Adding weight to the front solves this. However, without the added counterweight, the robot does more shuffling in place than walking and most of the forward movement is lost. The weight issue is not too much of a surprise as my design is based on the Piston Action, “Pug” toy, which does not have on board batteries but rather uses a wired remote to house them. I will continue to consider options for changes that might allow me to keep the batteries on the robot itself. But I had already considered that it might be fun to design a wired remote anyway. So I will focus on that for now with the possibility of also creating an alternate version that uses ballast in the front and onboard power. Still, I am quite happy with a relatively successful first test. I did end up running this test with the faster geared motor as it was handy. Good to know that I might have this option in later builds using this walking design. And yes John, I think you are right about beefing up the linkage for longevity of the part and I will make the adjustment in the next version. Thanks for the input. More to come! Link to comment Share on other sites More sharing options...
RoboCopy Posted June 8, 2020 Share Posted June 8, 2020 8 hours ago, RoboDerby said: I did it gang! My robot walks. Great walking action! Congrats Link to comment Share on other sites More sharing options...
robothut Posted June 8, 2020 Share Posted June 8, 2020 There you go-go -go. Nice walking speed a lot like a new Mr. Mercury or Jupiter robot as they both moved right along . Did you try running it with 1 battery "1.5 volts" just to see how that looked. Link to comment Share on other sites More sharing options...
Roboto Posted June 8, 2020 Share Posted June 8, 2020 Nice video with the walking action!! Link to comment Share on other sites More sharing options...
Brian.. Posted June 8, 2020 Share Posted June 8, 2020 There are quite a few variables that can be tweaked to achieve a good walk. A simple one is to try reducing the radius of the cam so that the legs don't move so far forward and backward. This may stop the leg lifting at the front. Moving the motor forward or backward a few mill can also have a big effect. The length of the rear strut is important and a variation of just 1 mm can have a major effect. Tiny faults in the balance can be disguised by raising or lowering the rear wheels. There's lots to tinker with. It's my favourite part of a build, getting it walking. The rest is icing on the cake. Link to comment Share on other sites More sharing options...
Martian Gil Posted June 11, 2020 Share Posted June 11, 2020 great job, my friend! looking forward to having one of your bots!! Link to comment Share on other sites More sharing options...
RoboDerby Posted June 30, 2020 Author Share Posted June 30, 2020 The journey continues. I have been working on some revisions to my original walking design for my 3D printed robot. The reason for the revisions was to solve issues with the shell of the feet making contact at the extremes of the leg travel, thus lifting the wheels off of the ground. I also was able to omit the need for added weight in the front to compensate for the weight of the batteries. I will now make some minor adjustments to some of the tolerances and move on to designing the upper parts of the robot. I still plan to revisit my original walking design to see if I can incorporate a wired controller and solve the original weight issue by moving the batteries out of the body and into the control. Link to comment Share on other sites More sharing options...
RoboCopy Posted June 30, 2020 Share Posted June 30, 2020 He’s fast! Link to comment Share on other sites More sharing options...
RoboDerby Posted June 30, 2020 Author Share Posted June 30, 2020 16 minutes ago, RoboCopy said: He’s fast! I still plan to try out a slower motor in the design. But, I am pleased to know that the faster motors are an option. I kind of like the hustle of this guy using the current motor. The new design uses 4.5v as opposed to the 3v I was using in the original design. So the motor is running even faster in the revision. But, I sacrificed some of the distance in the leg travel in order to prevent the leg from swinging forward beyond 0 degrees as this was contributing to some of the issues with version 1. As a result, I think that even despite adding more power in version 2, if I were race the two side by side, the original design would come out ahead. Link to comment Share on other sites More sharing options...
Roboto Posted June 30, 2020 Share Posted June 30, 2020 Great video and yes he is fast!! Link to comment Share on other sites More sharing options...
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now