I am very pleased to have received this kit. The design and workmanship is superb, as is the packaging. I am following the assembly instructions here: https://www.youtube.com/watch?v=oJ2Y9hZgCEY&feature=emb_logo.
I have successfully assembled the legs right up to the time of 5:40 in the video where I am instructed to install a spring to each joint on the legs. I hold the yellow/black limb with the yellow side up and try to insert a spring. I have tried over 10 times. I have tried inserting the spring on the black end, too. I have tried different pieces. There just is not enough space to get the compressed spring to fit. It's as if my springs have one too many coils.
The ID of my springs is 5.55 mm and the OD is 6.94 mm. The overall free length is 12.15 mm. My springs are made of wire with a diameter of 0.79 mm and have 7 coils. When compressed fully, this gives a length of 5.53 mm. The opening from the top of the button to the bottom of the white gizmo is 3.44 mm; if I add the distance from the bottom of the white gizmo to the top of the shoulder to the top of the button is measure 5.06 mm. In the video it looks like the springs have 7 coils; so I don't know what's changed to create my issue.
Can someone recommend how I can make these springs fit or how I can obtain springs that do fit.
Thanks in advance.
Our new kits all come with pre-assembled arms now. So the springs won't cause unexpected problems in the future.
For me, inserting the spring was also not an easy task.
I managed to insert a few springs by hand, but it was not pleasant.
Then I tried to print on a 3D printer a tweezer-type device from the message above. With its help, it also turned out to insert a couple of springs, but also not very convenient.
Then I drew my little spring holder model. With which I was able to compress the spring into the window, and then push it with a screwdriver into place. It also didn't work out perfectly. The holder could be improved. But the free springs are over, and disassembling the leg is no longer a hunt.
For me - bending the leg itself a little bit helped tremendously. I use one hand to push on a spring, and another one to apply counter pressure from the middle of the other side. After some wiggling the spring just "pops" into place with a noticeable clicking sound.
I read this topic while waiting for my Bittle and was expecting a hard time with the springs. So sorry to those who hard a hard time, but I was pleased to have very little trouble and just used my fingers. So to those like me wondering about prepping tools etc, give it a go first.
What I did and noticed:
I followed the orientation in the instruction video in case it's easier from one side
I pushed the springs a few times against the floor before trying
I noticed the slinky effect:if the spring tries to u-bend in a direction I oriented it so the bend (long) is out of the slot and the narrow part goes into the slot. With a couple of the harder to get in springs it seemed like a couple of coils first went in while the rest held and then the rest could be pushed down rather than trying to jam it all in at once
Hope this reassures and helps
Narrow the servo arm tab that receives the spring! I noticed that just putting a spring over that short servo tab with nothing assembled the fit is very snug - very little play. After having tried many of the other suggestions with no success but lots of sore fingers I decided to try before assembly, shaving a bit off the servo arm tab that receives the spring (the short tab/side of the servo arm) until the spring would slide EASILY onto it. This made all the difference in the world for me and made pushing the spring into place with my fingers quick and easy. I suspect that would help all alternative methods/tools as well.
For what it's worth, I used a metal 'spudger' to wedge the springs in. In the beginning, I struggled with them mightily. Because I'm a hacker, I have a dozen or so of them lying around for various uses, mainly prying things open.
Once I figured out how to use the spudger to wedge the springs in, it was smooth sailing (well, easier sailing, anyway).
Floss trick worked for me, thanks.
Is there not a servo-controlled tail? It is on the wiring diagram and the kit contains another long-wired servo.
I figured out a procedure that worked for me & posted a YouTube video, just in case this is helpful for others: https://youtu.be/DR-jUdI_MaQ
Install the spring from the leg side that does NOT have teeth in the servo holes facing up.
Make sure spring is aligned around servo arm, first.
Put a finger over the spring end attached to the servo so the spring doesn't pop out.
Use something flat, metal, and sturdy to push other side of spring - I used the end of maker tweezers.
Push the other spring end in as far as it'll go. Try to slide the edge of the spring side you are pushing in on a bit of an angle so some of the spring bulges out toward you, like a slinky.
Once you can feel the other end of the spring is in, push the bulging slinky bump of the spring in so the entire spring is compressed and straight.
Cheers & thanks again to @Rongzhong Li for such a wonderful project. Wishing you the best success!