Update. I took another pair of carved shoes to try a modified design of the wire and brass nut. This time I wrapped the wire around the groove on the outside of the brass nut (see original posting below for context). I then placed the nut in a hole at the toe (instead of in the ankle) and curved the wire up through the ankle hole in the shoe. The idea is to allow for more flexibility of the wire at the ankle so it may not break as easily under repeated bending. My wire and brass nut are now similar to what Sven and Mike have done. I posted some pics of the new shoe:
What may be different is that I am not permanently fixing the foot/shoe to the nut. The intent is for the design to allow me to have replacement armature parts, specifically wire. If my leg segment breaks I want to be able to swap out the wire and continue to use the shoe and possibly the brass nut. Hopefully this will allow me to do so since the brass nut and wire fit securely into the bottom of the shoe and I used hot glue (which I can release if needed) to hold it in place. In short, I can take the shoe off at any time.
End of update, the original posting follows..
I’ve been working on some tests for the armatures to be used in the next project. My design may not be original but I’m combining information from other stop motion animator blogs regarding tie-downs. I used the Hilligoss T-Shaped tie down for Vitruvius but this time I wanted to try something else. My new tie-downs are inspired by tips found in the blog archives of Mike and Sven and possibly other places that I can’t remember right now. For example, J-B Weld is the adhesive (Mike has mentioned that at one point) and the knurled brass nuts are placed in the foot (Sven posted something about those recently). I put the pics up on Flickr with notes and descriptions so go check them out if you like.
5 responses to “Armature 2008 – Tie Downs – UPDATED”
Very cool! I see the “funnel” at the top of the thumb screw makes a nice well for the J-B Kwik Weld to sit in. I’ll be interested to see how these work for you. 🙂
Hey, nice!!! I’m a little leery about the wires just being barely twisted in like that though…. I’d be afraid it would pop out pretty easily. I always try to get a solid physical connection and then the adhesive is just there to add security to it. Not sure if you’ve seen it, but I wrap the wire around the channel around the thumb nut and then twist it nice and tight, then gob the Kwikweld around that to form a solid fillet. If you check my Sept 2006 archives (I believe, that or Oct) you can see it.
I guess this way you can have smaller feet… something I’d like to do. And I like the carved shape of the feet! Great work!
Thanks Sven and Strider.
Yes, only time will tell if it truly works. What convinced me to go ahead was the test I did with a short strand of wire, the nut, and J-B Weld. I was able to lift a drafting table off the floor with this. I put the wire end through a hole in the top of the table and the only thing supporting the weight was the nut which was connected with J-B. I then pulled up on the wire which lifted the table about one foot off the floor. I assume that if it could withstand that amount of stress without snapping or pulling out then it would probaly hold my characters in place as well. Hope that text description made sense.
P.S. this armature is also a replacement design so if if fails then I just screw in a replacement leg and go on. I am planning (anticipating) failure of the wire this time around since I’ve had arms break in both Damocles and Vitruvius. grrrrrr
Just wanted to say that I love your blog. Back when I was living in Atlanta it felt like I was the only one out there doing stop motion, now there seems to be such a whirl of activity. I thought I would mention that I might be visiting friends in the ATL at the end of the month. Maybe you could join Tak and I for a drink while I’m out there…
I guess I would also agree with Mike on getting a solid physical connection between the wire and the nut. Although the test of lifting strength feels solid, that JB weld stuff gets really brittle. And as you bend the ankle, where the wire touches the brass, it’s guaranteed to shatter. Also, as you tiedown, the threaded rod may push the wire out of the top. Since you have such a nice foot/toe on the puppet, you actually have the luxury of placing the nut in the toe, that way you keep a length of wire that bends in between the epoxy joint and the ankle. It’s always a good rule of thumb to give yourself a small bit wire for stress relief between where you bend a joint and the hard epoxy point. ex: an extra loop above the shoulder before it connects to the torso, or epoxy the center a hand to the arm away from where the wrist bends. Wire armatures almost always will break right at or near where there is a hard connection point (or where there are any accidental nicks from handling with pliers, or slipped Exacto blades/scissors). Test it out: grab a length of wire with pliers or vise grips and lock it tightly, then bend the wire around. With the length try as many different shapes as you want- it won’t break. Then bend it up and down where the wire meets the grip of the pliers, just like where the wire would meet the epoxy at a shoulder joint. It breaks easily. So for a shoulder, it’s always best to give an extra loop of wire, like a small tight inverted U then back down to the hard weld. So for an ankle the bit of wire that makes an L to the toe nut really helps give necessary relief between where the ankle bends and the hard epoxy point at the toe. This would work especially well since you have enough foot length to work with…. just adding my 2 cents..
Thank you Kelly. Sure, let me know if you and Tak want to meet.
I haven’t tested this design beyond the strength test so back-and-forth movement at the ankle might pop out or break like you and Mike mentioned.
I was going for the ankle tie down like Sven did but wanted to reduce the bulk:
http://www.scarletstarstudios.com/blog/archives/2007/11/new_puppet_professor_ichbonnsen.html
So, I checked out Mike’s archives and now I see what he was doing with wrapping the wire around the groove of the brass nut.
http://darkmattr.blogspot.com/2006/09/day-10-wiretech-talk.html
Like Mike mentioned, I was trying to keep the bulk of the design down for smaller feet. The good news is that I should be able to easily re-design the shoe to accommodate the nut in the toe with the wire going up through the ankle.
More experimentation to come…