Originally shared by Nicholas Seward
https://www.youtube.com/attribution_link?a=lbQAJy4gM6c&u=/watch?v%3DT8sIGOBbTHg%26feature%3Dplayer_embedded
That’s really awesome. Love the design.
Oh man, this is amazing! I want one of this helios asap!
So freakin cool! I love the ridiculous bed size! Shouldn’t a complete circle be possible?
I love me some reprap but I always ask myself, “Self, what would be possible if it were all metal?” Wouldn’t the answer be: smaller, more rigid, faster? It would still make sense to do the gears and possibly other parts in printed plastic. W my smalls, there is a cost gain w some printed parts… and a rigidity, lower calibration steps, and lower part gain w some metal parts- at a higher cost. But ultimate cost ends up still low w very little trade off. Repraps prove it’s possible and pave the way for improvements w mixed manufacturing techniques.
Keep up the good work, bro!! I am dangerously close to doing a design exercise on this for trading out some parts in metal 
you got me w ridiculous build size, z belt, and printing on the table (ground?)!!
Brook
@Brook_Drumm I agree but not everything will be a win when you go to metal. In many cases it will add mass. However, in all cases it should reduce the size.
Right now it could print behind itself if you want to. If you want the whole donut, I would suggest a rotating base with a single slip ring for your power. The donut design could be even simpler in some ways.
I would love to see what you come up with. Hit me up if you want to bounce ideas or collaborate.
@Brook_Drumm If you want rigidity and lightness, carbon fiber is your answer. Boats use a foam core that provides shear strength to a fiberglass or carbon fiber sandwich. Carbon fiber is stiffer (less elastic) than fiber glass but is less tough.
So you would simply design your two arms to be easily wrapped with like 2 layers of carbon fiber, more rounded organic corners. The infill should be like tetrahedrons with that new subdivision infill. Doesn’t cost too much for such small parts either. If you want it really strong you want to use vacuum bagging to make the laminate as strong as possible, but afaik it works without as well.
Do you ever plan to release the plans?
@peter_rowser I currently working through the second iteration of the prototype. If all goes well, I will release within the month.
I’ll take a look at the designs go when you publish to see if I have anything to offer. I’m not a math guy like you, but with cncs and a waterjet, my brain translates designs into what I CAN do. I’ll start with the stock design and learn through building what you’ve designed.
Full donut? Heck yeah! I have an 8 foot diameter round table I hacked together in a round office… It would be awesome in the center of that table;)
Brook