rubherkitty wrote:If the design is strong enough, a skeleton made of molded plastic parts is the way to go. Cutting steel tubing and welding is time consuming.
Plastic may survive a doll drop better than welded tubing as well. Better to flex then bend a tube or break a weld.
Exactly. Some plastics are amazing too, there are glass filled nylons for example that definitely rival steel for strength to weight.
I am not sure many plastics would survive a drop better then steel typically would. regular mild steel has a very large plastic deformation range before failure. Poor welds might snap but good welds will rip the parent metal in half before failing.
One big advantage with plastic is its easier to just design a thick multi flange hinge to be made by the thousands via injection molding that might be difficult to machine/weld in steel. Much less worry about material cost, weight and labor cost for construction. The 2 vs 3 flange design of the hip joints is a good example, this would have been hard to make in steel. Being able to provide such thick beefy joints that are easily made may provide more strength in the event of a drop however.
Plastic on plastic joints can actually wear a lot less then steel on steel with no lubrication, depending on the plastic used. UHMW and teflon provide amazingly low wear with no lubrication for example.
Also plastic can make things that more resemble bones for more realism, and provide features the silicone can mechanically adhere to preventing delamination that is common in dolls with regular round skeleton bones. Thees are some of the features of the DSmini I am rather excited about.
The only major downside to plastic construction is when the wrong plastic is picked (Some plastics are super strong and durable, others weak and brittle. Some survive outdoors/UV, others for indoor use only, Some costly, others cheap. etc), and the cost of the mold requires you to have to produce a lot of parts for it to be cost effective vs machining things out of steel or other methods.
I would however suspect given DSdoll's commitment to quality that they have picked a good plastic for this dolls skeleton.
I don't think welded steel is anything to worry about with proper skill and quality control. Your car is welded together in many safety critical areas. So is every nuclear power plant, aircraft, boat, train, motorbike, bicycle and pretty much everything else that might kill you if it fails. They do however employ some very good welders and often use robotic welders.
I do think lack of skilled labor and quality control is something that will cause any design serious problems: welded, bolted, brazed, glued or riveted. I commend DSdoll's commitment to quality.
As for the OP's question: the squeaking noise could be the lock/spring washers, bolt rubbing in hinge, or a plastic pad between steel members of the hinge. I wouldn't jump to thinking they have already started to make larger DS with large plastic elements. Larger injection molds cost a lot more and they may be using the DSmini to try it out on. Smaller dolls also experience much lower stresses and are more suited to lightweight plastic skeletons.
I would love to hear from DS on this of course, but I wouldn't jump to any conclusions.
Every day people remind me why I like dolls better.
