Wire bumper fix demo
1/16" stainless steel wire or coat hanger wire appears to work with a layered plastic mounting. This minimum thickness required for stiffness. ABS plastic for auto work was used here, crinkle finish one side, since available in 15" sheets on ebay
for a strip all the way across the front; only a center section is shown here. I don't intend to complete a full modification, just show one approach with fairly good promise, for anyone needing this for their scandinavian or designer furniture.
The wire cross piece could be covered with heat shrink tube or duck tape should softening be of use.
Instead of carving grooves in thick plastic, a 1/16" backing is used and two 1/16" layers in blocks with gaps are glued to the backing -- here just with double sided transparent tape, adequate for testing. When satisfied, can be redone with crazy glue, gorilla glue, or epoxy (only certain glues work on plastic). A 1/8" gap is used for a loose fit around 1/16" wire, to obtain easy sliding. Ideally 1/8" plastic should be used for the blocks, to provide the smoothest possible bearing edge. Pre-gluing two 1/16" layers and smoothly cutting the edges may suffice, used here. Aluminum strips could also be used but won't glue as easily. Thin modeling wood won't have as hard a bearing surface, but painted might work, haven't tried.
Double sided tape is then applied to the entire blocked surface and attached to the front of the Neato bumper, positioning the wire bail at the proper distance.
The wire slides up when Neato tilts moving backwards, to not obstruct the movement by digging in at the front.
This extension is set to deflect the bumper off 1/2" wood resting on carpet, with the Neato slightly depressed into the surface. Note the wire extends up high on the bumper so glue hold at the top has leverage against the bottom edge fulcrum to withstand inward hits at the bottom, remaining stuck and depressing the bumper.Performance
Deflection from 1/2" wood is shown in this brief video, as well as how the extension did not interfere with Neato's backing up tilted, at least in this case. Software V3.1 just released adds some of the backing motion. A lot of thorough testing might reveal further problems, I am leaving to others. Video: http://youtu.be/aRxCbdIg0C0
At the same time the extension appears to slide properly over obstructions which do not trap the Neato, such as a broad circular chair base, which caused a trap with a non-sliding extension -- in this brief video: http://youtu.be/7mx7dXHlA9sCompletion Required for Function
To work usefully additional wire loops must be added aside the center one shown, completely covering the front, and the sides of the bumper must also be treated -- else Neato will slide over obstacles turning. The sides may not require the sliding feature and can be treated just with plastic strips, if a gap is left at the front corner as needed to accommodate tilting. Extensive testing would reveal any need for sliding the side pieces.Materials
No convenient source of this thickness stainless steel wire was found other than scavenging from a kitchen gadget "chef basket" -- the circular rim, providing only a couple feet (wildly different prices, cheapest http://www.amazon.com/gp/product/B004K719Y0/ref=oh_details_o00_s00_i00
). Thinner wire available in jewelry supply, inadequate. Copper, aluminum, or brass rod is too soft in this thickness. Painted steel coat hanger wire best alternative -- generally obtained only from dry cleaning, as everyone uses superior plastic hangers.... [edit: also available on ebay
, just found] Sources of materials not my specialty, so readers may know more.
Handling: harder steel wire this thick will not cut with electrical wire sheer cutters; a bolt cutter, such as on electrical crimp tools, can be used instead of the huge ones. Ends may need some filing finish. Dremel power cutters also suitable, or hacksaws.boring details of sources
Smallparts.com has varied types of plastic, pricey, unfamiliar in all. Nylon is used for nuts and bolts. PC or polycarbonate is Lexan, used for cups and windows, very hard to cut. PP Polypropylene is a superior replacement for polystyrene used in threads for heavy duty upholstery cloth. Plexiglass or acrylic, along with lexan sheets are used for picture frames, available in hardware stores up to 1/4" -- expensive. Vinyl of course is everywhere, but seems to be expensive. 1/16" ABS is cheap and cuts with scissors, though a really straight cut requires a knife or saw. 1/8" won't cut with scissors. The 1/16" thickness was found inexpensive only in auto trim supply on ebay
; 1/8" also at servocity. ABS is fairly flexible, but appears to work in this application, supported by Neato's bumper surface. Servocity.com sells it for robotics hobbies, just indicating suitability. Can be painted, too (paint usually needs a binder to stick to plastic; Krylon spray paint comes in a special plastic-ready line).
If anyone tries any of this bumper lowering, I hope they will post results for enjoyment of other Neato fans, and include lots of pictures (all this verbiage is just in case someone not into crafting things needs the info that was hard to obtain myself).