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Neato Tire Traction

PostPosted: August 13th, 2013, 4:00 pm
by joeschmo
I'm trying to figure out a way to increase Neato's traction on all surfaces. I'm thinking something spikey that will grip carpet/rugs really well but won't damage hardwood. I know there isn't much room between the tire and body of the neato so anything added to the tire would have to be pretty thin. Any ideas on something thin that would be effective?
A pic that Vic posted shows a white band around the center of the tire. What is that and does it help with traction?
It drives me nuts to see the neato spin it's wheels because I feel like it's balding the tires before my eyes...shortening their life.

Re: Neato Tire Traction

PostPosted: August 13th, 2013, 4:25 pm
by glnc222
[edit] 3D printer file for entire XV wheel, tread, and axle later post (or Mods & Repairs list top of main forum page)

[edit] Botvac wheels are also gears, not easily reproduced; below

The existing tread must be removed; there was a listing for replacement treads at Protech Robotics but might be entire wheel -- and expensive (at that price you should get a whole wheel...). Point is the tread might be removed.

[edit] To handle wet floors, which are slippery, iRobot Scooba uses replaceable foam tire treads, on wheels in six set packs around $14. So the method is already recognized in the industry.
The size is only 1.75" diameter too small for Neato (besides needing a shaft carve out). So one has to build the equivalent as shown in later posts. Scooba

An interesting replacement would be a toothed drive belt turned inside out (not necessarily Neato's fan drive belt size). Probably not available in the exact tire size needed so would have to be cut and glued, and possibly pinned into the hub at the ends, or at least together. Hard to glue vinyl rubber, polyurethane (gorilla glue) maybe. Whether this gives more traction would have to be tried. Expensive to experiment given replacement wheel prices. Robotshop and ServoCity are one source of drive belts.

Short of replacing the tread, it could be cut into a toothed pattern, slicing grooves into it with a saw or Dremel tool. Cutting through might make it fall off. Not clear how constructed.
Sewing pins could be stuck into it all around like auto tire studs -- usable only on carpet, which causes the most wheel slippage.

Another possible source of a tread material is the treads attached to caster wheels, which might be found in the right size to cut off and transfer to Neato wheels. Flexible treads are used for casters on hard floors when mats are not used.

Given the cost, I am pleased to leave this to enthusiasts with worse traction problems than mine.

[edit] toothed treads will wear out faster than smooth, possibly why not supplied that way to begin with.

[edit] another interesting approach on removed treads is something softer which compressing, presents a larger contact area. Foam weatherstrip comes to mind, heaver in closed cell type. Also Mouse Pad material.

Re: Neato Tire Traction

PostPosted: August 13th, 2013, 4:52 pm
by vic7767
Here is a possible solution that may work on the Neato drive wheels. Look for a #82 rubber band, it is 1/2" wide and has a 2-1/2" diameter. Pictured here is a similar solution using two smaller rubber bands. I have not tested this solution yet so you may be the first to test and report back with your results.

The other picture with the white neoprene band around the Neato drive wheels was a traction test I performed with poor results and a lot of plastic removal work to mount the two rings.

Re: Neato Tire Traction

PostPosted: August 13th, 2013, 5:06 pm
by glnc222
This was tried in thread "How To Increase Wheel Friction?" on severe problem of Vorwerk initially using a harder tread material, since replaced with Neato type wheels. Some question of wheel well clearance for any additional material, why I suspect tread replacement needed.

Added above a softer tread, foam rubber, might increase contact area. Mouse Pads possible source.

[edit]A better rubber band method was used on Roomba with success, might work on Neato with similar wheels, not tried.

Re: Neato Tire Traction

PostPosted: August 13th, 2013, 5:19 pm
by glnc222
Wonder if an experimental wheel hub could be made cutting out a circle in wood with a hole saw? Leaves a big pilot hole, maybe needs a bushing. Wrap with different things, foam etc. How is the wheel attached?
[edit] drive wheel assembly detail at

Wheel dimensions:
Hub diameter 2.5"[correction: 3"] tread thickness 1/8" with 1/16" depth broad teeth. Total O.D. 2.75".
The hub is not smooth but has long raised teeth engaging the tread material.
Wheel Thickness 9/16", with 1/16" depression around attachment side 1 7/8" across fitting around a raised rim on the motor arm, with a raised center hub on the wheel 3/8" wide 1/16" high. The drive shaft is a 5/16" shaft with flattened sides 1/4" apart.
Wheel fastens with a screw and attached washer 3/8" wide, with thread lock glue making initially very hard to unscrew.

So a 1/2" wood cutout would appear to replace the original wheel with a 1/16" spacer on the attachment side. Hardwood weight 1oz same as the plastic wheel. Drill center 1/4" and file out sides to 5/16" for the drive shaft. Some Mouse Pad material is just the 1/8" thickness required.

Re: Neato Tire Traction

PostPosted: August 13th, 2013, 11:01 pm
by glnc222
Our wheels are crafted from the finest hardwoods and variously finished to match your decor.
Neato wheel cut from wood with hole saw, filed to fit shaft

2.5" hole saw makes that size hole, with a plug 1/8" thinner, requiring a thicker tread; 1/16" radius expandable with 1/16" layer of mounting tape. Hard to find 2 5/8" hole saws, and not worth the money here. Guide hole is the requisite 1/4".

Don't have any #82 rubber bands and no need for the bags full they sell. But I do have a discarded mouse pad, so will see. Only one wheel so far. Only certified Neatologists should try filing accurately.

Re: Neato Tire Traction

PostPosted: August 14th, 2013, 2:08 am
by glnc222
Unusual Tread Possibilities

For hard floors -- unpredictable on carpet -- "Ruggies" and equivalent reusable (non-adhesive) carpet stickers, described as "Tacky grip Polymer technology grips the rug while hundreds of suction pockets grip the floor."

For carpet only -- definitely slips on hard floors -- self-sticking (double sided) velcro strap, which comes with a very shallow hook side compared to mounting types, so maybe suitable. Grips fibers well, how badly damaging unknown. A roll seems to run over surface fairly well, will try and test further. Regular velcro hook excellent for securing docking bases on carpet. [edit -- this was for mounting velcro, not straps, which don't add to traction on carpet, too shallow.] Sold for use in car trunks to secure storage organizers.

Re: Neato Tire Traction

PostPosted: August 14th, 2013, 9:21 am
I have the same problem :(

Neato has a really HARD time getting up a threshold from my hall ( hardwood ) to my Living room ( carpet. )
In fact 99% of the time .. Neato does not do the living room! :(

I have replaced the threshold 2 times .. with different thickness's of wood :(
( It does not seem to be very big nor very high for it to NOT be able to transition the threshold )

I have tried " cutting " Slits using a knife into the rubber of the wheels. To Gain Traction ( Did not Work )

I was going to try adding " rubber bands " But I not sure they would stay on the wheels.
But after reading the link glnc222 Posted. ( viewtopic.php?f=20&t=16113 ) Someone tried that and it didn't work :(

Its a real shame that the makers of Neato can not figure out a solution for thresholds.

In My First and Original post ...

Neato could be easily fixed with software! - Have it "LIFT and THEN BACKUP! Over The Threshold!
( Also Could Speed Up And Take a "RUN" At The Threshold ! ) Or At Least Try!

Anyway .. its a Big Bummer ..

Re: Neato Tire Traction

PostPosted: August 14th, 2013, 10:21 am
by mfortuna
I have pretty high thresholds from wood to tile and Neato has no issue at all with them. My roomba often gets stuck and eventually backs up.

I do have new tread so maybe that helps.

Re: Neato Tire Traction

PostPosted: August 14th, 2013, 1:06 pm
by joeschmo
I tried the rubber bands last night and it resulted in me disassembling a wheel because one of the bands slipped off jamming up the tire. While the rubber band idea might prevent some wear on the original treads, I didn't see any significant increase in traction.

Re: Neato Tire Traction

PostPosted: August 15th, 2013, 2:32 am
by glnc222
Traction Measures for Different Tread Materials

Net Thrust Over Static Drag (pounds force)
............................................ Carpet (with slider) ....Vinyl Kitchen Flooring
Neato's Original tread ................... 3.25 lbs ........................ 4 lbs
Mouse Pad Foam Dense Rubber ........ 3.5 lbs ......................... 6 lbs*
Velcro Self-Stick Strapping (hook) ..... 3.5 lbs ......................... 0.5 lbs
Ruggies carpet gripper .................. 5.5 lbs ......................... 6 lbs*
Rubber Band .............................. 3.25 lbs ........................ 5.25 lbs (see later post on mounting)
Gold Watch Chain ........................ (for hockey rinks only)
* postal scale stops at 6lbs, could exceed

(Only mounting velcro with deeper hooks apparently grips carpet well. Nothing with Ultramate, though.)
(The slippery carpet slider probably renders this measure equivalent to a more tacky carpet. Carpets vary in consistency and effect.)

Speed: no effect, about 6 in/sec spot cleaning, but varies over program phases. Consistent with feedback control of driver motor RPM, speeds settable in USB commands. The increased friction did not overcome Neato's drive. Highest speeds, though, were not tested. [edit] later no observed difference.
[edit] Motor load measurements show very slight increases with higher traction mouse pad treads amounting to a couple minutes run time. Motor load increase on carpet 100ma on 625ma, hard floors 50ma on 250ma (where the problem moldings are located). Sliders are still needed on carpet to reduce drag instead of using more motor power to overcome drag.

"Ruggies" non-adhesive carpet sticking material seems coated both sides with some tacky stuff to which dirt will cling, removable only with acetone, not alcohol. $2.50 per Neato vs 50 cents for mouse pad foam rubber. May not stick to crazy glue. Advanced silicone rubber very elastic, tacky consistency.
Ruggies carpet sticking material, $10 for 8 4" triangles, one per wheel

The 50 per cent increase in traction with mouse pad material is consistent with successfully climbing a problem 1/2" quarter round metal carpet edging which Neato could not previously climb, with wheels slipping on the metal.
wheels slipping on metal quarter round edging

Quarter round moldings are the most difficult because the sharp curvature limits wheel contact area to a single tangent point, at an angle to the weight pressure as well, reducing traction. The polished metal here is also slippery. Theoretically the softer mouse pad material maintains a larger contact area; the pad surface is not especially more tacky than Neato's original tread. The pad is cross hatch patterned on the bottom for surface gripping. I don't think rubber bands are especially different than Neato's tread, either. More on moldings in their own section below. Like higher traction softer car tires, the softer Neato material will wear faster, but should be easily replaced. How well it works in the end requires observing long term usage. One possible problem would be dirt accumulation on the surface reducing effectiveness. That can be corrected by dusting off fairly easily.

Tread Construction

Mouse Pad Material on Wood Testing Wheels

Custom wheels were made just for testing, and can be improved for permanent use. I did not want to risk destroying a Neato wheel removing its tread. I suspect ProTech's "tread" item is the entire wheel, as the larger unit is the whole motor assembly. Couldn't get an answer from them by email, guess would have to phone. Neato's wheel has thin blades extruded into the tread holding it in place -- compared to the slipping rubber bands reported. Ideally the mouse pad material would be installed on Neato's wheel hub discarding the original silicone tread. What's involved in removing the tread and configuring the replacement to fit I don't know yet. [edit] Attempting to obtain some extra wheels, uncertain. Or express an interest to persuade the more qualified members with some business in parts it would be worth offering some replacement treads ready to slip on.

Hand-made Wheel Details

For regular wooden wheel use I would tack the material down with counter sunk thin, #19 I think, brads or sewing pins (both needing a sub-1/16 drill on hardwood not to split it). (Softwood will work initially but loosen the grip on the drive shaft over time. Plastic is available but much more expensive in 1/2 inch thickness. Small 2 ft red oak boards pre-cut are at Lowes building supply in the U.S.

There was some confusion with the wheel measurements. The Neato diameter is 3". With a 2.5" hole saw cutting a 2 3/8" wheel I ended up matching adding a 1/4" layer of several parts: one mounting tape layer and two mouse pad layers separated by self-stick scotch tape. Ends of strips are crazy glued together. A 3" hole saw should make a wheel taking a single layer of mouse pad. I extended the pad inwards of the flat wheel edge matching thickness of Neato's tread.

Using the flat wheel a 1/16" nylon washer 5/16-3/8" I.D. is used between the wheel and the motor assembly.
The wheel wobbles slightly. A 1 7/8" or 1.75" hole saw or both, will cut a groove in the wheel (before cutting it out) fitting over the raised flange on the motor assembly same as Neato's own wheel, eliminating the washer. Greese is used on the inside surface. It seems the outer flange is used to stabilize the wheel. [edit]could be more a dust seal, and the shaft fit is the issue. Surface inside the groove perimeter must be reduced sanding not to rub, just like the original wheel. Better use a slice of hard wood dowel in place of the washer, glued as protrusion. Or bolting the disk into a drill, spin to sand selected part.
[edit] On second thought the washer surface may be needed for bearing, so a 1/4" I.D. washer can be countersunk in the wood before cutting and filed out with the wood. Some of the wobble might be due to the gap in fitting the drive shaft, hard to tell. A Dremel cutter bit could speed hole shaping, but not sure how easily controlled, very powerful. A regular drill cutting bit 1/4" did not cut hard wood. Maybe there are others.
Initially filed washer might serve as a tool guide for the wood.

The shaft screw must be counter sunk in the outer wheel surface to the level of the inserted drive shaft end, with a 7/16 or 1/2" bit.

Adjustable hole saws with a point cutter on a radial arm need a drill press to hold straight cutting. Others can be used on hand drills, requiring separate sized entire cylinders, more expensive.

Molding Height Transitions

Neato cannot climb too high a molding without a ramping approach or the top edge can grab the bottom tight enough to trap the vacuum. It is not a matter of traction per se; there are limits to the mechanics of the unit size, in turn limited by the need to navigate between obstacles. The whole business is a delicate balance of factors not readily apparent. Some high moldings are wide enough to provide a ramping slope, but others have a sort of quarter round finish at the top -- those problem curves. Neato needs to bump off moldings it cannot climb, but without modifying the bumper, mag strips must be used. [edit] When climbing, weight rests on the front and back, diminishing pressure and friction on the wheels. So better traction will help.

One solution for too high or poorly shaped moldings is to add to the molding a thin step of 1/8" hobby wood, basswood, available in narrow strips at craft stores and online suppliers. This creates a stairway Neato can climb, a series of more easily handled transitions. Whether such things are suitable for the architecture of a house is a matter of taste and circumstance. The strip must be fastened with tacks or self-stick tape. Paint and stain pens can be used.

An excellent tape approach might be the new 3M Command Adhesive strips, for hanging fixtures, which do not damage finishes, and remove by stretching them; fairly expensive. Regular self-stick mounting things have very hard to remove glue in some cases, when left on long periods, requiring acetone (nail polish remover) ruining any painted or varnished surface. Rental properties advise tenants to use only tack fittings for hangings instead of glued hangers damaging sheet rock surfacing.

Other Mods Links to all mods for utility cleaning at

glnc222, mentat, reporting.

Re: Neato Tire Traction

PostPosted: August 16th, 2013, 5:25 pm
by glnc222
"Ruggies" carpet gripper material added to traction table above: 5.5 lbs on carpet (so no difference hard floor and carpet), only stuff to increase there.
$2.50 per Neato vs 50 cents for mouse pad rubber. Still need a slider to reduce carpet drag instead of over powering with higher motor torque, reducing run time. But you never know what sprcial needs users have, so measured just in case.

Re: Neato Tire Traction

PostPosted: August 17th, 2013, 5:56 pm
by glnc222
Enhancing your wheels could turn out to be a simple matter of pulling off the original tread, cutting slits in some mouse pad material to fit, and gluing it on. Maybe the original tread can be put back on, too. Who knows?

Re: Neato Tire Traction

PostPosted: August 18th, 2013, 10:58 pm
by glnc222
USB motor load measures were taken showing very small increases in load for mouse pad treads, amounting to a couple minutes run time. 50ma increase on hard floors (where the problem moldings are), and 100ma on carpet (where drag is overcome). The original maximum run time is 70 minutes on carpet measured here, or over 90 minutes on hard floors. [edit] similar to higher traction car tires slightly lowering mileage. also confirms higher traction.

Re: Neato Tire Traction

PostPosted: August 19th, 2013, 2:27 am
by JEfromCanada
All we need now are durability studies for the mouse pad fix. Hopefully, the pads don't wear to the point of reduced adherence.

Re: Neato Tire Traction

PostPosted: August 19th, 2013, 4:51 am
by glnc222
The surface wear may not matter if the effect is from foam compression compared to the hard Neato treads. Frequent wheel service is unfamiliar but could be like changing the filter. Very cheap material.

Attempting to get another plastic wheel from Protech, which lists them used so probably salvage from broken motor assemblies. I suspect the tread may have been molded in place from liquid, so inelastic, and has to be sliced to unroll. [edit] There appear to be no separate wheels available. The hub has large crossing grooves fitting teeth molded into the tread, with metal tabs in the bottom visible through the transparent tread. So probably slid on and held by those, not clear which way exactly.

I speculate Neato wheels are from a caster supplier whose products are for heavy weight and has no market for flimsy things. Better the pad makers cutting finished tread strips.

[edit]Model Airplane Wheels
Wheels of the Neato 3" diameter are made for model planes with foam treads, such as Dave Brown Lite Flite brand wheels in hobby supplies. They are wider than Neato's, and say the hub can only be drilled out to 3/16" instead of Neato's 9/32 thick and wider oblong; might still be usable if examined. But interesting that this foam tread type of wheel is supplied by industry should vacuum makers choose to use them. Lots of different robot wheels available which might be adapted, but the adaption for Neato's shaft etc. could take as much work as custom sizing the wheel from scratch as in the following post.

Re: Neato Tire Traction

PostPosted: August 21st, 2013, 12:18 am
by glnc222
Pipe Cap Hand-Made Wheel

Another method of constructing a wheel, without hole saws, is slicing off part of a suitably sized PVC water pipe or conduit end cap as the rim of the wheel, to which the tread attaches, and a 1" round dowel slice as a hub drilled and filed for the drive shaft (plastic rod then also practical, but more expensive). Attach the dowel to the cap with two perimeter counter sunk screws through the end cap face, which is drilled the whole diameter of the shaft screw washer-flange to counter sink in the plastic. Advantage repeated hub attempts without risking entire wood disks tediously cut and expensive.

Some caps are shown with outside gripping ridges to avoid, others smooth surfaced.
The pipe size is not clear from plumbing ignorance, whether rated by pipe I.D. or O.D. The cap adds more going over the rated pipe size. Only 2" and 2.5" could be relevant, next being 3" too big, and will try a very cheap 2" eventually when I place another order with Amazon ($25 free shipping...). Not all sizes are stocked in stores and prices can vary widely online. Should not be more than $3.

Best not to remove a cap found somewhere in the house plumbing for this purpose.
Seems odd to have caps on pipes at all, for then what good is the pipe?

[edit] If a bearing washer is needed standard ones are too thick, so I'd just cut a ring out of some thin packaging plastic.

[edit] The "cap" fitting outside is the wrong part because rounded on top; the "plug" fitting inside, unthreaded, was found interesting rated 2", with 2 3/8 O.D., 2" I.D., flat 1/4" thick top, smooth sided. $2.25 HomeDepot.
"plug 2 in spigot"
Thick sides can thread small screws to secure treads. The drive shaft will have to fit part way into the top. Counter sinking the drive shaft screw needs a flat ended Forstner drill bit.

Re: Neato Tire Traction

PostPosted: August 24th, 2013, 12:17 am
by glnc222



[edit] Shaft screw metric M4 .70 pitch 12mm (1/2") flat head machine screw, standard conical counter sink eliminates need for flat recess Forstner bit
[edit2] the machine screw head is only 1/32 wider than the quarter inch shaft hole, why the washer is probably used. Still might work.
Drive shaft screw retains to shaft only, not pressing wheel to hub preventing turning.

[edit] centering drive shaft hole with a hand held drill: Higher precision is needed for a wheel axle than mounting a fixture. Easiest way is to use a 1/4" brad point bit into the centering hole left by the similar pointed forstner bit after making the recess. For twist drills without a drill press, an elaborate procedure is still possible:

Small metal drill guides keep bits straight but not fixed sideways. Brad-Point wood-working bits have pin tips to center in wood. Twist drill bits require clamping a wood block with a guide hole to the workpiece, with a method to position the hole. Drill a guided straight hole roughly centered in wood wide enough for the wheel. Draw a circle the wheel width on paper and punch or cut out a 1/4" hole in the center; tape this to the wood block over the bit as spindle. Then clamp with the wheel aligned to the drawn circle. Indents for the point of twist drills won't work, as hardness variations will push the bit sideways going in. Without a metal drill guide, press into the corner between right angled wood blocks to keep a bit straight.

[edit] finding center of traced circle: straight line across a bit off center. Compass needle at intersections, cross hatch out aways each side, connect by exact diameter line. Repeat on this line for a center crossing.

The hub can be screwed into the rim before drilling the axle hole, to do both at once.

The PVC cannot be spin sanded or filed as the soft material clogs the abrasive and teeth, smoothing out. At least at low speeds. Beware off center vibration high speed, Dremel etc. But cuts with wood saws, hand filing.

2.5" spigot slip plugs are available at twice the cost of 2" and only at plumbing supply distributors. Reduces tread to a single mouse pad layer 1/8" instead of a 5/16" tread, used in testing traction. Less tread atop retaining screws but easier assembly.

[edit] sawing tip: open end of the cup shape clamps to a table edge inside, with raised outside part compensated by paper or cardboard under thinner part. Blocks clamped alongside guide saw. Cup too wide for miter box.

[edit] Forstner bit: stop depth precisely with a small, like 4-40, machine screw through the back side. Cuts slowly, level by eye. Or a guide of a top block extending out over a bottom block, with a notch for the shaft (thinner than the head), all clamped together with the workpiece. The small hole for the screw can be used to center a compass on the back for a circle within which the dowel hub fits.

Re: Neato Tire Traction

PostPosted: August 24th, 2013, 4:21 pm
by glnc222
Rubber Band Fix

[edit]though not useful as a permanent fix, can be used to test value of improving the wheels with spot clean started at problem height transitions

Traction Hard Floor 5.25lbs, Carpet 3.25 lbs -- improvement on hard floors only.

Wide rubber bands will just barely fit over the tread within the wheel clearances to the fender and the wheel well top, a bit hard to work on through the tight space. However, they are under sideways pressure of turning wheels and work off the surface if not secured sideways, which is not so easy but may be possible.

Sewing pins cut off 1/8" as micro nails go well into the raised tread blocks, but cannot be counter sunk into the band because the elastic rubber pulls them to the top. So they may scratch hard floor finishes. There's too little clearance to cover them. Possibly applied to thin tape under the rubber band glued to the band's bottom.
sewing pins into rubber band

If used place on alternate sides every group of five blocks, eight around the wheel.

Pinless Method
Another way to secure the bands is with the gaps between the raised tread blocks, inserting some 1/8" material such as mouse pad rubber or a 2-3 layers of mounting tape into the gap, glued to the rubber band underneath, bracing against the opposite side raised tread block. For this it is best not to have the band stretched very much -- effects on glue. The 2.5" (folded loop length, half the total) #82 bands mentioned are tight, though uselessly -- and aren't in stores. #84 3.5" still stretches around. But #105 5" long with better 5/8" width (which can be narrowed if needed), can be cut to fit the circumference around 9" -- mail order likely needed. Ends can be sewn together with clear colored, very thin monofilament thread in Notions aisles, and crazy glue. Whether glue can hold to the filling blocks well enough has not been tested; there is not much area to create hold; sewing to those likely best. Glues won't stick to the silicone tread material. Lot of work but without wood-working tools used to make replacement wheels.

Another possibility is sewing the rubber band directly to the tread, tacking here and there, with less work than the above, and #84 bands at Staples. Doesn't support tread replacement easily and repeated many times is tearing up the tread, unless you can keep using the same pin holes. The durability isn't known.

I have not tested these methods.

[edit] Yet another untested: use pins under the band as tie points for sewing thread.

[edit] oops, another: sew lines across the tread block gaps once and for all as tie points, then repeatedly sew ties to replacement bands around them. Too loose? Up to the reader; I just prefer the certainty of replacing the wheels to use predictable tread methods were I to need this, and they are not sold separately. I doubt anyone is going to remove the tread to see if Neato's hub can be reused. Surprise me.

[edit] 9/14/13. Late addition. One more untested possibility: glue might not hold to the silicon, but might to the rubber band. Blocks of rubber cement in the gaps between the tread blocks might give sideways hold needed, against the opposite side block. Do all the blocks. Quicker than sewing anyway. #84 bands at Staples. You have to work the band on within the close fitting fender on the wheel arm.

Re: Neato Tire Traction

PostPosted: August 31st, 2013, 5:14 pm
by glnc222
Shaft screw metric M4 .70 pitch 12mm (1/2") flat head machine screw, standard conical counter sink eliminates need for flat recess Forstner bit on pipe fitting wheel. Single pieces Ace Hardware U.S.
[edit] the machine screw head is only 1/32 wider than the quarter inch shaft hole, why the washer is probably used. Still might work.

Disposable Neato wheel arriving next week to complete possibilities for tread replacement.

Standard Foam Tire Wheels
Noticed brand Dave Brown Flite Lite model airplane wheels have a foam tread of the sort sought for improving Neato, and even a 3" size offered -- maybe a little too wide at 3/4", not sure, and the hub not the same, could be as much work as making the whole wheel from pipe fitting I used. But shows the factory could get this sort of wheel tread supplied if they wanted to improve the product.

Also another 3D printing project possible: an adapter shaft for standard robotics/modeling wheels. These all seem to take a hex shaft for a standardized mounting. So maybe a plastic Neato drive motor shaft oblong on the motor side and hex for the wheels.

Vorwerk Mechanical Addition

The 2nd generation VR200 late 2014 has an unusual linkage added to the wheel which increases the effective wheel diameter against forward obstacles, but not running flat. Sort of a walking stick.
This mechanism keeps the low profile of the small wheels while making them effectively wider when climbing, quite a trick.

The Vorwerk part is on the inside of the wheel, but there is some space between the wheel and the case on Neato XV's, and it might be possible to make a similar addition to Neato's. Never know until tried.