Brush Sanding system; presentation and review
Since this came up in a thread some weeks ago, and our new NaxoFlex brushes have arrived, I thought I'd post it as a kind of FYI for those that might be interested in looking at it.
Rather than explain how they work, I'll let some pics do the talking;
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Above is a 150mm/width core, with the aluminum end cap detached, showing how the flap/brush strips attach to the core. Changing out a set of strips is very easy and fast, it is done in under a minute.
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Another pic of this core; the point of the brushes is to support the sanding flaps which makes the unit much more effective than one with just flaps.
Price for this unit was $185 for the core, and $65 for one complete set of strips.
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A unit mounted on a shaper w/ feeder. I think the pic speaks for itself so I won't elaborate.
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Another unit mounted on a handheld drill. This type of unit could easily be mounted on a spindle and used on the 'bot.
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Cores of the same diameter can be piggybacked to any desired length by detaching end caps and inserting adapters, as shown in this picture. The decorative crownpiece behind the cores was sanded using this system, resulting in a total sanding time of 3-5 minutes, including some slight manual touch up, rather than the ~hour it would have taken to manually sand off all the tool marks (0.5mm step over using a 1/8" ballpoint).
Regarding costs, cores seem to be priced at around $20-35/inch depending on width (the wider the cheaper). Strips are priced in the region of $0.5-1/inch (ditto).
To give a brief user review, I am quite pleased with an important caveat that I do not know how long the flaps will last -- they seem very high quality in the grit, but one never knows.
We are still experimenting with rotational speeds and feed speeds, but so far I am extremely statisfied with the results sanding mdf and softwoods. Especially machined mdf sands like a dream, very fast and perfect finish. Hardwoods, less so, but a coarser grit is plausibly demanded for those. Possibly a different grit medium as well, they offer several options.
The units seem well built, the finish is good, everything goes together exactly as it should without snagging or being loose, the aluminum is well machined and the vinyl (?) part of the core very neat; no gradations or residues.
In terms of operation, changing strips is a breeze. This is the main reason we chose to adopt the NaxoFlex system rather than any of the competitors I'm aware of.
Regarding possible options, all cores are built to order, so you have an enormous range of possible specs. Strips can also be custom made, for example using progressively finer grit along a strip, or using short flaps with coarse grit and long flaps with finer grit on the same strip (or alternating) so you can control finish by how much pressure you apply.
Delivery was on schedule, though due to the custom built nature of the system minimum time is three weeks (in Sweden). The company was very pleasant to deal with, they sent out a representative to demo their products extensively, offered to test sand samples, and stated that if we were not satisfied they would accept a return and credit us the cost. A nice touch was that they called when the order left their facility, and after a few days after delivery their sales rep called to ask how things were going.
We have used our starter units to sand flat surfaces, profiles and '3D' blanks. It seems to work really well for all applications, though complicated 3D blanks require manual sanding in the deepest and/or most confined areas. On one single job, sanding time (including coarse sanding, fine sanding and post-primer sanding) on flat surfaces, edges and profiles of 45 extremely large drawer fronts was reduced from the previous ~9 man-hours to ~1 man-hour: this represents a cost reduction of ~$260 just in labor costs. In other words the time/cost reduction on the first job paid for one complete unit, plus pocket change.
Summa, I'm very satisfied this far and have already started to compile our next order, which will be for a lot more strips of different grits as well as some more cores.
For those that have made it this far into the post, you might be wondering where the 'bot comes into play. Yes, this company also offers a system for use on CNC/linefeed machines with strips rotating on the "end" of a core like the above ones. That will be our next step after covering our bases on the normal cores, if that really works it would be very interesting, I think.
Finally, all of the above is specific to the products of one company, NaxoFlex, but there are several brands offered by different companies, and I have only looked at the European market.
