Message Thread:
Breaking edges efficiently and consistently
1/22/18
Hi,
I run a relatively new business that makes a combination of custom and standard sized dining tables, coffee tables, bar stools etc. which require us to process a variety of different sizes of panels (so flexibility is key). We use pine (Scot's pine) so they're not particularly expensive, and we want to be as efficient as possible.
Overall I'm happy with the process now, except for the edge breaking... currently we mainly use the oscillating edge sander and angle the wood up and down to round over the edges, which is smooth but it's not consistent at all, especially if the panels are warped even slightly. We've tried using roundover bits on a trimmer router (1/4" or maybe even shorter is the ideal radius, not looking for a big roundover...) but they tend to break out the pine every so often so need sanded again anyway, and with the small radius if there's the slightest bow in the wood the roundover won't be consistent...
I'm thinking of throwing money at a Unosand / Flextrim type sanding head (like the Unosand 140) in the hope that it'll break the edge consistently but they're not cheap and I can find no evidence that they really work for this task.. does anyone have any experience with these?
They seem to be the best option but with the soft pine will they be able to roundover the edge sufficiently to give the edge a bit of protection from knocks/wear...? What do you use for rounding over...? I've been trying to sort this problem for months now and don't really seem to be making much progress...
Thanks in advance
View larger image
http://www.unosand.com/unosand_machines.html
1/22/18 #2: Breaking edges efficiently and cons ...
Website: http://sunvalleywoodworks.com
Pine is generally a pita to work with, I avoid it at all costs... Trying to sand a consistent radius on a large number of panels with different employees would be futile. I'd look at using a shaper or router table with a feeder. With a dedicated set up, you could safely, quickly, and consistently climb feed and get a small radius onto your panels with out tear out.
1/23/18 #3: Breaking edges efficiently and cons ...
I agree, mostly. Climb cutting is not for the inexperienced.
I would opt for a 1/8" to 3/16" radius roundover shaper head with a bearing, cutting from below. 4-6 insert carbide chips, 5-7" in diameter ,and running about 8,00 to 10,000 rpm. Use a real, big boy shaper - 5hp or more - and feed the tops over the cutter flush with the table. A good 4 wheel feeder will smooth out the mill marks and push the top flat to the table.
If you have consistent thickness and need to round over the other side, have another cutter set made to do the top of the flattened panel, and do two for one.
Retire the router.
1/25/18 #4: Breaking edges efficiently and cons ...
Ok thanks for the advice, I'll try find someone local with a shaper who'll let me try this out..
I think I've decided against the brush sander type machines for now at least, they're just so so expensive for what they are (£2500 / $3500 for a 750w motor, VFD and plywood platform??), and the lack of competition (at least here in the UK) makes me inclined to think there are other methods of doing the same thing..
In the meantime I think we're going with hand sanding... it's a bit frustrating as we can make the rest of a tabletop (cutting, sanding top and sides, staining, spraying) consistently and in less than five minutes, but rounding over is not particularly consistent and a bottleneck too...
1/25/18 #5: Breaking edges efficiently and cons ...
I forgot to mention that the equipment choice should be influenced by the quantity of work it is capable of. The shaper I mentioned would be of several hundred pounds and this weight will help support the table tops it processes. That sander in the photo will tip over if you look at it wrong, so it will need a support system, larger table, sets just to get it to feed parts.
The shaper solution, while expensive, will process tops at about 15 - 30 lineal feet per minute with a feeder. a 3'x 4' top will take about a minute each, plus handling. 40 tops per hour, 320 tops a day.
Plan on having the anticipated labor savings pay for the machine in less than 5 years. My first guess is that the shaper, once set up and properly tooled, will be about 5 times faster than a router or hand sanding.
If you just to 'break' the edges (a subjective term), then a brush sander (larger diameter, backed brushes, a 120 grit or so) mounted at 45 degrees to the edge will work. Use a power feeder, and play with the feed speed to get the effect you want. Similar process times as the shaper. It is crucial that you design and build a larger table to support the mechanisms so vibration is minimized and ease of use is maximized. Just getting 40 tops an hour onto and off of the machine is a bit or work, and the machine's design can help you with that.
1/28/18 #6: Breaking edges efficiently and cons ...
Website: petesfloors.wordpress.com
I use an eighth inch round-over bit and a trim router. Then I use 80 grit E grade sandpaper.
2/1/18 #7: Breaking edges efficiently and cons ...
I prefer an offset base (trim) router, better stability/control, and a 1/16 - 1/8" radius. With difficult grain I do two passes, the first is a climb cut. Two routers/bits might be the way to go for larger radius when climb cutting is needed. I finish the edges/radii off with a light hand sanding using 220. I shoe shine sand the radius with a full sheet when more vigorous sanding is required.
3/15/18 #8: Breaking edges efficiently and cons ...
I prefer the offset rim too. Have to agree with the above there.
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