Replies

1. 
   WoodChuck34 | Mar 22, 2005 11:17pm | #1

   I don't know if its PC to mention it here, but Wood Magazine's current issue has an article that explains how to do just that.  Basically you mount the router on a long board or base that rides on 2 boards that stradle your work piece.  Then you just move it back and forth till your done.  I haven't tried it myself, but you better make sure everything is sitting on a flat surface and those stradle boards have been jointed.

    

   Chuck

1. 
   jackhall | Mar 23, 2005 01:21am | #4

   Yeah, I know you have to have a flat surface to work on.  A question I have is whether or not the routing action would place enough downward pressure on the board to cause it to flex downward resulting in an uneven surface.

2. 
   forestgirl | Mar 23, 2005 07:07am | #6

   No problem referring him to that article!  I just got the magazine, that design is a keeper.  Makes the consternation over having only a 6" jointer kinda fade into the background!forestgirl -- you can take the girl out of the forest, but you can't take the forest out of the girl ;-)Another proud member of the  "I Rocked With ToolDoc Club" .... :>) 

2. 
   RickL | Mar 23, 2005 12:36am | #2

   http://hersaf.com/cutters06.html    Look at the #H-R1250 series cutter.

   http://www.baileys-online.com/index.htm   Contact Baileys to get more info on the Luca Slab surfacer. Doesn't appear to be on line.

   www.woodwizz.com/

1. 
   jackhall | Mar 23, 2005 01:17am | #3

   I looked at those cutters.  How do they work with a typical router baseplate which only has a 1" diameter clearance hole for the bit?

1. 
   RickL | Mar 23, 2005 01:47am | #5

   Put a baseplate on with a bigger opening.
   The board will not flex as long as it's thick enough and you can always put supports under it for thin stock. See the planer sled for surfacing in a recent FWW for ideas.

   Edited 3/22/2005 7:12 pm ET by rick3ddd

1. 
   jackhall | Mar 23, 2005 07:11pm | #12

   Thanks.  I will look at the FWW article(s).  BTW is this concept of using a planer sled for surfacing boards a new idea?

1. 
   MarkRD | Mar 23, 2005 07:23pm | #15

   No not new. I remember reading it in FWW roughly in '95-'97...Mark

   Measure it with a micrometer, mark it with chalk, cut it with an ax.

2. 
   jackhall | Mar 23, 2005 07:47pm | #16

   OK.  Thaanks for the tip. I have the complete set of FWW issues since Vol 1, however, I have difficulty keeping track of the indexes.

3. 
   DougF | Mar 25, 2005 04:44pm | #26

   A friend of mine, an ex-engineer, build one many years ago to surface tapered guitar parts.  He referred to it as a milling table although the concept is the same: his router was afixed to a platform which transverses on the x axis and the platform moved on fixed rails on the y axis.  He uses a 3" bottom cutting rotary bit.  Rather than shiming the piece  to achieve the desired taper, or flatness, he built the table using heavy-duty lockable gimbles used on larger pleasure boats.  It is a beautiful piece of work, as are his guitars.

   Doug

4. 
   jackhall | Mar 29, 2005 07:38pm | #27

   Thanks for the info.  I made a guitar several years ago.  The sides and back were made out of rosewood, the neck was mahogany with ebony for the finger board.  I can't remember what I made the front out of but I do remember trying to taper the front where the lower part (where the higher frequency strings are located) was slightly thinner than the upper part.  I wound up getting it a little too thin and after many years the front has a slight warp.  Still sounds good though.

3. 
   MBL | Mar 23, 2005 07:22am | #7

   Dear Jackhall,

   A router is not a most proper tool for what you describe, due to

   1. Its high rpms ...

   2. Which relates to using small diameter cutters ...

   3. Which are meant for cutting with the vertical edge fundamentally ...

   4. or are meant for plunging straight down for a cut of BRIEF duration.

   5. The cutting edge upfront if, it is flat does not have good waste removal property, meaning it'd be cutting over waste, producing heat, wear, and requiring more effort and power. Totally flat entry is not a good design for cutting tools, unless they 'scoop', like jointers and planers do (and straight router bits at the vertical cutter edge).

   6. If a larger diamter cutter is deviced, the rpms would have to be lower, and the machine would need perhaps more support base.

   It is quite unsafe to use large diameter cutters on typical hand-hald routers. For instance, horizontal cut panel raiser bits are not meant for use in hand-held routers. Neither are bits of high mass due to lentgh recommended there, due to amplified vibrations and increased stresees.

   Increasing the diameter of the through hole of a base plate to accomodate large diameter bits is not advisable due to safety.

   You can use a regular straight bit designed for plunge cutting, which is slightly angled for some limitted, special planing (maybe a square foot of area or so). Make sure the bit is designed for Plunge-Cutting, though, not just for edge-cutting.

   Although the tip cutters upfront are not flat, a flat cut is still accomplished due to the bit moving horizontally. Only if you were to pluge straight down and up (as in drilling) would you have a conical bottom cut. Once you move the router horizontally, the cone is wiped out on a continuous basis.

   Also, as you imply, the geometrics of how to keep the work piece stable and level are not easy, unless the piece is heavy already, like say a butcher block.

   Even the effort of planing with a router, and the amount of waste and noise produced is more than enough to shy away from the intent.

   Please consdier the aproach very carefully, specially the personal safety aspect of it.

   Perhaps a hand plane would be a much better option for what you want to do?

   Best of all.

   -mbl-

1. 
   RickL | Mar 23, 2005 04:20pm | #10

   "Increasing the diameter of the through hole of a base plate to accomodate large diameter bits is not advisable due to safety."

   All the router manufacturers I know of offer alternate bases with larger hole sizes. Wing cutters and certain other cutters are certainly safe to use. It's a judgement call on the operators needs and experience. For a rookie they should consult the bit manufacturer and or consult an "expert" such as a magazine or book perhaps.

   Edited 3/23/2005 9:27 am ET by rick3ddd

2. 
   jackhall | Mar 23, 2005 07:16pm | #13

   It would be hard to disagree with any of the points you make concerning the advisability of using a router sled technique.  This is the first time I have heard about it but maybe it's an old approach that has been around for a long time. ???

1. 
   MBL | Mar 23, 2005 08:03pm | #17

   Dear Friend,The fact that some things may be possible may not relate to the fact that they be practical.Common sense can tell that if planing with router bits were an attractive technology, be assured it wouldn't be unheard of.The suggestion is not to go for the un-necessary. If it is necessary, usually no questions arise.-mbl-

1. 
   jackhall | Mar 23, 2005 09:03pm | #18

   Very good point again. 

1. 
   Alphonse | Mar 23, 2005 09:15pm | #19

   Thought I'd relate my experience with some of what you're trying to do.Back when I first started face milling with a router,carbide bits were hard to find,let alone in larger diameters.

    So I got an endmill,HSS,designed for use in low horsepower knee mills,AKA Bridgeports. 1/2" shank,1 1/2 " diameter.

   HSS will cut metal all day long,why not wood?Trick is,keep depth of cut shallow.Back then there were no variable speed routers either.Now you have a plethora of carbide cutters and VS.

   But the surfacing rig works fine,even kinda fun.If you can't find sufficient info in the above links I could likely give you some tips.My rig is very simple,and stows away in pieces.

2. 
   MBL | Mar 23, 2005 10:24pm | #20

   HSS will cut metal all day long,why not wood?Trick is,keep depth of cut shallow.Back then there were no variable speed routers either.
   -Alphonse-
   ...
   Dear Alphonse,Wood and metal cutting are two similar but not equivalent enterprises.Metal cutting speeds are low by factor of 10 or so compared to wood, and the feed rates may be much lower, like millimeters vs. inches, as well as the total amounts of materials removed by the cutting operations.At the machine shop, cutting wood is more difficult than cutting metal with existing equipment. Large-bore drill bits of tool steel, for instance, which are fine with steel, erode almost right away with wood.Carbide cutters, of course, have increased the potential of many of the wood-working tools.There is no question that the jig you have come up with is useful and fun to use, and in specific cases and conditions would certainly be a most proper choice.Just passing information, not trying to make decisions for others in any way.Best wishes.-mbl-

4. 
   forestgirl | Mar 23, 2005 08:02am | #8

   Here are a couple of bits I'm considering for an on-going project that requires exceptionally clean bottom-smoothing in a ~3" square.  Haven't tried them yet, though.

   Bit #1 [click] is a plunge-cutting straight bit with an extra cutter on the bottom.  Chip clearance should not be a problem.  Although I'd be using a small diamter version, it comes with up to a 2" diameter (see bottom of the page).

   Bit #2 is more like a regular straight or mortise bit, but has overlapping center tips.  Not sure how good the chip clearance would be on this one.  Maximum diamter is 1.5" minimum is 3/4"

   forestgirl -- you can take the girl out of the forest, but you can't take the forest out of the girl ;-)
   Another proud member of the  "I Rocked With ToolDoc Club" .... :>) 

1. 
   Curtis | Mar 23, 2005 02:37pm | #9

   Hi forestgirl

   have you looked at http://www.magnate.net/ they have bottom cutting bits (surface planing bits)  there prices are rather reasonable,I've been using there bits now for five years, the quality of there bits are the very best I've found.

   It cant hurt to take a look!

   Again the bottom cutting bits really do a great job.;-)

   have a good day.

    

    

    C.A.G.

1. 
   forestgirl | Mar 23, 2005 06:26pm | #11

   I'll take a look, Curtis.  I need to get as smooth a surface as possible.  Right now, I'm having to scrape some to remove the milling marks.  They're not bad, but they're definitely there.forestgirl -- you can take the girl out of the forest, but you can't take the forest out of the girl ;-)Another proud member of the  "I Rocked With ToolDoc Club" .... :>) 

2. 
   jackhall | Mar 23, 2005 07:22pm | #14

   Thanks for the info.  I looked at the bits and it seems that the bottom mounted cutter head would be a good addition.  But it also seems to me that any bit that could cut rabbets or dados would be suitable for surfacing.  BTW I am assuming that using a router to surface a large board with involve only small depths of cut.  I also assume ther would be some degree of milling marks left that would have to be scraped. 

1. 
   forestgirl | Mar 24, 2005 06:55pm | #21

   Hi JH, yes a dado or mortise bit would work for router-planing a surface.  The reason that Eagle bit (the first one) caught my eye is that the bottom cutter is supposed to provide an exceptionally smooth surface, which I need for my project to make production more efficient (minimize scraping or sanding).  For planing a piece of stock just to get it flat, you wouldn't really need that extra cutter, as you could simply sand or hand-plane out the milling marks from the router-planing.

   Router planing using a sled is an idea that's been around for a long time.  The author of the Wood Magazine article is no amateur:

   "...craftsman Craig Bentzley of Chalfont, Pennsylvania.  After more than 30 years of building furniture and restoring antiques...[produces] museum quality work."

   I've seen several router-planing articles in my overly-large library of woodworking magazines.  Bentzley (who works in front of a wall full of handplanes in the Wood picture) seems to use the technique primarily for "taming wild [figured] wood."  One of the clever applications I've seen is shaping out chair bottoms -- getting that gentle curve that comforts our be-hinds so nicely.  If the proper bit is used and the depth-of-cut is controlled carefully, there's really no reason not to try it.  It may not be "necessary," as you could always use hand planes, but sometimes it might be an excellent option.forestgirl -- you can take the girl out of the forest, but you can't take the forest out of the girl ;-)Another proud member of the  "I Rocked With ToolDoc Club" .... :>) 

1. 
   jackhall | Mar 24, 2005 10:38pm | #22

   Thanks for the further insight into use of the router sled.  Do you know of any specific FWW article on building such a sled?

1. 
   forestgirl | Mar 25, 2005 03:22am | #23

   "Do you know of any specific FWW article on building such a sled?"  Not off the top of my head. forestgirl -- you can take the girl out of the forest, but you can't take the forest out of the girl ;-)Another proud member of the  "I Rocked With ToolDoc Club" .... :>) 

2. 
   Alphonse | Mar 25, 2005 11:51am | #24

   FG,figured wood is indeed somewhere the method excels.Bird's eye,fiddleback,etc. all with no tearout.Being able to do such wood without having to rip and reglue just to get on my jointer saves my back.

   Another advantage,I have some African wood the FPL ID'd as Azobe,it wipes the edge off knives instantly.Carbide router bits hold up better,and my sharpener charges less for end grinds.

   The resulting surface usually needs a few swipes with a card scraper to remove millmarks.

   Oh,true butcher block is easy too.

5. 
   hairball | Mar 25, 2005 01:05pm | #25

       I remember many years ago seeing a device someone made for this same application, except he used a door to mount the router on. Yeah, I know - I thought the same thing when I first seen it. I can't remember if it was in FWW or some other magazine.

       The details escape me because it's been so long ago, but I'll try to remember how it was constructed. The heart of it was a door that had rails attached to it horizontally, one on each side and flush with each other at the top. They extended past the edge of the door 3-4 feet and were attached so that they were level. This provided a surface for the router to slide on and there had to have been a way to clamp or otherwise affix the router in place. The workpiece was positioned under this gizmo on a surface that was also leveled. After the workpiece was fixed in place and the depth set on the router, the router was fixed in place and the door was swung. The router was advanced incrementally until the entire surface was flat.

       I believe this system was designed for working with highly figured wood, but would be fine for any piece small enough to fit within the arcs. There would ultimately have to be fine adjustments made to compensate for the door jamb being out of plumb in either plane.

       Anyone else remember seeing this?

6. 
   GHR | Mar 29, 2005 08:35pm | #28

   Related to your question ---

   From tim to time I make raised edge table tops. The tops may have a 3/4" deep x 20" x 60" recess.

   I find a router, a 1/2" dia router bit, and 2 pieces of 3/4" plywood make suitable tool. The bottom is flat enough to scrape smooth.

   Perhaps a bowl cutter ( 1" dia cutter with a 1/8" radius on the coner) would do a better job.

   Router bits are cheap - even custom ones. Experiment.