April 23, 2017 at 11:29 am #2523
I have read where people have used up-cut spiral router bits and down-cut spiral router bits and some of the descriptions have left me feeling that I would have chosen the opposite one from what they did for the application described. So, I am inviting comments about which bit you would use for what application. Right off, I think it is important to state whether you are cutting an open edge or an internal slot. Also, whether it is a “hand held” operation or one with a router table.
Please…..let’s hear from you experienced woodworkers.
April 24, 2017 at 11:57 am #2524
When hand holding a router, I prefer the downcut, since it holds the router in place better. But I take very light cuts since it won’t clear the chips as well. When using it in a router table I prefer the upcut, since it will clear the chips down, onto the table. I usually use some kind of hold down, so the piece stays flat on the table anyway. Probably not the textbook answer, but it works for me.
Those are for internal cuts. I don’t think I use spiral bits on edges much, if at all.
April 24, 2017 at 12:19 pm #2525
Hey Bill –
I use up-cut spiral bits and end mills almost exclusively since they have met my needs which include groves, dadoes, rabbets and stock flattening. The groves, dadoes and rabbets have been largely performed using a router table. The results have been excellent; cuts have been crisp and smooth on edges and bottoms. Board flattening tasks have been performed exclusively with hand-held routers.
On occasion while kayak building I have had one or two of the strips change position after gluing and apparently misaligned clamping. To save the work, the offending area can be “thinned” of flattened by making a few passes with a router and an end mill (1/2″ or larger). New strip(s) overlay the target area and are glued/epoxied in place. Later, sanding fairs the work area.
Down-cut spiral bits are really problematic with joinery work since the debris from the cuts tends to collect in the joint and obfuscate the layout lines.
Hope this helps,
April 24, 2017 at 5:46 pm #2526
When it comes to their operations, spiral bits can be viewed as screw threads – left handed or right handed. They pull/push the bit or the work in the corresponding direction. It is said that down-cut spirals can pull the bit out of the chuck. I say, take light cuts and tighten your collet nut better. Likewise, they tend to “pull” the wood chips down (or up) towards the tip of the bit. This is helpful where the show face of the board is adjacent to the router plate. Think of trimming plywood edge and you want the top veneer kept pristine. Another example would be a through mortise where you want the chips to fly out the bottom. However, before you break through that work piece, you will be creating a lot of chips in your mortise first. This could cause a lot of turbulence during the cut. Here, an up-cut spiral is more beneficial. These will tend to pull the chips towards the base of the router (regardless of hand held or table mounted) clearing the mortise thereby reducing interference and providing a better cut. Despite it’s tendency to pull up the fibers, I have never had a problem cutting a mortise in this manner. My first cut is typically a very shallow scoring cut. (Or, you could scribe your mortise outline.) I don’t worry too much about layout lines, though. Machine work typically relies on jigs and set-ups.
Several bit manufacturers make dual-cut bits so you can straddle a sheet of plywood with the bit and reduce chipping on both faces. I guess it works. It’s still in the catalogs. And for the record, I don’t own a down-cut bit only up-cut.
April 24, 2017 at 8:50 pm #2527
Wow, good question, lot’s of answers! I tend to use the upcut bits. It cleans the hole out as I’m plunging and it’s important that I see what I’m doing. I tend to use the bits more for inlays but use them for mortises for the same reason. I don’t have a problem with a rough edge on inlays since I mark my cuts with a knife first. When using an upcut or downcut or any bit for that matter, it’s important to take small bites…The big difference is price, spiral bits are a lot more money. They seem last a bit longer but can be burnt by to much pressure just like a carbide bit. I don’t feel my router pushing or pulling when using either bit I can feel it when I start to push the bit too hard. When making mortises the shoulder of the tenon hides any roughness from the bit so I don’t concern myself with that.
April 25, 2017 at 5:44 pm #2529
Please forgive the typo in my earlier post. Therein grove = groove. Also, “…’thinned’ of flattened” should read, “‘thinned’ or flattened…” Sorry for the confusion…
April 26, 2017 at 4:20 pm #2530
Thank you Daryl, Mike, Joe and Charlie for your very detailed and wise responses. Good information all around. I have seen an up-cut leave a fuzzy edge when shallow cutting for an inlay, but, as Charlie says, it’s best to score the outline first with a knife to preserve the crisp edge. The most important thing for me to take away is that up-cut means “toward the router” and down-cut means “away from the router”. I can determine the best bit if I remember that.
April 29, 2017 at 4:46 pm #2531
I’ve seen all sorts of demos on inlay (I tend to like doing them by hand), but the best powered one was by Steve Latta (who has forgotten more about inlay than I will ever know). He uses a Dremel with one of his milling bits (I bought a ton of them, good for when I do use power). Here is the link:
Interesting since he’s the one who designed the Lie Nielsen inlay tools, so it’s OK to do either. When he uses his Dremel. he made a template that was 1/8″ smaller, and used the bit as an edge guide as he ran the cutter. I don’t know if they are upcut, downcut, side cut, or light saber cut, but they do a good job. Based on what he said, when it’s straight lines or arcs, he will do them by hand, but when compound curves, the Dremel comes out.
May 1, 2017 at 11:12 am #2532
I’ve heard of his Dremel bits but never saw the price. Is that for one bit? These seem rather fragile despite the 1/32 depth you may limit it to. Am I missing something?
May 1, 2017 at 11:44 pm #2534
Joe, When Daryl and I took the inlay class with Mother-of-Pearl inlay material, we used the Dremel bits with the 1/32″ cutter. They seemed reasonably robust.
May 2, 2017 at 11:22 am #2535
The Latta bits hold up for a long time. They were also about 1/3 the price when I bought a bunch of them about 10 years ago. Steve made a point of saying that you don’t take all the wood out, even for inlay, in one pass. I usually use them in 3 passes or even 4 if the wood is dense.
May 2, 2017 at 1:48 pm #2536
I mostly do my inlays/banding by hand especially with curved work since you’re really only scratching the surface. I make my cutter from old chisels or any scrap steel with body to it. I just make a quick jig first, sometimes I even do a jig first! I will use an upcut when removing wood for a fan inlay because it’s faster and the depth is easily controlled.
May 2, 2017 at 4:14 pm #2537
I’m a much bigger fan of inlay by hand than by power. It’s a much more controlled cut. But if it’s an irregular shape, I would make a template for a Dremel. However, from a design perspective, most irregular curves that look “right” are almost always compound curves from regular arcs. When I made my bed headboard, to get the camelback top, I used a compass with over a 7 foot radius connected to my router. It’s a series of several really large arcs. And with an arc, an inlay cut is easy to control by hand, except in woods like curly maple. Then the grain runs in so many places and ways, a rotary cut with a bit is better, just take 1/64″ cuts. Yes, that shallow. 4 passes and you have a perfect cut. Also, if possible, always cut “downhill” on a curve.
Any other ways?
May 3, 2017 at 8:39 am #2538
This discussion thread seems ripe for a presentation. Daryl, Charlie or others… how about it? I think many of the LIW members would be interested.
June 4, 2017 at 8:43 pm #2573
Ditto the presentation comment!
One thing I’m curious about, how would a down it pull the bit out of the collet? It is basically left hand thread, wouldn’t that push the bit up into the collet?
June 4, 2017 at 8:44 pm #2574
Also, I got my first downcut bit when I made a few of the ruler growth charts. The pine I used would chip out a little, so the downcut helped make the shallow grooves cleaner.
June 5, 2017 at 7:03 am #2576
Ben, one of my fears is the bit coming loose and making a lot more work for myself. No matter the type of bit, it can and does go right through or just wobbles at high speed on top of the workpiece. I tighten it up well and after a few passes I’ll check the tightness.You can also hear the change in pitch but by the time you stop the router it’s always to late. Handwork is much more relaxing!
June 5, 2017 at 11:20 am #2578
Ben, not sure I understand your concern. You’re not worried about the collet coming loose (if that’s what you are referring to). It simply the bit can be “pulled” out of the collet because of the “threading” action. The down-cut can pull it away from the base while the up-cut can push it toward the base. In practice, as long as the bit was in good condition – not bent – it should not pose a problem. I’ve never experienced an up-cut being pushed too deeply into the collet. But then, I tighten it well and check it after the first pass or two. I did have a bit that was damaged once. Without realizing it, I chucked it in the router and began working. To back up Charlie, the thing started making this awful racket. I immediately shut off the tool. The bent bit had worked its way loose and was vibrating like crazy. The piece was ruined but I was ok. Imagine that bit flying out at 20000 RPM. A bent bit is rare but it can happen.
As for spiral bits, make sure they and the collet are clean and tightened firmly. Then check it after running it.
And again, to concur with Charlie, I have taken to hand work on the operations where I can avoid power tools. More relaxing and more satisfying.
June 6, 2017 at 1:44 pm #2580
Now if I could only get Joe to agree with me about toothing planes!
June 7, 2017 at 1:38 pm #2587
I agree with you Charlie. They are real. I’ve seen them. Now if YOU would only appreciate their importance, we would have a lot in common.
June 7, 2017 at 2:44 pm #2588
I agree that an entire toothing PLANE is not really needed. Much too specialized and expensive. However, a toothing BLADE, now that can be useful. It’s among the few blades that can really do work on curly maple and bubinga. On the other hand, someone asked me at one of the shows (probably the one where I had the curly bubinga tables) how I planed them, and I answered, “With sandpaper.”
I really do like the idea of the toothed blade for prepping ornery woods, in that you can’t use sandpaper until you are done with edged tools. And it’s really pleasant to do as much work by hand as possible (says the guy with the 12 inch jointer!!!). If the need arises, I would get the toothed blade for my low angle jack plane.
June 11, 2017 at 7:50 pm #2591
I wonder if a hair clipper would work?
June 12, 2017 at 12:02 pm #2592
Charlie, why wonder when you can try it. Bring it to the Round Robin. Get out a nice board, a piece of curly cherry will do. Then get out your hair clippers and the members can see how well it works. Then Joe can try his toothed blade, and we will see if there are any differences.
And fair is fair. Let’s try them both on your hair as well.
June 12, 2017 at 5:14 pm #2593
Interesting, Daryl. I’ve shaved the hair on my arm before. I’m curious to see how my toothed blade will work on Charlie’s hair. I’m up for the challenge.
But first, is that a low angle clipper you’ll be using? I’d want to compare apples to apples. I’ll be using my low angle jack. If necessary, I can substitute my scraper plane.
June 12, 2017 at 11:00 pm #2594
I don’t have enough hair on my head to go through all the testing but I should have enough on my arms. I did sharpen my hair clippers pretty well and it should be fine for curly hair or Maple…Scraper planes! That’s another anchor I have an issue with!
June 13, 2017 at 12:36 pm #2595
I thought you might. That’s why I brought up! It’s one of the most useful, versatile tools in the repertoire. Every craftsman should own and use one. It will easily shave the stubble over from your clippers. You’ll see.
June 13, 2017 at 2:54 pm #2597
What’s the matter with placing black tape on your fingers to protect them from the heat caused by friction? Nothing like a little pain to make you appreciate fine woodworking!
June 14, 2017 at 12:26 pm #2598
Two years ago I got a splinter from a board in my wood pile. It’s the only conceivable way an infection found it’s way into my bloodstream. That splinter broke off under the skin, festered, and although removed, the damage was done. The infection spread to my spinal column. I needed emergency surgery on my spine and 8 weeks of intravenous antibiotics. I think I suffered enough for the cause. But we’ve all had our experiences! Ahh, shapers.
Ever drop an I-beam clamp on your foot?
June 14, 2017 at 3:49 pm #2599
Shapers! Slowly I turned, step by step, inch by inch! I use my shaper but I am very careful with it. Two of my finger tips were flayed by a shaper but expertly repaired in the hospital. It wasn’t easy but I finished shaping the molding that night. I lost some feeling in the fingers so the shaper scares the hell out of me. I still use it and am very careful about using wood with knots ( a knot caused the wood to catch). AHH, grinders.
June 15, 2017 at 11:32 am #2600
Grinders! I had this guy that owed me money once …
Long story short, that’s when I got my Unisaw.
June 15, 2017 at 11:58 am #2601
Let me guess, you made him an offer he couldn’t refuse.
June 15, 2017 at 12:39 pm #2602
I had money once! Then I started woodworking and started buying all the tools I needed. There were hundreds of them and every time I went to a seminar or a workshop I realized there were even more tools I couldn’t do without. I started to buy wood and realized there was wood I couldn’t do without either! They have turned my electricity and water off for non-payment but I have some collection of tools and wood!!! I go into my STUDIO and stare for hours, although I can only do so in the daylight. Trying to get my grandkids on the exercise bike, it’s attached to a generator. That’s okay right?? After all, I give them scrap wood and finishing nails to play with….
June 19, 2017 at 11:17 am #2603
What a cheap grandpa – no hammer?
Joe, let’s put it this way: It’s amazing what one can accomplish when they put their nose to the grind stone.
June 19, 2017 at 11:34 am #2604
My hammer broke when I was smashing their piggy banks! They were some tough banks
June 19, 2017 at 11:42 am #2605
I put my nose to the grindstone once. It’s not all it’s cracked up to be!
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