Cutting Tips

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Cutting Tips

Postby John » Mon Mar 16, 2009 11:16 am

"From John's Blog"

John, I have been trying the curf cut corner that you show in your video. It takes some thinking to get it right. Could you share your discoveries in getting these beautiful round corners just right. Thickness of wood, distance of cuts to each other, number of cuts to close up exactly to 90 degrees, adhesive used etc. Maybe I’m asking too much and need to just play but if you could offer some hints it would be helpful. Also, I lightly stoned the sides of the blade with the one slightly bent tooth and I have it back to a useful state. Blade does seem to clog. Thought about a double sided brush to sweep debris from teeth as you go. If I work it out, I’ll show you what I come up with.

I do wish you had included a detailed DVD of the process of the fine tuning. The 2 brief clips help but a verbal explanation of some length would help us to feel we are on the right track.

Photo link:[/img]http://picasaweb.google.com/BlairGlenn/JMP02#

Note the simple but effective setup for stabilizing the unit to my bench. I added a step up for ease of use rather than a dedicated location in my limited shop.

Blair Glenn
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Postby John » Mon Mar 16, 2009 11:34 am

Blair;

For kerf bending or making Squiggle Wood it is really important to use straight grain wood. Those woods that traditionally steam bend well tend to cold bend well. Also, we hand plane all four faces prior to cutting so there are no weak points in the stock and NO SANDING.

The fun is in the experimenting. We like to cold bend with single pass cuts, so the wider the stock, the thinner the stock. For the kerf spacing in the videos, we used a stack of old business cards and removed 2/3/4 cards between each pass depending on the spacing. The cards were pushed against a stop clamped to the fence. Once you know for sure your intent, you can make or engineer something more reliable for repetitive cuts. Others have suggested an Incra type jig--whatever works is all that matters.

Make 6 or 7 cuts and measure the angle of your bend without breaking your stock--a non-forced, easy bend. Let's say you can bend your stock 10 degrees with 6 passes at the spacing you have chosen. For a 90 degree bend, add 54 more cuts and you should be fine.

Stoning your blade after an accident works to continue a session, but it will not be as sharp as an undamaged blade because the saw teeth are sharpened to a point.

In stringy woods (poplar for example) the gullets can fill quickly on aggressive cuts. Use an old tooth brush to swipe when this happens. On woods like maple/rosewood/walnut/cherry we see very little, if any clogging using the crosscut blades. The rip blade cogs easily because it employs a traditional square cut rip tooth pattern.

I must emphasize the importance of play regarding this tool. It will do things you have never dreamed and it will keep you up at night thinking of ideas.

Time to wake up the sleeping 14 year old in your head and have some fun!

Hope this helps--

John
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Good Stuff!

Postby BobStrawn » Mon Mar 16, 2009 12:56 pm

Blair, if you click URL then paste the link, and then click url, you will get the link functioning.

http://picasaweb.google.com/BlairGlenn/JMP02#

I went to it and saw the curved wood! Nice! I think we will be seeing a lot of boxes like that in the future. I am thinking that for a divided layout for holding tools, this will also give us a new option.

How will we handle these curves in miniature? Common enough on big stuff, before the JMP, but now a neat way to do the tiny. Will we leave them raw, cover the inside of the curve with paper, fill the cracks with glue and then bend them, put veneer on the inside, or use flocking? I guess all of the above, but I wonder what classic form is going to be.

I am looking forward to making a Japanese style wooden puzzle with the JMP. What I suspect we will see more of or not see, is secret compartments. Thin slices well handled may make slices in the grain invisible. The ability to hide good tools in a toolbox, while making it appear full of loaners seems terribly appealing.

Bob
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Postby John » Mon Mar 16, 2009 2:21 pm

To be fair to Blair, I cut and pasted his comments from my blog to the forum and screwed up his link. Thanks for making it work!

Bob, you hit the nail on the head with this post. New capabilities will bring new project ideas. There is not a day that goes by that I don't have an idea for the JMP--and this is going to compound itself when we introduce our next new Silent Woodworking tool--it's a doozy! Hopefully we will be done filming by weeks end.

On top of that, we have yet another new product that when you see the videos, you will not believe what we did. This tool was designed specifically for the JMP but we discovered it works on power tools too--way cool.

I just love hyperbolic statements--particularly when we can back them up!


John
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kerf cutting continued

Postby Blair » Sat Mar 21, 2009 1:35 pm

I spent the day testing and measuring. I will put together a photo link of my results of kerf bending. ahesives etc.

Blair
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Still cutting

Postby Blair » Sat Mar 21, 2009 7:51 pm

John, you are very talented at keeping us all guessing at the "new amazing tools". It feels very much like when I was a kid and waiting for Christmas morning. I'm glad that I can afford your toys! My wife thinks different. Ahh, life is short.

I'm continuing to play with kerf bending and I thank you for your advise. The grain does play a huge part in the process as does the species of wood. I have also learned that before I try to bend, I tap the piece to get as much of the sawdust out as I can. I'm also taking a razor blade to the cuts to help get every bit of dust out. Bending slightly in the wrong direction seems to loosen the wood and it flexes a bit better. The thickness of the outside (or should I say thinness), makes a difference in how easily it bends. It's one thing to make a single bend and get it exactly 90 degrees but to calculate the locations for 4 bends and joining the straights will indeed be a chalenge. I'm trying but so far, failing more than suceeding. I can't wait to see some of the first posted photos of a round corner box! I'm imagining a drawer.

I know that steam bending is possible as well as a build up of laminated veneers, but this could be so much faster and cleaner looking. I also need to play with more adhesives. Epoxy is next on the list.



Blair Glenn

http://picasaweb.google.com/BlairGlenn/JointmakerProTestCuts#
Last edited by Blair on Mon Mar 23, 2009 5:38 pm, edited 2 times in total.
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Postby John » Mon Mar 23, 2009 9:50 am

Blair-

When we do kerf bends here, we slide a business card down the grooves to clean out the dust-if you don't do this, the dust acts as a wedge and can snap the piece.

I believe (I don't have as much time to experiment as many of our customers) that the best way to incorporate this technique is to skin one or both sides of the core (kerf piece) with veneer. Just my 2 cents.

The advantage is minimal spring back and really tight radii without the associated grain/equipment issues from using steam.

Another tip that really helps is to hand plane the outside surface prior to the kerf cuts. This unifies the surface and makes the piece ready for finish when appropriate.

John
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