Friday, February 4, 2011

Laser Reaming

Sometimes I like to bounce new ideas off of students. Sometimes I get a blank stare or "yea, that's cool", but yesterday after showing Pete Wiens how to drill and ream his stool seat with sight lines and mirrors it hit me that I needed something different. The problem is getting someone who isn't use to looking at sight lines and bevel guages to ream at the proper geometry to get all the legs really close to what they should be. Up til now "really close" was the best I could hope for. All I said to Pete was "what if we had lasers?", and today we have what you see below. With this set up anyone can ream the tapered holes for the legs spot on. It gives the students more confidence than I could ever imagine and it really sets up in seconds. If it were not simple then believe me, I would not fool with it.
It works like this. Go to the local home improvement store and pick up two cheap $15 B&D line lasers. They have a small magnet on the bottom. We built the base out of scrap wood with a heavy hardwood bottom for stability. It's good to have rubber glued under the base so they won't slide around on the bench. The dowel makes it adjustable for easy setup. The laser sits magnetized on a metal nut imbedded in the base.
Now on the bottom of your seat blank after you have drilled the straight holes from above the usual way, draw a perpindicular line across the hole to the sight line. Set up one of the lasers tilted to the drilling angle and sighting down the perpindicular line. The other laser will be adjusted to 90 degrees to the seeat blank and sighting straight down the sight line. Stay with me now.
Now all you have to do is start reaming keeping the crosshair of the lasers right on the top point of the reamer. That's it! It comes out perfect and I have not found a flaw yet.
A couple things to remember. Never look directly into a laser. This set up with this brand of lasers keeps the line of light lower than eye level. Also it helps to turn off the lights above your workbench. I have windows all around and still had no problem seeing the laser lines. Also turn the top of your tapered reamer slightly concave so the laser will fill in to the top of the reamer. I hope this will shead some light on reaming perfect angles. Good luck.

10 comments:

  1. Greg,
    All I can say is wow, wow, wow!! You knocked this one out of the park. I can see the rush on laser levels now,
    thanks for posting!
    Pete

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  2. Hey Greg,
    now you got me thinking! How about turning your legs with a small concave cone at the bottom so you can use the leg to sight (it gets trimmed anyway). I prefer this, as you know, because the leg can be warped. This way the footprint is always right! Gotta go buy some lasers, before they are all snatched up!

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  3. Hey Pete, That's even better sighting to the leg. I look forward to reaming the back post of the fan back then take measurements to see how close they get.Having students around changes the way I think about the chair process. What may seem easy to me is difficult to them so trying to see it through there point of view forces me to make it simple.

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  4. Thanks for the awesome idea... you took invisible planes and made them visible. Why do you reserve this technique for reaming - can't it also be used for boring the mortises?

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  5. Mike,
    I thought of this method after I had drilled the mortises from above. You're right, this method could be used in any number of ways to drill holes with angles. The laser will light the side of a drill bit as you drill spindle holes too. You could also map out sight lines and angles on an existing chair with lasers which will help you create an exact reproduction. Thanks for your comment.
    Greg

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  6. what a great idea I can't wait to give this a try.Bob

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  7. I made a set of "laser sights" and legged up a loop back. Thanks for sharing.

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  8. Greg I wanted you to know I used your idea and it works very well. It took a little time to set it up the first chair but, after that it went very well thanks for sharing this with us.

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  9. Please let me know the model number of the Black & Decker laser.
    Thank you

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  10. Thank you for the info. It sounds pretty user friendly. I guess I’ll pick one up for fun. thank u.
    Line Lasers

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