View Full Version : Solution to Problem

01-24-2012, 09:37 AM
I have come up with a totally new design for a wind chime and I need some help in its fabrication.

What I need to do is to mill five 1/4" dia. flat spot on the side of a 5/16" dia. aluminum rod. They are to be spaced 72 degrees apart and each one is 2" above the previous one so as to form a sprial stair like configuration. I have tried to make one so far and it did not turn out.

I used a vertically mounted dividing head to obtain the angles and I had the rod marked in 2" segements. Since the rod is so flexible, I had to slide the close to the jaws of the dividing head so I could mill the flat spot. I tried to be very careful to keep the top side of the rod oriented vertically as I slide it into the jaws for the next cut. Once moved and locked, the angle was changed and the new spot milled.

When it was done, the angle between the milled spots varied greatly. I assume that I didn't do a good job of keeping the top side of the rod oriented vertically as I slide it into the jaws. Is there some way I can accurately make the adjustmenting movements to the rod and still retain accuracy? I was thinking about making some sort of a temporary support for the bottom of the rod and move it for each cut so once the rod is locked into the jaws, it doesn't have to be repositioned. It seems rather "kluggie" to me. Is there a better way to do it? Thanks.

01-24-2012, 09:52 AM
That's the way I would do it (intermediate support). I don't see anything kludgy about it. Workholding fixtures are part of the game. Put the dividing head down at one end of the table, chuck the rod, install the support, mill the first flat, crank the table to the next position, move the support, rotate the rod, mill the next, etc.

The support could be as simple as a hole in a bar at your dividing head's center height that the rod can slide through, with a setscrew to keep the rod from vibrating. Make the bar L-shaped or T-shaped so it can be clamped down to the table.

01-24-2012, 10:25 AM
If your dividing head has a tailstock, set it up with that.

01-24-2012, 11:29 AM
Protip: Please make sure your wind chime has multiple distinct notes.

Your neighbor may become homocidal if it only goes "Ding.. Dong.. Ding..Dong..Ding..Dong" all day long as its placed in the windest spot of the yard.

01-25-2012, 09:30 AM
Protip: Please make sure your wind chime has multiple distinct notes.

Yes, my chimes have multi-tones. My tube-type chimes have six tubes of various lengths for different tones. My latest design has five different tones with the strikers on the five arms.

SGW - Thanks for the idea of the support with the hole in it to slide it along the the rod. That is how I will do it.

Jim Shaper
01-25-2012, 10:44 AM
After you move the bar, you can check for parallelism to the mill's table while reclamping. Use 123 blocks or what not and a straight edge across the fresh milled surface.

Or if your mill is level, you can just put a bubble level on the flat.