MadModder

The Shop => Tools => Topic started by: John Hill on November 28, 2015, 11:50:38 PM

Title: Helical milling device (OK for wooden candlesticks!!)
Post by: John Hill on November 28, 2015, 11:50:38 PM
I was playing in my shed today*....

(https://farm1.staticflickr.com/657/23359848136_d3ab4205b2_z.jpg)

I built this contraption on my milling machine, an assortment of gears mounted on the end of the mill table to couple the movement of the mill table to a rotary table which is mounted with the axis horizontal.  The mill feed screw has a 5mm pitch and for example with 1:1 coupling I am able to mill a helix with a 5mm pitch,  right now I have set it up ratio of 20:65 for a 16.25mm pitch.  I have allowed for compound gearing to get widely different ratios for particular jobs.  The gears are 'borrowed' from my Drummond lathe and there is quite a selection of them to choose from.  There are a lot of gears in use but three of them are idlers where a single idler would have been enough but I do not have any near the required size, there must be an odd number of idlers for a right hand thread.  Working out the design to mount so many idlers was the major challenge of this project.

In action...
(https://farm6.staticflickr.com/5629/23303416081_ffc2e9d54c_z.jpg)
... the mill power feed can drive the action or I can use the handle which will be necessary for any larger diameter work as there is a minimum speed that the power feed has sufficient torque.


The end result...
(https://farm1.staticflickr.com/700/23359831726_94ca16313f_z.jpg)
As you can see this is in wood but it should work equally well in plastic or metals.

There are a number of things that could be better, I need to make spacers to have the gears align properly and I really should have machined that raw painted end off the vertical bracket!

*It took much more than a day to make all the bits!!!
Title: Re: Helical milling device (OK for wooden candlesticks!!)
Post by: tom osselton on November 29, 2015, 02:06:25 AM
Nice build!  I thought doubleboost should have made one for his indexer . I have a large dividing head buried in the garage that has the shaft out the back to do that  I don't have any gears or chuck for it though.
Title: Re: Helical milling device (OK for wooden candlesticks!!)
Post by: John Hill on November 29, 2015, 02:45:15 AM
Thanks for the comments.

The shaft is not a fixture to the rotary table but it does have a thread that passes through the table and engages with the drawbar socket of the morse taper arbor that holds the screw on chuck.