Quill Construction

I am deviating from the plans a bit.  The major parts of the press are 0.8" to 1.0" in crosswise dimensions, I am scaling it up to 1.5".  The post is going to be 3/4" instead of 5/8".  The base will likely be increased to 5" in diameter.

Starting with  the (I hope) easiest part...

Quill Parts

I elected to use an ER11 Collet Extension which has a 8mm shaft that is about 4" long.  The excess shaft will be cut off after the test assembly.  The quill itself is made from 5/8" drill rod. The bearings are double sealed needle roller that I got from McMaster.  The OD is 12mm, just a shade smaller than the 1/2" OD ball bearings used in the original plans.  Jerry made his shaft and turned a JT-0 taper on the end to fit the micro chuck he used.  The only real change made to the quill housing was the size and depth of the bore to accommodate the different bearings.

Assembled Quill

Detail showing the end of the quill and the fit of the needle bearing and collet shaft.

Assembled Quill

The assembly after completion.  I will need to grind a couple of flats on the ends of the housing for the set screws to bite into.  I plan on using the micro toothed belt as i have a lot of the gear stock and likely the right size belt, all left over from my conversions I was doing to Meade LX50SD telescopes a number of years ago. The sprockets are easy to make, I bought a stick of the various sizes and I just cut off a slice.  A small thrust bearing of some sorts will be added to the bottom of the assembly to prevent thrust wear on the quill.  As light as the loads will be this likely will take the form of a sintered bronze washer.

Posted 7/2/2016

While working out the dimensions of the project I discovered that I would only have around 1/2" travel on the quill.  I am re-making the quill shaft longer to allow just under 1" of travel.  Easier to do now than wish i had later.

Posted 7/16/2016