Quill Conversion

ddvann79 · Post by **ddvann79** » Fri Nov 26, 2010 3:34 pm

aloneryd wrote:Your on my main thought. Your multiple bearing setup, is what Im looking for. Now my question,which I may have overlooked in your article is, can one mount the double bearing in the front section AND a rear bearing back toward the end by the hat bushing? Do you think the combination of these two separate bearing locations would increase the stability even more? This could be utilized to the gilmer setup as well, correct?
bergy

Please correct me if I'm wrong, but I gather you are talking about a three-bearing quill with two in the front and one in the rear. That's a very interesting concept. Based on other threads I've seen on this forum, I know it can be done if you are willing to mill the quill housing.

I'm no machinist, so maybe I'm in left field here, but if a two or three bearing setup in the front of the quill reduces runnout to +/- a thou, would you need to improve upon this? I certainly understand the desire to try just for the sake of accomplishment but how do you even measure differences less than .001" in a spindle?

holsgo · Post by **holsgo** » Fri Nov 26, 2010 3:39 pm

Again, here's where the travel indicator comes in. But, my adventure has ended well so far. I plan to use the machine for turning with a heavy 3 jaw chuck as well as light milling in primarily soft metals. My concern was runout and side thrust. I hopefully have improved both.
My next upgrade are cast iron tables which I'm getting off a Total Shop. This should add a bit of weight for what I need as well as make clamping to the table a bit more ridgid.
I have a 3hp cabinet saw so table saw functions are not my chief concern.

damagi · Post by **damagi** » Fri Nov 26, 2010 10:04 pm

billmayo wrote:Installing a second bearing on single bearing quills at the quill end or the splined end and having tested for hours at high speed, I find I have much less runout over time with the second bearing installed behind the front bearing. The 2 front bearings together appears to have less wear/play than just a single bearing on the quill end and one on the spline end. I use the double front bearing quill for light milling work (X/Y vise).

I have the following broken headstock that I use for checking quill bearings and for bent quill shafts
[ATTACH]11039[/ATTACH]

[ATTACH]11040[/ATTACH]

[ATTACH]11041[/ATTACH]

Makes sense...though I am curious as to whether you tested deflection with the quill fully retracted as well as fully extended?

billmayo · Post by **billmayo** » Fri Nov 26, 2010 10:44 pm

damagi wrote:Makes sense...though I am curious as to whether you tested deflection with the quill fully retracted as well as fully extended?

I try keep the quill lock tight and the quill fully retracted. I move the headstock or table for any milling operations and most of the time for other tasks. With the quill lock tightly, I have no noticeable deflection at any quill position. When moving the quill, I keep the quill lock snug to where the quill stays at any position when letting go of the quill feed handle. This way I eliminate any of the quill housing deflection inside the headstock casing.

I believe the Drive Sleeve bearings provide sufficent support for the quill splined end. So I have machined most of the quill shafts and housings for adding a second same size bearing behind the front bearing. I find a metal lathe with a larger than 1 3/4" spindle bore is needed to accurately do this machining.

Most of my tasks are with aluminum and cast iron/metal items, not woodworking tasks.

KDC · Post by **KDC** » Sat Jan 08, 2011 1:24 am

ahhhh, this is what I was looking for...as I need to add a second bearing behind the first one on my single quill 1972-78 SS.

Thanks!

Kola

billmayo · Post by **billmayo** » Sat Jan 08, 2011 11:36 am

kola wrote:ahhhh, this is what I was looking for...as I need to add a second bearing behind the first one on my single quill 1972-78 SS.

Thanks!

Kola

A note of caution: I am finding around 25% of the Poly-V quill shafts are bent/bowed (.003-.060 differences). The smaller differences are hard to detect even using the sanding disk.

I modified a broken headstock casing using a bracket and dial indication to check these differences for the Poly-V quills.

[ATTACH]11394[/ATTACH]

Adding a second bearing behind the front bearing requires maching of the quill housing and shaft (11mm) to fit the same size second bearing. This is not cheap for one set up.

I am currently waiting to test a converted Gilmer quill I had machined last week. It took several Gilmer quill shafts (2 trips) to find a straight one so I have to add the capability to check for straight Gilmer shafts.

KDC · Post by **KDC** » Sat Jan 08, 2011 5:31 pm

Up to .030 of runout? Wow. Is this runout coming for the shaft itself or is it when the shaft is mounted into the headstock with bearing? If it is in the shaft itself whats the cause? where they coming off the factory line like this or are they tweaked around from use?

I can machine the quill for the new bearing.(I think). I see one guy went with two. I guess if you are going to do it might as well machine it for two more.

This leads me back to an initial suggestion. How about the comparison from me doing the conversion to just buying the SS 2bearing upgrade? <scratching head> maybe it would be better to bite the bullet and buy the SS upgrade and slap it together.

Thanks!
Kola (newbie SS owner)

KDC · Post by **KDC** » Sat Jan 08, 2011 5:40 pm

another thought:

Is it possible to find a used 2 brg. quill on ebay, or CL and replace the bearings if needed?

holsgo · Post by **holsgo** » Sat Jan 08, 2011 6:27 pm

You are thinking along the lines of a Poly v drive assembly. This assembly has the 2 bearing quill, one at the taper end and one at the spline. What Bill and I have done is use the spindle from a gilmer, one bearing drive and modfy it. The gilmer machines don't accept the spline from the Poly v drive, thus if you were to convert you have a number of parts to convert.
So, to have multiple bearings without the full conversion (spindle, quill and drive) we just took a different route. To be short, I am quite happy with the conversion and it cost minimal except time. Plus it let me learn about some things.
The only thing I've pushed this machine with, even with my conversion, is lathe cutting steel, less so with alumium and way less so with brass. I'm going to fashion a follower rest to reduce deflection even further as well as a live center and deflection should be way down. However, I'm only trying to make my own brass knobs etc in the long run so I should be well suited.