Washer Guide - Home Shop Machinist

I just received an email from HSM where one guy improved the accuracy,
runout, deflection of his inexpensive drill press by bolting a snug fitting
washer to the top of his quill that rides inside the column against the
sides.
My first thought was, "Won't that introduce wear to the inside of the
column?" My second was, "Gee that does sound like it work work if you used
a softer sacrificial material fro your washer/spacer."
Not that I am convinced I want to do this to my drill presses, but I you
were to take this approach with the thought that you might want to use these
everyday. Not just once in a while what would you make that washer out of?
************* Text of email received *************
Improving Drill Press Accuracy
By Quincy Collins
Many budget-priced drill presses have a fair amount of runout, or play,
especially as the quill is extended. Mine is no exception, so I headed to
the internet to try to find a solution. The bulletin boards seemed to be
filled with owners unhappy with the accuracy of their drill presses.
Some suggested flattening the splines with a hammer to reduce play, which
seemed a little drastic to me. I then hit on this solution that has worked
for me and is a little more elegant than taking a hammer to the drill press.
The upper end of my quill, where it passes through the pulleys, had a
countersunk center mark. I simply drilled and tapped this location and used
a screw to attach a custom washer (Figure 1). The washer was sized on the
lathe for a close tolerance with the bore of the pulley shaft. This served
to stabilize the quill at all points in its travel.
The spindle runout of my drill press has been greatly reduced and drilling
is now a much happier and less frustrating job. I have limited shop time so
it was nice to have found a solution that was both quick and easy.
Thanks Quincy, your subscription has been extended by an issue!
*************

Reply to
Bob La Londe
Loading thread data ...
" snipped-for-privacy@krl.org" fired this volley in news:4a3aa825- snipped-for-privacy@m10g2000vbc.googlegroups.com:
Ultra high molecular weight WHAT? You mean, "Polyethylene"?
For lubricity, you might want to use extreme-temperature PTFE. Weird stuff to cut, but it wears almost forever in a metal bore, and produces about 1/10th the friction coefficient of UHMW-PE.
LLoyd
Reply to
Lloyd E. Sponenburgh
I saw that and immediately didn't like it. It seems to me that anything CAN be fixed right...unless you're in a hurry.
Reply to
Tom Gardner
Polyethylene is definitely the cheapest choice but will cold flow under pressure. Besides the PTFE mentioned below, which I've never worked with, I've had good luck with Nylatron, nylon with molybdenum disulfide filler (harder and stiffer than PE, no cold flow, machines well).
----- Regards, Carl Ijames
" snipped-for-privacy@krl.org" fired this volley in news:4a3aa825- snipped-for-privacy@m10g2000vbc.googlegroups.com:
Ultra high molecular weight WHAT? You mean, "Polyethylene"?
For lubricity, you might want to use extreme-temperature PTFE. Weird stuff to cut, but it wears almost forever in a metal bore, and produces about 1/10th the friction coefficient of UHMW-PE.
LLoyd
Reply to
Carl Ijames
So how do you fix them "right". Given the premise that throw them away and spend 10-20 times as much for a good drill press is not an option for most folks.

Reply to
Bob La Londe
Bob if you can see this (eternal sept sometimes doesn't always post my replies to other servers - or you may have me filtered out) reply and I'll write up the fix I did on my craftsman 15" DP #113213151. It isn't the perfect fix but is a big improvement and is simple to do. Art
Reply to
Artemus
Hey Art,
Sure post away. I'ld love to see your fix.
Bob

Reply to
Bob La Londe
Here ya go.
See diagram at
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the screws (#28) in the lower left. The bottom one goes thru #27 and into a threaded hole in the head. This hole is open inside the head all the way to the quill tube. I drilled the old threads (0.8-8 metric) in the head out and tapped with 1/4-28 threads. The head casting is not very thick and I wanted more threads in it than 1/4-20 would give. Next I threaded a 2" piece of 1/4" brass rod 1/4-28 for about 3/4" on one end and 1/4-20 on the other end for this knob
formatting link
end that contacts the quill tube was filed flat across w/ a slight chamfer on the corner.
To use just tighten it up so the quill play is nil but the quill still travels up/down easily. Tighten it some more and the quill will lock to hold the chuck at any depth.
It's been about 10 years since I've done this and it's still working just fine with no wear on the quill at all from the brass rod .
I can post some pics tomorrow if you need them. Art
Reply to
Artemus
Art, Thank you.
I've been a working all day on a part so I'm a little punchy. I'll read your comment and look at the diagram again in the morning, but a picture is always worth a thousand words.
Bob
Reply to
Bob La Londe
Some one here posted a link to images where they did something similar awhile back. They drilled two holes through the front casting offset at about 90 deg and then did the same thing with some bronze/brass inserts. The holes were in the front corners in the casting at about the same height as your hole. It looked really tacky, but he claimed it worked well and sounds good in theory. I've tried the one point as you mentioned but there is still too much play. Need at least two contact points to take out the slop in my presses...
But, the fix Bob passed on is for the spline area that slides up/down inside the quill.
Look at this image:
formatting link
Your fix takes the slop out of item: 6
Bob's fix (or what he passed on) takes the slop out of item: 11
Well... at least that is the way I see it...
Reply to
Leon Fisk

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