Subject: Re: Adjustable quill bore on milling machines?
From: Robert Bastow <TeenutNOSPAM@hotmail.com>
Date: Wed, 18 Aug 1999 04:15:05 -0400
The quill housing on the vertical head of my Deckel FP1, has JUST such an
There is a spring loaded, rack and pinion down feed on the quill, but this is
used only for light drilling and tapping.
Milling (and boring) operations are carried out with the quill locked and using
the table (power) upfeed.
This is one of the factors that contribute to the extreme rigidity and accuracy
of the Deckel.
Doug Jackson wrote:
> I've noticed that many drill presses have adjustable quill housings,
> in which there is a vertical slit in the head casting at the front of
> the quill bore. Two or three cross-bolts in front of the quill are
> tightened to adjust the bore diameter to precisely fit the outside
> diameter of the quill.
> A few years ago I modified a Delta 12" drill press by drilling a
> 1/4" hole in the front of the head casting, just behind the power
> switch (just above the top of the quill bore). I cut a vertical slit
> from this hole down to the bottom of the quill bore (just above the
> chuck). The purpose of the 1/4" hole was to prevent cracking of the
> casting above the slit. There wasn't enough meat in the head casting to
> pass a horizontal through-bolt in front of the quill, so I made a clamp
> out of a 1/2" machine screw and a few scraps of 1/4" steel plate. This
> clamp goes around the front of the head and serves in place of the
> horizontal through-bolts.
> The modification works beautifully. I can tighten the quill for
> precision drilling and *very* light milling with a cross-vise. I can
> also tighten the quill enough to keep it from moving when I let go of
> the downfeed handle- this is convenient in a lot of situations. I'm
> thinking about making a similar modification to my Chinese mill/drill.
> There even seems to be enough meat in the head for through-bolts (and
> besides, it's no huge loss if I screw it up: -)
> My question is this: it seems like the split bore would be useful in
> a *real* vertical milling machine, but the ones I've seen (at least the
> few that I've used- Bridgport & South Bend) do not have this feature. I
> can see how it could possibly reduce the rigidity of the machine
> (depending on the dimensions of the head around the quill bore) but it
> seems like the advantages of being able to tighten up the quill would
> outweigh this. Obviously this doesn't matter if you lock the quill, but
> it could help a lot for taking plunge cuts with an end mill (where the
> quill can't be locked because you're downfeeding).
> Does anybody know a reason why the split quill-bore might be a bad
> idea on a mill? Is is simply not necessary on the larger mills because
> of good manufacturing tolerances, or is there another downside to it?
> Elasticity of the through-bolts might affect rigidity when doing
> heavy milling cuts. However, looking at the tensile loads on the bolts,
> if you just use big enough through-bolts it should act just like a solid
> head. Of course the bolts would not resist shear strain along the
> plane of the slit (induced by radial loads on an end mill) but this
> should be minimal if there is enough iron in the head casting just
> behind the quill and directly above the slit.
> I dredged out some of my old Engineering Mechanics textbooks & did a
> rough calculation of the difference this modification would make to the
> overall rigidity of my mill/drill (assuming that the original "unsplit"
> bore had zero radial slop in the fit of the quill to begin with). I
> found that the loss of rigidity for the split bore is almost nil-
> especially compared to the (lousy) rigidity of the 4-1/2" column (but
> even on a Bridgeport it shouldn't make a significant difference, if I'm
> doing the calculations correctly). Am I overlooking something?
Subject: Re: Vertical Mill
From: Robert Bastow <"teenut"@ hotmail.com>
Date: Thu, 13 Jan 2000 04:16:49 GMT
It does have a slightly different geometry then the ubiquitous "Knee Mill". The
vertical saddle takes care of "Z" and Y" movements, the spindle ram takes care
of the "X" and also has a moveable quill on the vertical spindle for sensitive
drilling. Variable power feeds are available on Z and Y.
The work tables are bolted onto the vertical sadle and can be loosened and slid
from left to right without loosing register..thus giving surprisingly more
working width than appears at first sight. Two kinds of table are
available..the plain table..simply a large, tee-slotted angle plate, or the
Universal table which tilts and swivels in both axes.
The drive is all geared from a 2 HP 2 speed motor and all the gears are robust,
hardened and ground..even at top speed there is little "gear noise"
Bearings are my favorite type!!! Tail end of both spindles runs in pre-loaded
ABEC 9 angular contact bearings while the front end is a hardened and ground
cone running in a bronze bush with forced oil feed. These types of bearings can
be readily adjusted (axially) to give virtually zero end and side play. IMHO
the very best bearing arrangement for a precision machine tool. BTW The Myford
Super 7 is fitted with an identical arangement!! As was my Smart & Brown
One day I plan to chuck out the tapered roller bearings on the front end of my
Maximat Super II lathe spindle, and replace them with a similar taper bronze
bushing. The rear end already has the required preloaded angular contact
bearings and the requisite double nuts to adjust it axially.
"Kenneth W. Sterling" wrote:
> Looks like a great machine! Also looks like (and I *really* don't know
> squat) its got a "different" table arrangement, almost like one table can
> slide up and down on the other? How sturdy is the drive mechanism in the
> head? Any way to take up play in bearings, etc? Thanks for info.
> Robert Bastow <"teenut"@ hotmail.com> wrote in message
> > Deckel..indeed it is that what which I have FP1
> > Here are four or five good pics...you can see how versatile it is.
> > http://www.lathes.co.uk/deckel/index.html
> > teenut
> > "Fitch R. Williams" wrote:
> > >
> > > "Kenneth W. Sterling" <firstname.lastname@example.org> wrote:
> > >
> > > >I want a floor type machine (not
> > > >bench top or table top).
> > >
> > > Go find a Deckl (sp?) and look at it. There was one for sale near me
> > > recently - Nedra and I couldn't come to terms so I left it there. It was
> > > both horizontal and vertical. It was $2,000. Smaller than a BP, bugger
> > > than a mill drill. Perhaps Robert Bastow who I think has one can
> > > elaborate. From what I understand about it is a very good candidate for
> > > you to hunt for.
Subject: Re: Vertical Mill
From: Robert Bastow <"teenut"@ hotmail.com>
Date: Thu, 13 Jan 2000 04:43:38 GMT
That is indeed an excellent price..I paid a bit more than that (Plus nearly as
much to ship and install it!!) but it is in pristine condition.
Best price I have seen since was $4500 with plain table and 6500 with the
universal tilting table (Which mine has)
I have located a universal spiraling/dividing attachment, trying to beat the guy
down from $6800.00 for it !!!
Why the high speed head? Very, VERY expensive if you can even find one.
Top speed on the standard head (Horizontal and vertical) is 2000 rev/min
I have an water cooled "Precise" jig grinding spindle for mine..Expensive, yes,
but not in the $4-5000 range they will ask for the high speed head..and the
Precise winds up to 80,000 rev/min!!
I know of only one other machine for sale that has both tables..He wouldn't
split the plain table out for me..I am sure he wouldn't part the universal
If you scrounge around at "Evans the Scrap" you might find a large swivel base
from say a shaper vise...that could be adapted to give you rotation in one
direction at least. Add one of those $75.00 swiveling "Skoda" type tables from
MSC or Grizzly and you have your second axis!!
I passed on a Slotter head for $900.00 and have been kicking myself ever
since..even though it would have had to be shipped from Norway!!
> This is a very fine mill... I have one. The accesories are hard to find,
> though. $2000 is an excellent price for one. (It is a toolmaker's mill) If
> anyone reading this knows where I can find the tilt table or high speed head
> for this, I would love to hear from them.
> Fitch R. Williams wrote in message ...
> >"Kenneth W. Sterling" <email@example.com> wrote:
> >>I want a floor type machine (not
> >>bench top or table top).
> >Go find a Deckl (sp?) and look at it. There was one for sale near me
> >recently - Nedra and I couldn't come to terms so I left it there. It was
> >both horizontal and vertical. It was $2,000. Smaller than a BP, bugger
> >than a mill drill. Perhaps Robert Bastow who I think has one can
> >elaborate. From what I understand about it is a very good candidate for
> >you to hunt for.