A DIY & home improvement forum. DIYbanter

If this is your first visit, be sure to check out the FAQ by clicking the link above. You may have to register before you can post: click the register link above to proceed. To start viewing messages, select the forum that you want to visit from the selection below.

Go Back   Home » DIYbanter forum » Do - it - Yourself » Metalworking
Site Map Home Register Authors List Search Today's Posts Mark Forums Read Web Partners

Metalworking (rec.crafts.metalworking) Discuss various aspects of working with metal, such as machining, welding, metal joining, screwing, casting, hardening/tempering, blacksmithing/forging, spinning and hammer work, sheet metal work.

measuring play in quill+spindle of milling machines & drills



 
 
LinkBack Thread Tools Display Modes
  #1  
Old July 11th 08, 12:44 AM posted to rec.crafts.metalworking
external usenet poster
 
Posts: 25
Default measuring play in quill+spindle of milling machines & drills

rec.crafts.metalworking
measuring play in quill+spindle of milling machines & drills

I'm hoping that some here have measured the play in the quill+spindle
of bridgeport & equivilent millers, which will be a deciding factor when I
buy one in the future.
The measurements that I have made were by chucking a 10 inch piece of
bar stock and pulling 10 lbs left then 10 lbs right at the end with a spring
scale with the quill lock, when present, loose. A dial indicater set on the
spindle indicates the play.
A small bench size drill press, a $60 version, showed 13 thousandths
of an inch play, 8 for a full size and heavier drill press, and 5 for a
spanking new mill/drill from Harbor Freight. The last omitted the scale
which leaves it a bit questionable.
If anyone has made equivilent measurements, posting the results
here would be greatly appreciated.

Hul
Ads
  #2  
Old July 11th 08, 06:07 AM posted to rec.crafts.metalworking
external usenet poster
 
Posts: 1,124
Default measuring play in quill+spindle of milling machines & drills

Hul Tytus wrote:
rec.crafts.metalworking
measuring play in quill+spindle of milling machines & drills

I'm hoping that some here have measured the play in the quill+spindle
of bridgeport & equivilent millers, which will be a deciding factor when I
buy one in the future.
The measurements that I have made were by chucking a 10 inch piece of
bar stock and pulling 10 lbs left then 10 lbs right at the end with a spring
scale with the quill lock, when present, loose. A dial indicater set on the
spindle indicates the play.
A small bench size drill press, a $60 version, showed 13 thousandths
of an inch play, 8 for a full size and heavier drill press, and 5 for a
spanking new mill/drill from Harbor Freight. The last omitted the scale
which leaves it a bit questionable.
If anyone has made equivilent measurements, posting the results
here would be greatly appreciated.

I cobbled a massively abused Bridgeport 1-J head onto my ancient
round-ram Bridgeport mill some years ago. I did some checks on
it when I was done. I got about .001" total back and forth
movement when pushing about 50 Lbs one way, then the other way
on the spindle. I was measuring with a magnetic mount indicator
stand clamped onto the main head casting, so I was only
measuring quill+spindle radial play, not any flexing of the head
to base component stack. This amount of play is the
displacement of oil from the bearing balls, and will be zero
when the bearing is spinning. I can't find any movement at all
in the quill. Unless horribly worn, the Bridgeport quill is a
very fine fit, and rarely gets loose. The spindle bearings can
get worn out, and they can be pretty expensive ($300 - 700 a
set.) But, it is much easier to check them by listening when
they are run. If they sound rough, diesngage the direct-drive
clutch and try again. The motor and backgear bearings are cheap
and easy to replace, so don't reject it is only the small
bearings are noisy. You can spind the spindle by hand when the
direct-drive clutch is open, and then ONLY the spindle bearings
will be turning, so if it sounds OK then, it should be fine.

Jon
  #3  
Old July 11th 08, 06:39 AM posted to rec.crafts.metalworking
external usenet poster
 
Posts: 1,668
Default measuring play in quill+spindle of milling machines & drills

On Thu, 10 Jul 2008 22:44:21 +0000 (UTC), Hul Tytus
wrote:

rec.crafts.metalworking
measuring play in quill+spindle of milling machines & drills

I'm hoping that some here have measured the play in the quill+spindle
of bridgeport & equivilent millers, which will be a deciding factor when I
buy one in the future.
The measurements that I have made were by chucking a 10 inch piece of
bar stock and pulling 10 lbs left then 10 lbs right at the end with a spring
scale with the quill lock, when present, loose. A dial indicater set on the
spindle indicates the play.
A small bench size drill press, a $60 version, showed 13 thousandths
of an inch play, 8 for a full size and heavier drill press, and 5 for a
spanking new mill/drill from Harbor Freight. The last omitted the scale
which leaves it a bit questionable.
If anyone has made equivilent measurements, posting the results
here would be greatly appreciated.

Hul


There should be very close to zero play. Not more than a few tenths
between the quill and its housing, and none between the spindle and
the quill. What you've been measuring is play plus deflection. If you
were to plot your indicator reading vs. force applied, the play would
appear as a steep line starting at the origin; the elastic deflection
would be a relatively gentle and more or less straight slope. The knee
where the two parts of the curve join represents total free play. In
other words, play is the parts rattling around when small forces are
applied; after the free play is taken up, and you apply more force,
you're elastically deforming the machine.

Measure the quill play with the indicator base on the quill housing
and the point applied to the quill close to the housing. Try it with
the quill both locked and unlocked. Stick the indicator base to the
quill to detect spindle looseness. As much as possible, you want to
isolate what you're trying to measure.

The spindle runout, measured on the inside taper or with a known good
collet and pin, should be less than about 5 tenths. Perhaps a bit more
or less depending on what sort of work you expect to do. A good BP
spindle will be less than about .0002, though more may not be a
problem for non-critical work.

Any play in the spindle bearings in a mill is likely to cause trouble.

--
Ned Simmons
 




Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

Similar Threads
Thread Thread Starter Forum Replies Last Post
Bridgeport milling machines. Andrew VK3BFA Metalworking 16 August 25th 07 12:45 PM
Need info and size on Bridgeport M-head, J-head spindle and quill Quill Eddie Metalworking 1 June 27th 05 12:50 AM
new Grizzly G7944 quill play and motor mount - what to expect? dustybasemt Woodworking 3 May 3rd 05 03:35 AM
FA 'A treatsie on milling and milling machines' larry g Metalworking 0 November 9th 03 07:44 PM
Whitney Punch NO 24 Spindle Play Dr Jimmy Metalworking 1 October 29th 03 02:36 AM


All times are GMT +1. The time now is 06:24 AM.


Powered by vBulletin® Version 3.6.4
Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.SEO by vBSEO ©2010, Crawlability, Inc.
Copyright 2004-2014 DIYbanter.
The comments are property of their posters.