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What is the purpose of an extended spindle on a drill press?

Mikel Levy

Aluminum
Joined
Oct 19, 2009
Location
Seattle
This isn't something I've given much thought to in the past, but now that I'm looking to replace my drill press I was wondering if there's any advantage (or disadvantage) to a drill press with an extended spindle. Thanks for any information that might enlighten me.

Drill press 2.jpg Drill press 1.jpg
 
If the spindle has a Morse taper,the knockout key slot is accessable with the spindle retracted......Avert yer gaze here......buut if a taper tool /drillbit gets stuck ,you can do the old trick of a heavy dolly and hammer against the spindle to eject same.........My old Asquith radial had a #5 Morse q/c adaptor stuck in the spindle immovably ,till the day I scrapped it....and flogged the spindle with two sledges to get the Q/C driver out.
 
Johnk has it. That extended spindle you show is a Walker Turner design. I think of that as an earlier American design. I might also call that a “regular“ spindle. I think it was the imports that first put the knockout in the retracted part of the spindle. Every Arboga or Solberga I’ve seen is like that. Gives you more headroom under the spindle and more rigidity in the spindle. I think it’s overall a better and more desirable design.


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Your "regular spindle" is one that I think is no longer made. It is a 33 Jacobs taper with locking collar and requires a special chuck which, if still made, is hard to find and will be Chinese. In the picture, you can see the collar, which has a hole for a pin spanner wrench, just above the chuck body. These spindles were common around 1955-1980 and had a real advantage. Normally, a standard 33 Jacobs taper chuck is extremely difficult to remove once installed on the spindle. The locking collar version was made to be easily removed. The reason for removing the chuck was that there were several accessories that could be installed on the drill spindle in place of the chuck to allow mounting Morse taper drills, buffing, grinding, routing and shaping wood. Those accessories are quite scarce now.

The alternative spindle design that you call "extended" has a 2 Morse taper that allows using either Morse taper shank drills or a chuck with a Morse taper arbor. The extended length is to allow for the extractor slot to be accessible.

A few decades ago, Rockwell would sell some of their 1/2" capacity drill presses with either the 33 JTC or a 2 Morse taper spindle. It is quite easy to change the spindle from one to the other, if you have the parts. My 17" Rockwell variable speed drill came with the 33 JTC spindle. I made a new 2 MT spindle for it when I rebuilt it because I want the flexibility of being able to use Morse taper shank tools, either drill bits or different types of chuck.

The picture shows a Rockwell 17" quill with the 33 JTC spindle installed. Note the large male thread above the 33 JT. The collar on the chuck serves to pull the chuck tight onto the taper and also to force the chuck off the taper. Below is a 2 MT spindle, which is a pretty simple part to make from a 2 MT drill extension. As you can see, the part of the spindle that goes into the lower quill bearings is too slender to allow the 2 MT taper to fit inside the bearings, forcing the entire 2 MT portion to be below the bearings. Larger drill presses sometimes have the Morse taper up inside the quill bearings. In those machines, the extractor slot is only accessible when the quill is all the way out, exposing a slot through the quill to allow the wedge access to the slot in the spindle.

Some cheap drill presses will come from the factory with a cheap drill chuck already installed on a spindle with a Jacobs taper or even a European taper. It will probably be a difficult job to remove the chuck without damaging the spindle. And it may be difficult to find a good chuck to replace the bad one these days.

I advise getting a drill press with a Morse taper spindle unless you are looking for a smaller drill press with 1/4" or less capacity.

Larry

Rockwell 17 DP Spindle 1 (2).jpg
 
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First, let us agree a drill press is not a precision machine. It makes sorta round holes in sorta the right place.

Having said that, I'm strongly of the opinion a #2MT has limited application in a small DP. These small DPs are mostly used with a chuck and round shank drill bits. The range of drills for the #2MT is 1/2"-3/4" and most of the holes a small DP drills are <1/2".

The #2MT spindle with an adapter and chuck puts the point of the bit several inches further below the bearings than where it would be with a JT33 chuck. This extra wobble makes a crude machine even more so.

jack vines, who has DPs with both JT33 and #2MT. The chuck stays on the machine and the #2MT gathers dust on the tool board, unless the hole is in the 1/2"-3/4" range.
 
I think the answer is you could drill a hole down in a deep casting using a normal length drill bit.
 
I have a similar drill press with the locking ring chuck. Works fine and has never caused me any trouble. I think I put a rebuild kit into it at some point. A drill press is only as precise as the person using it. Do your layout right, punch and spot the hole with magnification and you can be within a few thou. As for roundness, I'll be happy to show you how to make out-of-round holes on a BP or any machine you like. :D
 
A handy process for a production part is to make a bushing plate and punch the hole location onto a part. Then with a drill press do all the holes. This allows an apprentice to do the holes and frees up the mill. A quality or even a hobby DP is a very useful machine.
Agree to have a CNC mill a job can go very fast.

I met a fellow who had a feeder and fixture on a single DP and with that one machine made a decent living. No, I won't tell the part because likely he is still producing it.
 
I have always preferred drills with a Morse taper because it gives you more flexibility as to what you can fit in it.
I have two DPs, both had chucks only but a few years ago I converted one to have a well supported MT2 taper. It has been so much more useful since. Here is a PDF with a description of the conversion Dropbox - Morse_taper_drill.pdf
 








 
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