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GreenLee 227 mortiser spindle

JPD

Plastic
Joined
Apr 30, 2018
Greetings all. This is more of a thought exercise now, as we were able to re-bore the severely bell mouthed spindle on my GreenLee mortiser, and it is now back in service. My question is, if one day I were to build a new spindle (easy enough, as it could be turned from a 2” by 21” bar), what would be the ideal design to hold the auger? The original design was a 3/4 bore, with a set screw that tangentially clamps a split collet. Over the course of its 80 years, tightening and tightening it caused the spindle to distort. Assuming I build a new spindle one day, what would be the modern approach? I explored the er collet idea but the cheap import chucks did not have adequate tolerance.
Thanks for the input
JP
 
Since i've worked on, and used to make/sell collets for Greenlee & Oliver mortisers, the subject has given me some thoughts over the years. :)

I used to be all gung-ho "convert to ER25".
That size will accommodate all the auger bits up through 1" or maybe even 1-1/4" chisels, which is pretty much the limit unless you have an old car mortiser. It is also a size that could be easily made integral in a spindle of the size that would typically take 3/4" Greenlee, or 7/8" Oliver collets. ER collets are cheap and quite effective. The spindle nose closer and wrench are replaceable, will take a lot of abuse without slipping, and should be easy to use in the confined area of a typical mortiser housing.

OTOH, many users never received a full set of tooling, or the correct augers are less available, so are unfamiliar how to set things up in a mortiser "correctlY":

1.) loosely assemble the auger in the chisel
2.a) either put the collet on top of the auger, auger & chisel still being in your hand
or
2.b) put the collet in the spindle and loosely start the grub screw in the collet flat just enough to let it hang there
3.) Put a piece of softwood on the table so when you drop the auger out of the chisel, it does not mar the spurs......
4.) Put the chisel and bit up in the machine.
5.) stick your thumbnail, or preferred gage on top of the chisel shoulder and shove the chisel up to the register, snug the set screw for the chisel to keep it there and remove your thumbnail.
6.) shove the auger up tight in the chisel, loosen the screw on the collet, and pull the collet down until it bottoms on top of the auger. Tighten the collet holding screw securely, Don't rotate the spindle with the auger tight up in the chisel.
7.) Loosen the chisel set screw, and shove the chisel up tight against the register, establishing the thumbnail clearance between auger and chisel at the business end. Tighten the chisel screw.
8.) on the collet, run the knurled nut up snug to the bottom face of the spindle so the collet cannot push up. The chisel can't push up because it is tight to the top of the collet. everything is secure.
9.) make some test cuts, rotate the chisel to square it. (so it cuts equally on both sides of the back edge), and re-secure it.

The old system works well with both new, smooth shank augers run in split collets;
& old legacy tooling with marred, distorted shanks can run fine in solid open-window collets.
In both cases, the externally threaded barrel and the knurled nut offer slip free positive depth location to keep the auger from pushing up and destroy itself and sometimes the chisel. The fact that tightening the collet does not cause it to draw in (up) makes it dead easy and fool-proof to set the clearance.

If you never run chisels over 1/2" in a manual feed machine, in primarily softwoods, & most of your auger shanks are new; any collet system will probably work. (never jaw chucks/drill chuck, of course). If, OTOH, the machine has powered feed, you like to use big chisels, and the work will often include hard, hardwoods, or there's lots of scarred up legacy tooling; then the old system has a lot to commend it.

I rebuilt the spindle on my Greenlee 228 auto about 40 years ago due to loose/broken long keys and wallered keyways (OEM/used instead of splines) that were causing it to jam on the feed strokes. The spindle nose on mine is still good, i think it might be hardened. I run big chisels, used to make tooling so have lots on hand in metric and conventional auger shank sizes in split and open window styles. Probably would stick with it even if i have to build a new spindle. I might retro-fit ball bearings instead of the scraped HS babbitt boxes, though. :)

Using the old system collets i would be more than comfortable the machine was capable of another century or century-&-a-quarter of solid work making the spindle out of pre-hard 4140 which is my go-to material for such. If the conversion to ER were made, the end of the spindle should be hardened and ground.

There's still at least one set of 7/8" Oliver bushings here.
Open window style, though. I don't think they made that size in split.
All my 3/4" bushings are sold or in use.

smt
 








 
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