High speed spindle


As I was messing around with text engraving, I realized that it would
be very cool to have a high speed spindle.
There is, apparently, a wide variety of purpose made and adapted
devices that are used for this:
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The best so far, looks to be this:
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This is a Bosch Colt palm router attached to the quill. It seems to be
nicely made, and low profile.
In my case, I can use a changeable toolholder to do the attaching, so
that it is easy to take off:
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This way, I could run a 1/8" end mill at 30,000 RPM, without using the
main mill's spindle bearings. I would use a brake to hold this
assembly in the quill.
It would be, as I said, a quick change setup, easy to be swapped
out. I would just need to figure out a safety interlock mechanism, so
that the main spindle would not be turned on accidentally with this
thing mounted.
It would seem that a holder is easy to make from 6061 or some such,
and the whole project can be done under $200.
I engraved some text yesterday, which took something like 19
minutes. I did it at 2,400 RPM. At 30,000 RPM, it could take only 1.5-2
minutes.
i
Reply to
Ignoramus11933
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Mount the high speed spindle along side the main spindle. When you need to use the high speed spindle, remove the tool from the main spindle, and lower it until the high speed spindle reaches the part. If it is just for engraving. putting a tool back into the main spindle, and the high speed might not reach the part, it depends on the job, and the setup, etc.
I once saw a machine where the high speed Precise Spindle was mounted off to the side, and on a separate slide.. It could be extended down with air, to an adjustable stop. or retracted. All mounted on a small linear slide assembly.
Reply to
Cross-Slide
To be more precise.. ( no pun intended) The extra slide was mounted to the side of the main spindle. So the Z axis moved both spindles up and down, but the high speed could be retracted or extended.
Reply to
Cross-Slide
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I think if Iggy looks around a bit..he can find a insertable high speed spindle in his price range. Not sure about his QD attachment though. Check out the first link above. While its not a heavy duty machine...it doesnt look too bad for engraving..and the price is right.
Gunner
Reply to
Gunner Asch
That palm router setup is nice. I like the idea of the pencil air grinder though, you could install one in a modified end mill holder and run the air line up through your unused draw bar hole which would mean no offset from the normal spindle location to deal with.
Reply to
Pete C.
I guess it depends on what you mean by engraving. Engraving is usually done with a spring loaded bit holder that is dragged (not spinning) along the surface of the material. This allows for engraving some surfaces that are not perfectly uniform and even to some degree engraving curved surfaces. I engraved the side of some larger sockets to see how far I could push it with mine. You can make your own spring loaded engraver with whatever size shaft is desirable. I would use a lathe, but if you have very low backlash or have backlash compensation programmed well in your control software you could do it on your CNC mill. If you don't want to make one there are atleast two different people selling them on Ebay. Dremel actually sells a decent tungsten conical point and a conical diamond dust point pretty cheap that work nicely in my drag engraver.
If you meant to "mill out" letters and only do it rarely then find yourself a high speed cutter of some kind and make your own mounting bracket for it. I'm using a couple motors and handpieces right now, but the first link Gunner listed is a nice example of one using a die grinder. Run out of your bit or mill holder will determine how small a cutter and/or how fast you can feed without breaking them. If you don't plan to use it often there are some pretty cheap drive solutions out there. A decent quality trim router turns at about 28,000 rpm and has a lot of power.
I would love to have one of those super high speed spindles that just go right into the mill like a collet, but they are expensive. Of course I would have to have a machine that would take them. LOL.
I look forward to seeing your ultimate solution.

Reply to
Bob La Londe
I will do this palm router thing. But only after I finish the mill's controls and this air brake issue.
i
Reply to
Ignoramus28889
That leaves no place for his spindle encoder and a rotating air connection at the top of the spindle.
Doable..but not practical?
Reply to
Gunner Asch
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Sure it does, his encoder will operate just as well on a hollow shaft as on a solid one...
Reply to
Pete C.
Actually, most engraving *is* done with a rotating bit, usually fixed, but sometimes in a spring loaded mount. All the plastic signs and nameplates you see are engraved with a rotary bit. Most engraving on stuff like anodized AL is also rotary cut (or lasered). Drag engraving is the exception, not the norm.
Iggy will find a high speed spindle and a nice carbide rotary engraving bit work nicely to engrave lettering and markings on aluminum or plastic enclosures which can be paint filled for a very nice result.
Reply to
Pete C.
What I means was using a small end mill to mill various shapes, such as text (as in making panels), or 3D patterns, like toys.
I think that this Bosch Colt palm router is the nicest cheap high speed motor, because:
1) It is relatively compact (unlike those die grinders), so I can mount it next to the quill and I do not need a lot of headroom for it. 2) It is a Bosch 3) It has a high horsepower (compared to alternatives) 4) It has variable speed 5) It has a very nice straight round neck for mounting 6) It is only $100-116. 7) It has a 1/4" collet.
i
Reply to
Ignoramus28889
Which brings up a question, how do you paint fill them? What paint etc
i
Reply to
Ignoramus28889
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Not if its plugged into the top of the spindle with an expanding arbor......
Reply to
Gunner Asch
Indeed. Pete is quite correct. A single flute cutter is most often used.
See Ebay ..search terms Gorton Cutter or Gorton Engraver followed by engraving cutter
Gunner, with a Gorton 3-Z pantograph
Reply to
Gunner Asch
When I was doing engraving (Gorton, Hermes, Green 106), I would use an Enamel Paint Stick (tradename: Engravocolor Sticks).
It fills in the engraved lines with a medium-soft enamel, that would harden.
_kevin
Reply to
karchiba
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Its likely Iggy can find cutters cheaper at some of his auctions or from some of his contacts from the auctions.
Gunner
Reply to
Gunner Asch
...
yep, me thinks Iggy be making a mistake to lose his hollow spindle just for an encoder. There are ways around it.
I see this thread hasn't mentioned spindle speeders. I use a unit that mounts just like any other tool and the ouput shaft turns 6X the input with a set of small collets. Scored mine on the bay for $200 and change.
Karl
Reply to
Karl Townsend
I thought I included at least one in the links I provided.
On the Gorton mill Im currently using...my top spindle speed is 5000 rpm So it will push one of those for up to 30k rpm
Gunner
Reply to
Gunner Asch
That stuff is harder to find in NMTB 30. Lots of it in 40-50 taper.
i
Reply to
Ignoramus28889
$5 CNC mills are hard to find too..but..as you proved..they are around
Gunner
Reply to
Gunner Asch

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