Newbie here with perhaps a basic basic question. Need to grove a
circle in a custom aluminum mounting plate for a C-face motor with a
protruding locating ring cast into the motor face. Don't have a mill
to do coordinate locating so I've drilled an exact sized hole for the
motor shaft and hope to mark the motor ring onto my mounting plate
directly with some sort of transfer ink such as that of a rubber stamp
pad but I don't know of such a compound to use. I then plan on using
my small rotary table and heavy duty drill press to grove the mark on
the plate (a depth of about an eigth of an inch) with an endmill I
purchased that corresponds to the the motor face ring in size. Does
this approach make sense, or is there another way. Is there such a
transfer compound or prussian blue with some viscuosity to effect a
good transfer mark? I suppose I could use a compass but I need it to
be precisely right on. Any suggestions? Thanks.

Manny
trg-s338

"trg-s338" wrote in message
...
Newbie here with perhaps a basic basic question. Need to grove a
circle in a custom aluminum mounting plate for a C-face motor with a
protruding locating ring cast into the motor face. Don't have a mill
to do coordinate locating so I've drilled an exact sized hole for the
motor shaft and hope to mark the motor ring onto my mounting plate
directly with some sort of transfer ink such as that of a rubber stamp
pad but I don't know of such a compound to use. I then plan on using
my small rotary table and heavy duty drill press to grove the mark on
the plate (a depth of about an eigth of an inch) with an endmill I
purchased that corresponds to the the motor face ring in size. Does
this approach make sense, or is there another way. Is there such a
transfer compound or prussian blue with some viscuosity to effect a
good transfer mark? I suppose I could use a compass but I need it to
be precisely right on. Any suggestions? Thanks.

Manny
trg-s338

Just an idea...

Mark the aluminum plate generously with indelible marker. Then place on the
motor shaft & spin the plate around - the locating ring will roughly mark
the location of the required recess.

Maybe a flycutter from the local harware shop would be better at cutting the
recess, they are not expensive and will have other future uses. The
spigot/drill for the flycutter would be centralized in the shaft hole.

*Need to grove a circle in a custom aluminum mounting plate for a
C-face motor with a protruding locating ring cast into the motor face. *
Don't have a mill [...] *I then plan on using
my small rotary table and heavy duty drill press to grove the mark on
the plate (a depth of about an eigth of an inch) with an endmill I
purchased that corresponds to the the motor face ring in size.

With a drill press, I'd be doing everything I could to keep the quill
as short as possible to minimize flex, give yourself barely enough
room to get the work under the cutter. Rough everything out with a
series of plunge cuts before trying to clean up the slot, and be
prepared for the forces to pull the cutter out of the chuck or the
chuck off the arbor. If as your description implies this unit is
large enough to have a morse taper spindle, try a morse taper collet
instead of a chuck. In addition to being more secure, it'll also be
shorter, and therefore stiffer. Milling also puts a lot of force into
your table, don't be suprised if it tries to move on you, possibly
throwing off your size.

Since you're cutting aluminum, another way might be to use a router
with a carbide bit and a circle jig. Take several light passes to get
to the final depth. Not done it myself, so I can't give you more
detail than that... I think it's been discussed here before if you
care to search the archives.

As an aside, if it makes life easier, you don't have to match both the
inside and the outside diameters of the protruding motor ring, only
the outside. Most gearboxes that these motors bolt to have an
extended mount that's completely open inside the locating ring.

--Glenn Lyford

"trg-s338" wrote: (clip) Is there such a
transfer compound or prussian blue with some viscuosity to effect a
good transfer mark? (clip)
^^^^^^^^^^^^^^^^^^
I would use Prussian blue on the flat surface, and let it dry. (Or even
Magic Marker.) Glue a little crocus cloth to the ring on the motor face,
and knock off the excess with a ball peen hammer, as though you were making
a gasket. It doesn't have to go all the way around, because you're going to
rotate the plate all the way around, removing the dye.

On Sep 15, 3:00*am, trg-s338 wrote:
Newbie here with perhaps a basic basic question. *Need to grove a
circle in a custom aluminum mounting plate for a C-face motor with a
protruding locating ring

But, you don't have a mill? Why not saw a ring from thick
sheet stock, file to fit the interior (or exterior) of the
motor face, then fasten to the plate with drill/tap/countersink
and flathead screws?

On 2008-09-15, trg-s338 wrote:
Newbie here with perhaps a basic basic question. Need to grove a
circle in a custom aluminum mounting plate for a C-face motor with a
protruding locating ring cast into the motor face. Don't have a mill
to do coordinate locating so I've drilled an exact sized hole for the
motor shaft and hope to mark the motor ring onto my mounting plate
directly with some sort of transfer ink such as that of a rubber stamp
pad but I don't know of such a compound to use.

To mark, take a wide point blue Magic Marker (or similar) and
color the whole zone near where you expect the groove to be and past.

Then put the motor in until the ring is in contact, and rotate
the motor a turn or two to rub off the marking where the groove should
be.

I then plan on using
my small rotary table and heavy duty drill press to grove the mark on
the plate (a depth of about an eigth of an inch) with an endmill I
purchased that corresponds to the the motor face ring in size. Does
this approach make sense,

No! Attempting to mill with a drill press is dangerous. The
chuck is normally mounted via a taper -- which is great for axial forces
like those encountered in drilling, but very bad with lateral forces
such as encountered in milling. What is likely to happen is that the
chuck will disconnect from the taper while still spinning at high speed
(the size of the mill is pretty small I think, from what else you have
said, which would call for high speeds). That spinning chuck with the
sharp milling cutter will then bounce all over the shop, perhaps chasing
you around the shop -- except that it will move faster than you can.

You say that you don't have a mill. Do you have a lathe? One
large enough to mount the motor mount plate onto a faceplate (or to hold
it in a 4-jaw chuck) and *turn* the groove -- with a bit ground for
trepaning.

or is there another way. Is there such a
transfer compound or prussian blue with some viscuosity to effect a
good transfer mark? I suppose I could use a compass but I need it to
be precisely right on.

You also need a better tool than a milling cutter in a drill
press to do this.

Any suggestions? Thanks.

Find someone with a milling machine or a lathe to help you.

Good Luck,
DoN.

--
Email: | Voice (all times): (703) 938-4564
(too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html
--- Black Holes are where God is dividing by zero ---

On Sep 15, 7:03*am, " wrote:



Since you're cutting aluminum, another way might be to use a router
with a carbide bit and a circle jig. Take several light passes to get
to the final depth. *Not done it myself, so I can't give you more
detail than that... *I think it's been discussed here before if you
care to search the archives.



* --Glenn Lyford

I second the router if you have one or can borrow one. You should be
able to use the end mill that you have if the shank is the right
size. You can use your rotary table . Just need some way to hold the
router in relation to the rotary table.

The router speed will be much higher that recommended, but you are
cutting aluminum. So should be okay if you feed slow.

Dan

On Sep 15, 3:30 pm, "DoN. Nichols" wrote:
On 2008-09-15, trg-s338 wrote:

Newbie here with perhaps a basic basic question. Need to grove a
circle in a custom aluminum mounting plate for a C-face motor with a
protruding locating ring cast into the motor face. Don't have a mill
to do coordinate locating so I've drilled an exact sized hole for the
motor shaft and hope to mark the motor ring onto my mounting plate
directly with some sort of transfer ink such as that of a rubber stamp
pad but I don't know of such a compound to use.

To mark, take a wide point blue Magic Marker (or similar) and
color the whole zone near where you expect the groove to be and past.

Then put the motor in until the ring is in contact, and rotate
the motor a turn or two to rub off the marking where the groove should
be.

I then plan on using
my small rotary table and heavy duty drill press to grove the mark on
the plate (a depth of about an eigth of an inch) with an endmill I
purchased that corresponds to the the motor face ring in size. Does
this approach make sense,

No! Attempting to mill with a drill press is dangerous. The
chuck is normally mounted via a taper -- which is great for axial forces
like those encountered in drilling, but very bad with lateral forces
such as encountered in milling. What is likely to happen is that the
chuck will disconnect from the taper while still spinning at high speed
(the size of the mill is pretty small I think, from what else you have
said, which would call for high speeds). That spinning chuck with the
sharp milling cutter will then bounce all over the shop, perhaps chasing
you around the shop -- except that it will move faster than you can.

You say that you don't have a mill. Do you have a lathe? One
large enough to mount the motor mount plate onto a faceplate (or to hold
it in a 4-jaw chuck) and *turn* the groove -- with a bit ground for
trepaning.

or is there another way. Is there such a
transfer compound or prussian blue with some viscuosity to effect a
good transfer mark? I suppose I could use a compass but I need it to
be precisely right on.

You also need a better tool than a milling cutter in a drill
press to do this.

Any suggestions? Thanks.

Find someone with a milling machine or a lathe to help you.

Good Luck,
DoN.

--
Email: | Voice (all times): (703) 938-4564
(too) near Washington D.C. |http://www.d-and-d.com/dnichols/DoN.html
--- Black Holes are where God is dividing by zero ---

Thanks for reiterating the risk in using the drill press as a mill. I
agree that doing this can be clearly dangerous. I just thought that
since the grove I'm trying to cut is only about a sixteenth of an inch
wide and perhaps less than an eighth deep, the stresses involve might
be acceptable. Your ideas about spinning the C-face onto the "blued"
plate to make the mark is self-evident although I don't know why I
didn't think of it. Dohh!

I suppose I could also just chuck a lathe tool bit of the appropriate
ground to width and lock the drill spindle and just carefully rotate
the rotary table while feeding lightly and incrementally until I
achieve the proper depth. I do have a lathe but it is non-operational
right now until I get it located and hooked up to my RPC in the garage
to power it up. In the meanwhile, I am looking for the easiest,
cheapest, and safe way to do this one time job with minimal fuss.
Thanks for all your input, you might have saved me from an endmill in
the eye scenario.

Manny
trg-s338