On 8/16/22 21:06, Leonardo Marsaglia wrote:
Hi guys. Sorry for the late reply and thanks to all for the answers.
I'll try to answer more or less to all in one reply to keep it organized.
The rotor is 125 mm long. Cuts are about 45 mm deep.
I forgot to mention that my universal mill is too small for the job so I'll
be doing this on the lathe (it's heavy enough and has brass bearings with
forced lube so it can handle it). So my idea is to cut the full length in
one pass. My feed is going to be ridiculously slow. I'll be pumping plenty
of coolant to keep it clean and cool. I finally got a HSS cutter that can
do the job (2.5 mm thick). So depending on the finish I'll decide whether I
go till the end with it or if I leave a few tenths of mm for fly cutting
finishing with carbide. The slots will hold graphite vanes because this is
for a dry vacuum pump.
I thought about wire EDM but I'm afraid that would cost more than what I
want to spend on this. By the way, an EDM machine is one good LCNC project
and I would love to build one. There was a guy on YouTube that used his CNC
converted mill to wire cut. He didn't submerge the part but rather flood it
as with coolant.
Thanks again guys for the help :)
That's something I've done several times. Needing slots cut in a socket
for a small ball screw, with a fine tapered thread on the outside and
matching
nuts, bored the socket until it was a slip fit for the screw, then slit
it, not with wire
but a brass disk on an arbor, sunk it in distilled water, wrapped a
ground wire
around the arbor and connected the resistor and discharge cap to the part,
ran the mill at 500 revs, and an x feed of about a thou a minute. The
brass disk
is around 30 thou thick, the nut was used as a jig by laying it on the
flat, and
cutting to the bottom of the socket 3 times, fresh water for each time,
making a
6 petal socket that could be tightened onto the screw by the tapered nut
and
threads. That was 5 or 6 years ago, its the drive shaft for the x screw
in my Sheldon
lathe. Actually 3 nuts as it runs in torrington needles with hard needle
thrust
washers on each end, all with 50 tpi threads so the end play could be
zeroed out.
Now driven by a 2nm 3 phase motor, backlash is under 1.4 thou, most of
it in the
ball nut. best idea I could come up with at the time. Worked well and
still is. I
cheated to cut the tapered threads using g76 by using an L spec distance
one
thread short of the full length of the tapered section. I got 3 of those
screws from
Stuart Stevenson and have never seen that small a ball screw, about 8mm
since.
No room in the Sheldons for anything bigger. Constraining the nut, which
has no
threads or mounting flange was a bigger problem.
El mar., 16 de agosto de 2022 04:13, andrew beck <[email protected]>
escribió:
I would weld a lathe parting or grooving tool to a round shank at about the
right dia cutter
And away you go.
Easy
On Tue, 16 Aug 2022, 3:23 pm Gregg Eshelman via Emc-users, <
[email protected]> wrote:
How thick is it axially? If it's pretty thin it should be sandwiched
between two pieces of softer metal. Go slow on the feed, high on the
speed
to make a lot of shallow passes with a slightly narrow cutter. Then use a
full width cutter for a single full depth pass to clean up the slot
sides.
I'd also make a bandsaw cut to near full depth in each slot to reduce the
amount of material for the cutter to remove and provide a path for lube
to
get in/out.
On Monday, August 15, 2022 at 08:38:06 AM MDT, Leonardo Marsaglia <
[email protected]> wrote:
Hi guys, I hope you are doing well
I need to make some slots on a rotor I'm building and I would like to
know
what do you think about fly cutting the slots with one tool only with
reduced feed off course.
The slots are 45 mm deep and 6 mm wide, the rotor is made of 4140 steel
(I
attached a basic picture of the rotor). I could purchase the hss disk
cutter off course, but if I can get away with welding and grinding my own
tool it would be great because those cutters aren't cheap and I'll be
only
using it for this job only.
The problem is, I'm afraid the carbide cutter will break soon making all
this process a waste of time.
What do you think?
_______________________________________________
Emc-users mailing list
[email protected]
https://lists.sourceforge.net/lists/listinfo/emc-users
_______________________________________________
Emc-users mailing list
[email protected]
https://lists.sourceforge.net/lists/listinfo/emc-users
_______________________________________________
Emc-users mailing list
[email protected]
https://lists.sourceforge.net/lists/listinfo/emc-users
Cheers, Gene Heskett.
--
"There are four boxes to be used in defense of liberty:
soap, ballot, jury, and ammo. Please use in that order."
-Ed Howdershelt (Author, 1940)
If we desire respect for the law, we must first make the law respectable.
- Louis D. Brandeis
Genes Web page <http://geneslinuxbox.net:6309/>
_______________________________________________
Emc-users mailing list
[email protected]
https://lists.sourceforge.net/lists/listinfo/emc-users
