On Sep 30, 6:47*pm, David Lesher wrote:
"DoN. Nichols" writes:
Don, I was specifically trying to keep it simple and on-topic. The OP's
concern is getting a VFD {or other solution} for his case. I just didn't
want him buying some weird eBay VFD that WAS single phase...because
he assumed "VFD == 3 phase"
* *Have you *ever* seen a VFD -- on eBay or elsewhere -- which was
single phase output? *I haven't, and I think that it because there is
not much benefit from variable frequency with single phase motors.
Nope; but if it existed, someone likely got suckered on eBay....
Again....TMI
* *Perhaps -- but I find people here like to know the "why" of an
answer, not just the "you can (or can't) do it" type *of response.
No dispute, but to me it looked we were swamping the OP with data...
* *O.K. *So to him, the benefit is not having a noisy rotary
converter generating heat between operations. *He can leave the VFD on
full time if he wants, and get very little waste power.
Don't know; but he can speak for himself if he wishes...
And how many ram types would do that?
* *You mean rcm? *Quite a few have -- and I first learned about it
from the studies that Fitch (used to be a regular here) posted in a
series of articles as he studied the construction of a rotary converter
for his shop.
OK, I'll take your judgement on same...
* *And *I* can't get commercial three phase (even though it runs
past about a quarter block from here (you've seen my place -- just up at
the top of the hill there is medium HV three phase passing by)) -- in
part because of town regulations -- which prohibit any hobby machine
tool with a 3HP or larger motor. *
Sure you can. It may involve paying off someone ["Motor? Naw, he has a
3 phase electric furnace to heat his basement. Nothing larger than a
clock motor at his house...."] at City Hall or....
Even if I could, the charge from the power company is well beyond what I
can afford -- and they charge industrial rates for three phase -- which
means that they base the charge on the peak current draw during the
month, and you pay as though you have drawn that much full time through
the month.
The other person found that was the case there, too. The 3-phase order
form came with an enema kit disguised as the rate schedule...
Of course, as a big single-phase user; I bet he now makes all his
neighbors lights blink, so the utility will spend $$$ to upgrade that....
--
A host is a host from coast to
& no one will talk to a host that's close........[v].(301) 56-LINUX
Unless the host (that isn't close).........................pob 1433
is busy, hung or dead....................................20915-1433
Gentlemen,
Swamp away. I may not understand it. But I want it. All of it. I am
a very studious fellow. Sort of like a python swallowing a large
meal. It may take a while but I'll get there...
Here's the critter I bought:
http://www.driveswarehouse.com/Drive...0-022NFU2.html
I think I've figured out that both types of converter are in my
future. The VFD shipped today. It should get the bench mill running.
Today I began taking inventory of some of the other 3 phase stuff I've
bought over the years. What happened was this. There was a time I
thought that getting 3 phase service to me was imminent. Then the
electric company threw me a curve ball. That's why I happen to have
this stuff.
Among the items gathering dust is a Delta Unisaw (table saw). It has
a 7.5 HP motor. The freebie plenum box has a 7.5 HP motor.
Although I'm told it's good to have an idler motor that's a little
bigger than the load I hope to be able to roll my own rotary phase
converter from the motor in the plenum box. I will make the most
rudimentary thing possible. Once I've determined that both motors run
I will attempt to finesse the thing into something more
sophisticated. It should help to have the mill up and running so that
I can make stuff for the project. Of course I make that statement
pretending I have a clue about lathes and mills. But I don't.
Nevertheless, I do have a modest library of books on the subject.
I've been mining ebay for years for old books that pre-date the
computer age. At least several of these are encyclopedic manuals on
machining.
Here's a more basic question for your collective wisdom. Where to
mount the mill? I have a very heavy duty table that came as a base
for a Diacro single station hole punch. The foot print of the table
is just a tad wider than the mill base. But the base is just a tad
longer (1") than the table.
Notwithstanding that the table is strong enough I'm worried about the
high center of gravity. If I bolt the table to the floor and the mill
to the table does that sound like a suitable arrangement?
Or should the mill be on a big heavy, long table?
Then there's tooling. I hope to buy some kind of lot assortment on
ebay. I looked tonight. A couple of guys are selling it saying
they're retiring. Of course I still don't know an end mill from a
collet.
Tomorrow morning we're off to Wichita Falls to fetch the lathe.
Thanks to all.
Vernon