Jeff Liebermann <jeffl@cruzio.com> wrote in
news:cmiq0ft8djj575i3cg0d23449oisec8sf9@4ax.com:
>> Problem solved. The other manner would be to get and use a
>>variable speed drill to start with.
>
> Ummm... we're discussing a drill press, not a hand drill.
>
First "drill press we had was a huge 5/8" chuck 1/2 horse drill
clamp mounted on a press arm made for that purpose.
I am pretty sure it was single speed.
But my new Ridgid battery operated hand drill is VERY powerful, and
would make a great drill to mount on such a 'press'.
It is the most impressive little drill I have seen in a long time,
and the first one I ever bought. Ridgid makes very good quality
products.
Reply by Jeff Liebermann●January 1, 20202020-01-01
On Tue, 31 Dec 2019 08:14:52 +0000 (UTC),
DecadentLinuxUserNumeroUno@decadence.org wrote:
>Jeff Liebermann <jeffl@cruzio.com> wrote in
>news:632i0fd6kcsmaf8alnr0ln2diku3n3j2hj@4ax.com:
>
>> Ummm... I hate to mention the obvious, but the original question
>was
>> about lowering the speed of a drill press, not a reciprocating or
>> rotating saw blade. Please adjust your comments accordingly.
> Umm... OK. In my experience, if it has the moniker "drill press",
>it already has speed alteration capability built into it. Usually in
>the form of a series of pulleys and a belt yielding known rpm rates.
>
> If it is a simple drill motor mounted onto a press arm, it is not
>really a drill press.
Sorta. Converting pully or gear drive drill press to 3-phase motor
and VFD is essentially converting it to a direct drive drill press.
<https://www.google.com/search?q=drill+press+direct+drive&tbm=isch>
Your explanation also doesn't explain why there are a small but
growing number of drill presses retrofitted with a VFD appearing on
the web. There must be some benefits to performing the conversion
from pulley to electronic speed control.
<https://www.google.com/search?tbm=isch&q=%22drill+press%22+%22vfd%22+conversion>
So far, the justifications I can conjure are:
1. Low RPM (100 rpm) for drilling large holes in acrylic, etc.
2. Use with fly cutters at low RPM.
3. Use with a direct drive drill press (most of which already have
some kind of speed control):
4. Use on a gear head drill press where the VFD plus 3-phase motor
are cheaper than new gears, shifters, and 1 phase induction motor.
5. Instant stop braking (using load resistor in VFD).
6. Much noise and less vibration.
7. Availability of cheap 3 phase motors and VFD's.
8. Use for solenoid coil winding, where VERY slow RPM is needed.
> And after all this stupid crap of spending money on controllers and
>futzing around with it, one could simply go to harbor freight and buy
>a cheap chinese job for some ridiculously low price like $50 bucks or
>so, and VOILA! suddenly all your speed woeds are solved and you now
>have an item you actually can properly refer to as a drill press.
Have you seen what Harbor Fright is delivering as a low priced drill
press? The last time I visited to the local store, the table was no
longer cast iron, but rather stamped sheet metal. It also wasn't even
close to flat, and would bend if you clamped anything to it. Somehow,
every time I buy something at Harbor Fright, there is always something
that's not quite correct or economized to below marginal.
>It isn't like the person in the thread is performing precision
>drilling operations. So a cheap chinese knock off of real machine
>tool should be fine.
True. Precision drilling is done with a vertical mill or CNC
machining center. However, a VFD doesn't do anything to improve the
precision of a drill press.
> Problem solved. The other manner would be to get and use a
>variable speed drill to start with.
Jeff Liebermann <jeffl@cruzio.com> wrote in
news:632i0fd6kcsmaf8alnr0ln2diku3n3j2hj@4ax.com:
> Ummm... I hate to mention the obvious, but the original question
was
> about lowering the speed of a drill press, not a reciprocating or
> rotating saw blade. Please adjust your comments accordingly.
>
Umm... OK. In my experience, if it has the moniker "drill press",
it already has speed alteration capability built into it. Usually in
the form of a series of pulleys and a belt yielding known rpm rates.
If it is a simple drill motor mounted onto a press arm, it is not
really a drill press.
And after all this stupid crap of spending money on controllers and
futzing around with it, one could simply go to harbor freight and buy
a cheap chinese job for some ridiculously low price like $50 bucks or
so, and VOILA! suddenly all your speed woeds are solved and you now
have an item you actually can properly refer to as a drill press.
It isn't like the person in the thread is performing precision
drilling operations. So a cheap chinese knock off of real machine
tool should be fine.
Problem solved. The other manner would be to get and use a
variable speed drill to start with.
Reply by ●December 30, 20192019-12-30
On Saturday, 28 December 2019 08:11:34 UTC, jurb...@gmail.com wrote:
> Been in contracting and I tell you two things, take it or leave it.
>
> DO NOT lower the speed of any saw. It is stupid for many reasons.
I have a compound mitre saw with 2 speeds. Lower speed works better for some things.
> They tell you to lower the blade for thinner wood on the table saw, BULLShIT, leave it sticking up as far as it goes unless you are using like a dado blade to cut grooves or something like that.
it really depends what you want to achieve most, the cut is different. There is also a safety difference, neither option being ideal.
NT
Reply by John Doe●December 30, 20192019-12-30
jurb6006@gmail.com wrote:
> DO NOT lower the speed of any saw. It is stupid for many reasons.
> The only real exception is a jigsaw, and only once in a while.
That is contradictory.
It is not rocket science. There are some situations in which slower than
100% saw speed is obviously better. If not, then it's not used.
But seriously...
"Like a sawzall"
I don't use one.
I use the speed controller a lot on my homemade belt sander, too.
Slowing the speed when needed allows better control of material removed.
I installed the speed controller in the center of a 1 foot extension
cord. Works great. Whether a speed controller works well or not is easy
to tell. If it doesn't work well for a particular tool, the tool is
plugged directly into the wall.
But seriously...
Reply by Jeff Liebermann●December 29, 20192019-12-29
On Sat, 28 Dec 2019 00:11:29 -0800 (PST), jurb6006@gmail.com wrote:
>Been in contracting and I tell you two things, take it or leave it.
>DO NOT lower the speed of any saw. It is stupid for many reasons.
>They tell you to lower the blade for thinner wood on the table saw, BULLShIT, leave it sticking up as far as it goes unless you are using like a dado blade to cut grooves or something like that.
>I know and I am done explaining things to everyone. I know from experience.
>Like a sawzall, keep it floored or risk the blade. Try to plunge cut at low seed. Get a whole box of blades until you learn how to do it right.
>A router, floor it at all times.
>The only real exception is a jigsaw, and only once in a while.
>Don't take my advice, you might get too successful.
Ummm... I hate to mention the obvious, but the original question was
about lowering the speed of a drill press, not a reciprocating or
rotating saw blade. Please adjust your comments accordingly.
Plunge cutting with a Sawzall is easier with a specialized blade:
<http://spyderproducts.com/tools/3x3-blades/>
Lowering the blade on a table saw is generally a bad idea because it
tends to raise thin panels off the table. In extreme cases, it can
cause the panel to "chatter" up and down.
Running a router at full speed or really slow are both problems. This
explains the problems:
<https://www.woodmagazine.com/woodworking-tips/techniques/routing/speed>
--
Jeff Liebermann jeffl@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558
Reply by ●December 28, 20192019-12-28
jurb6006@gmail.com wrote in news:60abddc6-2766-4575-b335-9d0b08a18da3
@googlegroups.com:
>
> DO NOT lower the speed of any saw. It is stupid for many reasons.
>
I agree, however, all sawblades are made to no specific standard,
and as such all differ as far as ideal cutting rpm.
In any case faster seems would be better as slower can lead to
burning on the work and reduced blade / blade tip life.
Unlike meatl machining, cuting wood is usually faster is better as
there is not usually a point at which a 'crash' occurs as in metal
machining where to fast a feed or speed can cause a catastrophic
failure and crash, and can even launch potentially deadly 'grenades'
once that happens.
Reply by ●December 28, 20192019-12-28
Been in contracting and I tell you two things, take it or leave it.
DO NOT lower the speed of any saw. It is stupid for many reasons.
They tell you to lower the blade for thinner wood on the table saw, BULLShIT, leave it sticking up as far as it goes unless you are using like a dado blade to cut grooves or something like that.
I know and I am done explaining things to everyone. I know from experience.
Like a sawzall, keep it floored or risk the blade. Try to plunge cut at low seed. Get a whole box of blades until you learn how to do it right.
A router, floor it at all times.
The only real exception is a jigsaw, and only once in a while.
Don't take my advice, you might get too successful.
Reply by Jeff Liebermann●December 28, 20192019-12-28
On Fri, 27 Dec 2019 23:53:05 -0000 (UTC), John Doe
<always.look@message.header> wrote:
>I have read something about inductive motors (assuming the drill press
>uses one) not working with speed controllers? It's a relatively large
>motor with only one speed.
My guess(tm) is that your unspecified model drill press uses a single
phase induction motor or if it's a really big drill press, a 3 phase
induction motor.
This video answers some of your questions:
Will A Dimmer Switch or Transformer Control An Induction Motor's
Speed?
<https://www.youtube.com/watch?v=tXJOtWPPRwE> (9:55)
Note that the light dimmer control in the video is essentially a PWM
controller.
However, the author of the video is wrong about one item. There is
such a thing as a VFD (variable frequency drive) with a single phase
input and output. For example:
<https://www.wolfautomation.com/blog/vfds-for-single-phase-motors/>
The article explains some of the limitations of this derangement.
Instead, what you should use is a single phase to 3 phase VFD, driving
a 3 phase induction motor. 3 phase motors are very common, fairly
cheap, quite efficient, quiet, and do not use starting and running
capacitor phase shifters, which are in my never humble opinion, an
abomination. Also, notice that the author of the above URL lists
"drill press" as a 3 phase application.
You'll probably find examples of such variable speed drill press
application on:
<https://www.practicalmachinist.com>
(I'm too lazy to search).
YouTube video on drill presses and VFD speed controls:
VFD Drive Drill Press Lathe & Mill (Variable Speed) DIY.
<https://www.youtube.com/watch?v=nFPX1pW3Sl8> (9:32)
Installing a VFD on a Drill Press.
<https://www.youtube.com/watch?v=23lwqq9uGg4> (23:00)
<https://www.youtube.com/watch?v=Y8yT8-JYIQE> (14:36)
You'll probably need to buy a digital tachometer to measure the
spindle RPM. Something like this:
<https://www.ebay.com/itm/332908532113>
Or, if you setup the drill press for a single pully ratio, a simple
conversion chart from drive frequency to spindle RPM.
Incidentally, I've done one such VFD conversion on a Craftsman 10"
drill press, and one on a Shizuoka vertical mill. Both went fairly
smoothly after we decoded the creative English translation of the
Chinese instruction manual. The above videos should demonstrate that
it's fairly simple to install, but hardly plug-and-play.
--
Jeff Liebermann jeffl@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558
Reply by Michael Terrell●December 27, 20192019-12-27
On Friday, December 27, 2019 at 6:53:09 PM UTC-5, John Doe wrote:
> I'm not asking for insurance. I have better than usual free veterans'
> healthcare. And I take responsibility for my actions.
>
> AC 10-220V 4000W PWM AC Motor Speed Controller
>
> I have a motor speed controller that works for controlling some of my
> saws. I'm wondering if there are any major obvious problem with trying
> it on my drill press. Will it burn up my controller? I like that
> controller. It might be a little sloppy, but it comes in handy.
>
> I have read something about inductive motors (assuming the drill press
> uses one) not working with speed controllers? It's a relatively large
> motor with only one speed.
>
> Thanks.
If it a simple induction motor, I wouldn't try it. I would find a similar 3phase motor and a VFD to control it. Anything will leave almost no torque, and burn up the motor.