Leeson 1.5HP DC Motor Pulsing
Rick Unland
with the 1.5HP DC motor. Tonight I was turning a 10" piece of Imbuia and the
lathe started motor began pulsing at lower speeds. I have the belt on my
Nova 3000 set to the highest setting and was in the 25 to 50% range. The
motor pulses and the drive system pulses with it. I tried slowing the motor
down by exerting a load on the bowl with my gloved hand and could not stop
it. So the HP is definitely there. I just dont understand why it pulses all
of a sudden like this, is it normal for a DC motor of this size to pulse? Is
it an artifact of the voltage regulator?
Any help would be greatly appreciated, this is a new setup and was purchased
less then two months ago. Having never had a DC motor of this type I am
unsure as to what normal should be for this situation, if this is all normal
than fine if not, I would like to get it fixed right away. I plan on turning
some very large pieces in the next few weeks and I want to be sure of the
safety.
Thank you in advance
Rick
P.S> My lathe and the motor is pictured on my web site at
http://rocket.web2.com/woodworking.htm
Chuck Woodruff
slightly and the hunting will go away. The control uses a voltage signal from
the motor as a speed reference and IR adjusts the sensitivity to that signal.
You want it just on the verge of being unstable. I market controls and that is
not an unusual problem since the goal is to get close to being unstable.
Chuck Woodruff, Seattle
Martin H. Eastburn
motor is going slooooow for the slow speed ? Perhaps you have it to slow.
I think the HP of the motor without load might be the surging issue, but once under load
(more than your hand can do) it would settle down.
I seem to recall the motor has a sensing unit within it that feeds back to the controller.
It is acting as a servo system out of tune - wants more speed, has to much in the return
so it idles up/down in a cyclic mode.
I don't know the low constant speed or the top speed of the motor - I have the sales catalog -
(don't know model..) - but perhaps your belting is out of step - e.g. low end very slow, or
high end very fast. Perhaps just a belt adjustment is needed.
Martin
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NRA LOH, NRA Life
NRA Second Amendment Task Force Charter Founder
Martin Eastburn, Barbara Eastburn
@ home on our computer old...@pacbell.net
Jon Schilling
I saw your post...I kept reading the next threads...
I have some experience with your situation...I was going to suggest what
Chuck Woodruff has recommended..
Chuck is the one who helped me fine tune my dc motor when I had to buy a new
board for my controller, and
set it up for my turning conditions...You should be able to get it smoothing
out....Note: I attended the
Symposium in Provo in 1997... The demonstraters used several Woodfast lathes
...I noted, especially with
the one that Ray Key and Ray Allen used, much pulsing...I don't recall the
lathes being variable speed,
but if they were this was correctable as I found out..
good luck,
Jon Schilling
Chuck Woodruff wrote in message <764nng$cbo$1...@news-2.news.gte.net>...
>What you need to adjust is a small round pot labled IR. Turn it down,ccw,
>slightly and the hunting will go away. The control uses a voltage signal
from
>the motor as a speed reference and IR adjusts the sensitivity to that
signal.
>You want it just on the verge of being unstable. I market controls and that
is
>not an unusual problem since the goal is to get close to being unstable.
>
>Chuck Woodruff, Seattle
>
>Rick Unland wrote:
>
>> I just thought I would ask if any of you out there have experienced this
>> with the 1.5HP DC motor. Tonight I was turning a 10" piece of Imbuia and
the
Rick Unland
Thank you very much. I am on my way to go do that now. I really
appreciate the fast reply, it will make it a much nicer day now that I know
what is going on. I hate being ignorant:-) Anyway, thanks again. Ill let you
know how it turns out.
Thank you
Rick
Chuck Woodruff wrote in message <764nng$cbo$1...@news-2.news.gte.net>...
>What you need to adjust is a small round pot labled IR. Turn it down,ccw,
>slightly and the hunting will go away. The control uses a voltage signal
from
>the motor as a speed reference and IR adjusts the sensitivity to that
signal.
>You want it just on the verge of being unstable. I market controls and that
is
>not an unusual problem since the goal is to get close to being unstable.
>
>Chuck Woodruff, Seattle
>
>Rick Unland wrote:
>
>> I just thought I would ask if any of you out there have experienced this
>> with the 1.5HP DC motor. Tonight I was turning a 10" piece of Imbuia and
the
Rick Unland
Jon Schilling wrote in message <36865...@news.worldaccessnet.com>...
>Rick,
Snip of good advice
>Note: I attended the
>Symposium in Provo in 1997... The demonstraters used several Woodfast
lathes
>...I noted, especially with
>the one that Ray Key and Ray Allen used, much pulsing...I don't recall the
>lathes being variable speed,
>but if they were this was correctable as I found out..
>good luck,
>Jon Schilling
Jon,
It sounds like these symposiums are the way to go, I cant wait for one
to go too. I appreciate your response, I am going down to the garage to turn
now so will take advantage of Chuck's advice pronto. I have a lot of large
turnings to do over the next few weeks and I feel much better knowing what
the problem was.
Thanks
Rick
Rick Unland
I was planning on calling Leeson first thing Monday, wasn't expecting
too much though. The last time I called and asked for tech support the woman
who answered the phone stated that she was tech support and the info she
gave was totally wrong.
The belting is presently set for 3600 RPM and the motor was set to 25 to
50%, this would give an effective rpm of 862 to 1725. The motor doesn't
pulse nearly as badly above 50% but always below. I plan on playing with the
sensing unit today to see if I can adjust it to make the surging disappear.
I really appreciate the response, I have a lot of turning to do and was
worried that the system was going bad on me. I don't have any experience
with this type motor so am in the dark when strange or unexpected things
occur.
Again thank you
Rick
Martin H. Eastburn wrote in message <3685E78A...@pacbell.net>...