[victorofga]

no it is not..
what I tried to say he might need to change the control.. motor might be still good..

I know a milling spindle require different than a simple spindle in a router..
for a router I don't have to know the spindle postion, what important for tapping..

[ihavenofish]

there is no other control. its a pair.

[hanermo]

As was said..
This is a simple issue, in reality.
Rigid tapping requires servos.

Best, overall ,choice is ac brushless servos of suitable capacity.
I use 2.5 kW cont on my lathe, with 30.000 counts/turn.

On a small, low power hobbylathe, nothing else will ever work well.
No it wont.
You dont need a big servo lke mine you just need a servo.
Lots of advice may appear re:contrary, ask for 3A/3B threads done in steel as examples.


On big industrial stuff, 25 kW+ , many things change. Not your case, afaik.

[victorofga]

probably I didn't expressed it right...

the attached picture shows a bldc motor..

what I meaning, since its fluctuating, very possible the control has some fault.. and it is not simple task to tracking back
mightbe faster to changing out the whole control, and sending out somewhere to fix it

meanwhile a new replacement makes working the machine..

reason I pulled example my situation, because my vfd cost about 150 or so.. this control for this bldc also cost approximately 150...

to tracking down a week long an error, mightbe not affordable..

that is what I tried to pointing out..
yet im clear a vfd and the bldc control ""different""

but.. on the end both control checking the load, and adjust the power ... if somehow it misinterpret the values then sending too much, then immediately readjust... with other words an error loop occurring..
I just cant explain better

in my meanin a great thing if someone has the knowledge for this, but practically it wont be affordable..

[ihavenofish]

ok, one more time again.

the motor is not producing the correct amount of torque across its range.

the drive IS most likely at fault. we know this. that is what he is trying to diagnose and fix if possible - or at least make better. hes starting by ruling out the obvious - first some bad wiring, now some fluctuating / noisy analogue signals. maybe this will cure the drive enough to cut well - most likely it wont and he moves to the next link in the chain. skyfire gave some programming options to try (im not sure if hes done those yet, or if they apply to his drive at all).

there is currently NO alternative drive that is affordable that will run this motor properly, otherwise wed all have one and this thread wouldnt exist. the one in that picture is (if its the one keling had listed) is also known to be bad. there is a long history with these drives and motors and never been a resolution.

this has nothing to do with rigid tapping. this machine cant tap at all it has no encoder. this is about getting the existing motor to produce the correct amount of torque - or at lease usable torque.

[victorofga]

thank you to clearing..

I like to learn,,, but on other hand always first questioning what worth..

little surprising me that this control and motor so proprietary.. I got used from china we can replace almost everything simple way..

I know exactly what means a bad machine..
youre circling in the shop and don't know what would you do next...

the kelingstuff I just pulled up as sample.. not known it can not be substituted..


we will see wheres he ending up..

[victorofga]

a picture anyway would help to find, if it were a really unique design or coming from a factory like shenzen hishine..

theres another topic on the forum..

http://www.cnczone.com/forums/news-a...ontroller.html

[daniellyall]

ihavenofish don't respond to victorofga he has no ears

[victorofga]

okay

im apologize to be so hardheaded..

it just looking impossible that there wouldn't be solution..

I think this machine a greatly designed something, but same way cant visualize that beside mechanical design, he would design from scratch the whole electronics..

[G59]

the motor is not producing the correct amount of torque across its range.

What is the correct amount?

At what RPM?

And finally you are comparing it to what other motor drive combination?

For me, best way to put an end to it all, crack open your wallet and go buy a good brushless dc drive.

Chinese engineers have for the longest time been grossly over exagerating the max power of their electric motors. Maybe this is also the case?

And on the question of maybe this could be mach3 related, I doubt it. I had an old mill that I could run at 60 rpm all day in direct drive and it was stable and tons of power. I'm willing to bet it's all drive problems.

[victorofga]

you might be hit the nail..
and the whole system is run on the edge..

this all topic just surreal.. hard to imagine one design a machine and the first machine looking like other companies making years development..

sure there were some knowledgeable guys..

[ihavenofish]

What is the correct amount?

At what RPM?

And finally you are comparing it to what other motor drive combination?

For me, best way to put an end to it all, crack open your wallet and go buy a good brushless dc drive.

Chinese engineers have for the longest time been grossly over exagerating the max power of their electric motors. Maybe this is also the case?

And on the question of maybe this could be mach3 related, I doubt it. I had an old mill that I could run at 60 rpm all day in direct drive and it was stable and tons of power. I'm willing to bet it's all drive problems.

/me slams head on desk

search sangmutan on this forum.

i cant explain this any more clearly than i already have.

[johnno402002]

Hi,
victorofa, what you say about this not being cost effective is correct, many hours. But I'm not doing this for the money, it's a hobby, and myself and my Son are learning a lot.

I did consider replacing the motor and drive with a Hishine set, but they were quite vague on what tuning parameters were available. And until I buy and install them, I wont know if it's any better, so I decided to have a go at isolating the problem. One thing hishine did say was that the motors they are selling now have much better permanent magnets in them compared to even two years ago. The other thing that I had not really understood was that they have two motors in the 2.2 kw size, a 3600 rpm motor and a 6000 rpm motor. The 3600 one has twice the torque of the 6000 rpm one, so I guess I'm trying to have my cake and eat it to, high torque and high rpm.

I pulled the skyfire drive out and pulled the case off it to look at the boards, and it's all Skyfire boards in there. There looks to be a bit of corrosion on the metal brackets and on some of the soldered joints, but nothing serious enough to cause a problem. The boards just looked a little old to me, not sure when they would have been made. If you were buying one now you would get a newer board. I'll have to go back in there and have a look at the main control chip, to see if I can get some instructions on its setup options.

I expected to be able to isolate the problem one way or another by braking the circuit in half, but it just showed I had problems both ways. I found a noise source on the computer, it's one of my sons old gaming machines and I hadn't noticed a little black wifi dongle sitting in the usb port beside the usb for the mill. I thought I'd found the problem, but it only made a small difference.

I've been all over the Jamen motion board manual, it does not seem to have any adjustments or config built in.

One thing that is better though, the unexplained changes in rpm seem to have gone since we fixed the loose feedback connection

[victorofga]

well, what I said I don't have electronic challenge..
I just seeing it from a practical view..

the RPM
im from Europe..
3 phase motors, with 60Hz 1440 or 2880
if different that's I think only the electronics and frequency enhancing.., or is it possible with winding?

while oi know it is not vfd, but higher rpm makes less power output.. so im really watching what you finding..

for the usb, I have a simple plotter, can be connected trough on usb and parallel... usb don't seems to work... with paralell works like a dream..
someone told me possible windows has some timing issue, that's why loosing data, and plotter forget to cut parts.. or cut criss-cross..

that's why in my meaning tracking back an error likely you doing here, same than learning this all, and almost same work like design a new one..

but really glad to withness one capable to handle it..

thank you for your update...

[victorofga]

the rust on the board also could be a problem..
I had to fix a couple of smd led modul... while soldering was looking ok, it had a kind of ""snow"" on the board on random places..

again it was looking ok even under the microscope.. some lightchip started to work after hot air, some chip I had to completely resoldering..
a 1/8 by 1/8 sized chip with 6 leg you could imagine how little soldering paste need..
so the least rust makes bad connection..

[johnno402002]

I've done a bit more work trying to find where the noise on the spindle voltage signal is coming from.

First, I've disconnected the power connection to the spindle drive, the noise was still there, so it's not coming from the spindle drive.

Next, I added ferrite beads on both ends of the usb cable. No change there either.

I then removed the skyfire breakout board completely, and then powered jamen motion board from my lab power supply. The noise was gone from the spindle output signal on the motion board.

So I then had a look at the output from the power supply on the skyfire breakout board, which usually supplies it, but it was clean.

Now with the breakout board out, the axis drives and everything else were turned off, so as I put the breakout board back I've been checking the spindle output signal as I connect each thing back up.

I've found the noise comes back when the axis drives are powered up, and each axis drive is producing a different noise pattern. One is almost clean, the other two make a lot of noise. I tried a ferrite core around the
power supply into one of the noisy drives, with the other two turned off, and it made no difference. This was when the drive was just powered up, not driving the axis. So more work to come to work out how to fix it.

So, basically, since the axis drives are not manufactured by skyfire, I can now say that everything made by skyfire is ok as far as this noise problem goes.

[handlewanker]

Hi....presumably everyone else who has this set up also has the same problem.....but we'll only be hearing from those that subscribe to this forum, the others will be going back to Skyfire.com for advice......that means Skyfire.com should have a solution........World sales rely on a satisfied customer base.

My opinion is that if Skyfire.com are aware of a problem then that part should be recalled and replacements supplied etc.

BTW.....how does delving into the innards of the electronics to do DIY trouble shooting affect the warranty?......in most cases a device is sealed with a definite sticker covering the entry points to deter any such DIY intrusion that would void a warranty claim.

If Defeng allows DIY intrusion to the electronics and still supports a warranty claim he's asking for trouble.
Ian.

[daniellyall]

has the grounding been done correctly so everything is at a star point then goes out to ground, a semains white paper I read said it is best to have high and low voltages on there own star point side by side

[johnno402002]

Hi Ian,

Well, after quite a few failed attempts to get a response from Defeng on this issue, or any communication at all, including a sales enquiry, I came to the conclusion that there is no warranty. And to be honest, for the price I paid for the machine, I don't expect one. I remain very happy with what I got for the money I paid, and indeed very grateful that I got anything at all.

I doubt that every one else with my setup has this problem, as I said only two of the three axis drives are causing the issue. When I get to the bottom of it I expect it to be a minor thing that is causing it.

regards,

John

[johnno402002]

Hi Daniellyall,

Has the grounding been done properly? I'm not sure yet. The AC circuit ground, definitely yes, it is built safely. What I see is a lot of separate dc supplies in there, There are two dc circuits on the motion board, one from the incoming usb and the other coming from the skyfire breakout board power supply. Each of the axis drives takes 240 ac in, so there is a power supply in there somewhere. The spindle drive is the same, so that is five of them. Should they be all tied together, I'm not so sure. What I do have to check is that they are not tied together in such a way that ground loops have been formed. Still some checking to do yet.

regards,

John