- Andrey's UHU HP
-
Registered
Andrey's UHU HP
Today has finished installation UHU HP on my machine tool. It works! I am very happy!
-
-
Registered
Congrats Andrey - another feather to the cap!
nice looking heatsinks - and a very compact setup!
have fun!
-
Registered
Need help!
I have a question. The motors heat up to 50 degrees of Celsius in 30 minutes. It is possible to struggle somehow with this problem? Motors are presented on a photos.
-
Registered
First thing is this a problem at all?
after 3 hrs - my motors are hot - though not exactly measured the temperature - but still hot.
I think you can try by limiting the current - in my case I have more current flowing in than required.
if possible chk with a clamp meter the current which is drawn here.
also does your UHU heatsink get hot?
RGDS
IRfan
-
Registered
50 degrees celcius shouldnt be a problem, If it stabalizes there I wouldn't worry about it. What's the Vref on the HP-UHU board set to? It looks like the plate on the motor says 9.5A so you should set Vref to around 95mV.
If the motor has very low inductance the larger ripple current might contribute to the heating. Adding an external inductor to smooth the current might help but will affect the performance of the motor slightly.
But again, personally I wouldn't worry about the motors getting 50°C. For reference the datasheet for my motors specs a 50°C rise when operating at it's continuos rating (ie. 70°C case temperature at 20°C ambient).
/Henrik.
-
Registered
Irfan and Henrik, thanks for answers!
I do not know temperature will increase further. I worry for encoders HEDL-5640#A06! Unfortunately I have not measured temperature UHU heatsink! Vref precisely to measure it was not presented possible. Voltmeter indications not constants. Figures constantly "jump". Exposed an experiment method while work of motors did not become smooth and stable. Can motors not are intended for long work? Can to me cooling by fans will help?
-
Registered
Hi Andrey,
If Vref is not stable there's something wrong with the board, your setup or the instrument you're using to measure Vref.
Power up the logic supply for the board (15V) but leave the motor powersupply turned off or disconnected from the HP-UHU. Set your instrument to measure DC-voltage (200mV range if it has one) and connect the black lead to GND of the incoming logic power, then connect the positive lead to the Vref test-point on the PCB, next to trim-pot. The voltage must be stable and adjustable with the trim-pot, set it to around 95mV.
Forced air cooling of the motors will help with the temperature but if the current limit circuit on the board doesn't work then you're in trouble. Make sure you get a stable Vref so you can set the current limit to what the motor is rated for.
What is your motor powersupply voltage?
/Henrik.
-
Registered
Hi, Henrik!
I spent measurements as you write. But tomorrow I will try once again. When motors have been established on the machine tool, axis Z did not move upwards. I rotated VR16 while axis Z has not begun movement. On other axes VR16 it is established in average position.
72V is my motor powersupply voltage.
Andrey.
-
Registered
-
Registered
Hi,
Can't say about the design of the motor but if you only get a 25° temperature rise over one hour I wouldn't worry about it - 50°C is no problem for a motor like that. I found a datasheet for your encoder and it specifies either 70°C or 100°C operating temeprature depending on the the specific type of encoder so again, 50° shouldn't be any problem at all.
What worries me is that you can't get a stable reading on the reference voltage, I'd look into that a bit more if I where you....
-
Member
What amazes me is how little windings there are.
John
-
Registered
Hi!
So voltmeter indications when I measure Vref vary.
"http://www.youtube.com/watch?v=UZTZ7o0lEws"]YouTube - Video
-
Registered
Hi,
That looks weird. You are measuring between the negative (GND) of the 15V supply and the Vref testpad on the PCB aren't you?
Are you SURE the meter is functioning properly? Connect a 100k and 1k resistor in series across 5V (1k closest to GND) then measure the voltage across the 1k resistor, it should be close to 50mV and stable (if the 5V is stable)
Something is wrong here and you need to figure out what it is.
/Henrik.
-
Registered
Hi!
The voltmeter works correctly. When I measure the battery the size АА or ААА the voltmeter shows stably 1,5V. Probably on millivolts the voltmeter works not correctly? Even when +15V it is switched off, indications "jump". It is visible on video. Tomorrow I will make measurements as you advise!
-
Registered
-
Registered
Hi,
Well, if it works for you then it works...I was under the impression you had a problem...
Please tell me what value you have on resistors R53, R54, R17, R18 and R20 and check that VR16 is 5k and not anything else.
/Henrik.
-
Registered
-
Registered
Hi Andrey,
Your previous test shows with the 100k and 1k resisotrs shows that there's no problem with the meters - that's good! There has to be something wrong with your board because the Vref should and must be stable otherwise the current limit circuit won't work properly.
Is that a zero ohm "resistor" you have for R54? It looks like a small cap....
Anyway, first temporarily remove the 1N4148 diode, then measure the voltage on both sides of R53 (4.7k). On one side you should have 5V and on the other side you should have between 1.65V and ~2.5V depending on the position of the Vref pot - is that correct?
Now figure out which "side" of R17 (2.1k) that goes to the Vref pot and measure the voltage there, by turning the pot you should be able to adjust the voltage and it should be stable as soon as you stop turning - is that working?
If not, check for bad solder joints wrong resistor values or a faulty pot also check C16 and C17 caps. If it is working just continue measuring "down" the chain until you find where the problem is.
-
Registered
Hi Henrik!
I could measure Vref! My error was that I measured between pin15 U10 and J3. I have inattentively read your message where you wrote "You are measuring between the negative (GND) of the 15V supply and the Vref testpad on the PCB are not you?".
Vref "X"---100mV
"Y"---100mV
"Z"---320mV
If I reduce Vref by axis Z then the machine tool table does not rise upwards. It is possible to leave value 320mV?.
Andrey.
-
Registered
Ohh, that explains it then. Pin15 of U10 is PC-GND which is isolated from the logic level GND of the board....
Having a Vref of 320mV means that the current limit kicks in at 32A while the drive is rated for 25A - not a very good idea. This also might explain why your motor is getting hot, it's rated ~9A. Sounds to me like the motor is just to small or you need to change the reduction ratio.
- Andrey's UHU HP
Posting Permissions
- You may not post new threads
- You may not post replies
- You may not post attachments
- You may not edit your posts
-
Forum Rules