Hi all.
Purchased a new mill to start small production prototypes and seems to be loosing steps In y axis.was only cutting model board at 1.5mm depth and 300 on feed rate.
Any advice How to prevent this much appreciated.
Luke
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Hi all.
Purchased a new mill to start small production prototypes and seems to be loosing steps In y axis.was only cutting model board at 1.5mm depth and 300 on feed rate.
Any advice How to prevent this much appreciated.
Luke
Need more info regarding make/model of machine.
Are you using Mach3 with it ? if so, what do you have the motor tunings set to ?
Hi thanks for the reply it's running mach3.got 8.2nm motors steppers. Champion 20v conversation.
http://i941.photobucket.com/albums/a...pscrlgqldy.jpg
http://i941.photobucket.com/albums/a...psrdppnfyl.jpg
When you say mill are you meaning a router type machine ?
Numbers seems to be all over the place.
Is the motor layout like this ?
1 on Z axis
1 on Y axis
2 on X axis (X on one side and A on the other ?)
If they are then X and A should have the same settings for a start because they have to work in harmony, the velocity and acceleration on A are too high.
If the machine can't physically achieve the settings you've put it will loose steps
Only one motor on each axis the 4th axis is detachable.so currently of the machine.what sort of feed should be reasonable for this machine currently only running 200 mm pm
Are you sure it's loosing steps or just not moving the correct amount.? Those numbers for X & Y suggest 2.5mm pitch running 2000 micro steps which would work out 800 Steps per and your not set to that amount so would be some error.?
Similair with Z axis and working on same pitch but with 1000 micro step = 400 steps per again your not quite there.!
Need lot more info to help correctly with setup and what can achieve.
Voltage the drivers are using. (also make and model of drives)
Micro stepping set on drives.
Ballscrew or Lead screw and the pitch. Ie distance traveled for one Revolution.
Units set in Mach Ie: MM or inch
What size motors and frame size Ie Nema 23 or 34.? They look like 34's.!
I see a Laptop in back ground are you using this to run machine via parallel port.?
Give this info and we can help better thou you should be getting much more than you are now without loosing steps.
Thank you for the reply will update later with more information
Hi.think the motors are nema 34 there 8.2nm.Quote:
Originally Posted by JAZZCNC
I'm using the laptop to run the machine through port.
its set to running in mm.
If possible could you guide me in the direction to find the rest of the information as im not sure where to find this information.
would be amazing to having it running as it should so your help is much appreciated
Ok well could do with a close up picture of the little white switches on the drives.
Also if you turn each axis screw one revolution how far does it move.?
Big problem could be the Laptop. Mach 3 doesn't support Laptops when used with parallel port and they are a known cause of problems.
My advise is to try a normal computer first before doing anything else. Other option is to dump the parallel port and invest in a external motion control card but won't get into that just yet.!!
Who setup the machine and converted it.? . . . 8.5Nm nema 34 motors is massive overkill for this machine and it's actually reducing performance not increasing. This is a common error due to thinking bigger is better but it's really not in most cases and unless correctly matched regards Voltage etc then they actually reduce performance and waste money.!!
SW
1 - ON
2 - ON
3 - OFF
4 - OFF
5 - ON
6 - OFF
7 - ON
8 - ON
Output Current(A): 5.7
RMS current: 4.00
micro step: 1600 pulse/rev
Standstill current: half dynamic current
microstep 1600 probably means (360/1.8)x8 = 1600 in which case 1/8 microstep
I think motors are 6A
Thank you for your reply.im trying to get more information for you as you've been a great help just a bit unsure where to find the rest.what is a normal feed rate for this type of machine on aluminium
Do you have any screens on the cables to the steppers (I don't see any) or perhaps consider cat5 twisted pairs for the step and dir etc. ..Clive
I don't know the answer to this as I don't use a machine like it or cut aluminium, it would only be a guess by searching for other people's settings and you can do that yourself.Quote:
Originally Posted by lukecnc2012
However I do know you need to find out how far the X and Y move for one revolution of the driving screw.
Also set the acceleration and velocity to be the same for X and Y so they work better on curves.
thank you for the reply what is the best way to find the steps per revolution. I guess moving the machine in hand wheel is a start.Quote:
Originally Posted by EddyCurrent
No, not how many steps per revolution but how many millimeters does the table move for one revolution of the stepper motor, you need this for both X and Y directions.Quote:
Originally Posted by lukecnc2012
Looking at the photo, your stepper motors appear to be directly coupled to the end of the lead screws and therefore have a 1:1 ratio.
In Mach 3 the calculation for 'steps per' is;
((360 degrees / motor step angle) * microstep value) / screw pitch
So for your machine we don't know the screw pitch and that is what you need to do by turning the screw one rev and measuring the table distance moved.
As an example for my machine the calculation is;
((360/1.8) * 8) / 10 = 160 steps per.
Similar to what jazzcnc said but using 1/8 microstep it looks like your machine has a screw pitch of 2.0176mm which sounds a bit odd.
Eddy's correct and to do the maths we need the screw pitch. . .BUT . . . There is another way to do this if you don't know. (thou in your case it's not hard to find out)
In Mach on the settings Tab there is an option to "Set steps per Unit" it's just above the reset button.
To do this you will need to accurately measure how far the machine moves. (Tape measure isn't accurate enough)
when you click the button it will ask which Axis to calibrate then after this it will ask how far to move. Enter an amount, soon as you click enter the machine will move in a positive direction. Mach will then ask how far it moved, so measure distance and enter into box then it will calculate the STEPS PER for you.
Do this for each axis and you'll be set. The longer the distance you can measure and the more accurate the better.
hi guys getting an error saying ( cant have a move of zero) this comes up when i go to type in the distance i want the machine to move
also have noticed the machine does not like moving to axis at same time manually. Ive been programming and 5axis machinist for last 10 years but this has got me confused.
Maybe watch this video;
http://www.youtube.com/watch?v=SG-RRpInAts
thanks will have a look.
Is there any companies that can set these up.as this is all very new and not sure I'm 100% with adjusting stuff
Where abouts in uk are you.?
Shipston on stour.
still researching information on getting it set up hopefully will get there soon, I have the option to have encoders fitted would this be worth it
With encoders you get feedback so things like missing steps should not happen. Many people use just stepper motors without feedback and they work fine, but only when everything else is right. If your machine is not working right, as you are saying, then I would suggest the reason needs to found before thinking about fitting encoders otherwise you would probably just be wasting money.
I think you need to getting it working as it is first then you might decide it's good enough without encoders. I don't know why you didn't follow through with the free advice here.
Thanks for the reply. I'm trying to follow the advice as it is much appreciated watched videos on YouTube etc and the advice is great have an understanding of what is required and tried to measure the moving to work the calculations out for the motors but for some reason I get an error come up
LukeQuote:
Originally Posted by lukecnc2012
I don't think you are helping yourself, if you want help you need to give feedback to the questions asked. Is the mill fitted with ball screws or acme type screws. What is the voltage of the power supplies etc. you need to say exactly what is going wrong to sort this out methodically.
You might be losing steps due to noise on the cables etc. ..Clive