Y Axis keeps losing Steps

[Normsthename]

Hi
I have recently finished building my Steel Router (See 3D Cad File!) and it is working great apart from a consistant problem with the Y Axis losing Steps.
I designed the Router myself after looking at all the designs around, and used all the good ideas!
The main frame is made from 60mm x 2mm wall Steel Box Section, and the Gantry is made from 30mm x 1.5mm wall Box Steel Section and it is quite strong
It has a working range of approx. 1000mm x 600mm x 150mm and uses 5mm Screws on the X & Y Axis and a 3mm Screw on the Z Axis.
I have just changed it over to a 2050w Router to replace the 701w Tile Cutter router that I was using, and it is much better cutting.
Now onto the actual problem, I use Mach2 and the fastest cutting speed I can use is 1200mm/min which works out to just over 47" per Minute.
If I cut any faster the Y Axis loses Steps, there is no drag on any of the screws, I can easily turn them by hand.
The other Axis do not lose their Steps, I would have thought the X Axis with the most load on it would be the first one to have a problem.
Am I expecting too much or do you think that I have a problem?

Any ideas much appreciated.

Thanks

Andy

P.S I will post some actual photos when I get around to taking some and not cutting wood

[jcc3inc]

Sir,

There are at least (3) possibilities;
1) Too much load at some point for your steppers
2) A problem going thru resonance of the stepper
3) Driver DC voltage too low
4) Maybe you have some interference.
5) Is your accel too high???

One approach would be to disconnect your motors from the machine and see if you still lose steps. You need some sort of indicator on your affected motor to detect lost steps. This eliminates the machine aspects from the motors.

Regards,
Jack C.

[ger21]

What size are the motors, what drives are you using, and what voltage are they running at? Also, are they trapezoidal screws?

[Normsthename]

What size are the motors, what drives are you using, and what voltage are they running at? Also, are they trapezoidal screws?

The X & Y are 5mm Ballscrews, and the Z Axis is a 3mm Trapezoidal screw.
I bought the Electronics package ready built & wired to my supplied cable Lengths, I told them all about my Setup and this is the package that they recommended :-

3 x DCNC-57-610-01 double shaft 1.0nm stepper motors
Step Angle 1.8 (200 step/rev)
Rated Current/Phase: 2A
Rated Voltage: 3.4v
6 Wire Motor (can be used with both uni and bipolar Drivers)
Holding Torque: 0.9nm (160 oz)

3 x 2.1A stepper drivers

Ringcore 45V,12V,5V DC 5A module

There are at least (3) possibilities;
1) Too much load at some point for your steppers

All the shafts rotate very freely, and can easily be turned by two fingers.

2) A problem going thru resonance of the stepper

What are the symptoms, and how do you cure the problem?

3) Driver DC voltage too low

I don't know, I bought the package ready built.

4) Maybe you have some interference.

Is this interference from the Router?
I have the Router Mains nowhere near the Electronic cables.

5) Is your accel too high???

When I was trying to tune the motors, the acceleration was the setting that caused the most problems with the motor losing steps.
I have it turned down really low, I will check the settings tomorrow

One approach would be to disconnect your motors from the machine and see if you still lose steps. You need some sort of indicator on your affected motor to detect lost steps. This eliminates the machine aspects from the motors.

What sort of indicator do I need?
Sorry for all the dumb answers, but electonics are not my strong point...

Just a thought, could I set the X & Y softlimits to the same value say 600mm, and then swap the X & Y motors around on the Electronics box to see if the problem switches motors??
Would this rule out a faulty motor???

Thanks for all your help.

Andy

[Halfnutz]

Those motors are very small for a machine that size. I am suprised you are getting the speeds you are with them.
Steppers are not designed for high speeds usually (some are, but most are not).

I think you would need larger motors to go any faster, and have enough torque to move through the wood, but 50IPM is quite good for actual cutting speed on a gantry router.

[Normsthename]

Those motors are very small for a machine that size. I am suprised you are getting the speeds you are with them.
Steppers are not designed for high speeds usually (some are, but most are not).

I think you would need larger motors to go any faster, and have enough torque to move through the wood, but 50IPM is quite good for actual cutting speed on a gantry router.

Thanks for the advice
So if I am cutting at 47IPM that is quite respectable for my setup using Stepper Motors.
What are the alternatives to Steppers?

Andy

[Jason Marsha]

You can get stronger steppers and you will be able to cut much faster.
Servo motors start to get expensive quickly.

Jason

[ger21]

Get some ±400 oz-in motors and a ±60V power supply and you should be able to get around 200 ipm.