Losing steps/position, again

[JAZZCNC]

As it is losing steps in all directions (though X is most noticable) I am tempted to also rule out mechanical binding?

It would be a mistake not to check it out.

What machine is it again.?

[ngwagwa]

Denford Microrouter.

Last time it was faulty I did clean all the nuts but it was only when I fitted a new BOB that it stopped knocking and losing steps.

I have just been over to the workshop and regarding the velocity and acceleration settings X and Y were set at 3000 and 150. When first turned on (lo and behold) the machine jogged several times along X with no knocking. Set them to V=1000 and A=50 was knocking when jogged, Also tried 500 and 20 still knocking.

[ngwagwa]

[QUOTE=JAZZCNC;115603]It would be a mistake not to check it out.

BINGO and thanks to JAZZCNC. Disconnected the drives nuts and jogged for about 10 minutes with no knocking noises, gave them a liberal spray of silicone lubricant, reassembled and all seems sweet.

So, is it possible to replace the stepper motor with one with a bit more gut? I can't see any markings on the current ones.

[JAZZCNC]

[QUOTE=ngwagwa;115630]

It would be a mistake not to check it out.

BINGO and thanks to JAZZCNC. Disconnected the drives nuts and jogged for about 10 minutes with no knocking noises, gave them a liberal spray of silicone lubricant, reassembled and all seems sweet.

So, is it possible to replace the stepper motor with one with a bit more gut? I can't see any markings on the current ones.

Great glad your sorted.

Regards changing the steppers then often with these machnes if using original boards then it's not the steppers that are weak it's the fact they are run with low voltage drives, usualy between 30-40Vdc depending on model. Changing the steppers alone won't make any difference because the drives and voltage are the weak link.

Are you using the original drives etc that came with the machine.?

[ngwagwa]

Hi, The control box is a right jungle but as far as I can see the original drivers are used for X,Y&Z and there is an additional HY-DIV268N-5A for the 4th AXIS. As I am not using the 4th axis could I try using that driver?

[JAZZCNC]

Hi, The control box is a right jungle but as far as I can see the original drivers are used for X,Y&Z and there is an additional HY-DIV268N-5A for the 4th AXIS. As I am not using the 4th axis could I try using that driver?

Won't make much difference if you haven't got the volts to go with it. Volts are what give steppers there speed.

To be honest without knowing more about what's inside I'm relutant to advise any more and suggest until you know exactly what you have and the voltages you have that you don't go messing about because it's very easy to kill these boards.

Based on expereince of these machines I think you'll find the only way to get them to go faster and be reliable is a full retro-fit with new drives, psu and motion controller the motors you can usually keep. When this is done it transforms the machine to another level, but it costs money.

[ngwagwa]

Am I correct that a retro-fit would mean a new motion cotroller, PSU and 3 new drivers and if this is the case could I (for the time being) just use a new driver on the X Axis and use two HY-DIV268N-5A drivers for Y and Z?

[JAZZCNC]

Am I correct that a retro-fit would mean a new motion cotroller, PSU and 3 new drivers and if this is the case could I (for the time being) just use a new driver on the X Axis and use two HY-DIV268N-5A drivers for Y and Z?

Yes for the best effect a full refit is required. However like I said before it's the volts that give you the speed and with those drives, you have a maximum of 48v. However, they are rubbish TB based drives and if you run them anywhere near 48v they will die quickly so you are going to be limited to around 40vdc to be safe.

You need to test the voltage the drives are running at now to get an idea of what will work best. If you do buy new drives then go for something better than those you have. Digital drives are cheap now and can be found for around £40. They will outperform those drives by a large margin and be much smoother and more reliable.

Also using an Ethernet-based motion controller will make a massive difference to how the machine performs compared to the parallel port. When combined with Digital drives running with a voltage around 56Vdc the performance compared to the standard machine will blow your mind.
I converted what I think is the exact same machine(using original steppers) and it would easily reach 15Mtr/min rapid speeds but was derated to 10mmtr/min for use and will cut at those feeds if required. It's been running flawlessly for nearly 3yrs and is used every day to make molds etc.

You really do get what you pay for, so if you want the best save up and dump the rubbish your using now.