Spindle too heavy?

[Isaac]

I have a small aluminium framed machine that was previously using a small 200 watt spindle. I changed to a 1.5kw spindle and after a few weeks its started making a rough noise on the Z axis. Thing is, is if I increase the speed/acceleration it sounds normal and like the spindle is no issue for it but I'm worried it will kill another driver chip(when doing 3d work) like a I did a few weeks back. Would springs on the Z axis rails help(pushing back against the Z axis) alleviate the weight problem. If I use my hand to lift the spindle a touch they sound returns to normal.

Thanks, any idea would be great!

Isaac

[irving2008]

"Doctor, I have a pain, what could be wrong with me?"
"a pimple or cancer, take your pick"


* What's the machine,
* how is the z-axis driven (e.g. belt/pulley sizes, ballscrew/pitch, leadscrew/pitch?),
* what is the z-axis motor (NEMA size, torque, current rating.)
* what voltage/driver board/PSU
* What velocity/acceleration (original/new)
* what's the weight of the two spindles
* anything else that might be relevant

[JAZZCNC]

I'll Take a wild guess it's 3020/6040 or some rubbish from Devon.!!

Springs cost pennys so try them is the easy answer to that question. They will help not indure but you obviously have issues so a better solution is to heal problem not cover it up with parcel tape.!

Give the details irving asked and we can advise more specific.!

[Isaac]

I'll Take a wild guess it's 3020/6040 or some rubbish from Devon.!!

Springs cost pennys so try them is the easy answer to that question. They will help not indure but you obviously have issues so a better solution is to heal problem not cover it up with parcel tape.!

Give the details irving asked and we can advise more specific.!

Hi. it is a 3040. It uses leadscrews and nema24 motors. I will check the power from the supply shortly and see what its pushing out. The electronics are all original. It is about 3.5 years old now and is in the process of being upgrades(ran out of cash while building my 1200x600 laser). :)
I will check the rest of the details shortly and let you know.

Thanks. Isaac

[Isaac]

Hi. it is a 3040. It uses leadscrews and nema24 motors. I will check the power from the supply shortly and see what its pushing out. The electronics are all original. It is about 3.5 years old now and is in the process of being upgrades(ran out of cash while building my 1200x600 laser). :)
I will check the rest of the details shortly and let you know.

Thanks. Isaac

The steppers are 2.5a, 1.8degree steppers. Voltage is 24v I believe, cant find my multimeter to check.

Original accel was 80, Velocity 400 (MM for units)
New better sounding values are 120/500

Spindle is about 6kg, old one probably less than 1kg.

Thanks

[JAZZCNC]

The steppers are 2.5a, 1.8degree steppers. Voltage is 24v I believe, cant find my multimeter to check.

Original accel was 80, Velocity 400 (MM for units)
New better sounding values are 120/500

Spindle is about 6kg, old one probably less than 1kg.

Thanks

To get around this correctly will be uneconomical because you'll probably need to replace most of the electronics including motor. Only you can decide if the machine is worth the cost and trouble.?

I would just devise some counter weight like the springs idea has it will be a lot cheaper and probably easier.

[EddyCurrent]

Would you put a tractor engine in a mini ? put the old spindle back in and either use it like that or sell the whole machine to be replaced with something larger.

[irving2008]

That machine has 1204 trapezoidal lead screws with Delrin or bronze nuts so very inefficient. The stepper motors are probably 1.1 or 1.5Nm. I'd hazard a guess the Z-axis stepper is struggling with that additional weight. You either need to counterbalance it, or upgrade the stepper/driver combo or replace the leadscrew with a ballscrew.

As Jazz says, you're on a hiding to nothing....

[Isaac]

Would you put a tractor engine in a mini ? put the old spindle back in and either use it like that or sell the whole machine to be replaced with something larger.

Old spindle died, which is why I bought the 1.5kw ready for the upgrade.

I will counterbalance it for now, only needs to last another 4-8 weeks while I order the rest of the parts and build it. Is there a method to choosing a spring or is it just trial and error. I reduced the accel to 50 today and it did a full 3d job just fine and the noise wasn't too bad but noticable. I also cut some Aluminium for the first time and I'm pretty please with the result. This machine will be my fulltime foam cutter once the new one is up and running.

Cheers for the help guys, Isaac

[GEOFFREY]

As a very quick cheap short term fix you could try rigging a "bungee". G.