GRBL problem

[Clockman]

I have been trying to get my speeds and acceleration sorted on GRBL I can get the X axis $110 set to 1800.000 and that is as far as I can go without a grinding noise or a complete stall, but that is fine and fast enough for me, but the Y axis $111 can only go to 700.000 without stalling, I am using the same Nema 23 stepper motors on all axis, I have a 1605 screw drive and Hiwin linear rails, has anyone any idea why I can not get the Y axis to go any faster without stalling the acceleration on both axis is set to 300.000,
I hope this is posted in the right place

[Adrian]

Difference in mass between the two axis? If it's a traditional gantry machine on one axis you're just moving the router/spindle and the other you're moving the gantry and the router/spindle.

Other than that check that everything is moving freely on both and that the drivers are set to the same power output if they are adjustable.

[Clockman]

Thank's Adrian, it is a traditional gantry machine and yes of course that makes sense now that you mention it, the drivers are set to the same power, and everything was moving freely when I built it, the gantry is quite heavy, and the controller I have is Invetables X Controller which I believe can deliver 4amps max, I was wondering if upgrading to Nema 34 stepper motors would make any difference.

[martin54]

How much money you got
When it comes to CNC upgrades it's a bottomless pit
Some upgrades you may see a big difference & others not much difference at all because there is always something else that then becomes the problem that needs fixing.
If you are limited to 4 amps then just changing to nema 34 motors is probably not going to make much if any difference, you would also need to change not just the motors but the motor mounts & the motor connections to the ball screws
Power supplies may also be an issue depending on what type of power supply you are using.
I take it the Y axis is driven by 2 motors which are both set up exactly the same way. Getting the balance right between the rate of acceleration & the max velocity can take some time to get right, often an axis will stall because you are trying to accelerate to quickly rather than it has reached the max velocity it can travel at.

[Clockman]

Thank's martin, I see what you mean, how much money you got, I am just trying to speed my 3D carvings up a little and the Y-axis is holding me back, as Adrian explained it has too much mass to move, I have reduced the acceleration, that helped with the grinding noise, I am looking at the X-Controller that I have, and I need to know what output I am using at the moment, how many amps the stepper can take, maybe I can increase it a bit, yes if I get better steppers I will need new drivers or perhaps a better controller, and I do not know what controller I should be looking at, something that outputs more than 4 amps, I will keep reading whatever I can find on this subject,

[martin54]

I am guessing you have a control board that has the motion control & stepper drivers all built into one. The amp limit is generally down to what drivers you have for the stepper motors. What type of power supply & what it outputs can also be a limiting factor.
Also when it comes to machine movement (depending on your system) the control system can limit the speed to that of your slowest axis & that would generally be the z axis on most machines so your slower y axis may not even be a factor in slow 3D carving times.
On a 3D carve the z axis is almost constantly moving & if you have a slow plunge rate set your whole machine will move very slowly. You can generally get round this by setting the plunge rate of your 3D finishing tool to the same rate as the feedrate, this can make a huge difference to carving times

[RickW3DS]

What Martin said...
set plunge rate to feed rate. It just works.

[Clockman]

Thank you, Martin and Rick, I have an X-Controller from Inventables, and yes all in one, and the max output is 4amps per motor, my stepper motors are capable of 4.2 amps if wired in bipolar parallel, which they are not so they are only getting 2.1 amps, I have been reading about this, and I am going to wire them in parallel Tomorrow to see if this makes a difference, I will also set the Z plunge rate to the feed rate, good tip thanks

[Clockman]

I have finished wiring and fine-tuning and all seems to be working well at the moment, just jogging it, I will do a 3D carve soon and set the plunge rate to the feed rate and hopefully, that will speed things up, thank you all for your help