Please help! Printer speed is so slow

Hi guys,
I have a problem, so we are a team building a 3d printer for a prototype for school and the printer is made in wood ( it doesn't have to print). But we need to show the movement. So we used a ramps 1.4 with nema 23 and TB6560 drivers. We spend whole week trying figuring out how to speed up our printer, it needs to move 5 INCHES/S OR MORE. BUT NO LUCK, the speed is so slow ( it's like 1 inch/s or slow). We are using ballscrew for x and y as the printer is kind big (2.5 feet in x and h and 1.5 inches in z). Can anyone help us to figure out the problem
Thank you

People often say that running steppers 1:1 with ball screws is real slow.
You might need to run a gear set or pulley/belt setup to get you a 5:1 to speed it up to where you want it.

There are several factors here.
1. The software side
What are the defaults for top speed?
What is the default speed?
If you send gcode that tells it to move @10mm/s, how fast does it actually move?
If you send gcode to move 10mm, how far does it actually move?
How many steps/mm are set in the firmware?
2. Electronics
How many steps per rotation does the stepper have? (usually 200 or sometimes 400).
What microstepping is set on the TB6560 driver?
3. Hardware
What thread does the ballsrew have? (How many mm per turn)

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We cannot use belt for ball screw
@srek i set the maximum speed to be 9000 and min 7000 we tried to set the speed of 127mm/s in g code but no luck, whatever speed is moving slowly and making noices, the step per mm is 581 and it moves the correct distance that we set in the g code. The motor is 200 steps per rev and we are usiing 16 microstepping with12v power supply. The thread has 5 threded ber inch

Noises - hmmm. Hard to say but could be missed steps. Have you looked at the steppers to determine what current they draw? Have you tuned the driver so it's delivering the needed current. What happens when you try to run a stepper unloaded (disconected frm the lead screw)? Those are big motors and pull a fair amount of current. Very few 3DPrinters use NEMA 23s.

Have you tried to use anything else to drive the motor insead of the RAMPS? A simple arduino setup that creates step signals would be sufficient to see if the driver and motor are ok.

---

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[merlin-hotend.de]
[www.hackerspace-ffm.de]

Quote
seattle_phil
Noises - hmmm. Hard to say but could be missed steps. Have you looked at the steppers to determine what current they draw? Have you tuned the driver so it's delivering the needed current. What happens when you try to run a stepper unloaded (disconected frm the lead screw)? Those are big motors and pull a fair amount of current. Very few 3DPrinters use NEMA 23s.

I fix the noises but the speed still slow as we want to, someone told us that we need to use 24V instead of 12V so we are trying that tomorrow.

Quote
Srek
Have you tried to use anything else to drive the motor insead of the RAMPS? A simple arduino setup that creates step signals would be sufficient to see if the driver and motor are ok.

Yes we did with simple Arduino code and they works fines ( good speed )

200 x 16 / 581steps= 5.5077mm pitch for the ballscrew. Pretty unusual....

Ballscrews are faster than trapezoidal screws and threaded rods, but I doubt they can run at 127mm/s
I have 4mm pitch ballscrews in my printer and I'm happy to run them at 30mm/s ( 40mm/s tops )

Im not an expert but there are some things here that are likely to cause issues. Hopefully the more knowledgeable will jump in if this is relevant.
127mm/sec is fast. Many here are printing down at 30mm/s so I would reduce that.
You set the min speed to 7000 ???? What units is that in? Clearly the min speed needs to be lower than the speed you want to print at. And the max should be higher.
Heres the thing I am questioning - If you ask it to move above the max speed what is the resultant speed? If you min speed is to high can the controller/driver/motor handle it. The motors are driven by a series of pulses, the frequency is limited to the max the controller can provide. If you try to send at a higher frequency the timing could get screwed or the motors just not respond fast enough.

Quote
o_lampe
200 x 16 / 581steps= 5.5077mm pitch for the ballscrew. Pretty unusual....

Ballscrews are faster than trapezoidal screws and threaded rods, but I doubt they can run at 127mm/s
I have 4mm pitch ballscrews in my printer and I'm happy to run them at 30mm/s ( 40mm/s tops )

We need to run at that speed or close to it but we still couldn't get even half of it (60mm/s)

Quote
MCcarman
Im not an expert but there are some things here that are likely to cause issues. Hopefully the more knowledgeable will jump in if this is relevant.
127mm/sec is fast. Many here are printing down at 30mm/s so I would reduce that.
You set the min speed to 7000 ???? What units is that in? Clearly the min speed needs to be lower than the speed you want to print at. And the max should be higher.
Heres the thing I am questioning - If you ask it to move above the max speed what is the resultant speed? If you min speed is to high can the controller/driver/motor handle it. The motors are driven by a series of pulses, the frequency is limited to the max the controller can provide. If you try to send at a higher frequency the timing could get screwed or the motors just not respond fast enough.

Yes I have reduced the minimum to be 10mm/s if I used above speed the speed doesn't change even that, we made some changes in acceleration and jerk and we improve a little bit but we still didn't reach what we want